WorldWideScience

Sample records for plant growth physiological

  1. Plant Physiology and Development

    DEFF Research Database (Denmark)

    Taiz, Lincoln; Zeiger, Eduardo; Møller, Ian Max

    Throughout its twenty-two year history, the authors of Plant Physiology have continually updated the book to incorporate the latest advances in plant biology and implement pedagogical improvements requested by adopters. This has made Plant Physiology the most authoritative, comprehensive......, and widely used upper-division plant biology textbook. In the Sixth Edition, the Growth and Development section (Unit III) has been reorganized and expanded to present the complete life cycle of seed plants from germination to senescence. In recognition of this enhancement, the text has been renamed Plant...... Physiology and Development. As before, Unit III begins with updated chapters on Cell Walls and Signals and Signal Transduction. The latter chapter has been expanded to include a discussion of major signaling molecules, such as calcium ions and plant hormones. A new, unified chapter entitled Signals from...

  2. Impact of lead tolerant plant growth promoting rhizobacteria on growth, physiology, antioxidant activities, yield and lead content in sunflower in lead contaminated soil.

    Science.gov (United States)

    Saleem, Muhammad; Asghar, Hafiz Naeem; Zahir, Zahir Ahmad; Shahid, Muhammad

    2018-03-01

    Present study was conducted to evaluate the effect of lead tolerant plant growth promoting rhizobacteria (LTPGPR) on growth, physiology, yield, antioxidant activities and lead uptake in sunflower in soil contaminated with lead under pot conditions. Three pre-characterized LTPGP strains (S2 (Pseudomonas gessardii strain BLP141), S5 (Pseudomonas fluorescens A506) and S10 (Pseudomonas fluorescens strain LMG 2189)) were used to inoculate sunflower growing in soil contaminated with different levels (300, 600 and 900 mg kg -1 ) of lead by using lead nitrate salt as source of lead. Treatments were arranged according to completely randomized design with factorial arrangements. At harvesting, data regarding growth attributes (root shoot length, root shoot fresh and dry weights), yield per plant, physiological attributes (Chlorophyll 'a', 'b' and carotenoids content), antioxidant activities (Ascorbate peroxidase, catalase, superoxide dismutase and glutathione reductase), proline and malanodialdehyde content, and lead content in root, shoot and achenes of sunflower were recorded. Data were analysed by standard statistical procedures. Results showed that lead contamination reduced the plants growth, physiology and yield at all levels of lead stress. But application of LTPGPR in soil contaminated with lead improved plant growth, physiology, yield, and antioxidant activities, proline, and reduced the malanodialdehyde content (that is reduced by the application of different strains in lead contamination) of sunflower as compared to plants grown in soil without inoculation. Inoculation also promoted the uptake of lead in root, shoots and reduced the uptake of lead in achenes of plants as compared to plants in lead contamination without inoculation. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Impact of plant growth promoting bacillus subtilis on growth and physiological parameters of bassia indica (indian bassia) grown udder salt stress

    International Nuclear Information System (INIS)

    Abeer, H.; Asma, A. H.; Allah, A.; Qarawi, A.; Shalawi, A.; Dilfuza, E.

    2015-01-01

    In this study, the role of a salt-tolerant plant growth-promoting bacterium (PGPR), Bacillus subtilis, in the alleviation of salinity stress during the growth of Indian bassia (Bassia indica (Wight) A.J. Scott), was studied under ccontrolled growth chamber conditions following seed inoculation. Physiological parameters such as neutral and phospholipids, fatty acid composition as well as photosynthetic pigments, were investigated. Salinity inhibited shoot and root length by 16 and 42 percentage, dry weight by 37 and 23 percentage respectively and negatively affected physiological parameters. Inoculation of unstressed and salt-stressed Indian bassia with B. subtilis significantly improved root and shoot growth, total lipid content, the phospholipid fraction, photosynthetic pigments (chlorophyll a and b and carotenoid contents) and also increased oleic (C 18:1 ), linoleic (C 18:2 ) and linolenic (C 18:3 ) acids in plant leaves compared to uninoculated plants. The salt-tolerant PGPR, B. subtilis could act synergistically to promote the growth and fitness of Indian bassia plants under salt stress by providing an additional supply of an auxin (IAA) and induce salt stress resistance by reducing stress ethylene levels. (author)

  4. Protocol: optimising hydroponic growth systems for nutritional and physiological analysis of Arabidopsis thaliana and other plants

    Science.gov (United States)

    2013-01-01

    Background Hydroponic growth systems are a convenient platform for studying whole plant physiology. However, we found through trialling systems as they are described in the literature that our experiments were frequently confounded by factors that affected plant growth, including algal contamination and hypoxia. We also found the way in which the plants were grown made them poorly amenable to a number of common physiological assays. Results The drivers for the development of this hydroponic system were: 1) the exclusion of light from the growth solution; 2) to simplify the handling of individual plants, and 3) the growth of the plant to allow easy implementation of multiple assays. These aims were all met by the use of pierced lids of black microcentrifuge tubes. Seed was germinated on a lid filled with an agar-containing germination media immersed in the same solution. Following germination, the liquid growth media was exchanged with the experimental solution, and after 14-21 days seedlings were transferred to larger tanks with aerated solution where they remained until experimentation. We provide details of the protocol including composition of the basal growth solution, and separate solutions with altered calcium, magnesium, potassium or sodium supply whilst maintaining the activity of the majority of other ions. We demonstrate the adaptability of this system for: gas exchange measurement on single leaves and whole plants; qRT-PCR to probe the transcriptional response of roots or shoots to altered nutrient composition in the growth solution (we demonstrate this using high and low calcium supply); producing highly competent mesophyll protoplasts; and, accelerating the screening of Arabidopsis transformants. This system is also ideal for manipulating plants for micropipette techniques such as electrophysiology or SiCSA. Conclusions We present an optimised plant hydroponic culture system that can be quickly and cheaply constructed, and produces plants with similar

  5. Preliminary results of Physiological plant growth modelling for human life support in space

    Science.gov (United States)

    Sasidharan L, Swathy; Dussap, Claude-Gilles; Hezard, Pauline

    2012-07-01

    Human life support is fundamental and crucial in any kind of space explorations. MELiSSA project of European Space Agency aims at developing a closed, artificial ecological life support system involving human, plants and micro organisms. Consuming carbon dioxide and water from the life support system, plants grow in one of the chambers and convert it into food and oxygen along with potable water. The environmental conditions, nutrient availability and its consumption of plants should be studied and necessarily modeled to predict the amount of food, oxygen and water with respect to the environmental changes and limitations. The reliability of a completely closed system mainly depends on the control laws and strategies used. An efficient control can occur, only if the system to control is itself well known, described and ideally if the responses of the system to environmental changes are predictable. In this aspect, the general structure of plant growth model has been designed together with physiological modelling.The physiological model consists of metabolic models of leaves, stem and roots, of which concern specific metabolisms of the associated plant parts. On the basis of the carbon source transport (eg. sucrose) through stem, the metabolic models (leaf and root) can be interconnected to each other and finally coupled to obtain the entire plant model. For the first step, leaf metabolic model network was built using stoichiometric, mass and energy balanced metabolic equations under steady state approach considering all necessary plant pathways for growth and maintenance of leaves. As the experimental data for lettuce plants grown in closed and controlled environmental chambers were available, the leaf metabolic model has been established for lettuce leaves. The constructed metabolic network is analyzed using known stoichiometric metabolic technique called metabolic flux analysis (MFA). Though, the leaf metabolic model alone is not sufficient to achieve the

  6. MORPHOLOGICAL AND PHYSIOLOGICAL CHARACTERISTICS OF GROWTH AND DEVELOPMENT OF PLANTS IN HIGH SALINITY

    Directory of Open Access Journals (Sweden)

    O. M. Vasilyuk

    2015-10-01

    Full Text Available The effect of increasing salinity to the morpho-metric parameters of Salix alba L., which dominated in the coastal areas on rivers of Steppe Dnieper, is investigated. We added Mg as salt MgSO4 * 3H2O in the range of concentration: 0.5, 1.0, 1.5, 2.0 and 2.5 g/l in a solution of willow cuttings. In the solution was added and plant growth regulator "Kornevin" the synthetic origin. The negative effect of salt at a concentration from 1.0 g/l to 2.5 g/l in the dynamics of growth and development was found. The correlation between the size and salinity in dynamics of growth and development of plant were demonstrated: in the growth of shoots (R = 0.83, 0.91 and 0.95, in the growth of roots (R = 0.92, 0.68 and 0.84 respectively depended from salt concentration. The length of the leaf blade was from 4% to 8%, from 7% to 43%, from 333% to 11% (R = 0,68, 0,93, 0,61, depending on the concentration of salt and during observing compared with control (distilled water. "Kornevin" and combined effect of salt increased the length of the leaf blade growth by 4-5, 2-4, 3-5 times, the roots by7 and 3-14 times, the shoots by 3-4, 6-7 and 5-7 times in the dynamics of growth compared with control (MgSO4, 2,5 g/l. The recommendations regarding for the advisability of using the plant growth regulator "Kornevin", as very effective plant growth preparation that promoted rooting and activated physiological processes of plant organism, expressed protective effect in conditions of excessive salinity, were provided. Key words: the morpho-metric index, the plant growth regulators, abiotic factors, salinity factor, the adaptation.

  7. The Effect of Zinc Oxide Nanoparticles on Safflower Plant Growth and Physiology

    Directory of Open Access Journals (Sweden)

    Z. Hafizi

    2018-02-01

    Full Text Available In this paper, a study of the effect of ZnO nanoparticles on safflower growth and physiology was performed. Each of these elements plays a particular role in the plant life, the presence of these elements is necessary for plant’s life cycle and growth. Zinc deficiency causes the biggest problems in safflower’s production. Considering the importance of nanoparticles in today's world, this research investigated the effect of Zinc oxide nanoparticles on the concentration of guaiacol peroxidase, polypeptide oxidase, dehydrogenase and malondialdehyde in four plant sample groups in greenhouse and laboratory conditions. Results of showed that malondialdehyde enzyme increased with different treatments of various concentrations of Zinc oxide. The enzyme guaiacol oxidase increased at concentrations of 100 mg/L and polyphenol oxide at concentrations of 10 and 500 mg/L and dehydrogenase in 1000 mg/L and decreased in other treatments. In addition to showing the effect of nanoparticles in plants, these findings determine the beneficial concentrations of nanoparticles that have a positive effect on the level of enzymes in plants.

  8. Intelligent Growth Automaton of Virtual Plant Based on Physiological Engine

    Science.gov (United States)

    Zhu, Qingsheng; Guo, Mingwei; Qu, Hongchun; Deng, Qingqing

    In this paper, a novel intelligent growth automaton of virtual plant is proposed. Initially, this intelligent growth automaton analyzes the branching pattern which is controlled by genes and then builds plant; moreover, it stores the information of plant growth, provides the interface between virtual plant and environment, and controls the growth and development of plant on the basis of environment and the function of plant organs. This intelligent growth automaton can simulate that the plant growth is controlled by genetic information system, and the information of environment and the function of plant organs. The experimental results show that the intelligent growth automaton can simulate the growth of plant conveniently and vividly.

  9. Root bacterial endophytes alter plant phenotype, but not physiology

    DEFF Research Database (Denmark)

    Henning, Jeremiah A.; Weston, David J.; Pelletier, Dale A.

    2016-01-01

    (root:shoot, biomass production, root and leaf growth rates) and physiological traits (chlorophyll content, net photosynthesis, net photosynthesis at saturating light-Asat, and saturating CO2-Amax). Overall, we found that bacterial root endophyte infection increased root growth rate up to 184% and leaf...... growth rate up to 137% relative to non-inoculated control plants, evidence that plants respond to bacteria by modifying morphology. However, endophyte inoculation had no influence on total plant biomass and photosynthetic traits (net photosynthesis, chlorophyll content). In sum, bacterial inoculation did......Plant traits, such as root and leaf area, influence how plants interact with their environment and the diverse microbiota living within plants can influence plant morphology and physiology. Here, we explored how three bacterial strains isolated from the Populus root microbiome, influenced plant...

  10. Plant aquaporins: roles in plant physiology.

    Science.gov (United States)

    Li, Guowei; Santoni, Véronique; Maurel, Christophe

    2014-05-01

    Aquaporins are membrane channels that facilitate the transport of water and small neutral molecules across biological membranes of most living organisms. Here, we present comprehensive insights made on plant aquaporins in recent years, pointing to their molecular and physiological specificities with respect to animal or microbial counterparts. In plants, aquaporins occur as multiple isoforms reflecting a high diversity of cellular localizations and various physiological substrates in addition to water. Of particular relevance for plants is the transport by aquaporins of dissolved gases such as carbon dioxide or metalloids such as boric or silicic acid. The mechanisms that determine the gating and subcellular localization of plant aquaporins are extensively studied. They allow aquaporin regulation in response to multiple environmental and hormonal stimuli. Thus, aquaporins play key roles in hydraulic regulation and nutrient transport in roots and leaves. They contribute to several plant growth and developmental processes such as seed germination or emergence of lateral roots. Plants with genetically altered aquaporin functions are now tested for their ability to improve plant resistance to stresses. This article is part of a Special Issue entitled Aquaporins. Copyright © 2013 Elsevier B.V. All rights reserved.

  11. The effect of lichen-dominated biological soil crusts on growth and physiological characteristics of three plant species in a temperate desert of northwest China.

    Science.gov (United States)

    Zhuang, W W; Serpe, M; Zhang, Y M

    2015-11-01

    Biocrusts (biological soil crusts) cover open spaces between vascular plants in most arid and semi-arid areas. Information on effects of biocrusts on seedling growth is controversial, and there is little information on their effects on plant growth and physiology. We examined impacts of biocrusts on growth and physiological characteristics of three habitat-typical plants, Erodium oxyrhynchum, Alyssum linifolium and Hyalea pulchella, growing in the Gurbantunggut Desert, northwest China. The influence of biocrusts on plant biomass, leaf area, leaf relative water content, photosynthesis, maximum quantum efficiency of PSII (F(v)/F(m)), chlorophyll, osmotic solutes (soluble sugars, protein, proline) and antioxidant enzymes (superoxide dismutase, catalase, peroxidase) was investigated on sites with or without biocrust cover. Biomass, leaf area, leaf water content, photosynthesis, F(v)/F(m) and chlorophyll content in crusted soils were higher than in uncrusted soils during early growth and lower later in the growth period. Soluble sugars, proline and antioxidant enzyme activity were always higher in crusted than in uncrusted soils, while soluble protein content was always lower. These findings indicate that biocrusts have different effects on these three ephemeral species during growth in this desert, primarily via effects on soil moisture, and possibly on soil nutrients. The influence of biocrusts changes during plant development: in early plant growth, biocrusts had either positive or no effect on growth and physiological parameters. However, biocrusts tended to negatively influence plants during later growth. Our results provide insights to explain why previous studies have found different effects of biocrusts on vascular plant growth. © 2015 German Botanical Society and The Royal Botanical Society of the Netherlands.

  12. Plant growth promoting effect of Bacillus amyloliquefaciens H-2-5 on crop plants and influence on physiological changes in soybean under soil salinity.

    Science.gov (United States)

    Kim, Min-Ji; Radhakrishnan, Ramalingam; Kang, Sang-Mo; You, Young-Hyun; Jeong, Eun-Ju; Kim, Jong-Guk; Lee, In-Jung

    2017-07-01

    This study was aimed to identify plant growth-promoting bacterial isolates from soil samples and to investigate their ability to improve plant growth and salt tolerance by analysing phytohormones production and phosphate solubilisation. Among the four tested bacterial isolates (I-2-1, H-1-4, H-2-3, and H-2-5), H-2-5 was able to enhance the growth of Chinese cabbage, radish, tomato, and mustard plants. The isolated bacterium H-2-5 was identified as Bacillus amyloliquefaciens H-2-5 based on 16S rDNA sequence and phylogenetic analysis. The secretion of gibberellins (GA 4 , GA 8 , GA 9 , GA 19 , and GA 20 ) from B. amyloliquefaciens H-2-5 and their phosphate solubilisation ability may contribute to enhance plant growth. In addition, the H-2-5-mediated mitigation of short term salt stress was tested on soybean plants that were affected by sodium chloride. Abscisic acid (ABA) produced by the H-2-5 bacterium suppressed the NaCl-induced stress effects in soybean by enhancing plant growth and GA 4 content, and by lowering the concentration of ABA, salicylic acid, jasmonic acid, and proline. These results suggest that GAs, ABA production, and the phosphate solubilisation capacity of B. amyloliquefaciens H-2-5 are important stimulators that promote plant growth through their interaction and also to improve plant growth by physiological changes in soybean at saline soil.

  13. Growth, physiology and flowering of chrysanthemum var. Punch as ...

    African Journals Online (AJOL)

    Growth retardants have been proven to prevent excessive stem elongation and reduce internode length in plants by inhibiting the effect of cell division and enlargement of cell in plants. This study was aimed to evaluate the effect of concentrations of daminozide and maleic hydrazide on growth, physiology and flowering of ...

  14. Key physiological properties contributing to rhizosphere adaptation and plant growth promotion abilities of Azospirillum brasilense.

    Science.gov (United States)

    Fibach-Paldi, Sharon; Burdman, Saul; Okon, Yaacov

    2012-01-01

    Azospirillum brasilense is a plant growth promoting rhizobacterium (PGPR) that is being increasingly used in agriculture in a commercial scale. Recent research has elucidated key properties of A. brasilense that contribute to its ability to adapt to the rhizosphere habitat and to promote plant growth. They include synthesis of the auxin indole-3-acetic acid, nitric oxide, carotenoids, and a range of cell surface components as well as the ability to undergo phenotypic variation. Storage and utilization of polybetahydroxyalkanoate polymers are important for the shelf life of the bacteria in production of inoculants, products containing bacterial cells in a suitable carrier for agricultural use. Azospirillum brasilense is able to fix nitrogen, but despite some controversy, as judging from most systems evaluated so far, contribution of fixed nitrogen by this bacterium does not seem to play a major role in plant growth promotion. In this review, we focus on recent advances in the understanding of physiological properties of A. brasilense that are important for rhizosphere performance and successful interactions with plant roots. © 2011 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

  15. Physiology of Plants, Science (Experimental): 5315.41.

    Science.gov (United States)

    Gunn, William C.

    This unit of instruction deals with the physiological activities of plants. Attention is focused on the principles which underlie the activities of the typical green land plant. Emphasis is placed on biological processes such as photosynthesis, water transport, light responses, mineral nutrition, reproduction, and growth. The prerequisite for…

  16. Physiological, structural and molecular traits activated in strawberry plants after inoculation with the plant growth-promoting bacterium Azospirillum brasilense REC3.

    Science.gov (United States)

    Guerrero-Molina, M F; Lovaisa, N C; Salazar, S M; Martínez-Zamora, M G; Díaz-Ricci, J C; Pedraza, R O

    2015-05-01

    The plant growth-promoting strain REC3 of Azospirillum brasilense, isolated from strawberry roots, prompts growth promotion and systemic protection against anthracnose disease in this crop. Hence, we hypothesised that A. brasilense REC3 can induce different physiological, structural and molecular responses in strawberry plants. Therefore, the aim of this work was to study these traits activated in Azospirillum-colonised strawberry plants, which have not been assessed until now. Healthy, in vitro micropropagated plants were root-inoculated with REC3 under hydroponic conditions; root and leaf tissues were sampled at different times, and oxidative burst, phenolic compound content, malondialdehyde (MDA) concentration, callose deposition, cell wall fortification and gene expression were evaluated. Azospirillum inoculation enhanced levels of soluble phenolic compounds after 12 h post-inoculation (hpi), while amounts of cell wall bound phenolics were similar in inoculated and control plants. Other early responses activated by REC3 (at 24 hpi) were a decline of lipid peroxidation and up-regulation of strawberry genes involved in defence (FaPR1), bacterial recognition (FaFLS2) and H₂O₂ depuration (FaCAT and FaAPXc). The last may explain the apparent absence of oxidative burst in leaves after bacterial inoculation. Also, REC3 inoculation induced delayed structural responses such as callose deposition and cell wall fortification (at 72 hpi). Results showed that A. brasilense REC3 is capable of exerting beneficial effects on strawberry plants, reinforcing their physiological and cellular characteristics, which in turns contribute to improve plant performance. © 2014 German Botanical Society and The Royal Botanical Society of the Netherlands.

  17. Germination, growth and physiological responses of Senegalia ...

    African Journals Online (AJOL)

    For plants growth and physiological responses, seedlings were individually cultivated in plastic bags (25×12 cm) containing non-sterile soil and watered with four salt solutions (0, 86, 171 and 257 mM NaCl). Four months after the plants' cultivation, the results showed that for all species, the salinity reduced significantly the ...

  18. Fatality of salt stress to plants: Morphological, physiological and ...

    African Journals Online (AJOL)

    Fatality of salt stress to plants: Morphological, physiological and biochemical aspects. ... This adverse effect of salt stress appears on whole plant level at almost all growth stages including germination, seedling, vegetative ... from 32 Countries:.

  19. Halophytic Companion Plants Improve Growth and Physiological Parameters of Tomato Plants Grown under Salinity

    International Nuclear Information System (INIS)

    Karakas, S.; Cullu, M. A.; Kaya, C.; Dikilitas, M.

    2016-01-01

    Salinity becomes a major concern when soil salt concentration becomes excessive in growth medium. Halophytes are capable of accumulating high concentrations of NaCl in their tissues, thus using halophytic plants in crop rotations or even in mixed cropping systems may be a promising management practices to mitigate salt stress related yield loses. Salinity induced yield losses and related physiological parameters on tomato plants (Lycopersicon esculentum Mill. cv. SC2121) grown with or without halophytic companion plants (SalsolasodaL. and Portulacaoleracea L.) were investigated in pot experiment. Treatments consist of four soil type (collected from Harran plain-Turkey) with similar physical properties but varying in salinity level: electrical conductivity (EC): 0.9, 4.2, 7.2, and 14.1 dS m/sup -1/. The reduction in plant total dry weight was 24, 19, and 48 percent in soils with slight (4.2dS m/sup -1/), moderate (7.2 dS m/sup -1/) and high (14.1 dS m/sup -1/) salinity as compared to non-saline soil (0.9 dS m/sup -1/), respectively. Leaf content of proline, malondialdehyde (MDA), catalase (CAT) and peroxidase (POX) enzyme activity increased with increasing level of salinity. In tomato plants grown in consociation with Salsolasoda, salinity induced DM decrease was only 6, 12 and 28% in soils with slight, moderate and high salinity as compared to non-saline soil, respectively. However, when Portulaca oleracea used as companion plant, no significant change in biomass or fruit yield was observed. This study showed that mixed planting with Salsolasodain high saline soils may be an effective phyto-remediation technique that may secure yield formation and quality of tomato. (author)

  20. Genotypic variation in growth and physiological responses of ...

    African Journals Online (AJOL)

    Beyaz Fasulye, Boncuk Sırık, Kökez, Oturak and Sırık) was investigated in terms of morphological and physiological. Plants were grown in a plant growth chamber at 26/18°C (day/night) temperature with RH 70% and 450 m-2 s-1 light intensity.

  1. Growth and physiological responses of some Capsicum frutescens varieties to copper stress

    Science.gov (United States)

    Jadid, Nurul; Maziyah, Rizka; Nurcahyani, Desy Dwi; Mubarokah, Nilna Rizqiyah

    2017-06-01

    Copper (Cu) is an essential micronutrient participating in various physiological processes. However, excessive uptake of this micronutrient could potentially affect plant growth and development as well as plant productivity. In this present work, growth and physiological responses of some Capsicum frustescens varieties to Cu stress were determined. Three C. frutescens varieties used in this work were var. Bara, CF 291, and Genie. In addition, these varieties were treated with different concentration of Cu (0, 30, 70, and 120 ppm). The growth and physiological responses measured in this work included plant height, root length, malondialdehyde (MDA), and chlorophyll. The result showed that all varieties tested relatively displayed plant growth reduction including plant height and root length. Likewise, an increase of MDA level, a major bioindicator for oxidative damage was also found in all varieties following exposure to elevated Cu concentration. Finally, the chlorophyll content was also affected indicated by a decreased amount of chlorophyll, especially in var. CF291. The overall results demonstrated that elevated Cu concentration might decrease C. frutescens productivity where among the three varieties tested, var CF 291 seemed to be the most sensitive varieties to Cu stress.

  2. Water in the physiology of plant: thermodynamics and kinetic

    Directory of Open Access Journals (Sweden)

    Maurizio Cocucci

    2011-02-01

    Full Text Available Molecular properties of water molecule determine its role in plant physiology. At molecular level the properties of water molecules determine the behaviour of other plant molecules; in particular its physic characteristics are important in the operativeness of macromolecules and in plant thermoregulation. Plant water supply primarily dependent on thermodynamics properties in particular water chemical potential and its components, more recently there are evidences that suggest an important role in the water kinetic characteristics, depending, at cell membrane level, in particular plasmalemma, on the presence of specific water channel, the aquaporines controlled in its activity by a number of physiological and biochemical factors. Thermodynamics and kinetic factors controlled by physiological, biochemical properties and molecular effectors, control water supply and level in plants to realize their survival, growth and differentiation and the consequent plant production.

  3. Effects of rhizobia and plant growth promoting bacteria inoculation ...

    African Journals Online (AJOL)

    Plant growth promoting rhizobacteria (PGPR) stimulate plant growth by producing phytohormone which enhances the growth and physiological activities of the host plant. Recently, legume bacteria (Rhizobium spp.) have been considered as a PGPR for legume as well as non-legumes and have the potential for growth ...

  4. Plant Physiology in Greenhouses

    NARCIS (Netherlands)

    Heuvelink, E.; Kierkels, T.

    2015-01-01

    Since 2004 Ep Heuvelink and Tijs Kierkels have been writing a continuing series of plant physiology articles for the Dutch horticultural journal Onder Glas and the international edition In Greenhouses. The book Plant Physiology in Greenhouses consists of 50 of their plant physiology articles. The

  5. Evolutionary plant physiology: Charles Darwin's forgotten synthesis

    Science.gov (United States)

    Kutschera, Ulrich; Niklas, Karl J.

    2009-11-01

    Charles Darwin dedicated more than 20 years of his life to a variety of investigations on higher plants (angiosperms). It has been implicitly assumed that these studies in the fields of descriptive botany and experimental plant physiology were carried out to corroborate his principle of descent with modification. However, Darwin’s son Francis, who was a professional plant biologist, pointed out that the interests of his father were both of a physiological and an evolutionary nature. In this article, we describe Darwin’s work on the physiology of higher plants from a modern perspective, with reference to the following topics: circumnutations, tropisms and the endogenous oscillator model; the evolutionary patterns of auxin action; the root-brain hypothesis; phloem structure and photosynthesis research; endosymbioses and growth-promoting bacteria; photomorphogenesis and phenotypic plasticity; basal metabolic rate, the Pfeffer-Kleiber relationship and metabolic optimality theory with respect to adaptive evolution; and developmental constraints versus functional equivalence in relationship to directional natural selection. Based on a review of these various fields of inquiry, we deduce the existence of a Darwinian (evolutionary) approach to plant physiology and define this emerging scientific discipline as the experimental study and theoretical analysis of the functions of green, sessile organisms from a phylogenetic perspective.

  6. Evolutionary plant physiology: Charles Darwin's forgotten synthesis.

    Science.gov (United States)

    Kutschera, Ulrich; Niklas, Karl J

    2009-11-01

    Charles Darwin dedicated more than 20 years of his life to a variety of investigations on higher plants (angiosperms). It has been implicitly assumed that these studies in the fields of descriptive botany and experimental plant physiology were carried out to corroborate his principle of descent with modification. However, Darwin's son Francis, who was a professional plant biologist, pointed out that the interests of his father were both of a physiological and an evolutionary nature. In this article, we describe Darwin's work on the physiology of higher plants from a modern perspective, with reference to the following topics: circumnutations, tropisms and the endogenous oscillator model; the evolutionary patterns of auxin action; the root-brain hypothesis; phloem structure and photosynthesis research; endosymbioses and growth-promoting bacteria; photomorphogenesis and phenotypic plasticity; basal metabolic rate, the Pfeffer-Kleiber relationship and metabolic optimality theory with respect to adaptive evolution; and developmental constraints versus functional equivalence in relationship to directional natural selection. Based on a review of these various fields of inquiry, we deduce the existence of a Darwinian (evolutionary) approach to plant physiology and define this emerging scientific discipline as the experimental study and theoretical analysis of the functions of green, sessile organisms from a phylogenetic perspective.

  7. 14-3-3 proteins in plant physiology.

    Science.gov (United States)

    Denison, Fiona C; Paul, Anna-Lisa; Zupanska, Agata K; Ferl, Robert J

    2011-09-01

    Plant 14-3-3 isoforms, like their highly conserved homologues in mammals, function by binding to phosphorylated client proteins to modulate their function. Through the regulation of a diverse range of proteins including kinases, transcription factors, structural proteins, ion channels and pathogen defense-related proteins, they are being implicated in an expanding catalogue of physiological functions in plants. 14-3-3s themselves are affected, both transcriptionally and functionally, by the extracellular and intracellular environment of the plant. They can modulate signaling pathways that transduce inputs from the environment and also the downstream proteins that elicit the physiological response. This review covers some of the key emerging roles for plant 14-3-3s including their role in the response to the plant extracellular environment, particularly environmental stress, pathogens and light conditions. We also address potential key roles in primary metabolism, hormone signaling, growth and cell division. Copyright © 2011 Elsevier Ltd. All rights reserved.

  8. Exogenously applied plant growth regulators enhance the morpho-physiological growth and yield of rice under high temperature

    Directory of Open Access Journals (Sweden)

    Shah Fahad

    2016-08-01

    Full Text Available A two-year experiment was conducted to ascertain the effects of exogenously applied plant growth regulators (PGR on rice growth and yield attributes under high day (HDT and high night temperature (HNT. Two rice cultivars (IR-64 and Huanghuazhan were subjected to temperature treatments in controlled growth chambers and four different combinations of ascorbic acid (Vc, alpha-tocopherol (Ve, brassinosteroids (Br, methyl jasmonates (MeJA and triazoles (Tr were applied. High temperature severely affected rice morphology, and also reduced leaf area, above- and below-ground biomass, photosynthesis, and water use efficiency, while increased the leaf water potential of both rice cultivars. Grain yield and its related attributes except number of panicles, were reduced under high temperature. The HDT posed more negative effects on rice physiological attributes, while HNT was more detrimental for grain formation and yield. The Huanghuazhan performed better than IR-64 under high temperature stress with better growth and higher grain yield. Exogenous application of PGRs was helpful in alleviating the adverse effects of high temperature. Among PGR combinations, the Vc+Ve+MejA+Br was the most effective treatment for both cultivars under high temperature stress. The highest grain production by Vc+Ve+MejA+Br treated plants was due to enhanced photosynthesis, spikelet fertility and grain filling, which compensated the adversities of high temperature stress. Taken together, these results will be of worth for further understanding the adaptation and survival mechanisms of rice to high temperature and will assist in developing heat-resistant rice germplasm in future.

  9. Plant growth enhancement and associated physiological responses are coregulated by ethylene and gibberellin in response to harpin protein Hpa1.

    Science.gov (United States)

    Li, Xiaojie; Han, Bing; Xu, Manyu; Han, Liping; Zhao, Yanying; Liu, Zhilan; Dong, Hansong; Zhang, Chunling

    2014-04-01

    The harpin protein Hpa1 produced by the bacterial blight pathogen of rice induces several growth-promoting responses in plants, activating the ethylene signaling pathway, increasing photosynthesis rates and EXPANSIN (EXP) gene expression levels, and thereby enhancing the vegetative growth. This study was attempted to analyze any mechanistic connections among the above and the role of gibberellin in these responses. Hpa1-induced growth enhancement was evaluated in Arabidopsis, tomato, and rice. And growth-promoting responses were determined mainly as an increase of chlorophyll a/b ratio, which indicates a potential elevation of photosynthesis rates, and enhancements of photosynthesis and EXP expression in the three plant species. In Arabidopsis, Hpa1-induced growth-promoting responses were partially compromised by a defect in ethylene perception or gibberellin biosynthesis. In tomato and rice, compromises of Hpa1-induced growth-promoting responses were caused by a pharmacological treatment with an ethylene perception inhibitor or a gibberellin biosynthesis inhibitor. In the three plant species, moreover, Hpa1-induced growth-promoting responses were significantly impaired, but not totally eliminated, by abolishing ethylene perception or gibberellin synthesis. However, simultaneous nullifications in both ethylene perception and gibberellin biosynthesis almost canceled the full effects of Hpa1 on plant growth, photosynthesis, and EXP2 expression. Theses results suggest that ethylene and gibberellin coregulate Hpa1-induced plant growth enhancement and associated physiological and molecular responses.

  10. Plant physiology meets phytopathology: plant primary metabolism and plant-pathogen interactions.

    Science.gov (United States)

    Berger, Susanne; Sinha, Alok K; Roitsch, Thomas

    2007-01-01

    Phytopathogen infection leads to changes in secondary metabolism based on the induction of defence programmes as well as to changes in primary metabolism which affect growth and development of the plant. Therefore, pathogen attack causes crop yield losses even in interactions which do not end up with disease or death of the plant. While the regulation of defence responses has been intensively studied for decades, less is known about the effects of pathogen infection on primary metabolism. Recently, interest in this research area has been growing, and aspects of photosynthesis, assimilate partitioning, and source-sink regulation in different types of plant-pathogen interactions have been investigated. Similarly, phytopathological studies take into consideration the physiological status of the infected tissues to elucidate the fine-tuned infection mechanisms. The aim of this review is to give a summary of recent advances in the mutual interrelation between primary metabolism and pathogen infection, as well as to indicate current developments in non-invasive techniques and important strategies of combining modern molecular and physiological techniques with phytopathology for future investigations.

  11. A Review of Plant Growth Substances

    Directory of Open Access Journals (Sweden)

    D.A. Agboola

    2014-10-01

    Full Text Available Plant growth substances are compounds, either natural or synthetic that modifies or controls through physiological action, the growth and maturation of plants. If the compound is produced within the plant, it is called a plant hormone or phytohormone. In general, it is accepted that there are five major classes of plant hormones. They are Auxins (IAA, Cytokinins, Gibberellins, Ethylene and Abscisic Acid. However, there are still many plant growth substances that cannot be grouped under these classes, though they also perform similar functions, inhibiting or promoting plant growth. These substances include Brassinosteroids (Brassins, Salicylic Acid, Jasmonic Acid, Fusicoccin, Batasins, Strigolactones, Growth stimulants (e.g. Hymexazol and Pyripropanol, Defoliants (e.g. Calcium Cyanamide, Dimethipin. Researchers are still working on the biosynthetic pathways of some of these substances. Plant growth substances are very useful in agriculture in both low and high concentrations. They affect seed growth, time of flowering, the sex of flowers, senescence of leaves and fruits, leaf formation, stem growth, fruit development and ripening, plant longevity, and even plant death. Some synthetic regulators are also used as herbicides and pesticides. Therefore, attention should be paid to the production and synthesis of these substances so that they affect plants in a way that would favour yield.

  12. Circadian regulation of hormone signaling and plant physiology.

    Science.gov (United States)

    Atamian, Hagop S; Harmer, Stacey L

    2016-08-01

    The survival and reproduction of plants depend on their ability to cope with a wide range of daily and seasonal environmental fluctuations during their life cycle. Phytohormones are plant growth regulators that are involved in almost every aspect of growth and development as well as plant adaptation to myriad abiotic and biotic conditions. The circadian clock, an endogenous and cell-autonomous biological timekeeper that produces rhythmic outputs with close to 24-h rhythms, provides an adaptive advantage by synchronizing plant physiological and metabolic processes to the external environment. The circadian clock regulates phytohormone biosynthesis and signaling pathways to generate daily rhythms in hormone activity that fine-tune a range of plant processes, enhancing adaptation to local conditions. This review explores our current understanding of the interplay between the circadian clock and hormone signaling pathways.

  13. PHYSIOLOGICAL AND BIOCHEMICAL MARKERS OF SALINITY TOLERANCE IN PLANTS

    Directory of Open Access Journals (Sweden)

    Mustafa YILDIZ

    2011-02-01

    Full Text Available Salt stress limits plant productivity in arid and semi arid regions. Salt stress causes decrease in plant growth by adversely affecting physiological processes, especially photosynthesis. Salinity tolerance is defined as the ability of plant to maintain normal rowth and development under salt conditions. Salt stress results in accumulation of low molecular weight compounds, termed compatible solutes, which do not interfere with the normal biochemical reactions. These compatible solutes such as carbohydrates, polyols, amino acids and amides, quaternary ammonium compounds, polyamines andsoluble proteins may play a crucial role in osmotic adjustment, protection of macromolecules, maintenance of cellular pH and detoxification of free radicals. On the other hand, plants subjected to environmental stresses such as salinity produce reactive oxygen species (ROS and these ROS are efficiently eliminated by antioxidant enzyme systems. In plant breeding studies, the use of some physiological and biochemical markers for improving the salt tolerance in plants is crucial. In this review, the possibility of using some physiological and biochemical markers as selection criteria for salt tolerance is discussed.

  14. The induction mutation effects of "6"0Co gamma radiation on physiological growth of tomato

    International Nuclear Information System (INIS)

    Gusti Ngurah Sutapa; I Gde Antha Kasmawan

    2016-01-01

    Almost all types of cuisine in Indonesia are using tomatoes as the base material of manufacture. The nutritional value contained in tomatoes is also quite high, because there is a number of vitamin content required by the human body. In addition, the tomatoes in plants featured national horticultural commodity and priority on a number of provinces in Indonesia. So many benefits of tomatoes indicates that the productivity of tomatoes should be improved. One improvement in terms of quality can be done by means of mutation induction with gamma radiation of Co-60. Induction of mutations are genetic changes caused by human effort, one of them is by using radioactive materials. Gamma rays of Co-60 from the IRPASENA facility was exposed to tomato seeds at doses of 50, 100, 150, 200 and 250 Gy. And then measurements were conducted on the physiological growth of leaf width, plant height, number of fruit and wet weight of tomatoes from week 1 until harvest. The results showed a growth curve of tomato is in accordance with sigmoidal plant physiological growth curve. Optimal physiological growth of tomato plants was obtained at dose of gamma radiation of 100 Gy. At this optimal dose physiological growth of tomato plants is the best (superior) than in doses below and above 100 Gy and control. (author)

  15. The effect of salinity on the growth, morphology and physiology of ...

    African Journals Online (AJOL)

    The salinity of water and soil decreases the growth and yield of agricultural products. Salinity affects many physiological and morphological processes of plant by influencing soil solution osmotic potential and ion absorption and accumulation of minerals. To evaluate the effect of salinity on some physiological and ...

  16. Biofertilizer: a novel formulation for improving wheat growth, physiology and yield

    International Nuclear Information System (INIS)

    Hassan, T.; Bano, A.

    2016-01-01

    Bacillus cereus and Pseudomonas moraviensis strains were inoculated singly as well as in consortium with two different carriers i.e., maize straws and sugarcane husk in the formulation of biofertilizer. Plant growth promoting rhizobacteria (PGPR) strains used in biofertilizer were phosphate solubilizer and exhibited strong antifungal activities. Both PGPR used in formulation was maintained 15-16.5 * 10/sup 8/ cfu g-1 in carrier material after 40d. The field experiment was conducted at Quaid-e-Azam University Islamabad on wheat for two consecutive years (2011-2012) simultaneously in pots and field. Plants sampling for growth and physiological parameters was made after 57d of sowing and at maturity for yield parameters. Single inoculation of Pseudomonas moraviensis and Bacillus cereus with maize straw and sugarcane husk increased plant height and fresh weight by 18-30% and protein, proline, sugar contents and antioxidant activities by 25-40%. There were 20% increases in spike length, seeds/spike and seed weight in single inoculation. Co-inoculation of PGPR further increased plant growth, physiology and yield by 10-15% over single inoculation with carriers. PGPR consortium with sugarcane husk and maize straw (biofertilizer formulation) increased 20-30% plant growth chlorophyll, sugar, protein contents, antioxidants activities and yield parameters. It is inferred that carrier based biofertilzer effectively increased growth, maintained osmotic balance and enhanced the activities of antioxidant enzymes and yield parameters. (author)

  17. Response of morphological and physiological growth attributes to foliar application of plant growth regulators in gladiolus 'white prosperity'

    International Nuclear Information System (INIS)

    Sajjad, Y.; Jaskani, M. J.; Qasim, M.

    2014-01-01

    Gladiolus is very popular among ornamental bulbous plants mainly used as cut flower and greatly demanded in the world floral market. Production of inferior quality spikes is one of the major hurdles for their export. The research was conducted under Faisalabad conditions to evaluate the use of plant growth regulators in order to improve the vegetative, floral and physiological attributes. Gladiolus plants were sprayed thrice with different concentrations (0.1, 0.4, 0.7 and 1mM) of gibberellic acid, benzylaminopurine and salicylic acid at three leaf stage, five leaf stage and slipping stage. Foliar application of 1mM gibberellic acid increased the plant height (122.14cm), spike length (58.41cm), florets spike-1 (13.49), corm diameter (4.43cm), corm weight (25.34g) and total cormel weight (20.45g) compared to benzylaminopurine and salicylic acid. Gibberellic acid at 1mM concentration also increased the total chlorophyll content to 7.72mg/g, total carotenoids (1.61mg/g), total soluble sugars (3.68mg/g) followed by application of benzylaminopurine. Salicylic acid application at 1mM concentration decreased the number of days to flower (64.93) compared to 76.12 days in non treated plants. (author)

  18. Physiological conjunction of allelochemicals and desert plants.

    Science.gov (United States)

    Yosef Friedjung, Avital; Choudhary, Sikander Pal; Dudai, Nativ; Rachmilevitch, Shimon

    2013-01-01

    Plants exchange signals with other physical and biological entities in their habitat, a form of communication termed allelopathy. The underlying principles of allelopathy and secondary-metabolite production are still poorly understood, especially in desert plants. The coordination and role of secondary metabolites were examined as a cause of allelopathy in plants thriving under arid and semiarid soil conditions. Desert plant species, Origanum dayi, Artemisia sieberi and Artemisia judaica from two different sources (cultivar cuttings and wild seeds) were studied in their natural habitats. Growth rate, relative water content, osmotic potential, photochemical efficiency, volatile composition and vital factors of allelopathy were analyzed at regular intervals along four seasons with winter showing optimum soil water content and summer showing water deficit conditions. A comprehensive analysis of the volatile composition of the leaves, ambient air and soil in the biological niche of the plants under study was carried out to determine the effects of soil water conditions and sample plants on the surrounding flora. Significant morpho-physiological changes were observed across the seasons and along different soil water content. Metabolic analysis showed that water deficit was the key for driving selective metabolomic shifts. A. judaica showed the least metabolic shifts, while A. sieberi showed the highest shifts. All the species exhibited high allelopathic effects; A. judaica displayed relatively higher growth-inhibition effects, while O. dayi showed comparatively higher germination-inhibition effects in germination assays. The current study may help in understanding plant behavior, mechanisms underlying secondary-metabolite production in water deficit conditions and metabolite-physiological interrelationship with allelopathy in desert plants, and can help cull economic benefits from the produced volatiles.

  19. Physiological conjunction of allelochemicals and desert plants.

    Directory of Open Access Journals (Sweden)

    Avital Yosef Friedjung

    Full Text Available Plants exchange signals with other physical and biological entities in their habitat, a form of communication termed allelopathy. The underlying principles of allelopathy and secondary-metabolite production are still poorly understood, especially in desert plants. The coordination and role of secondary metabolites were examined as a cause of allelopathy in plants thriving under arid and semiarid soil conditions. Desert plant species, Origanum dayi, Artemisia sieberi and Artemisia judaica from two different sources (cultivar cuttings and wild seeds were studied in their natural habitats. Growth rate, relative water content, osmotic potential, photochemical efficiency, volatile composition and vital factors of allelopathy were analyzed at regular intervals along four seasons with winter showing optimum soil water content and summer showing water deficit conditions. A comprehensive analysis of the volatile composition of the leaves, ambient air and soil in the biological niche of the plants under study was carried out to determine the effects of soil water conditions and sample plants on the surrounding flora. Significant morpho-physiological changes were observed across the seasons and along different soil water content. Metabolic analysis showed that water deficit was the key for driving selective metabolomic shifts. A. judaica showed the least metabolic shifts, while A. sieberi showed the highest shifts. All the species exhibited high allelopathic effects; A. judaica displayed relatively higher growth-inhibition effects, while O. dayi showed comparatively higher germination-inhibition effects in germination assays. The current study may help in understanding plant behavior, mechanisms underlying secondary-metabolite production in water deficit conditions and metabolite-physiological interrelationship with allelopathy in desert plants, and can help cull economic benefits from the produced volatiles.

  20. Enhanced growth, yield and physiological characteristics of rice under elevated carbon dioxide

    Science.gov (United States)

    Abzar, A.; Ahmad, Wan Juliana Wan; Said, Mohd Nizam Mohd; Doni, Febri; Zaidan, Mohd Waznul Adly Mohd; Fathurahman, Zain, Che Radziah Che Mohd

    2018-04-01

    Carbon dioxide (CO2) is rapidly increasing in the atmosphere. It is an essential element for photosynthesis which attracts attention among scientists on how plants will perform in the rising CO2 level. Rice as one of the most important staple food in the world has been studied on the growth responses under elevated CO2. The present research was carried out to determine the growth and physiology of rice in elevated CO2 condition. This research was carried out using complete randomized design with elevated (800 ppm) and ambient CO2. Results showed that growth parameters such as plant height, tillers and number of leaves per plant were increased by elevated CO2. The positive changes in plant physiology when exposed to high CO2 concentration includes significant change (p<0.05) in yield parameters such as panicle number, grain number per panicle, biomass and 1000 grain weight under the elevated CO2 of 800 ppm.

  1. Growth, physiology and yield responses of Amaranthus cruentus ...

    African Journals Online (AJOL)

    Amaranthus cruentus, Corchorus olitorius and Vigna unguiculata are traditional leafy vegetables with potential to improve nutritional security of vulnerable people. The promotion of these crops is partly hindered by the lack of agronomic information. The effect of plant spacing on growth, physiology and yield of these three ...

  2. Eucalypt plants are physiologically and metabolically affected by infection with Ceratocystis fimbriata.

    Science.gov (United States)

    da Silva, André Costa; de Oliveira Silva, Franklin Magnum; Milagre, Jocimar Caiafa; Omena-Garcia, Rebeca Patricia; Abreu, Mário Castro; Mafia, Reginaldo Gonçalves; Nunes-Nesi, Adriano; Alfenas, Acelino Couto

    2018-02-01

    Ceratocystis wilt, caused by Ceratocystis fimbriata, is currently one of the most important disease in eucalypt plantations. Plants infected by C. fimbriata have lower volumetric growth, lower pulp yields and reduced timber values. The physiological bases of infection induced by this pathogen in eucalypt plant are not known. Therefore, this study aims to assess the physiological and metabolic changes in eucalypt clones that are resistant and susceptible to C. fimbriata. Once, we evaluated in detail their leaf gas exchange, chlorophyll a fluorescence, water potential, metabolite profiling and growth-related parameters. When inoculated, the susceptible clone displayed reduced water potential, CO 2 assimilation rate, stomatal conductance, transpiration rate, photochemical quenching coefficient, electron transport rate, and root biomass. Inoculated resistant and susceptible clones both presented higher respiration rates than healthy plants. Many compounds of primary and secondary metabolism were significantly altered after fungal infection in both clones. These results suggest that, C. fimbriata interferes in the primary and secondary metabolism of plants that may be linked to the induction of defense mechanisms and that, due to water restrictions caused by the fungus in susceptible plants, there is a partial closure of the stomata to prevent water loss and a consequent reduction in photosynthesis and the transpiration rate, which in turn, leads to a decrease in the plant's growth-related. These results combined, allowed for a better understanding of the physiological and metabolic changes following the infectious process of C. fimbriata, which limit eucalypt plant growth. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  3. Urban plant physiology: adaptation-mitigation strategies under permanent stress.

    Science.gov (United States)

    Calfapietra, Carlo; Peñuelas, Josep; Niinemets, Ülo

    2015-02-01

    Urban environments that are stressful for plant function and growth will become increasingly widespread in future. In this opinion article, we define the concept of 'urban plant physiology', which focuses on plant responses and long term adaptations to urban conditions and on the capacity of urban vegetation to mitigate environmental hazards in urbanized settings such as air and soil pollution. Use of appropriate control treatments would allow for studies in urban environments to be comparable to expensive manipulative experiments. In this opinion article, we propose to couple two approaches, based either on environmental gradients or manipulated gradients, to develop the concept of urban plant physiology for assessing how single or multiple environmental factors affect the key environmental services provided by urban forests. Copyright © 2014 Elsevier Ltd. All rights reserved.

  4. The central regulation of plant physiology by adenylates.

    Science.gov (United States)

    Geigenberger, Peter; Riewe, David; Fernie, Alisdair R

    2010-02-01

    There have been many recent developments concerning the metabolic, transport and signalling functions of adenylates in plants, suggesting new roles for these compounds as central regulators of plant physiology. For example, altering the expression levels of enzymes involved in the equilibration, salvaging, synthesis and transport of adenylates leads to perturbations in storage, growth and stress responses, implying a role for adenylates as important signals. Furthermore, sensing of the internal energy status involves SNF1-related kinases, which control the expression and phosphorylation of key metabolic enzymes. ATP also acts as an apoplastic signalling molecule to control cell growth and pathogen responses. These new results could shed light on the emerging question of whether energy homeostasis in plant cells differs from mechanisms found in microbes and mammals. Copyright 2009 Elsevier Ltd. All rights reserved.

  5. Fifth workshop on seedling physiology and growth problems in oak plantings (abstracts).

    Science.gov (United States)

    Janette R. Thompson; Richard C. Schultz; J.W. Van Sambeek

    1993-01-01

    Research results and ongoing research activities in field performance of planted trees, seedling propagation, physiology, genetics, acorn germination, and natural regeneration for oaks are described in 30 abstracts.

  6. Physiological integration affects growth form and competitive ability in clonal plants

    Czech Academy of Sciences Publication Activity Database

    Herben, Tomáš

    2004-01-01

    Roč. 18, - (2004), s. 493-520 ISSN 0269-7653 R&D Projects: GA ČR(CZ) GA206/02/0953 Institutional research plan: CEZ:AV0Z6005908 Keywords : competitive ability * Physiological integration * clonal plants Subject RIV: EF - Botanics Impact factor: 3.215, year: 2004

  7. Effect of polyethylene coated calcium carbide on physiology, photosynthesis, growth and yield of sweet pepper

    International Nuclear Information System (INIS)

    Ahmed, W.; Yaseen, M.; Arshad, M.; Shahid, M.

    2014-01-01

    Polyethylene coated calcium carbide (PCC) is a potent and continuous slowly releasing source of acetylene and ethylene. It potentially improves plant growth by affecting physiology of plant. A pot study was conducted to investigate comparative effects of different rates of PCC on growth and yield attributes of sweet pepper. PCC performed better when applied with soil applied fertilizers. Results revealed that hormonal properties of calcium carbide significantly influenced physiological nutrient use efficiency and vegetative growth by affecting photosynthetic and physiological parameters of sweet pepper. Application of 20 mg PCC kg/sup -1/ soil with soil applied recommended dose of NPK fertilizers significantly improved the net photosynthetic rate by 32%, stomatal conductance by 11%, transpiration rate by 14%, carboxylation efficiency by 47%, physiological water use efficiency by 13%, physiological nitrogen use efficiency by 29% over the control treatment. This improvement in physiological attributes resulted in increase in leaf area by 20%, leaf area index by 78%, total plant dry weight by 35%, flower and fruits by 29% and fruit yield by 24% compared to the treatment of alone recommended dose of NPK fertilizers. Present study suggests that application of PCC particularly at the rate of 20mg PCC kg/sup -1/ soil plus recommended dose of NPK fertilizers improved about 25% sweet pepper production compared to its production in the alone recommended fertilizer treatment. (author)

  8. Plasma Membrane H(+)-ATPase Regulation in the Center of Plant Physiology.

    Science.gov (United States)

    Falhof, Janus; Pedersen, Jesper Torbøl; Fuglsang, Anja Thoe; Palmgren, Michael

    2016-03-07

    The plasma membrane (PM) H(+)-ATPase is an important ion pump in the plant cell membrane. By extruding protons from the cell and generating a membrane potential, this pump energizes the PM, which is a prerequisite for growth. Modification of the autoinhibitory terminal domains activates PM H(+)-ATPase activity, and on this basis it has been hypothesized that these regulatory termini are targets for physiological factors that activate or inhibit proton pumping. In this review, we focus on the posttranslational regulation of the PM H(+)-ATPase and place regulation of the pump in an evolutionary and physiological context. The emerging picture is that multiple signals regulating plant growth interfere with the posttranslational regulation of the PM H(+)-ATPase. Copyright © 2016 The Author. Published by Elsevier Inc. All rights reserved.

  9. Demonstrating the Effects of Light Quality on Plant Growth.

    Science.gov (United States)

    Whitesell, J. H.; Garcia, Maria

    1977-01-01

    Describes a lab demonstration that illustrates the effect of different colors or wavelengths of visible light on plant growth and development. This demonstration is appropriate for use in college biology, botany, or plant physiology courses. (HM)

  10. Timing effects of heat-stress on plant physiological characteristics and growth: a field study with prairie vegetation

    Directory of Open Access Journals (Sweden)

    Dan Wang

    2016-11-01

    Full Text Available More intense, more frequent, and longer heat-waves are expected in the future due to global warming, which could have dramatic agricultural, economic and ecological impacts. This field study examined how plant responded to heat-stress (HS treatment at different timing in naturally-occurring vegetation. HS treatment (5 days at 40.5 ºC were applied to 12 1m2 plots in restored prairie vegetation dominated by Andropogon gerardii (warm-season C4 grass and Solidago canadensis (warm-season C3 forb at different growing stages. During and after HS, air, canopy, and soil temperature were monitored; net CO2 assimilation (Pn, quantum yield of photosystem II (ФPSII, stomatal conductance (gs, and internal CO2 level (Ci of the dominant species were measured. One week after the last HS treatment, all plots were harvested and the biomass of above-ground tissue and flower weight of the two dominant species was determined. HS decreased physiological performance and growth for both species, with S. canadensis being affected more than A. gerardii, indicated by negative heat stress effect on both physiological and growth responses. There were significant timing effect of heat stress on the two species, with greater reductions in the photosynthesis and productivity occurred when heat stress was applied at later-growing season. The reduction in aboveground productivity in S. canadensis but not A. gerardii could have important implications for plant community structure by increasing the competitive advantage of A. gerardii in this grassland. The present experiment showed that heat stress, though ephemeral, may promote long-term effects on plant community structure, vegetation dynamics, biodiversity, and ecosystem functioning of terrestrial biomes when more frequent and severe heat stress occur in the future.

  11. Degradation of PVC/HC blends. II. Terrestrial plant growth test.

    Science.gov (United States)

    Pascu, Mihaela; Agafiţei, Gabriela-Elena; Profire, Lenuţa; Vasile, Cornelia

    2009-01-01

    The behavior at degradation by soil burial of some plasticized polyvinyl chloride (PVC) based blends with a variable content of hydrolyzed collagen (HC) has been followed. The modifications induced in the environment by the polymer systems (pH variation, physiologic state of the plants, assimilatory pigments) were studied. Using the growth test of the terrestrial plants, we followed the development of Triticum (wheat), Helianthus annus minimus (little sunflower), Pisum sativum (pea), and Vicia X hybrida hort, during a vegetation cycle. After the harvest, for each plant, the quantities of chlorophyll and carotenoidic pigments and of trace- and macroelements were determined. It was proved that, in the presence of polymer blends, the plants do not suffer morphological and physiological modifications, the products released in the culture soil being not toxic for the plants growth.

  12. Near-UV radiation acts as a beneficial factor for physiological responses in cucumber plants.

    Science.gov (United States)

    Mitani-Sano, Makiko; Tezuka, Takafumi

    2013-11-05

    Effects of near-UV radiation on the growth and physiological activity of cucumber plants were investigated morphologically, physiologically and biochemically using 3-week-old seedlings grown under polyvinyl chloride films featuring transmission either above 290 nm or above 400 nm in growth chambers. The hypocotyl length and leaf area of cucumber seedlings were reduced but the thickness of leaves was enhanced by near-UV radiation, due to increased upper/lower epidermis thickness, palisade parenchyma thickness and volume of palisade parenchyma cells. Photosynthetic and respiratory activities were also promoted by near-UV radiation, associated with general enhancement of physiological/biochemical responses. Particularly, metabolic activities in the photosynthetic system of chloroplasts and the respiratory system of mitochondria were analyzed under the conditions of visible light with and without near-UV radiation. For example, the activities of NAD(P)-dependent enzymes such as glyceraldehyde-3-phosphate dehydrogenase (G3PDH) in chloroplasts and isocitrate dehydrogenase (ICDH) in mitochondria were elevated, along with levels of pyridine nucleotides (nicotinamide coenzymes) [NAD(H) and NADP(H)] and activity of NAD kinase (NADP forming enzyme). Taken together, these data suggest that promotion of cucumber plant growth by near-UV radiation involves activation of carbon and nitrogen metabolism in plants. The findings of this research showed that near-UV radiation reaching the Earth's surface is a beneficial factor for plant growth. Copyright © 2013. Published by Elsevier B.V.

  13. Host physiological condition regulates parasitic plant performance: Arceuthobium vaginatum subsp. cryptopodum on Pinus ponderosa.

    Science.gov (United States)

    Bickford, Christopher P; Kolb, Thomas E; Geils, Brian W

    2005-12-01

    Much research has focused on effects of plant parasites on host-plant physiology and growth, but little is known about effects of host physiological condition on parasite growth. Using the parasitic dwarf mistletoe Arceuthobium vaginatum subsp. cryptopodum (Viscaceae) and its host Pinus ponderosa, we investigated whether changes in host physiological condition influenced mistletoe shoot development in northern Arizona forests. We conducted two studies in two consecutive years and used forest thinning (i.e., competitive release) to manipulate host physiological condition. We removed dwarf mistletoe shoots in April, before the onset of the growing season, and measured the amount of regrowth in the first season after forest thinning (Study I: n=38 trees; Study II: n=35 trees). Thinning increased tree uptake of water and carbon in both studies, but had no effect on leaf N concentration or delta13C. Mistletoe shoot growth was greater on trees with high uptake of water and carbon in thinned stands than trees with low uptake in unthinned stands. These findings show that increased resource uptake by host trees increases resources to these heterotrophic dwarf mistletoes, and links mistletoe performance to changes in host physiological condition.

  14. Plant growth promotion and Penicillium citrinum

    Directory of Open Access Journals (Sweden)

    Choo Yeon-Sik

    2008-12-01

    Full Text Available Abstract Background Endophytic fungi are known plant symbionts. They produce a variety of beneficial metabolites for plant growth and survival, as well as defend their hosts from attack of certain pathogens. Coastal dunes are nutrient deficient and offer harsh, saline environment for the existing flora and fauna. Endophytic fungi may play an important role in plant survival by enhancing nutrient uptake and producing growth-promoting metabolites such as gibberellins and auxins. We screened roots of Ixeris repenes (L. A. Gray, a common dune plant, for the isolation of gibberellin secreting endophytic fungi. Results We isolated 15 endophytic fungi from the roots of Ixeris repenes and screened them for growth promoting secondary metabolites. The fungal isolate IR-3-3 gave maximum plant growth when applied to waito-c rice and Atriplex gemelinii seedlings. Analysis of the culture filtrate of IR-3-3 showed the presence of physiologically active gibberellins, GA1, GA3, GA4 and GA7 (1.95 ng/ml, 3.83 ng/ml, 6.03 ng/ml and 2.35 ng/ml, respectively along with other physiologically inactive GA5, GA9, GA12, GA15, GA19, GA20 and, GA24. The plant growth promotion and gibberellin producing capacity of IR-3-3 was much higher than the wild type Gibberella fujikuroi, which was taken as control during present study. GA5, a precursor of bioactive GA3 was reported for the first time in fungi. The fungal isolate IR-3-3 was identified as a new strain of Penicillium citrinum (named as P. citrinum KACC43900 through phylogenetic analysis of 18S rDNA sequence. Conclusion Isolation of new strain of Penicillium citrinum from the sand dune flora is interesting as information on the presence of Pencillium species in coastal sand dunes is limited. The plant growth promoting ability of this fungal strain may help in conservation and revegetation of the rapidly eroding sand dune flora. Penicillium citrinum is already known for producing mycotoxin citrinin and cellulose digesting

  15. Soil compaction and growth of woody plants

    Energy Technology Data Exchange (ETDEWEB)

    Kozlowski, T.T. [Univ. of California, Berkeley (United States). Dept. of Environmental Science, Policy and Management

    1999-07-01

    Although soil compaction in the field may benefit or inhibit the growth of plants, the harmful effects are much more common. This paper emphasizes the deleterious effects of predominantly high levels of soil compaction on plant growth and yield. High levels of soil compaction are common in heavily used recreation areas, construction sites, urban areas, timber harvesting sites, fruit orchards, agroforestry systems and tree nurseries. Compaction can occur naturally by settling or slumping of soil or may be induced by tillage tools, heavy machinery, pedestrian traffic, trampling by animals and fire. Compaction typically alters soil structure and hydrology by increasing soil bulk density; breaking down soil aggregates; decreasing soil porosity, aeration and infiltration capacity; and by increasing soil strength, water runoff and soil erosion. Appreciable compaction of soil leads to physiological dysfunctions in plants. Often, but not always, reduced water absorption and leaf water deficits develop. Soil compaction also induces changes in the amounts and balances of growth hormones in plants, especially increases in abscisic acid and ethylene. Absorption of the major mineral nutrients is reduced by compaction of both surface soils and subsoils. The rate of photosynthesis of plants growing in very compacted soil is decreased by both stomatal and non-stomatal inhibition. Total photosynthesis is reduced as a result of smaller leaf areas. As soils become increasingly compacted respiration of roots shifts toward an anaerobic state. Severe soil compaction adversely influences regeneration of forest stands by inhibiting seed germination and growth of seedlings, and by inducing seedling mortality. Growth of woody plants beyond the seedling stage and yields of harvestable plant products also are greatly decreased by soil compaction because of the combined effects of high soil strength, decreased infiltration of water and poor soil aeration, all of which lead to a decreased

  16. Soil compaction and growth of woody plants

    International Nuclear Information System (INIS)

    Kozlowski, T.T.

    1999-01-01

    Although soil compaction in the field may benefit or inhibit the growth of plants, the harmful effects are much more common. This paper emphasizes the deleterious effects of predominantly high levels of soil compaction on plant growth and yield. High levels of soil compaction are common in heavily used recreation areas, construction sites, urban areas, timber harvesting sites, fruit orchards, agroforestry systems and tree nurseries. Compaction can occur naturally by settling or slumping of soil or may be induced by tillage tools, heavy machinery, pedestrian traffic, trampling by animals and fire. Compaction typically alters soil structure and hydrology by increasing soil bulk density; breaking down soil aggregates; decreasing soil porosity, aeration and infiltration capacity; and by increasing soil strength, water runoff and soil erosion. Appreciable compaction of soil leads to physiological dysfunctions in plants. Often, but not always, reduced water absorption and leaf water deficits develop. Soil compaction also induces changes in the amounts and balances of growth hormones in plants, especially increases in abscisic acid and ethylene. Absorption of the major mineral nutrients is reduced by compaction of both surface soils and subsoils. The rate of photosynthesis of plants growing in very compacted soil is decreased by both stomatal and non-stomatal inhibition. Total photosynthesis is reduced as a result of smaller leaf areas. As soils become increasingly compacted respiration of roots shifts toward an anaerobic state. Severe soil compaction adversely influences regeneration of forest stands by inhibiting seed germination and growth of seedlings, and by inducing seedling mortality. Growth of woody plants beyond the seedling stage and yields of harvestable plant products also are greatly decreased by soil compaction because of the combined effects of high soil strength, decreased infiltration of water and poor soil aeration, all of which lead to a decreased

  17. Radiolytically degraded sodium alginate enhances plant growth, physiological activities and alkaloids production in Catharanthus roseus L.

    Directory of Open Access Journals (Sweden)

    M. Naeem

    2015-10-01

    Full Text Available Catharanthus roseus (L. G. Don (Family Apocynaceae is a medicinal plant that produces indole alkaloids used in cancer chemotherapy. The anticancerous alkaloids, viz. vinblastine and vincristine, are mainly present in the leaves of C. roseus. High demand and low yield of these alkaloids in the plant has led to explore the alternative means for their production. Gamma irradiated sodium alginate (ISA has proved as a plant growth promoting substance for various medicinal and agricultural crops. A pot culture experiment was carried out to explore the effect of ISA on plant growth, physiological activities and production of anticancer alkaloids (vinblastine and vincristine in C. roseus at 120 and 150 days after planting (DAP. Foliar application of ISA (0, 20, 40, 60, 80 and 100 mg L−1 significantly improved the performance of C. roseus. 80 mg L−1 of ISA enhanced the leaf-yield by 25.3 and 30.2% and the herbage-yield by 29.4 and 34.4% at 120 and 150 DAP, respectively, as compared to the control. The spray treatment of ISA at 80 mg L−1 improved the yield of vinblastine by 66.7 and 71.4% and of vincristine by 67.6 and 75.6% at 120 and 150 DAP, respectively, in comparison to the control. As compared to control, the application of ISA at 80 mg L−1 resulted in the maximum swell in the content and yield of vindoline, increasing them by 18.9 and 20.8% and by 81.8 and 87.2% at 120 and 150 DAP, respectively.

  18. Smoke produced from plants waste material elicits growth of wheat (Triticum aestivum L. by improving morphological, physiological and biochemical activity

    Directory of Open Access Journals (Sweden)

    Muhammad Iqbal

    2018-03-01

    Full Text Available The experimental work presented in this study was carried out with the hypothesis that plant derived smoke enhanced the morphological, physiological and biochemical attributes of a cereal crop, wheat (Triticum aestivum L.. Furthermore, this study supported the hypothesis that plant derived smoke acts as vegetative growth promoter, inexpensive, rapid and most appropriate eco-friendly bio-fertilizer for sustainable agriculture. Plant derived smoke was generated by burning of plant material (leaf, straws etc in a specially designed furnace, and seeds were treated with this smoke for different time duration. Four level of plant derived smoke (1 h, 2 h, 3 h and 4 h along with control were tested on four wheat cultivars in CRD repeated pot experiment. The smoke-related treatments modified number of morphological, physiological and biochemical features of wheat. Compared with the control, aerosol smoke treatment of the seeds significantly improved root length (2.6%, shoot length (7.7%, RFW (0.04%, SFW (0.7%, SDW (0.1% and leaf area (63.9%. All the smoke-related treatments significantly promoted RWC (17.3%, water potential (1.5%, osmotic potential (1.4% and MSI (14.6% whereas a pronounced increase in chlorophyll a (24.9%, chlorophyll b (21.7% and total chlorophyll contents (15.5% were recorded in response to aerosol-smoke treatments. Plant derived smoke exposure applied for short time i.e. 1 h & 2 h induced significant results as compared to prolonged PDS exposure (3 h and 4 h. The best results were observed in Pak-13 and Glaxy-13 wheat cultivars. These findings indicated that the plant-derived smoke treatment has a great potential to improve morphological, physiological and biochemical features of wheat crop.

  19. water stress mediated changes in growth, physiology and secondary metabolites of desi ajwain (trachyspermum ammi l.)

    International Nuclear Information System (INIS)

    Azhar, N.; Hussain, B.; Abbasi, K.Y.

    2011-01-01

    Biotic and abiotic stresses exert a considerable influence on the production of several secondary metabolites in plants; water stress is one of the most important abiotic stress factors. This study was carried out to elucidate the effect of drought stress on growth, physiology and secondary metabolite production in desi ajwain (Trachyspermum ammi L.). Plants were grown in pots and three drought levels (100%, 80% and 60%) of field capacity were created. The experiment was laid out in complete randomized design (CRD) with three replicates. Data on growth, physiological and biochemical parameters were recorded and analyzed statistically. Physiological parameters like transpiration rate and stomatal conductance decreased concentration increased. The photosynthetic rate showed significantly with increasing water stress levels, but internal CO/sub 2/ non-significant reduction from 100% field capacity to 80% field capacity but increased at 60% field capacity. Growth parameters including plant height, herb fresh and dry weights were reduced significantly with increasing stress levels, while total phenolic contents and chlorophyll contents increased under water stress conditions. These results suggest that cultivation of medicinal plants like desi ajwain under drought stress could enhance the production of secondary metabolites. (author)

  20. Understanding the Biological Roles of Pectins in Plants through Physiological and Functional Characterizations of Plant and Fungal Mutants

    DEFF Research Database (Denmark)

    Stranne, Maria

    The plant cell wall is a dynamic structure and it is involved in regulating a number of physiological features of plants such as physical strength, growth, cell differentiation, intercellular communication, water movement and defense responses. Pectins constitute a major class of plant cell wall...... polysaccharides and consist of backbones rich in galacturonic acids, which are decorated with a range of functional groups including acetyl esters and arabinan sidechains. Although much effort has been made to uncover biological functions of pectins in plants and remarkable progresses have taken place, many...... aspects remain elusive. Studies described in this thesis aimed at gaining new insights into the biological roles of pectin acetylation and arabinosylation in the model plant Arabidopsis thaliana. The thesis consists of four chapters: physiological characterization of cell wall mutants affected in cell...

  1. How to Do It. Plant Eco-Physiology: Experiments on Crassulacean Acid Metabolism, Using Minimal Equipment.

    Science.gov (United States)

    Friend, Douglas J. C.

    1990-01-01

    Features of Crassulacean Acid Metabolism plants are presented. Investigations of a complex eco-physiological plant adaptation to the problems of growth in an arid environment are discussed. Materials and procedures for these investigations are described. (CW)

  2. PHYSIOLOGICAL AND AGROECOLOGICAL ASPECTS OF CADMIUM INTERACTIONS WITH BARLEY PLANTS: AN OVERVIEW

    Directory of Open Access Journals (Sweden)

    A VASSILEV

    2003-07-01

    Full Text Available This work is a review of author’s previous publications, unpublished results as well as available literature on barley responses to Cd contamination. The physiological backgrounds of the acute Cd toxicity in barley plants are briefly described. Some data characterizing the chronic Cd toxicity in barley have been also provided in relation to its possible use for seed production and Cd phytoextraction on Cd-contaminated agricultural soils. Information about the main physiological factors limiting growth of Cd-exposed barley plants and grain yield, seedling quality as well as Cd phytoextraction capacity of barley grown in Cd-contaminated soils is presented.

  3. Plant growth regulator interactions in physiological processes for controlling plant regeneration and in vitro development of Tulbaghia simmleri

    Czech Academy of Sciences Publication Activity Database

    Kumari, A.; Baskaran, P.; Plačková, Lenka; Omámiková, Hana; Nisler, Jaroslav; Doležal, Karel; Van Staden, J.

    2018-01-01

    Roč. 223, APR (2018), s. 65-71 ISSN 0176-1617 R&D Projects: GA MŠk(CZ) LO1204 Institutional support: RVO:61389030 Keywords : Endogenous hormone * Exogenous hormone application * In vitro regeneration * Ornamental and medicinal plant * Physiological process * Tulbaghia simmleri Subject RIV: EB - Genetics ; Molecular Biology OBOR OECD: Plant sciences, botany Impact factor: 3.121, year: 2016

  4. Genotypic Differences in Growth and Physiological Responses to Transplanting and Direct Seeding Cultivation in Rice

    Directory of Open Access Journals (Sweden)

    Song Chen

    2009-06-01

    Full Text Available The field experiments were conducted to investigate the growth and physiological responses of six super hybrid rice combinations to two planting methods, transplanting (TP and direct seeding (DS during 2006–2007 and 2007–2008. The 1000-grain weight and number of tillers per plant at the early growth stage, the maximum quantum yield of PSII (Fv/Fm and transpiration rate (Tr were higher in DS plants than in TP ones, whereas the grain yield, number of panicles per square meter, seed setting rate, net photosynthetic rate (Pn and stomatal conductance were lower in DS plants. However, little difference was detected in number of grains per panicle, stem (shoot and leaf weight between the combinations in the two planting methods. The responses of plant growth and physiological traits to planting method differed greatly among the six combinations. In both planting methods, Chouyou 58 and Yongyou 6 had the highest and lowest panicle biomass and Pn, respectively. The higher yield of Chunyou 58 was associated with more numbers of panicles per square meter and grains per panicle in both planting methods. The results indicate that lower grain yield in DS relative to TP is attributed to more excessive tillers at the early stage, lower leaf biomass and photosynthetic rate at the late stage.

  5. [Isolation and physiological characteristics of endophytic actinobacteria from medicinal plants].

    Science.gov (United States)

    Du, Huijing; Su, Jing; Yu, Liyan; Zhang, Yuqin

    2013-01-04

    To isolate, incubate and characterize cultivable endophytic antinobacteria from medicinal plants, and analyze the diversity of the endophytic antinobacteria, then explore the novel microbial resources. Ten media were used to isolate endophytic antinobacteria from 37 fresh medicinal plant tissue samples. The optimal cultivation conditions for endophytic antinobacteria were determined by comparison. Based on the morphology of the colonies and cells of the new isolates, we chose 174 isolates to analyze their 16S rRNA gene sequences and the diversity of the medicinal plant endophytic antinobacteria. The physiological characteristics of 27 representative strains were studied using Biolog GEN III MicroPlates, API 50CH and API ZYM kits. In total 940 endophytics affiliated to 47 genera of 30 families were isolated, among which more than 600 actinobacteria belonged to 34 genera and 7 unknown taxa. Good growth of the endophytic antinobacteria on PYG (peptone-yeast-glycerol) medium with pH 7.2 at 28-32 degrees C was observed. Physiological characteristics differences of these isolates related to their phylogenetic relationships. Greater differences were shown among the strains from the same host plants than those from differ,ent plants grown in the same area. There are great diverse endophytic actinobacteria inside the medicinal plants. No direct relationship of the endophytic actinobacteria from medicinal plants with the host plants in the sole carbon source utilization, fermentation of carbon sources to produce acid and the enzyme activities was found, while it seemed that the physiological characteristics of the isolates related to the geographical distribution of their host.

  6. Regulating plant physiology with organic electronics.

    Science.gov (United States)

    Poxson, David J; Karady, Michal; Gabrielsson, Roger; Alkattan, Aziz Y; Gustavsson, Anna; Doyle, Siamsa M; Robert, Stéphanie; Ljung, Karin; Grebe, Markus; Simon, Daniel T; Berggren, Magnus

    2017-05-02

    The organic electronic ion pump (OEIP) provides flow-free and accurate delivery of small signaling compounds at high spatiotemporal resolution. To date, the application of OEIPs has been limited to delivery of nonaromatic molecules to mammalian systems, particularly for neuroscience applications. However, many long-standing questions in plant biology remain unanswered due to a lack of technology that precisely delivers plant hormones, based on cyclic alkanes or aromatic structures, to regulate plant physiology. Here, we report the employment of OEIPs for the delivery of the plant hormone auxin to induce differential concentration gradients and modulate plant physiology. We fabricated OEIP devices based on a synthesized dendritic polyelectrolyte that enables electrophoretic transport of aromatic substances. Delivery of auxin to transgenic Arabidopsis thaliana seedlings in vivo was monitored in real time via dynamic fluorescent auxin-response reporters and induced physiological responses in roots. Our results provide a starting point for technologies enabling direct, rapid, and dynamic electronic interaction with the biochemical regulation systems of plants.

  7. Physiological and proteomic analysis of plant growth enhancement by the rhizobacteria Bacillus sp. JS.

    Science.gov (United States)

    Kim, Ji Seong; Lee, Jeong Eun; Nie, Hualin; Lee, Yong Jae; Kim, Sun Tae; Kim, Sun-Hyung

    2018-02-01

    In this study, the effects of the plant growth-promoting rhizobacterium (PGPR), Bacillus sp. JS on the growth of tobacco (Nicotiana tabacum 'Xanthi') and lettuce (Lactuca sativa 'Crispa'), were evaluated by comparing various growth parameters between plants treated with the bacterium and those exposed to water or nutrient broth as control. In both tobacco and lettuce, fresh weight and length of shoots were increased upon exposure to Bacillus sp. JS. To explain the overall de novo expression of plant proteins by bacterial volatiles, two-dimensional gel electrophoresis was performed on samples from PGPR-treated tobacco plants. Our results showed that chlorophyll a/b binding proteins were significantly up-regulated, and total chlorophyll content was also increased. Our findings indicate the potential benefits of using Bacillus sp. JS as a growth-promoting factor in agricultural practice, and highlight the need for further research to explore these benefits.

  8. [Effects of soil moisture content and light intensity on the plant growth and leaf physiological characteristics of squash].

    Science.gov (United States)

    Du, She-ni; Bai, Gang-shuan; Liang, Yin-li

    2011-04-01

    A pot experiment with artificial shading was conducted to study the effects of soil moisture content and light intensity on the plant growth and leaf physiological characteristics of squash variety "Jingyingyihao". Under all test soil moisture conditions, 30% shading promoted the growth of "Jingyingyihao", with the highest yield at 70% - 80% soil relative moisture contents. 70% shading inhibited plant growth severely, only flowering and not bearing fruits, no economic yield produced. In all treatments, there was a similar water consumption trend, i. e., both the daily and the total water consumption decreased with increasing shading and decreasing soil moisture content. Among all treatments, 30% shading and 70% - 80% soil relative moisture contents had the highest water use efficiency (2.36 kg mm(-1) hm(-2)) and water output rate (1.57 kg mm(-1) hm(-2)). The net photosynthetic rate, transpiration rate, stomatal conductance, and chlorophyll content of squash leaves decreased with increasing shading, whereas the intercellular CO2 concentration was in adverse. The leaf protective enzyme activity and proline content decreased with increasing shading, and the leaf MAD content decreased in the order of 70% shading, natural radiation, and 30% shading. Under the three light intensities, the change characteristics of squash leaf photosynthesis, protective enzyme activity, and proline and MAD contents differed with the increase of soil relative moisture content.

  9. On the language and physiology of dormancy and quiescence in plants.

    Science.gov (United States)

    Considine, Michael J; Considine, John A

    2016-05-01

    The language of dormancy is rich and poetic, as researchers spanning disciplines and decades have attempted to understand the spell that entranced 'Sleeping Beauty', and how she was gently awoken. The misleading use of 'dormancy', applied to annual axillary buds, for example, has confounded progress. Language is increasingly important as genetic and genomic approaches become more accessible to species of agricultural and ecological importance. Here we examine how terminology has been applied to different eco-physiological states in plants, and with pertinent reference to quiescent states described in other domains of life, in order to place plant quiescence and dormancy in a more complete context than previously described. The physiological consensus defines latency or quiescence as opportunistic avoidance states, where growth resumes in favourable conditions. In contrast, the dormant state in higher plants is entrained in the life history of the organism. Competence to resume growth requires quantitative and specific conditioning. This definition applies only to the embryo of seeds and specialized meristems in higher plants; however, mechanistic control of dormancy extends to mobile signals from peripheral tissues and organs, such as the endosperm of seed or subtending leaf of buds. The distinction between dormancy, quiescence, and stress-hardiness remains poorly delineated, most particularly in buds of winter perennials, which comprise multiple meristems of differing organogenic states. Studies in seeds have shown that dormancy is not a monogenic trait, and limited study has thus far failed to canalize dormancy as seen in seeds and buds. We argue that a common language, based on physiology, is central to enable further dissection of the quiescent and dormant states in plants. We direct the topic largely to woody species showing a single cycle of growth and reproduction per year, as these bear the majority of global timber, fruit, and nut production, as well being

  10. Effects of rare earth elements and REE-binding proteins on physiological responses in plants.

    Science.gov (United States)

    Liu, Dongwu; Wang, Xue; Chen, Zhiwei

    2012-02-01

    Rare earth elements (REEs), which include 17 elements in the periodic table, share chemical properties related to a similar external electronic configuration. REEs enriched fertilizers have been used in China since the 1980s. REEs could enter the cell and cell organelles, influence plant growth, and mainly be bound with the biological macromolecules. REE-binding proteins have been found in some plants. In addition, the chlorophyll activities and photosynthetic rate can be regulated by REEs. REEs could promote the protective function of cell membrane and enhance the plant resistance capability to stress produced by environmental factors, and affect the plant physiological mechanism by regulating the Ca²⁺ level in the plant cells. The focus of present review is to describe how REEs and REE-binding proteins participate in the physiological responses in plants.

  11. Analysing growth and development of plants jointly using developmental growth stages.

    Science.gov (United States)

    Dambreville, Anaëlle; Lauri, Pierre-Éric; Normand, Frédéric; Guédon, Yann

    2015-01-01

    Plant growth, the increase of organ dimensions over time, and development, the change in plant structure, are often studied as two separate processes. However, there is structural and functional evidence that these two processes are strongly related. The aim of this study was to investigate the co-ordination between growth and development using mango trees, which have well-defined developmental stages. Developmental stages, determined in an expert way, and organ sizes, determined from objective measurements, were collected during the vegetative growth and flowering phases of two cultivars of mango, Mangifera indica. For a given cultivar and growth unit type (either vegetative or flowering), a multistage model based on absolute growth rate sequences deduced from the measurements was first built, and then growth stages deduced from the model were compared with developmental stages. Strong matches were obtained between growth stages and developmental stages, leading to a consistent definition of integrative developmental growth stages. The growth stages highlighted growth asynchronisms between two topologically connected organs, namely the vegetative axis and its leaves. Integrative developmental growth stages emphasize that developmental stages are closely related to organ growth rates. The results are discussed in terms of the possible physiological processes underlying these stages, including plant hydraulics, biomechanics and carbohydrate partitioning. © The Author 2014. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  12. Growth and physiological characteristics of the weed false johnsongrass ( Sorghum arundinaceum (Desv. Stapf

    Directory of Open Access Journals (Sweden)

    Deborah Amorim Martins

    2016-02-01

    Full Text Available ABSTRACT Sorghum arundinaceum (Desv. Stapf is a weed that belongs to the Poaceae family and is widespread throughout Brazil. Despite the frequent occurrence, infesting cultivated areas, there is little research concerning the biology and physiology of this species. The objective of this research was to evaluate the growth, carbon partitioning and physiological characteristics of the weed Sorghum arundinaceum in greenhouse. Plants were collected at regular intervals of seven days, from 22 to 113 days after transplanting (DAT. In each sample, we determined plant height, root volume, leaf area and dry matter, and subsequently we perfomed the growth analysis, we have determined the dry matter partitioning among organs, the accumulation of dry matter, the specific leaf area, the relative growth rate and leaf weight ratio. At 36, 78 and 113 DAT, the photosynthetic and transpiration rates, stomatal conductance, CO2 concentration and chlorophyll fluorescence were evaluated. The Sorghum arundinaceum reached 1.91 in height, with slow initial growth and allocated much of the biomass in the roots. The photosynthetic rate and the maximum quantum yield of FSII are similar throughout the growth cycle. At maturity the Sorghum arundinaceum presents higher values of transpiration rate, stomatal conductance and non-photochemical quenching coefficient (NPQ.

  13. Physiological and biochemical perspectives of non-salt tolerant plants during bacterial interaction against soil salinity.

    Science.gov (United States)

    Radhakrishnan, Ramalingam; Baek, Kwang Hyun

    2017-07-01

    Climatic changes on earth affect the soil quality of agricultural lands, especially by increasing salt deposition in soil, which results in soil salinity. Soil salinity is a major challenge to growth and reproduction among glycophytes (including all crop plants). Soil bacteria present in the rhizosphere and/or roots naturally protect plants from the adverse effects of soil salinity by reprogramming the stress-induced physiological changes in plants. Bacteria can enrich the soil with major nutrients (nitrogen, phosphorus, and potassium) in a form easily available to plants and prevent the transport of excess sodium to roots (exopolysaccharides secreted by bacteria bind with sodium ions) for maintaining ionic balance and water potential in cells. Salinity also affects plant growth regulators and suppresses seed germination and root and shoot growth. Bacterial secretion of indole-3-acetic acid and gibberellins compensates for the salt-induced hormonal decrease in plants, and bacterial 1-aminocyclopropane-1-carboxylate (ACC) deaminase synthesis decreases ethylene production to stimulate plant growth. Furthermore, bacteria modulate the redox state of salinity-affected plants by enhancing antioxidants and polyamines, which leads to increased photosynthetic efficiency. Bacteria-induced accumulation of compatible solutes in stressed plants regulates plant cellular activities and prevents salt stress damage. Plant-bacterial interaction reprograms the expression of salt stress-responsive genes and proteins in salinity-affected plants, resulting in a precise stress mitigation metabolism as a defense mechanism. Soil bacteria increase the fertility of soil and regulate the plant functions to prevent the salinity effects in glycophytes. This review explains the current understanding about the physiological changes induced in glycophytes during bacterial interaction to alleviate the adverse effects of soil salinity stress. Copyright © 2017 Elsevier Masson SAS. All rights

  14. The effects of light-emitting diode lighting on greenhouse plant growth and quality

    Directory of Open Access Journals (Sweden)

    Margit Olle

    2013-06-01

    Full Text Available The aim of this study is to present the light emitting diode (LED technology for greenhouse plant lighting and to give an overview about LED light effects on photosynthetic indices, growth, yield and nutritional value in green vegetables and tomato, cucumber, sweet pepper transplants. The sole LED lighting, applied in closed growth chambers, as well as combinations of LED wavelengths with conventional light sources, fluorescent and high pressure sodium lamp light, and natural illumination in greenhouses are overviewed. Red and blue light are basal in the lighting spectra for green vegetables and tomato, cucumber, and pepper transplants; far red light, important for photomorphogenetic processes in plants also results in growth promotion. However, theoretically unprofitable spectral parts as green or yellow also have significant physiological effects on investigated plants. Presented results disclose the variability of light spectral effects on different plant species and different physiological indices.

  15. Plant growth regulators and ascorbic acid effects on physiological quality of wheat seedlings obtained from deteriorated seeds

    International Nuclear Information System (INIS)

    Moori, S.; Eisv, H.R.

    2017-01-01

    This study attempted to examine the effect of seed priming using plant growth regulators and vitamin C on the physiological traits of non-aged and aged seeds of wheat and their obtained seedlings. Accelerated aging (AA) method (40 degree C, RH=100% for 72h) was used for aging seeds. The seeds were pre-treated by gibberellin (GA), salicylic acid (SA), brassinosteroid (BR), and ascorbic acid (AS). Some seed traits such as germination and electric conductivity (EC) and seedling traits such as malondialdehyde (MDA) content, activity of some antioxidant enzymes, soluble protein content (SP), soluble sugar (SS), and proline were measured seven days after germination. The results showed that accelerated aging of seeds reduces the germination percentage and speed, increases soluble sugar, and reduces soluble protein, activity of catalase (CAT), peroxidase (POD) and superoxide dismutase (SOD) in the seedling. Pre-treatment of the aged seed by GA had the maximum positive impact on seed germination and seedling growth. Priming improved germination indices, quality of seedling, and seedling resistance against the oxidative stress caused by AA. It also improved cell membrane integrity and thus reduced seeds’ EC. Priming increased the activity of CAT, POD and SOD enzymes in both aged and non-aged seeds. When the deteriorated seeds were primed, proline and SS contents of the seedling increased significantly, but SP and MDA decreased. In general, pre-treatment of the non-aged and aged seeds by gibberellin improved the physiological quality of the seed and seedling. (author)

  16. Promotion of plant growth by Pseudomonas fluorescens strain SS101 via novel volatile organic compounds

    NARCIS (Netherlands)

    Park, Yong-Soon; Dutta, Swarnalee; Ann, Mina; Raaijmakers, Jos M.; Park, Kyungseok

    2015-01-01

    Abstract Volatile organic compounds (VOCs) from plant growth-promoting rhizobacteria (PGPR) play key roles in modulating plant growth and induced systemic resistance (ISR) to pathogens. Despite their significance, the physiological functions of the specific VOCs produced by Pseudomonas fluorescens

  17. Positive impact of bio-stimulators on growth and physiological activity of willow in climate change conditions

    Science.gov (United States)

    Piotrowski, Krzysztof; Romanowska-Duda, Zdzisława

    2018-04-01

    The aim of this research was to evaluate the physiological activity and growth of willow (Salix viminalis L.) plants cultivated under the conditions of adverse temperature and soil moisture content, and to assess the effect of the foliar application of Biojodis (1.0%) and Asahi SL (0.03%) bio-stimulators, or a mixture of Microcistis aeruginosa MKR 0105 and Anabaena PCC 7120 cyanobacteria under such changing growth conditions. The obtained results showed different reactions to the applied constant or periodically changed temperature and soil moisture content. The plants which grew at periodically changed adverse temperature (from -5 to 40oC) or in scantily (20% m.c.) or excessively (60% m.c.) watered soils, grew slowly, in comparison with those growing at 20oC and in optimally moistened soil (30% m.c.). Foliar application of Biojodis and Asahi SL cyanobacteria increased the growth of willow at optimal and adverse temperature or in scantily and excessively moistened soil. The changes in plant growth were associated with the changes in electrolyte leakage, activity of acid or alkaline phosphatases, RNase, index of chlorophyll content in leaves and gas exchange. The above indicates that the foliar application of the studied cyanobacteria and bio-stimulators partly alleviates the harmful impact of adverse temperature and water stress on growth and physiological activity of willow plants

  18. GABA signalling modulates plant growth by directly regulating the activity of plant-specific anion transporters.

    Science.gov (United States)

    Ramesh, Sunita A; Tyerman, Stephen D; Xu, Bo; Bose, Jayakumar; Kaur, Satwinder; Conn, Vanessa; Domingos, Patricia; Ullah, Sana; Wege, Stefanie; Shabala, Sergey; Feijó, José A; Ryan, Peter R; Gilliham, Matthew; Gillham, Matthew

    2015-07-29

    The non-protein amino acid, gamma-aminobutyric acid (GABA) rapidly accumulates in plant tissues in response to biotic and abiotic stress, and regulates plant growth. Until now it was not known whether GABA exerts its effects in plants through the regulation of carbon metabolism or via an unidentified signalling pathway. Here, we demonstrate that anion flux through plant aluminium-activated malate transporter (ALMT) proteins is activated by anions and negatively regulated by GABA. Site-directed mutagenesis of selected amino acids within ALMT proteins abolishes GABA efficacy but does not alter other transport properties. GABA modulation of ALMT activity results in altered root growth and altered root tolerance to alkaline pH, acid pH and aluminium ions. We propose that GABA exerts its multiple physiological effects in plants via ALMT, including the regulation of pollen tube and root growth, and that GABA can finally be considered a legitimate signalling molecule in both the plant and animal kingdoms.

  19. Physiological and biochemical characterization of Azospirillum brasilense strains commonly used as plant growth-promoting rhizobacteria.

    Science.gov (United States)

    Di Salvo, Luciana P; Silva, Esdras; Teixeira, Kátia R S; Cote, Rosalba Esquivel; Pereyra, M Alejandra; García de Salamone, Inés E

    2014-12-01

    Azospirillum is a plant growth-promoting rhizobacteria (PGPR) genus vastly studied and utilized as agriculture inoculants. Isolation of new strains under different environmental conditions allows the access to the genetic diversity and improves the success of inoculation procedures. Historically, the isolation of this genus has been performed by the use of some traditional culture media. In this work we characterized the physiology and biochemistry of five different A. brasilense strains, commonly used as cereal inoculants. The aim of this work is to contribute to pose into revision some concepts concerning the most used protocols to isolate and characterize this bacterium. We characterized their growth in different traditional and non-traditional culture media, evaluated some PGPR mechanisms and characterized their profiles of fatty acid methyl esters and carbon-source utilization. This work shows, for the first time, differences in both profiles, and ACC deaminase activity of A. brasilense strains. Also, we show unexpected results obtained in some of the evaluated culture media. Results obtained here and an exhaustive knowledge revision revealed that it is not appropriate to conclude about bacterial species without analyzing several strains. Also, it is necessary to continue developing studies and laboratory techniques to improve the isolation and characterization protocols. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Information Integration and Communication in Plant Growth Regulation.

    Science.gov (United States)

    Chaiwanon, Juthamas; Wang, Wenfei; Zhu, Jia-Ying; Oh, Eunkyoo; Wang, Zhi-Yong

    2016-03-10

    Plants are equipped with the capacity to respond to a large number of diverse signals, both internal ones and those emanating from the environment, that are critical to their survival and adaption as sessile organisms. These signals need to be integrated through highly structured intracellular networks to ensure coherent cellular responses, and in addition, spatiotemporal actions of hormones and peptides both orchestrate local cell differentiation and coordinate growth and physiology over long distances. Further, signal interactions and signaling outputs vary significantly with developmental context. This review discusses our current understanding of the integrated intracellular and intercellular signaling networks that control plant growth. Copyright © 2016 Elsevier Inc. All rights reserved.

  1. Physiology of woody plants

    CERN Document Server

    Hazewinkel, Michiel; Pallardy, Stephen G

    1996-01-01

    This completely revised classic volume is an up-to-date synthesis of the intensive research devoted to woody plants. Intended primarily as a text for students and a reference for researchers, this interdisciplinary book should be useful to a broad range of scientists from agroforesters, agronomists, and arborists to plant pathologists, ecophysiologists, and soil scientists. Anyone interested in plant physiology will find this text invaluable. Key Features * Includes supplementary chapter summaries and lists of general references * Provides a solid foundation of reference information * Thoroughly updated classic text/reference.

  2. Physiological responses of Vetiver plant (Vetiver zizanioides to municipal waste leachate

    Directory of Open Access Journals (Sweden)

    Sasan Mohsenzadeh

    2016-06-01

    Full Text Available Vetiver plant is tolerant to acidity and temperature variations. Has rapid growth for biomass production and has high tolerance to organic and non-organic compounds in municipal waste leachate for example heavy metals. So this plant is good for landfill cultivation. In this study, physiological responses to municipal waste leachate were studied. Statistical design was a randomized complete block and each block treated with different concentrations of latex at levels of zero, 15, 30, 45 and 60 percent compared to the original latex waste. The leachate collected from the Shiraz landfill and brought into the greenhouse. The physiological characterization including leaf area, dry weight, chlorophyll, anthocyanin, proline, soluble sugars and total protein were measured. The result indicated that the dry weight, chlorophyll and anthocyanin decrease with increasing of latex concentration. The leaf area, leaf relative water, soluble sugars and total protein increased with increasing latex concentration. Proline concentration at 15 percent of leachate increased significantly compared to controls, whereas at higher concentrations decreased. According to the results, it is recommended that 45 percent of leachate in a landfill can be used to irrigate Vetiver. This is the maximum concentration of leachate that Vetiver plant can survive as green space. Primary filtration of leachate before using is recommended. If the aim is more growth or perfume application from root, less concentration of leachate is better.

  3. Amplification of heat extremes by plant CO2 physiological forcing.

    Science.gov (United States)

    Skinner, Christopher B; Poulsen, Christopher J; Mankin, Justin S

    2018-03-15

    Plants influence extreme heat events by regulating land-atmosphere water and energy exchanges. The contribution of plants to changes in future heat extremes will depend on the responses of vegetation growth and physiology to the direct and indirect effects of elevated CO 2 . Here we use a suite of earth system models to disentangle the radiative versus vegetation effects of elevated CO 2 on heat wave characteristics. Vegetation responses to a quadrupling of CO 2 increase summer heat wave occurrence by 20 days or more-30-50% of the radiative response alone-across tropical and mid-to-high latitude forests. These increases are caused by CO 2 physiological forcing, which diminishes transpiration and its associated cooling effect, and reduces clouds and precipitation. In contrast to recent suggestions, our results indicate CO 2 -driven vegetation changes enhance future heat wave frequency and intensity in most vegetated regions despite transpiration-driven soil moisture savings and increases in aboveground biomass from CO 2 fertilization.

  4. Biological significance of complex N-glycans in plants and their impact on plant physiology.

    Science.gov (United States)

    Strasser, Richard

    2014-01-01

    Asparagine (N)-linked protein glycosylation is a ubiquitous co- and post-translational modification which can alter the biological function of proteins and consequently affects the development, growth, and physiology of organisms. Despite an increasing knowledge of N-glycan biosynthesis and processing, we still understand very little about the biological function of individual N-glycan structures in plants. In particular, the N-glycan-processing steps mediated by Golgi-resident enzymes create a structurally diverse set of protein-linked carbohydrate structures. Some of these complex N-glycan modifications like the presence of β1,2-xylose, core α1,3-fucose or the Lewis a-epitope are characteristic for plants and are evolutionary highly conserved. In mammals, complex N-glycans are involved in different cellular processes including molecular recognition and signaling events. In contrast, the complex N-glycan function is still largely unknown in plants. Here, in this short review, I focus on important recent developments and discuss their implications for future research in plant glycobiology and plant biotechnology.

  5. Potato type I and II proteinase inhibitors: modulating plant physiology and host resistance.

    Science.gov (United States)

    Turra, David; Lorito, Matteo

    2011-08-01

    Serine protease inhibitors (PIs) are a large and complex group of plant proteins. Members of the potato type I (Pin1) and II (Pin2) proteinase inhibitor families are among the first and most extensively characterized plant PIs. Many insects and phytopathogenic microorganisms use intracellular and extracellular serine proteases playing important roles in pathogenesis. Plants, however, are able to fight these pathogens through the activation of an intricate defence system that leads to the accumulation of various PIs, including Pin1 and Pin2. Several transgenic plants over-expressing members of the Pin1 and Pin2 families have been obtained in the last twenty years and their enhanced defensive capabilities demonstrated against insects, fungi and bacteria. Furthermore, Pin1 and Pin2 genetically engineered plants showed altered regulation of different plant physiological processes (e.g., dehydratation response, programmed cell death, plant growth, trichome density and branching), supporting an endogenous role in various plant species in addition to the well established defensive one. This review summarizes the current knowledge about Pin1 and Pin2 structure, the role of these proteins in plant defence and physiology, and their potential exploitation in biotechnology.

  6. MORPHOLOGICAL AND PHYSIOLOGICAL CHANGES ON Schizolobium parahybaVAR .Amazonicum(HUBER EX DUCKE BARNEBY PLANTS INTOXICATED BY GLYPHOSATE

    Directory of Open Access Journals (Sweden)

    Kaléo Dias Pereira

    2017-06-01

    Full Text Available The objective of this study was to evaluate the morphological and physiological changes in paricá plants (Schizolobium parahyba var. amazonicum intoxicated by glyphosate. The experiment was conducted in a protected environment using paricá plants during their planting stage, which were intoxicated with increasing doses of glyphosate: 0 (control; 43.2; 86.2; 129.6 and 172.8 g.ha-1. At 7 and 21 days after the application of the herbicide, the photosynthesis, transpiration, stomatal conductance and leaf temperature were measured. The visual intoxication degree and the growth of the shoot and the root of the plants were evaluated 21 days after the application. Paricá shows symptoms of visual intoxication characterized by chlorosis/winding, evolving to necrosis/abscission of the youngest leaflets. The growth of the stem and the roots of the intoxicated plants is preserved; however, an expressive leaf loss occurs, and paricá may have adaptation mechanisms to tolerate the action of the herbicide molecule. The photosynthesis decrease promoted by an indirect action of glyphosate represents the main reduction on the growth of plants. The decrease on the stomatal conductance, which was the most sensitive physiological variable to glyphosate, resulted in lower transpiration rates, which, consequently, caused increases on the leaf temperature.

  7. Some Recent Advances in Plant Physiology

    Science.gov (United States)

    Stafford, G. A.

    1972-01-01

    A popular review of plant physiological research, emphasizing those apsects of plant metabolism where there has been a recent shift in emphasis that is not yet reflected in secondary school advanced texts. (AL)

  8. Peat soil composition as indicator of plants growth environment

    Science.gov (United States)

    Noormets, M.; Tonutare, T.; Kauer, K.; Szajdak, L.; Kolli, R.

    2009-04-01

    Exhausted milled peat areas have been left behind as a result of decades-lasting intensive peat production in Estonia and Europe. According to different data there in Estonia is 10 000 - 15 000 ha of exhausted milled peat areas that should be vegetated. Restoration using Sphagnum species is most advantageous, as it creates ecological conditions closest to the natural succession towards a natural bog area. It is also thought that the large scale translocation of vegetation from intact bogs, as used in some Canadian restoration trials, is not applicable in most of European sites due to limited availability of suitable donor areas. Another possibility to reduce the CO2 emission in these areas is their use for cultivation of species that requires minimum agrotechnical measures exploitation. It is found by experiments that it is possible to establish on Vaccinium species for revegetation of exhausted milled peat areas. Several physiological activity of the plant is regulated by the number of phytohormones. These substances in low quantities move within the plant from a site of production to a site of action. Phytohormone, indole-3-acetic acid (IAA) is formed in soils from tryptophane by enzymatic conversion. This compound seems to play an important function in nature as result to its influence in regulation of plant growth and development. A principal feature of IAA is its ability to affect growth, development and health of plants. This compound activates root morphology and metabolic changes in the host plant. The physiological impact of this substance is involved in cell elongation, apical dominance, root initiation, parthenocarpy, abscission, callus formation and the respiration. The investigation areas are located in the county of Tartu (58˚ 22' N, 26˚ 43' E), in the southern part of Estonia. The soil of the experimental fields belongs according to the WRB soil classification, to the soils subgroups of Fibri-Dystric Histosols. The investigation areas were

  9. EFFECT OF DROUGHT STRESS INDUCED BY MANNITOL ON PHYSIOLOGICAL PARAMETERS OF MAIZE (ZEA MAYS L. SEEDLINGS AND PLANTS

    Directory of Open Access Journals (Sweden)

    Katarzyna Możdżeń

    2015-02-01

    Full Text Available Plants are exposed to various stress factors which might lead to structural damage and physiological function abnormalities. Drought is one of the environmental stress factors that reduce the productivity of plants. The aim of our study was to determine the influence of drought stress induced by mannitol (-0.5 and -1.5MPa on selected physiological processes in Z. mays L. In the first stage we studied the effect of mannitol on the germination. In the second stage the effect of mannitol on the growth of plants germinated on distilled water and watered with mannitol in growth phase were measured. Mannitol, which decreased the water content in a concentration-dependent manner, had an inhibitory effect on germination and growth of seedlings and adult plants. Electrolyte leakage of cell membranes of the Z. mays seedlings showed high disturbances in the functioning of the membrane structures in the osmotic drought conditions. Similar results were obtained for maize roots, shoots and leaves in both treatment studies. Chlorophyll content showed only significant differences in plants from treated during the growth phase. Drought stress caused a decrease in chlorophyll content by almost a half compared to the control plants. Measurements of chlorophyll fluorescence of plant leaves from the second stage of experiments showed changes in fluorescence activity parameters Fv/Fm, NPQ, Rfd, qP, ect.; gas exchange measurements also showed changes in activity in each of the two phases.

  10. Modelling of salad plants growth and physiological status in vitamin space greenhouse during lighting regime optimization

    Science.gov (United States)

    Konovalova, Irina; Berkovich, Yuliy A.; Smolyanina, Svetlana; Erokhin, Alexei; Yakovleva, Olga; Lapach, Sergij; Radchenko, Stanislav; Znamenskii, Artem; Tarakanov, Ivan

    2016-07-01

    The efficiency of the photoautotrophic element as part of bio-engineering life-support systems is determined substantially by lighting regime. The artificial light regime optimization complexity results from the wide range of plant physiological functions controlled by light: trophic, informative, biosynthetical, etc. An average photosynthetic photon flux density (PPFD), light spectral composition and pulsed light effects on the crop growth and plant physiological status were studied in the multivariate experiment, including 16 independent experiments in 3 replicates. Chinese cabbage plants (Brassica chinensis L.), cultivar Vesnianka, were grown during 24 days in a climatic chamber under white and red light-emitting diodes (LEDs): photoperiod 24 h, PPFD from 260 to 500 µM/(m ^{2}*s), red light share in the spectrum varying from 33% to 73%, pulsed (pulse period from 30 to 501 µs) and non-pulsed lighting. The regressions of plant photosynthetic and biochemical indexes as well as the crop specific productivity in response to the selected parameters of lighting regime were calculated. Developed models of crop net photosynthesis and dark respiration revealed the most intense gas exchange area corresponding to PPFD level 450 - 500 µM/(m ^{2}*s) with red light share in the spectrum about 60% and the pulse length 30 µs with a pulse period from 300 to 400 µs. Shoot dry weight increased monotonically in response to the increasing PPFD and changed depending on the pulse period under stabilized PPFD level. An increase in ascorbic acid content in the shoot biomass was revealed when increasing red light share in spectrum from 33% to 73%. The lighting regime optimization criterion (Q) was designed for the vitamin space greenhouse as the maximum of a crop yield square on its ascorbic acid concentration, divided by the light energy consumption. The regression model of optimization criterion was constructed based on the experimental data. The analysis of the model made it

  11. Allocation, stress tolerance and carbon transport in plants: how does phloem physiology affect plant ecology?

    Science.gov (United States)

    Savage, Jessica A; Clearwater, Michael J; Haines, Dustin F; Klein, Tamir; Mencuccini, Maurizio; Sevanto, Sanna; Turgeon, Robert; Zhang, Cankui

    2016-04-01

    Despite the crucial role of carbon transport in whole plant physiology and its impact on plant-environment interactions and ecosystem function, relatively little research has tried to examine how phloem physiology impacts plant ecology. In this review, we highlight several areas of active research where inquiry into phloem physiology has increased our understanding of whole plant function and ecological processes. We consider how xylem-phloem interactions impact plant drought tolerance and reproduction, how phloem transport influences carbon allocation in trees and carbon cycling in ecosystems and how phloem function mediates plant relations with insects, pests, microbes and symbiotes. We argue that in spite of challenges that exist in studying phloem physiology, it is critical that we consider the role of this dynamic vascular system when examining the relationship between plants and their biotic and abiotic environment. © 2015 John Wiley & Sons Ltd.

  12. Knowledge about plant is basis for successful cultivation : new international standard handbook on plant physiology

    NARCIS (Netherlands)

    Esch, van H.; Heuvelink, E.; Kierkels, T.

    2015-01-01

    Plant physiology in Greenhouses’ is the new international standard handbook on plant knowledge for the commercial greenhouse grower. It relates the functioning of the plant to the rapid developments in greenhouse cultivation. It is based on a continuing series of plant physiology articles published

  13. Prognosis of physiological disorders in physic nut to N, P, and K deficiency during initial growth.

    Science.gov (United States)

    Santos, Elcio Ferreira; Macedo, Fernando Giovannetti; Zanchim, Bruno José; Lima, Giuseppina Pace Pereira; Lavres, José

    2017-06-01

    The description of physiological disorders in physic nut plants deficient in nitrogen (N), phosphorus (P) and potassium (K) may help to predict nutritional imbalances before the appearance of visual symptoms and to guide strategies for early nutrient supply. The aim of this study was to evaluate the growth of physic nuts (Jatropha curcas L.) during initial development by analyzing the gas exchange parameters, nutrient uptake and use efficiency, as well as the nitrate reductase and acid phosphatase activities and polyamine content. Plants were grown in a complete nutrient solution and solutions from which N, P or K was omitted. The nitrate reductase activity, phosphatase acid activity, polyamine content and gas exchange parameters from leaves of N, P and K-deficient plants indicates earlier imbalances before the appearance of visual symptoms. Nutrient deficiencies resulted in reduced plant growth, although P- and K-deficient plants retained normal net photosynthesis (A), stomatal conductance (g s ) and instantaneous carboxylation efficiency (k) during the first evaluation periods, as modulated by the P and K use efficiencies. Increased phosphatase acid activity in P-deficient plants may also contribute to the P use efficiency and to A and gs during the first evaluations. Early physiological and biochemical evaluations of N-, P- and K-starved plants may rely on reliable, useful methods to predict early nutritional imbalances. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  14. Engineered nanomaterials for plant growth and development: A perspective analysis.

    Science.gov (United States)

    Verma, Sandeep Kumar; Das, Ashok Kumar; Patel, Manoj Kumar; Shah, Ashish; Kumar, Vinay; Gantait, Saikat

    2018-07-15

    With the overwhelmingly rapid advancement in the field of nanotechnology, the engineered nanomaterials (ENMs) have been extensively used in various areas of the plant system, including quality improvement, growth and nutritional value enhancement, gene preservation etc. There are several recent reports on the ENMs' influence on growth enhancements, growth inhibition as well as certain toxic impacts on plant. However, translocation, growth responses and stress modulation mechanisms of ENMs in the plant systems call for better and in-depth understanding. Herein, we are presenting a comprehensive and critical account of different types of ENMs, their applications and their positive, negative and null impacts on physiological and molecular aspects of plant growth, development and stress responses. Recent reports revealed mixed effects on plants, ranging from enhanced crop yield, epi/genetic alterations, and phytotoxicity, resulting from the ENMs' exposure. Creditable research in recent years has revealed that the effects of ENMs on plants are species specific and are variable among plant species. ENM exposures are reported to trigger free radical formation, responsive scavenging, and antioxidant armories in the exposed plants. The ENMs are also reported to induce aberrant expressions of microRNAs, the key post-transcriptional regulators of plant growth, development and stress-responses of plants. However, these modulations, if judiciously done, may lead to improved plant growth and yield. A better understanding of the interactions between ENMs and plant responses, including their uptake transport, internalization, and activity, could revolutionize crop production through increased disease resistance, nutrient utilization, and crop yield. Therefore, in this review, we are presenting a critical account of the different selected ENMs, their uptake by the plants, their positive/negative impacts on plant growth and development, along with the resultant ENM-responsive post

  15. Roles of gibberellin catabolism and signaling in growth and physiological response to drought and short-day photoperiods in Populus trees.

    Directory of Open Access Journals (Sweden)

    Christine Zawaski

    Full Text Available Survival and productivity of perennial plants in temperate zones are dependent on robust responses to prolonged and seasonal cycles of unfavorable conditions. Here we report whole-genome microarray, expression, physiological, and transgenic evidence in hybrid poplar (Populus tremula × Populus alba showing that gibberellin (GA catabolism and repressive signaling mediates shoot growth inhibition and physiological adaptation in response to drought and short-day (SD induced bud dormancy. Both water deprivation and SDs elicited activation of a suite of poplar GA2ox and DELLA encoding genes. Poplar transgenics with up-regulated GA 2-oxidase (GA2ox and DELLA domain proteins showed hypersensitive growth inhibition in response to both drought and SDs. In addition, the transgenic plants displayed greater drought resistance as evidenced by increased pigment concentrations (chlorophyll and carotenoid and reductions in electrolyte leakage (EL. Comparative transcriptome analysis using whole-genome microarray showed that the GA-deficiency and GA-insensitivity, SD-induced dormancy, and drought response in poplar share a common regulon of 684 differentially-expressed genes, which suggest GA metabolism and signaling plays a role in plant physiological adaptations in response to alterations in environmental factors. Our results demonstrate that GA catabolism and repressive signaling represents a major route for control of growth and physiological adaptation in response to immediate or imminent adverse conditions.

  16. Influence of ambient and enhanced ultraviolet-B radiation on the plant growth and physiological properties in two contrasting populations of Hippophae rhamnoides

    International Nuclear Information System (INIS)

    Yang, Y.; Yao, Y.; He, H.

    2008-01-01

    Two contrasting sea buckthorn (Hippophae rhamnoides L.) populations from low and high altitude regions were employed to investigate the effects of prevailing and enhanced ultraviolet-B (UV-B) radiation on plant growth and physiological properties under a UVB-enhanced/exclusion system. The experimental design included three UV-B regimes, including excluded (-UVB), near-ambient (NA) and enhanced UV-B (+UVB) radiation. Compared with the control (-UVB), NA caused the formation of smaller but thicker plant leaves in both sea buckthorn populations, paralleled with significant increments of carotenoids and UV-absorbing compounds as well as improved water economy. NA also induced more biomass partition from shoot to root, but CO2 assimilation rate (A), photosynthetic area and biomass accumulation were unaffected. The low-altitude population seemed sensitive to +uvB, as indicated by the decreases in total biomass, A and ascorbic acid content (Asa, an antioxidant) compared with NA. However, little +UVB effect occurred on the high-altitude population, and we suggest that the higher tolerance of this population could be associated with its specific morphological and physiological characteristics, such as small but thick leaves and high-level of Asa content, as well as its greater physiological modification in response to NA, e.g., increases in protective compounds (carotenoids and UV-absorbing compounds) and improvement in water economy, in comparison to the low-altitude population, which form an effective adaptation strategy to enhanced UV-B stress

  17. Elements of plant physiology in theophrastus' botany.

    Science.gov (United States)

    Pennazio, Sergio

    2014-01-01

    For thousands of years the plants were considered only as a source of food and medicine, and as ornamental objects. Only from the fifth century BC, some philosophers of Ancient Greece realized that the plants were living organisms but, unfortunately, their works have come to us as fragments that we often know from the biological works of Aristotle. This eminent philosopher and man of science, however, did not give us a complete work on the plants, which he often promised to write. From scattered fragments of his conspicuous biological work, it emerges a concept of nutritive soul that, in the presence of heat and moisture, allows plants to grow and reproduce. The task of writing a comprehensive botanical work was delegated to his first pupil, Theophrastus, who left us two treatises over time translated into the various languages up to the current versions (Enquiry into plants, On the causes of plants). The plant life is described and interpreted on the basis of highly accurate observations. The physiological part of his botany is essentially the nutrition: According to Theophrastus, plants get matter and moisture from the soil through root uptake and process the absorbed substances transforming them into food, thanks to the heat. The processing (pepsis, coction) of matter into the food represents an extraordinary physiological intuition because individual organs of a plant appear to perform its specific transformation. Despite that Theophrastus did not do scientific experiments or use special methods other than the sharpness of his observations, he can be considered the forerunner of a plant physiology that would take rebirth only after two millennia.

  18. The Scientific Development of the Physiology of Plants in the American Tropics

    Directory of Open Access Journals (Sweden)

    Marco V. Gutiérrez

    2002-06-01

    Full Text Available This paper is a research and journalistic work that summarizes and synthesizes the scientific development of the physiology of plants in the American tropics, also known as the Neotropics. It contains the contributions of numerous biologists interested in the physiology of tropical plants. The fabulous structural and functional diversity of tropical forests is still the major driver of research in this field. Classical physiological work involving tropical plants, such as the discovery of C4 photosynthesis in sugarcane, is invoked to exemplify the historical and current importance of physiological research in the tropics, and its applications in agriculture, forestry and conservation. An historical background describing the early and more recent development of a tradition on the physiological study of tropical plants is followed by a summary of the research conducted on the physiology of tropical crops. Common areas of interest and influence between the fields of crop physiology and plant ecophysiology are identified and exemplified with problems on the environmental physiology of crops like coffee and cassava. The physiology of tropical forest plants is discussed in terms of its contributions to general plant physiological knowledge in areas such as photosynthetic metabolism and plant water relations. Despite the impressive technical advances achieved during the past decade, the importance of continuous development of appropriate instrumentation to study and measure the physiology of plants in situ is stressed. Although the basic metabolic processes that underlie the mechanisms of plant responses to the environment are probably highly conserved and qualitatively similar among tropical and temperate plants, it is also apparent that tropical plants exhibit metabolic peculiarities. These include aspects of photosynthetic metabolism, phloem transport physiology, sensitivity to low temperatures, reproduction, responses to climatic seasonality, and a

  19. Influence of plant maturity, shoot reproduction and sex on vegetative growth in the dioecious plant Urtica dioica.

    Science.gov (United States)

    Oñate, Marta; Munné-Bosch, Sergi

    2009-10-01

    Stinging nettle (Urtica dioica) is a herbaceous, dioecious perennial that is widely distributed around the world, reproduces both sexually and asexually, and is characterized by rapid growth. This work was aimed at evaluating the effects of plant maturity, shoot reproduction and sex on the growth of leaves and shoots. Growth rates of apical shoots, together with foliar levels of phytohormones (cytokinins, auxins, absicisic acid, jasmonic acid and salicylic acid) and other indicators of leaf physiology (water contents, photosynthetic pigments, alpha-tocopherol and F(v)/F(m) ratios) were measured in juvenile and mature plants, with a distinction made between reproductive and non-reproductive shoots in both males and females. Vegetative growth rates were not only evaluated in field-grown plants, but also in cuttings obtained from these plants. All measurements were performed during an active vegetative growth phase in autumn, a few months after mature plants reproduced during spring and summer. Vegetative growth rates in mature plants were drastically reduced compared with juvenile ones (48 % and 78 % for number of leaves and leaf biomass produced per day, respectively), which was associated with a loss of photosynthetic pigments (up to 24 % and 48 % for chlorophylls and carotenoids, respectively) and increases of alpha-tocopherol (up to 2.7-fold), while endogenous levels of phytohormones did not differ between mature and juvenile plants. Reductions in vegetative growth were particularly evident in reproductive shoots of mature plants, and occurred similarly in both males and females. It is concluded that (a) plant maturity reduces vegetative growth in U. dioica, (b) effects of plant maturity are evident both in reproductive and non-reproductive shoots, but particularly in the former, and (c) these changes occur similarly in both male and female plants.

  20. Evaluating physiological responses of plants to salinity stress

    KAUST Repository

    Negrão, Sónia

    2016-10-06

    Background Because soil salinity is a major abiotic constraint affecting crop yield, much research has been conducted to develop plants with improved salinity tolerance. Salinity stress impacts many aspects of a plant’s physiology, making it difficult to study in toto. Instead, it is more tractable to dissect the plant’s response into traits that are hypothesized to be involved in the overall tolerance of the plant to salinity. Scope and conclusions We discuss how to quantify the impact of salinity on different traits, such as relative growth rate, water relations, transpiration, transpiration use efficiency, ionic relations, photosynthesis, senescence, yield and yield components. We also suggest some guidelines to assist with the selection of appropriate experimental systems, imposition of salinity stress, and obtaining and analysing relevant physiological data using appropriate indices. We illustrate how these indices can be used to identify relationships amongst the proposed traits to identify which traits are the most important contributors to salinity tolerance. Salinity tolerance is complex and involves many genes, but progress has been made in studying the mechanisms underlying a plant’s response to salinity. Nevertheless, several previous studies on salinity tolerance could have benefited from improved experimental design. We hope that this paper will provide pertinent information to researchers on performing proficient assays and interpreting results from salinity tolerance experiments.

  1. Impact of a plant-based diet on behavioural and physiological traits in sea bass (Dicentrarchus labrax)

    OpenAIRE

    Benhaim, David; Begout, Marie-laure; Pean, Samuel; Manca, Michael; Prunet, Patrick; Chatain, Beatrice

    2013-01-01

    Replacing aquaculture feeds based on fisheries-derived resources with plant-based diets could be a relevant strategy to improve the sustainability of aquaculture. Recent studies on sea bass have shown that the total and early replacement of marine products by plant products would have a moderate effect on fish growth and body lipid content. Whether a plant-based diet impacts behavioural and physiological traits possibly linked to fish welfare, is not known, however. Here, we studied the effec...

  2. A Monte Carlo/response surface strategy for sensitivity analysis: application to a dynamic model of vegetative plant growth

    Science.gov (United States)

    Lim, J. T.; Gold, H. J.; Wilkerson, G. G.; Raper, C. D. Jr; Raper CD, J. r. (Principal Investigator)

    1989-01-01

    We describe the application of a strategy for conducting a sensitivity analysis for a complex dynamic model. The procedure involves preliminary screening of parameter sensitivities by numerical estimation of linear sensitivity coefficients, followed by generation of a response surface based on Monte Carlo simulation. Application is to a physiological model of the vegetative growth of soybean plants. The analysis provides insights as to the relative importance of certain physiological processes in controlling plant growth. Advantages and disadvantages of the strategy are discussed.

  3. The gravitational plant physiology facility-Description of equipment developed for biological research in spacelab

    Science.gov (United States)

    Heathcote, D. G.; Chapman, D. K.; Brown, A. H.; Lewis, R. F.

    1994-01-01

    In January 1992, the NASA Suttle mission STS 42 carried a facility designed to perform experiments on plant gravi- and photo-tropic responses. This equipment, the Gravitational Plant Physiology Facility (GPPF) was made up of a number of interconnected units mounted within a Spacelab double rack. The details of these units and the plant growth containers designed for use in GPPF are described. The equipment functioned well during the mission and returned a substantial body of time-lapse video data on plant responses to tropistic stimuli under conditions of orbital microgravity. GPPF is maintained by NASA Ames Research Center, and is flight qualifiable for future spacelab missions.

  4. Comparative effects of partial rootzone drying and deficit irrigation on growth and physiology of tomato plants

    Directory of Open Access Journals (Sweden)

    Savić Slađana

    2009-01-01

    Full Text Available The effects of partial rootzone drying (PRD, deficit irrigation (DI, and full irrigation (FI on tomato physiology were investigated. In PRD and DI plants, leaf water potential values and stomatal conductance were significantly lower, while xylem ABA concentration was greater compared to FI plants. Photosynthesis was similar for all treatments. Water use efficiency was improved by PRD and DI, which reduced fruit dry weight, but had no effect on dry weight of leaves and stems.

  5. Induction of phenolic metabolites and physiological changes in chamomile plants in relation to nitrogen nutrition.

    Science.gov (United States)

    Kováčik, Jozef; Klejdus, Bořivoj

    2014-01-01

    Alternative tools, such as the manipulation of mineral nutrition, may affect secondary metabolite production and thus the nutritional value of food/medicinal plants. We studied the impact of nitrogen (N) nutrition (nitrate/NO3(-) or ammonium/NH4(+) nitrogen) and subsequent nitrogen deficit on phenolic metabolites and physiology in Matricaria chamomilla plants. NH4(+)-fed plants revealed a strong induction of selected phenolic metabolites but, at the same time, growth, Fv/Fm, tissue water content and soluble protein depletion occurred in comparison with NO3(-)-fed ones. On the other hand, NO3(-)-deficient plants also revealed an increase in phenolic metabolites but growth depression was not observed after the given exposure period. Free amino acids were more accumulated in NH4(+)-fed shoots (strong increase in arginine and proline mainly), while the pattern of roots' accumulation was independent of N form. Among phenolic acids, NH4(+) strongly elevated mainly the accumulation of chlorogenic acid. Within flavonoids, flavonols decreased while flavones strongly increased in response to N deficiency. Coumarin-related metabolites revealed a similar increase in herniarin glucosidic precursor in response to N deficiency, while herniarin was more accumulated in NO3(-)- and umbelliferone in NH4(+)-cultured plants. These data indicate a negative impact of NH4(+) as the only source of N on physiology, but also a higher stimulation of some valuable phenols. Nitrogen-induced changes in comparison with other food/crop plants are discussed. Copyright © 2013 Elsevier Ltd. All rights reserved.

  6. Isolation and biological activity of a new plant growth regulator of Vicia faba L

    International Nuclear Information System (INIS)

    Sembdner, G.; Dathe, W.; Bergner, C.; Roensch, H.

    1983-01-01

    Jasmonic acid was identified as a plant growth inhibitor of the pericarp of Vicia faba by means of gas-liquid chromatography, high resolution mass spectrometry as well as 1 H and 13 C NMR. The highest level of jasmonic acid was reached during intensive pericarp growth. Jasmonic acid is a plant growth inhibitor possessing a relative activity in the wheat seedling bioassay of 1-2.5 % compared to ABA (=100%). Contrary to ABA, jasmonic acid does not cause retardation of leaf emergence. In the dwarf rice gibberellin bioassay relative low concentrations of jasmonic acid inhibit both autonomous and GA 3 -stimulated growth. Jasmonic acid does not influence seed germination of Amaranthus caudatus. The possible physiological role of jasmonic acid in the Vicia pericarp and the distribution in plants of this new plant growth regulator type are discussed. (author)

  7. Isolation and biological activity of a new plant growth regulator of Vicia faba L

    Energy Technology Data Exchange (ETDEWEB)

    Sembdner, G.; Dathe, W.; Bergner, C.; Roensch, H. (Akademie der Wissenschaften der DDR, Halle/Saale. Inst. fuer Biochemie der Pflanzen)

    1983-01-01

    Jasmonic acid was identified as a plant growth inhibitor of the pericarp of Vicia faba by means of gas-liquid chromatography, high resolution mass spectrometry as well as /sup 1/H and /sup 13/C NMR. The highest level of jasmonic acid was reached during intensive pericarp growth. Jasmonic acid is a plant growth inhibitor possessing a relative activity in the wheat seedling bioassay of 1-2.5 % compared to ABA (=100%). Contrary to ABA, jasmonic acid does not cause retardation of leaf emergence. In the dwarf rice gibberellin bioassay relative low concentrations of jasmonic acid inhibit both autonomous and GA/sub 3/-stimulated growth. Jasmonic acid does not influence seed germination of Amaranthus caudatus. The possible physiological role of jasmonic acid in the Vicia pericarp and the distribution in plants of this new plant growth regulator type are discussed.

  8. Nuclear techniques in plant pathology 1. Plant disease control and physiology of parasitism

    International Nuclear Information System (INIS)

    Menten, J.O.M.; Ando, A.; Tulmann Neto, A.

    1986-01-01

    Nuclear techniques are advantageously used in several areas of plant pathology. Among them are: induction of mutation for disease resistance, studies with pesticides, disease control through pathogen inactivation, induction of variability and stimulation in pathogens and natural enemies, studies of microorganism physiology and diseased plant physiology, effect of gamma radiation on pesticides, technology of pesticides application, etc. (Author) [pt

  9. Physiological and genetic basis of plant tolerance to excess boron

    Directory of Open Access Journals (Sweden)

    Kastori Rudolf R.

    2008-01-01

    Full Text Available Boron (B deficit as well as excess may significantly limit the organic production in plants. In extreme cases they may kill the affected plants. Boron excess occurs primarily in arid and semiarid regions, in saline soils or in consequence to human action. Excessive boron concentrations retard plant growth and cause physiological and morphological changes (chlorosis and necrosis first of all in leaf tips and then in marginal or intercostal parts of the lamina. Physiological mechanisms of plant tolerance to boron excess have not been studied in sufficient detail. The predominant opinion holds that they are based on restricted uptake and accumulation of boron in the root and aboveground plant parts. Significant differences in boron excess tolerance have been observed not only between different crops but even between different genotypes of the same crop. This has enabled the breeding of crop genotypes and crops adapted to growing on soils rich in available boron and intensified the research on the inheritance of plant tolerance to high B concentration. Sources of tolerance to high B concentration have been found in many crops (wheat, mustard, pea, lentil, eucalypt. Using different molecular techniques based on PCR (RAPD, SRAP, plant parents and progenies have been analyzed in an attempt to map as precisely as possible the position of B-tolerant genes. Small grains have been studied in greatest detail for inheritance of B tolerance. B tolerance in wheat is controlled by at least four additive genes, Bo1, Bo2, Bo3 and Bo4. Consequently, there exists a broad range of tolerance levels. Studies of Arabidopsis have broadened our understanding of regulation mechanisms of B transport from roots to above ground parts, allowing more direct genetic manipulations.

  10. Plant growth regulation by the light of LEDs; LED ko wo tsukatta shokubutsu saibai gijutsu

    Energy Technology Data Exchange (ETDEWEB)

    Watanabe, H. [Mitsubishi Chemical Co., Tokyo (Japan). Yokohama Research Center

    1996-03-01

    Light Emitting Diode (LED) has not only an excellent display function for the luminescent device but also a superior feature without other lamps as light source for plant growth. It was National Aeronautics and Space Administration (NASA) to find out such merit for this light source for plant growth and try at first to use for plant growth at the space. They began to examine the LED application to the light source for the plant growth at the space since a stage at high cost of the LED, to develop some researches centered at cultivation of lettuce, wheat, and others. Finding out future possibility of cost-down of the LEDs on the cost/performance and large merits of the LEDs for control of the plant growth and plant physiology, authors have conducted some cultivation experiments of the plants using the LEDs for light source some years ago. In this papers, characterizations, actual possibility, and future developments of the LEDs for the light sources of the plant growth, are introduced. 5 refs., 4 figs.

  11. Study of Plant Growth Promoting Rhizobacteria (PGPR and Drought on Physiological Traits and Ultimate Yield of Cultivars of Oilseed Rape (Brassica spp. L.

    Directory of Open Access Journals (Sweden)

    pooya arvin

    2018-02-01

    Full Text Available Introduction Oilseed rape (Brassica spp L. is one of the valuable oilseed crops which has been attracting attention in recent years. Iran is located in a semi-arid region, and water shortage has caused problems, namely providing drinking water as much as water supply for crop production. Not only does Plant Growth Promoting Rhizobacteria (PGPR make plant growth stimulating hormones like Auxin and Gibberellin but also can ease stress conditions by producing ABA. Consequently, considering the current water shortage crisis in Iran, we took three main criteria into account: the roles of PGPRs in increasing resistance to abiotic stress, relief of drought effects, and the importance of cultivation of oilseed rape. The present research has been compiled to study drought and some Plant Growth Promoting Rhizobacteria (PGPR on Physiological Traits and Ultimate Yield of Cultivars of Oilseed Rape. Materials and Methods The current study was done on the basis of two simultaneous experiments (under stress and non-stress experiments during 2010- 2011 growing season at Agriculture and Natural Resources Research Station of Torogh, Mashhad is situated in East-North of Iran (36° N, 59° E, 1003 ASL . Two research sites (under stress and no-stress fields were selected beside each other. This region has a semi-arid climate (annual rainfall 286 mm. The experimental design was factorial based on randomized completely block design with three replications in each experiment. The first treatment was Plant Growth Promoting Rizobactria, including B0: no inoculation (control, B1: co-inoculation (Pseudomonas flourescens 169+P. putida 108, B2: inoculation with P. flourescens 169 and B3: inoculation with P. putida 108. Second treatment was cultivar, including Hayola401 and Hayola330 cultivars belong to Brassica napus, Parkland and Goldrush cultivars belong to B. rapa and BP18 and landrace cultivars belong to B.juncea .Greenness index, plant height, relative water content

  12. Growth and physiological responses to water and nutrient stress in ...

    African Journals Online (AJOL)

    Growth and physiological responses to water and nutrient stress in oil palm. ... changes in growth, physiology and nutrient concentration in response to two watering regimes (well-watered and water-stress conditions) and ... from 32 Countries:.

  13. Impact of Selenium Supplementation on Growth and Selenium Accumulation on Spinach (Spinacia oleracea L.) Plants

    OpenAIRE

    Azadeh SAFFARYAZDI; Mehrdad LAHOUTI; Ali GANJEALI; Hassan BAYAT

    2012-01-01

    Selenium (Se) has been proved to be an essential element for humans and animals. However, less is known about its effects on plants. A hydroponic experiment was carried out to investigate the effects of selenium on growth, selenium accumulation and some physiological characteristics of spinach (Spinacia oleracea L. cv. �Missouri�) plants. Plants were grown in Hoagland nutrient solution amended with sodium selenite at 0 (control), 1, 2, 4, 6 and 10 mg.L-1 for 28 days. Growth parameters like sh...

  14. Wound-induced endogenous jasmonates stunt plant growth by inhibiting mitosis.

    Directory of Open Access Journals (Sweden)

    Yi Zhang

    Full Text Available When plants are repeatedly injured their growth is stunted and the size of organs such as leaves is greatly reduced. The basis of this effect is not well-understood however, even though it reduces yield of crops injured by herbivory, and produces dramatic effects exemplified in ornamental bonsai plants. We have investigated the genetic and physiological basis of this "bonsai effect" by repeatedly wounding leaves of the model plant Arabidopsis. This treatment stunted growth by 50% and increased the endogenous content of jasmonate (JA, a growth inhibitor, by seven-fold. Significantly, repeated wounding did not stunt the growth of the leaves of mutants unable to synthesise JA, or unable to respond to JA including coi1, jai3, myc2, but not jar1. The stunted growth did not result from reduced cell size, but resulted instead from reduced cell number, and was associated with reduced expression of CycB1;2. Wounding caused systemic disappearance of constitutively expressed JAZ1::GUS. Wounding also activates plant immunity. We show that a gene, 12-oxo-phytodienoate reductase, which catalyses a step in JA biosynthesis, and which we confirm is not required for defence, is however required for wound-induced stunting. Our data suggest that intermediates in the JA biosynthetic pathway activate defence, but a primary function of wound-induced JA is to stunt growth through the suppression of mitosis.

  15. Wound-induced endogenous jasmonates stunt plant growth by inhibiting mitosis.

    Science.gov (United States)

    Zhang, Yi; Turner, John G

    2008-01-01

    When plants are repeatedly injured their growth is stunted and the size of organs such as leaves is greatly reduced. The basis of this effect is not well-understood however, even though it reduces yield of crops injured by herbivory, and produces dramatic effects exemplified in ornamental bonsai plants. We have investigated the genetic and physiological basis of this "bonsai effect" by repeatedly wounding leaves of the model plant Arabidopsis. This treatment stunted growth by 50% and increased the endogenous content of jasmonate (JA), a growth inhibitor, by seven-fold. Significantly, repeated wounding did not stunt the growth of the leaves of mutants unable to synthesise JA, or unable to respond to JA including coi1, jai3, myc2, but not jar1. The stunted growth did not result from reduced cell size, but resulted instead from reduced cell number, and was associated with reduced expression of CycB1;2. Wounding caused systemic disappearance of constitutively expressed JAZ1::GUS. Wounding also activates plant immunity. We show that a gene, 12-oxo-phytodienoate reductase, which catalyses a step in JA biosynthesis, and which we confirm is not required for defence, is however required for wound-induced stunting. Our data suggest that intermediates in the JA biosynthetic pathway activate defence, but a primary function of wound-induced JA is to stunt growth through the suppression of mitosis.

  16. Separating the effects of partial submergence and soil oxygen demand on plant physiology.

    Science.gov (United States)

    van Bodegom, Peter M; Sorrell, Brian K; Oosthoek, Annelies; Bakker, Chris; Aerts, Rien

    2008-01-01

    In wetlands, a distinct zonation of plant species composition occurs along moisture gradients, due to differential flooding tolerance of the species involved. However, "flooding" comprises two important, distinct stressors (soil oxygen demand [SOD] and partial submergence) that affect plant survival and growth. To investigate how these two flooding stressors affect plant performance, we executed a factorial experiment (water depth x SOD) for six plant species of nutrient-rich and nutrient-poor conditions, occurring along a moisture gradient in Dutch dune slacks. Physiological, growth, and biomass responses to changed oxygen availability were quantified for all species. The responses were consistent with field zonation, but the two stressors affected species differently. Increased SOD increased root oxygen deprivation, as indicated by either raised porosity or increased alcohol dehydrogenase (ADH) activity in roots of flood-intolerant species (Calamagrostis epigejos and Carex arenaria). While SOD affected root functioning, partial submergence tended more to reduce photosynthesis (as shown both by gas exchange and 13C assimilation), leaf dark respiration, 13C partitioning from shoots to roots, and growth of these species. These processes were especially affected if the root oxygen supply was depleted by a combination of flooding and increased SOD. In contrast, the most flood-tolerant species (Juncus subnodulosus and Typha latifolia) were unaffected by any treatment and maintained high internal oxygen concentrations at the shoot : root junction and low root ADH activity in all treatments. For these species, the internal oxygen transport capacity was well in excess of what was needed to maintain aerobic metabolism across all treatments, although there was some evidence for effects of SOD on their nitrogen partitioning (as indicated by 865N values) and photosynthesis. Two species intermediate in flooding tolerance (Carex nigra and Schoenus nigricans) responded more

  17. Sixth workshop on seedling physiology and growth problems in oak plantings (abstracts); 1995 September 18-20; Tomahawk, WI.

    Science.gov (United States)

    Ronald M. Teclaw

    1996-01-01

    Research results and ongoing research activities in field performance of planted trees, seedling propagation, physiology, genetics, acorn germination ,and natural regeneration for oaks are described in 29 abstracts.

  18. Eighth workshop on seedling physiology and growth problems in oak plantings (abstracts). 2001 September 9-12; Hiwassee, GA.

    Science.gov (United States)

    S. Sung; P.P. Kormanik; W.J. Ostrosina; J.G. Isebrands

    2002-01-01

    Research results and ongoing research activities in field performance of planted trees, seedling propagation, physiology, genetics, acorn germination, and natural regeneration for oaks are described in 21 abstracts.

  19. Physiological Integration Affects Expansion of an Amphibious Clonal Plant from Terrestrial to Cu-Polluted Aquatic Environments

    Science.gov (United States)

    Xu, Liang; Zhou, Zhen-Feng

    2017-03-01

    The effects of physiological integration on clonal plants growing in aquatic and terrestrial habitats have been extensively studied, but little is known about the role in the extension of amphibious clonal plants in the heterogeneous aquatic-terrestrial ecotones, especially when the water environments are polluted by heavy metals. Ramets of the amphibious clonal herb Alternanthera philoxeroides were rooted in unpolluted soil and polluted water at three concentrations of Cu. The extension of populations from unpolluted terrestrial to polluted aqueous environments mainly relied on stem elongation rather than production of new ramets. The absorbed Cu in the ramets growing in polluted water could be spread horizontally to other ramets in unpolluted soil via physiological integration and redistributed in different organs. The performances of ramets in both terrestrial and aquatic habitats were negatively correlated with Cu intensities in different organs of plants. It is concluded that physiological integration might lessen the fitness of connected ramets in heterogeneously polluted environments. The mechanical strength of the stems decreased with increasing Cu levels, especially in polluted water. We suggest that, except for direct toxicity to growth and expansion, heavy metal pollution might also increase the mechanical risk in breaking failure of plants.

  20. Recent progress in plant nutrition research: cross-talk between nutrients, plant physiology and soil microorganisms.

    Science.gov (United States)

    Ohkama-Ohtsu, Naoko; Wasaki, Jun

    2010-08-01

    Mineral nutrients taken up from the soil become incorporated into a variety of important compounds with structural and physiological roles in plants. We summarize how plant nutrients are linked to many metabolic pathways, plant hormones and other biological processes. We also focus on nutrient uptake, describing plant-microbe interactions, plant exudates, root architecture, transporters and their applications. Plants need to survive in soils with mineral concentrations that vary widely. Describing the relationships between nutrients and biological processes will enable us to understand the molecular basis for signaling, physiological damage and responses to mineral stresses.

  1. 15. international conference on plant growth substances: Program -- Abstracts

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-12-31

    Since the 14th Conference in Amsterdam in 1991, progress in plant hormone research and developmental plant biology has been truly astonishing. The five ``classical`` plant hormones, auxin, gibberellin, cytokinin, ethylene, and abscisic acid, have been joined by a number of new signal molecules, e.g., systemin, jasmonic acid, salicylic acid, whose biosynthesis and functions are being understood in ever greater detail. Molecular genetics has opened new vistas in an understanding of transduction pathways that regulate developmental processes in response to hormonal and environmental signals. The program of the 15th Conference includes accounts of this progress and brings together scientists whose work focuses on physiological, biochemical, and chemical aspects of plant growth regulation. This volume contains the abstracts of papers presented at this conference.

  2. The role of plant physiology in hydrology: looking backwards and forwards

    Science.gov (United States)

    Roberts, J.

    2007-01-01

    conservative? An important contribution both to the similar and low transpiration is the likely reduction of stomatal conductance of the foliage associated with increasing air humidity deficit. A greater response is usually found when initial conductances are highest. Also contributing to similarities in transpiration from forest stands would be a compensatory role of understories and that deficits in soil moisture may not come into play until severe soil water deficits occur. Physiological studies have been conducted in many locations overseas. The modest transpiration of tropical rainforest is intriguing - Why is tropical rainforest transpiration so low? In common with temperate trees the reduction of stomatal conductance of tropical trees in association with increasing air humidity deficit will limit transpiration. In addition the high leaf area index of tropical rainforest creates conditions in the lower canopy layers that mean transpiration from those layers is much reduced from what might be possible. As well as being used to quantify and understand transpiration, physiological techniques might be used to assess when plants require water. What is the first signal that plants need water? Studies on sugar cane in Mauritius indicated that leaf growth was the most sensitive measure. A look forward to the future suggests that there will be a continued need for physiological measurements particularly where other techniques more suited to extensive vegetation are not appropriate. There are many unresolved issues about water use from fragmented, heterogeneous vegetation and physiological approaches are best suited to these. The measurement of sap flow in individual stems will be an important methodology in the future but there are still methodological issues to resolve.

  3. Pollen viability, physiology, and production of maize plants exposed to pyraclostrobin+epoxiconazole.

    Science.gov (United States)

    Junqueira, Verônica Barbosa; Costa, Alan Carlos; Boff, Tatiana; Müller, Caroline; Mendonça, Maria Andréia Corrêa; Batista, Priscila Ferreira

    2017-04-01

    The use of fungicides in maize has been more frequent due to an increase in the incidence of diseases and also the possible physiological benefits that some of these products may cause. However, some of these products (e.g., strobilurins and triazoles) may interfere with physiological processes and the formation of reproductive organs. Therefore, the effect of these products on plants at different developmental stages needs to be better understood to reduce losses and maximize production. The effect of the fungicide pyraclostrobin+epoxiconazole (P+E) was evaluated at different growth stages in meiosis, pollen grain viability and germination, physiology, and production of maize plants in the absence of disease. An experiment was carried out with the hybrid DKB390 PROII and the application of pyraclostrobin+epoxiconazole at the recommended dose and an untreated control at 3 different timings (S1 - V10; S2 - V14; S3 - R1) with 5 replications. Gas exchange, chlorophyll fluorescence, pollen viability and germination, as well as the hundred-grain weight were evaluated. Anthers were collected from plants of S1 for cytogenetic analysis. The fungicide pyraclostrobin+epoxiconazole reduced the viability of pollen grains (1.4%), but this was not enough to reduce production. Moreover, no differences were observed in any of the other parameters analyzed, suggesting that P+E at the recommended dose and the tested stages does not cause toxic effects. Copyright © 2016 Elsevier Inc. All rights reserved.

  4. Dust deposition effects on growth and physiology of the endangered Astragalus jaegerianus (Fabaceae)

    Science.gov (United States)

    Wijayratne, Upekala C.; Scoles-Sciulla, Sara J.; Defalco, Lesley A.

    2009-01-01

    Human expansion into the Mojave Desert is a significant threat to rare desert plants. While immediate habitat loss is often the greatest concern, rare plants situated near areas where soil surfaces experience frequent disturbance may be indirectly impacted when fine particulate dust accumulates on leaf surfaces. Remaining populations of the federally listed Astragalus jaegerianus (Lane Mountain milkvetch) occur on land open to expanding military activities and on adjacent public land with increasing recreational use. This study was initiated to determine whether dust accumulation could decrease the vigor and fitness of A. jaegerianus through reduced growth. Beginning in early May 2004, plants located on Bureau of Land Management (BLM) land were dusted bimonthly at canopy-level dust concentrations ranging from 0 to 32 g/m2, and physiology and growth were monitored until late June when plants senesced. The maximum experimental dust level simulates dust concentrations of Mojave Desert perennials neighboring military activities at a nearby army training center. Average shoot growth declined with increasing dust accumulation, but seasonal net photosynthesis increased. Further investigation of plants grown in a greenhouse supported similar trends. This pattern of greater net photosynthesis with increasing dust accumulation may be explained by higher leaf temperatures of dusted individuals. Ambient dust deposition measured in traps near field plants (May 2004–July 2004) ranged from 0.04–0.17 g/m2/ d, which was well below the lowest level of dust on experimental plants (3.95 g/m2/d). With this low level of ambient deposition, we expect that A. jaegerianus plants in this population were not greatly affected by the dust they receive at the level of recreational use during the study.

  5. INTERNATIONAL SCIENTIFIC CONFERENCE «PLANT PHYSIOLOGY AND GENETICS – SUCCESSES AND CHALLENGES», 24\\26 SEPTEMBER 2014, SOFIA, REPUBLIC OF BULGARIA

    OpenAIRE

    F. B. Musayev; E. G. Kozar

    2014-01-01

    24-26 September 2014 in the Republic of Bulgaria the International scientific and practical conference entitled «Plant Physiology and Genetics – Achievements and Challenges» was hold. The forum discussed the biotechnology and genetic approaches for environmental and sustainable agriculture; genetic resources and biodiversity; efficient use of plant nutrition and symbiotic interaction; regulation of plant growth and development; photosynthesis under stress conditions.

  6. Seasonal bone growth and physiology in endotherms shed light on dinosaur physiology.

    Science.gov (United States)

    Köhler, Meike; Marín-Moratalla, Nekane; Jordana, Xavier; Aanes, Ronny

    2012-07-19

    Cyclical growth leaves marks in bone tissue that are in the forefront of discussions about physiologies of extinct vertebrates. Ectotherms show pronounced annual cycles of growth arrest that correlate with a decrease in body temperature and metabolic rate; endotherms are assumed to grow continuously until they attain maturity because of their constant high body temperature and sustained metabolic rate. This apparent dichotomy has driven the argument that zonal bone denotes ectotherm-like physiologies, thus fuelling the controversy on dinosaur thermophysiology and the evolution of endothermy in birds and mammal-like reptiles. Here we show, from a comprehensive global study of wild ruminants from tropical to polar environments, that cyclical growth is a universal trait of homoeothermic endotherms. Growth is arrested during the unfavourable season concurrently with decreases in body temperature, metabolic rate and bone-growth-mediating plasma insulin-like growth factor-1 levels, forming part of a plesiomorphic thermometabolic strategy for energy conservation. Conversely, bouts of intense tissue growth coincide with peak metabolic rates and correlated hormonal changes at the beginning of the favourable season, indicating an increased efficiency in acquiring and using seasonal resources. Our study supplies the strongest evidence so far that homeothermic endotherms arrest growth seasonally, which precludes the use of lines of arrested growth as an argument in support of ectothermy. However, high growth rates are a distinctive trait of mammals, suggesting the capacity for endogenous heat generation. The ruminant annual cycle provides an extant model on which to base inferences regarding the thermophysiology of dinosaurs and other extinct taxa.

  7. Physiological and biochemical responses of thyme plants to some antioxidants

    Directory of Open Access Journals (Sweden)

    SALWA A. ORABI

    2014-11-01

    Full Text Available Orabi SA, Talaat IM, Balbaa LK. 2014. Physiological and biochemical responses of thyme plants to some antioxidants. Nusantara Bioscience 6: 118-125. Two pot experiments were conducted to investigate the effect of tryptophan, nicotinamide and α-tocopherol (each at 50 and 100 mg/L on plant growth, essential oil yield and its main constituents. All treatments significantly promoted plant height, and increased fresh and dry mass (g/plant of thyme (Thymus vulgaris L.. The treatment with 100 mg/L nicotinamide showed increasing in total potassium mainly in the first cut. Total soluble sugars, oil percentage and oil yield and protein recorded increments with tryptophan treatments. Treatment of Thymus plants with 100 mg/L nicotinamide observed the highest percentage of thymol (67.61%. Oxygenated compounds recorded the highest value with 50 mg/L α-tocopherol treatment, while the maximum non-oxygenated ones resulted from the application of 100 mg/L nicotinamide. All treatments under study significantly affected the activity of oxidoreductase enzymes (POX and PPO. Nicotinamide at the concentration of 100 mg/L recorded the highest increments in APX and GR and the lowest values in oxidoreductase enzyme activities added to the lowest values of lipid peroxidation to enhance the best protection of thyme plants.

  8. Global plant-responding mechanisms to salt stress: physiological and molecular levels and implications in biotechnology.

    Science.gov (United States)

    Tang, Xiaoli; Mu, Xingmin; Shao, Hongbo; Wang, Hongyan; Brestic, Marian

    2015-01-01

    The increasing seriousness of salinization aggravates the food, population and environmental issues. Ameliorating the salt-resistance of plants especially the crops is the most effective measure to solve the worldwide problem. The salinity can cause damage to plants mainly from two aspects: hyperosmotic and hyperionic stresses leading to the restrain of growth and photosynthesis. To the adverse effects, the plants derive corresponding strategies including: ion regulation and compartmentalization, biosynthesis of compatible solutes, induction of antioxidant enzymes and plant hormones. With the development of molecular biology, our understanding of the molecular and physiology knowledge is becoming clearness. The complex signal transduction underlying the salt resistance is being illuminated brighter and clearer. The SOS pathway is the central of the cell signaling in salt stress. The accumulation of the compatible solutes and the activation of the antioxidant system are the effective measures for plants to enhance the salt resistance. How to make full use of our understanding to improve the output of crops is a huge challenge for us, yet the application of the genetic engineering makes this possible. In this review, we will discuss the influence of the salt stress and the response of the plants in detail expecting to provide a particular account for the plant resistance in molecular, physiological and transgenic fields.

  9. Plant responses to plant growth-promoting rhizobacteria

    NARCIS (Netherlands)

    Loon, L.C. van

    2007-01-01

    Non-pathogenic soilborne microorganisms can promote plant growth, as well as suppress diseases. Plant growth promotion is taken to result from improved nutrient acquisition or hormonal stimulation. Disease suppression can occur through microbial antagonism or induction of resistance in the plant.

  10. Transcriptional responses to sucrose mimic the plant-associated life style of the plant growth promoting endophyte Enterobacter sp. 638.

    Science.gov (United States)

    Taghavi, Safiyh; Wu, Xiao; Ouyang, Liming; Zhang, Yian Biao; Stadler, Andrea; McCorkle, Sean; Zhu, Wei; Maslov, Sergei; van der Lelie, Daniel

    2015-01-01

    Growth in sucrose medium was previously found to trigger the expression of functions involved in the plant associated life style of the endophytic bacterium Enterobacter sp. 638. Therefore, comparative transcriptome analysis between cultures grown in sucrose or lactate medium was used to gain insights in the expression levels of bacterial functions involved in the endophytic life style of strain 638. Growth on sucrose as a carbon source resulted in major changes in cell physiology, including a shift from a planktonic life style to the formation of bacterial aggregates. This shift was accompanied by a decrease in transcription of genes involved in motility (e.g., flagella biosynthesis) and an increase in the transcription of genes involved in colonization, adhesion and biofilm formation. The transcription levels of functions previously suggested as being involved in endophytic behavior and functions responsible for plant growth promoting properties, including the synthesis of indole-acetic acid, acetoin and 2,3-butanediol, also increased significantly for cultures grown in sucrose medium. Interestingly, despite an abundance of essential nutrients transcription levels of functions related to uptake and processing of nitrogen and iron became increased for cultures grown on sucrose as sole carbon source. Transcriptome data were also used to analyze putative regulatory relationships. In addition to the small RNA csrABCD regulon, which seems to play a role in the physiological adaptation and possibly the shift between free-living and plant-associated endophytic life style of Enterobacter sp. 638, our results also pointed to the involvement of rcsAB in controlling responses by Enterobacter sp. 638 to a plant-associated life style. Targeted mutagenesis was used to confirm this role and showed that compared to wild-type Enterobacter sp. 638 a ΔrcsB mutant was affected in its plant growth promoting ability.

  11. Transcriptional responses to sucrose mimic the plant-associated life style of the plant growth promoting endophyte Enterobacter sp. 638.

    Directory of Open Access Journals (Sweden)

    Safiyh Taghavi

    Full Text Available Growth in sucrose medium was previously found to trigger the expression of functions involved in the plant associated life style of the endophytic bacterium Enterobacter sp. 638. Therefore, comparative transcriptome analysis between cultures grown in sucrose or lactate medium was used to gain insights in the expression levels of bacterial functions involved in the endophytic life style of strain 638. Growth on sucrose as a carbon source resulted in major changes in cell physiology, including a shift from a planktonic life style to the formation of bacterial aggregates. This shift was accompanied by a decrease in transcription of genes involved in motility (e.g., flagella biosynthesis and an increase in the transcription of genes involved in colonization, adhesion and biofilm formation. The transcription levels of functions previously suggested as being involved in endophytic behavior and functions responsible for plant growth promoting properties, including the synthesis of indole-acetic acid, acetoin and 2,3-butanediol, also increased significantly for cultures grown in sucrose medium. Interestingly, despite an abundance of essential nutrients transcription levels of functions related to uptake and processing of nitrogen and iron became increased for cultures grown on sucrose as sole carbon source. Transcriptome data were also used to analyze putative regulatory relationships. In addition to the small RNA csrABCD regulon, which seems to play a role in the physiological adaptation and possibly the shift between free-living and plant-associated endophytic life style of Enterobacter sp. 638, our results also pointed to the involvement of rcsAB in controlling responses by Enterobacter sp. 638 to a plant-associated life style. Targeted mutagenesis was used to confirm this role and showed that compared to wild-type Enterobacter sp. 638 a ΔrcsB mutant was affected in its plant growth promoting ability.

  12. Physiological responses of sweet potato (Ipomoea batatas L. plants due to different copper concentrations

    Directory of Open Access Journals (Sweden)

    Cristina Copstein Cuchiara

    2015-12-01

    Full Text Available At low concentrations, Cu is considered as an essential micronutrient for plants and as a constituent and activator of several enzymes. However, when in excess, Cu can negatively affect plant growth and metabolism. Therefore, the aim of this study was to evaluate physiological responses of sweet potato plants at different Cu concentrations by measuring morphological parameters, antioxidant metabolism, stomatal characteristics, and mineral profile. For this purpose, sweet potato plants were grown hydroponically in complete nutrient solution for six days. Then, the plants were transferred to solutions containing different Cu concentrations, 0.041 (control, 0.082, and 0.164 mM, and maintained for nine days. The main effect of increased Cu concentration was observed in the roots. The sweet potato plants grown in 0.082 mM Cu solution showed increased activity of antioxidant enzymes and no changes in growth parameters. However, at a concentration of 0.164 mM, Cu was transported from the roots to the shoots. This concentration altered morpho-anatomical characteristics and activated the antioxidant system because of the stress generated by excess Cu. On the basis of the results, it can be concluded that the sweet potato plants were able to tolerate Cu toxicity until 0.082 mM.

  13. Photochemical oxidants injury in rice plants. III. Effect of ozone on physiological activities in rice plants

    Energy Technology Data Exchange (ETDEWEB)

    Nakamura, H; Saka, H

    1978-01-01

    Experiments were made to determine the effect of photochemical oxidants on physiological activities of rice plants. Rice plants were fumigated with ozone at concentrations of 0.12-0.20 ppm for 2-3 hr to investigate acute injury and at 0.05 and 0.09 ppm for daily exposure from 3.0 leaf stage to assess the effect of ozone on growth. It was observed that malondialdehyde produced by disruption of the components of the membrane increased in the leaves exposed to ozone. Ozone reduced the RuBP-carboxylase activity in both young and old leaves 12-24 hr after fumigation. In the young leaves the activity of this enzyme recovered to some extent after 48 hr, but it did not show any recovery in the old leaves. On the other hand, ozone remarkably increased the peroxidase activity and slightly increased acid phosphatase in all leaves. Abnormally high ethylene evolution and oxygen uptake were detected in leaves soon after ozone fumigation. In general, high molecular protein and chlorophyll contents in the detached leaves decreased with incubation in dark, particularly in the old ones. These phenomena were more accelerated by ozone fumigation. Kinetin and benzimidazole showed significant effects on chlorophyll retention in ozone-exposed leaves. Reduction of plant growth and photosynthetic rate was recognized even in low concentration of ozone in daily exposure at 0.05 and 0.09 ppm. From these results it was postulated that ozone may cause the senescence of leaves in rice plants.

  14. Stimulation of the growth of Jatropha curcas by the plant growth promoting bacterium Enterobacter cancerogenus MSA2.

    Science.gov (United States)

    Jha, Chaitanya Kumar; Patel, Baldev; Saraf, Meenu

    2012-03-01

    A novel Enterobacter cancerogenus MSA2 is a plant growth promoting gamma-proteobacterium that was isolated from the rhizosphere of Jatropha cucas a potentially important biofuel feed stock plant. Based on phenotypic, physiological, biochemical and phylogenetic studies, strain MSA2 could be classified as a member of E. cancerogenus. However, comparisons of characteristics with other known species of the genus Enterobacter suggested that strain MSA2 could be a novel PGPB strain. In vitro studies were carried for the plant growth promoting attribute of this culture. It tested positive for ACC (1-aminocyclopropane-1-carboxylic acid) deaminase production, phytase, phosphate solubilization, IAA (Indole acetic acid) production, siderophore, and ammonia production. The isolate was then used as a inoculant for the vegetative study of Jatropha curcas plant. Enterobacter cancerogenus MSA2 supplemented with 1% carboxymethylcellulose showed overall plant growth promotion effect resulting in enhanced root length (124.14%), fresh root mass (81%), fresh shoot mass (120.02%), dry root mass (124%), dry shoot mass (105.54%), number of leaf (30.72%), chlorophyll content (50.41%), and biomass (87.20%) over control under the days of experimental observation. This study was designed for 120 days and was in triplicate and the data was collected at every 30 days.

  15. The role of silicon in physiology of the medicinal plant (Lonicera japonica L.) under salt stress

    Science.gov (United States)

    Gengmao, Zhao; Shihui, Li; Xing, Sun; Yizhou, Wang; Zipan, Chang

    2015-08-01

    Silicon(Si) is the only element which can enhance the resistance to multiple stresses. However, the role of silicon in medicinal plants under salt stress is not yet understood. This experiment was conducted to study the effects of silicon addition on the growth, osmotic adjustments, photosynthetic characteristics, chloroplast ultrastructure and Chlorogenic acid (CGA) production of Honeysuckle plant (Lonicera japonica L.) under salt-stressed conditions. Salinity exerted an adverse effect on the plant fresh weight and dry weight, whilst 0.5 g L-1 K2SiO3·nH2O addition obviously improved the plant growth. Although Na+ concentration in plant organs was drastically increased with increasing salinity, higher levels of K+/Na+ ratio was obtained after K2SiO3·nH2O addition. Salinity stress induced the destruction of the chloroplast envelope; however, K2SiO3·nH2O addition counteracted the adverse effect by salinity on the structure of the photosynthetic apparatus. K2SiO3·nH2O addition also enhanced the activities of superoxide dismutase and catalase. To sum up, exogenous Si plays a key role in enhancing its resistance to salt stresses in physiological base, thereby improving the growth and CGA production of Honeysuckle plant.

  16. Effect of cadmium on growth, protein content and peroxidase activity in pea plants

    International Nuclear Information System (INIS)

    Bavi, K.; Kholdebarin, B.

    2011-01-01

    n this study the effects of different cadmium chloride concentrations (5, 10, 20, 50, and 100 mu M) on some physiological and biochemical processes including seed germination, root and shoot fresh and dry weight, protein content and peroxidase activity in peas (Cicer arietinum cv. pars) were investigated. Cadmium did not have any significant effect on the rate of pea seed germination. However, it affected the subsequent growth rate in these plants. Higher cadmium concentrations specially at 50 and 100 mu M reduced plant growth significantly. Leaf chlorosis, wilting and leaf abscission were observed in plants treated with cadmium. Protein content in pea roots reduced significantly in the presence of high cadmium concentrations. Low concentrations of CdCl/sub 2/ resulted in higher peroxidase activity both in roots and shoots of pea plants. (author)

  17. Effects of Planting Date and Plant Density on Physiological Indices, Quantity and Quality Traits of Two Varieties of Marigold (Calendula officinalis L.

    Directory of Open Access Journals (Sweden)

    A Sepehri

    2016-07-01

    Full Text Available Introduction Marigold (Calendula officinalis L. is originated from North West Africa and Mediterranean area, is a medicinal plant used for several purposes. It is an annual herb or short-lived perennial from the Asteraceae family with yellow or orange flowers. The Marigold has been used as a traditional medicine and food dye, but is currently used as an anti-inflammatory and wound healer. It is grown for drug, obtained from the flowers. The flowers blossom during summer three or more times per year. The essential oil of yellow or orange petals of Calendula officinalis L. is one of the important yield components which is used for food and medicine. Moreover, the seed has an oil content of 5-20 %. Seed oil could be used as a binder in paints, coating and cosmetics. Growth, development and production of medicinal plants, as well as other plants are affected by genetic and agronomic factors. Planting date and plant density are two most important factors that can affect yield and yield components. Planting date affects the quantity and quality of secondary metabolites of medicinal plants. The optimum sowing date and plant density can improve the light and temperature absorption and other factors during the growing season. The positive effects of optimal planting date and plant density has been described by a number of researchers. The Plant population is dependent on the plant characters, growth period, time and method of cultivation. Also, the suitable sowing date has advantages for maximum production. Early sowing in the spring causes weakly establishment of plant and late planting date shortens growth period and simultaneous flowering period due to high temperature in summer. In this study, the effects of plant density and planting date on physiological indices, quantity and quality of two varieties of spare and compact marigold has been evaluated. Materials and Methods In order to determine the effects of planting date and plant density on

  18. Plant Growth Promoting Rhizobacteria and Silicon Synergistically Enhance Salinity Tolerance of Mung Bean

    KAUST Repository

    Mahmood, Sajid

    2016-06-17

    The present study explored the eco-friendly approach of utilizing plant-growth-promoting rhizobacteria (PGPR) inoculation and foliar application of silicon (Si) to improve the physiology, growth, and yield of mung bean under saline conditions. We isolated 18 promising PGPR from natural saline soil in Saudi Arabia, and screened them for plant-growth-promoting activities. Two effective strains were selected from the screening trial, and were identified as Enterobacter cloacae and Bacillus drentensis using matrix-assisted laser desorption ionization-time-of-flight mass spectrometry and 16S rRNA gene sequencing techniques, respectively. Subsequently, in a 2-year mung bean field trial, using a randomized complete block design with a split-split plot arrangement, we evaluated the two PGPR strains and two Si levels (1 and 2 kg ha−1), in comparison with control treatments, under three different saline irrigation conditions (3.12, 5.46, and 7.81 dS m−1). The results indicated that salt stress substantially reduced stomatal conductance, transpiration rate, relative water content (RWC), total chlorophyll content, chlorophyll a, chlorophyll b, carotenoid content, plant height, leaf area, dry biomass, seed yield, and salt tolerance index. The PGPR strains and Si levels independently improved all the aforementioned parameters. Furthermore, the combined application of the B. drentensis strain with 2 kg Si ha−1 resulted in the greatest enhancement of mung bean physiology, growth, and yield. Overall, the results of this study provide important information for the benefit of the agricultural industry.

  19. Plant Growth Promoting Rhizobacteria and Silicon Synergistically Enhance Salinity Tolerance of Mung Bean

    KAUST Repository

    Mahmood, Sajid; Daur, Ihsanullah; Al-Solaimani, Samir G.; Ahmad, Shakeel; Madkour, Mohamed H.; Yasir, Muhammad; Hirt, Heribert; Ali, Shawkat; Ali, Zahir

    2016-01-01

    The present study explored the eco-friendly approach of utilizing plant-growth-promoting rhizobacteria (PGPR) inoculation and foliar application of silicon (Si) to improve the physiology, growth, and yield of mung bean under saline conditions. We isolated 18 promising PGPR from natural saline soil in Saudi Arabia, and screened them for plant-growth-promoting activities. Two effective strains were selected from the screening trial, and were identified as Enterobacter cloacae and Bacillus drentensis using matrix-assisted laser desorption ionization-time-of-flight mass spectrometry and 16S rRNA gene sequencing techniques, respectively. Subsequently, in a 2-year mung bean field trial, using a randomized complete block design with a split-split plot arrangement, we evaluated the two PGPR strains and two Si levels (1 and 2 kg ha−1), in comparison with control treatments, under three different saline irrigation conditions (3.12, 5.46, and 7.81 dS m−1). The results indicated that salt stress substantially reduced stomatal conductance, transpiration rate, relative water content (RWC), total chlorophyll content, chlorophyll a, chlorophyll b, carotenoid content, plant height, leaf area, dry biomass, seed yield, and salt tolerance index. The PGPR strains and Si levels independently improved all the aforementioned parameters. Furthermore, the combined application of the B. drentensis strain with 2 kg Si ha−1 resulted in the greatest enhancement of mung bean physiology, growth, and yield. Overall, the results of this study provide important information for the benefit of the agricultural industry.

  20. Physiological response of soybean genotypes to plant density

    NARCIS (Netherlands)

    Gan, Y; Stulen, [No Value; van Keulen, H; Kuiper, PJC

    2002-01-01

    Response of soybean (Glycine max (L.) Merr.) to plant density has occupied a segment of agronomic research for most of the century. Genotype differences have been noted especially in response to planting date, lodging problems and water limitation. There is limited information on the physiological

  1. Ligand Receptor-Mediated Regulation of Growth in Plants.

    Science.gov (United States)

    Haruta, Miyoshi; Sussman, Michael R

    2017-01-01

    Growth and development of multicellular organisms are coordinately regulated by various signaling pathways involving the communication of inter- and intracellular components. To form the appropriate body patterns, cellular growth and development are modulated by either stimulating or inhibiting these pathways. Hormones and second messengers help to mediate the initiation and/or interaction of the various signaling pathways in all complex multicellular eukaryotes. In plants, hormones include small organic molecules, as well as larger peptides and small proteins, which, as in animals, act as ligands and interact with receptor proteins to trigger rapid biochemical changes and induce the intracellular transcriptional and long-term physiological responses. During the past two decades, the availability of genetic and genomic resources in the model plant species, Arabidopsis thaliana, has greatly helped in the discovery of plant hormone receptors and the components of signal transduction pathways and mechanisms used by these immobile but highly complex organisms. Recently, it has been shown that two of the most important plant hormones, auxin and abscisic acid (ABA), act through signaling pathways that have not yet been recognized in animals. For example, auxins stimulate cell elongation by bringing negatively acting transcriptional repressor proteins to the proteasome to be degraded, thus unleashing the gene expression program required for increasing cell size. The "dormancy" inducing hormone, ABA, binds to soluble receptor proteins and inhibits a specific class of protein phosphatases (PP2C), which activates phosphorylation signaling leading to transcriptional changes needed for the desiccation of the seeds prior to entering dormancy. While these two hormone receptors have no known animal counterparts, there are also many similarities between animal and plant signaling pathways. For example, in plants, the largest single gene family in the genome is the protein kinase

  2. Oligo-Alginate with Low Molecular Mass Improves Growth and Physiological Activity of Eucomis autumnalis under Salinity Stress

    Directory of Open Access Journals (Sweden)

    Piotr Salachna

    2018-04-01

    Full Text Available Biopolymers have become increasingly popular as biostimulators of plant growth. One of them, oligo-alginate, is a molecule that regulates plant biological processes and may be used in horticultural practice as a plant growth regulator. Biostimulators are mainly used to improve plant tolerance to abiotic stresses, including salinity. The aim of the study was to assess the effects of salinity and oligo-alginate of various molecular masses on the growth and physiological activity of Eucomis autumnalis. The species is an ornamental and medicinal plant that has been used for a long time in the traditional medicine of South Africa. The bulbs of E. autumnalis were coated using depolymerized sodium alginate of molecular mass 32,000; 42,000, and 64,000 g mol−1. All of these oligo-alginates fractions stimulated plant growth, and the effect was the strongest for the fraction of 32,000 g mol−1. This fraction was then selected for the second stage of the study, when plants were exposed to salt stress evoked by the presence of 100 mM NaCl. We found that the oligo-alginate coating mitigated the negative effects of salinity. Plants treated with the oligomer and watered with NaCl showed smaller reduction in the weight of the above-ground parts and bulbs, pigment content and antioxidant activity as compared with those not treated with the oligo-alginate. The study demonstrated for the first time that low molecular mass oligo-alginate may be used as plant biostimulator that limits negative effects of salinity in E. autumnalis.

  3. Nickel accumulation and its effect on growth, physiological and biochemical parameters in millets and oats.

    Science.gov (United States)

    Gupta, Vibha; Jatav, Pradeep Kumar; Verma, Raini; Kothari, Shanker Lal; Kachhwaha, Sumita

    2017-10-01

    With the boom in industrialization, there is an increase in the level of heavy metals in the soil which drastically affect the growth and development of plants. Nickel is an essential micronutrient for plant growth and development, but elevated level of Ni causes stunted growth, chlorosis, nutrient imbalance, and alterations in the defense mechanism of plants in terms of accumulation of osmolytes or change in enzyme activities like guiacol peroxidase (POD), catalase (CAT), and superoxide dismutase (SOD). Ni-induced toxic response was studied in seedlings of finger millet, pearl millet, and oats in terms of seedling growth, lipid peroxidation, total chlorophyll, proline content, and enzymatic activities. On the basis of germination and growth parameters of the seedling, finger millet was found to be the most tolerant. Nickel accumulation was markedly lower in the shoots as compared to the roots, which was the highest in finger millet and the lowest in shoots of oats. Plants treated with a high concentration of Ni showed significant reduction in chlorophyll and increase in proline content. Considerable difference in level of malondialdehyde (MDA) content and activity of antioxidative enzymes indicates generation of redox imbalance in plants due to Ni-induced stress. Elevated activities of POD and SOD were observed with high concentrations of Ni while CAT activity was found to be reduced. It was observed that finger millet has higher capability to maintain homeostasis by keeping the balance between accumulation and ROS scavenging system than pearl millet and oats. The data provide insight into the physiological and biochemical changes in plants adapted to survive in Ni-rich environment. This study will help in selecting the more suitable crop species to be grown on Ni-rich soils.

  4. Biochar amendment of fluvio-glacial temperate sandy subsoil: Effects on maize water uptake, growth and physiology

    DEFF Research Database (Denmark)

    Ahmed, Fauziatu; Arthur, Emmanuel; Plauborg, Finn

    2018-01-01

    Coarse sandy soils have poor water retention capacity, which may constrain crop growth during drought. We investigated the effect of biochar amendment to subsoil on crop physiological processes and maize yield, comparing irrigated and drought conditions. A two-year greenhouse experiment was condu......Coarse sandy soils have poor water retention capacity, which may constrain crop growth during drought. We investigated the effect of biochar amendment to subsoil on crop physiological processes and maize yield, comparing irrigated and drought conditions. A two-year greenhouse experiment...... was conducted with one-time application of straw biochar at concentrations of 0%, 1%, 2% and 3% (B0, B1, B2 and B3). Maize was planted twice in the same large pots one week and again 12 months after biochar application. Plants were fully irrigated until flowering; thereafter, half of them were subjected...... to drought. Our results indicate B2 and B3 increased soil water content at field capacity. Leaf water potential, stomatal conductance, photosynthesis and transpiration were maintained in B2 and B3 during the drying cycle in year one and in all biochar levels in year two. In the first year, B3 induced...

  5. Phytochrome, plant growth and flowering

    Science.gov (United States)

    King, R. W.; Bagnall, D. J.

    1994-01-01

    Attempts to use artificially lit cabinets to grow plants identical to those growing in sunlight have provided compelling evidence of the importance of light quality for plant growth. Changing the balance of red (R) to far-red (FR) radiation, but with a fixed photosynthetic input can shift the phytochrome photoequilibrium in a plant and generate large differences in plant growth. With FR enrichment the plants elongate, and may produce more leaf area and dry matter. Similar morphogenic responses are also obtained when light quality is altered only briefly (15-30 min) at the end-of-the-day. Conversely, for plants grown in natural conditions the response of plant form to selective spectral filtering has again shown that red and far-red wavebands are important as found by Kasperbauer and coworkers. Also, where photosynthetic photon flux densities (PPFD) of sunlight have been held constant, the removal of far-red alone alters plant growth. With FR depletion plants grown in sunlight are small, more branched and darker green. Here we examine the implications for plant growth and flowering when the far-red composition of incident radiation in plant growth chambers is manipulated.

  6. Phytochrome, plant growth and flowering

    Energy Technology Data Exchange (ETDEWEB)

    King, R.W.; Bagnall, D.J. [CSIRO, Canberra (Australia)

    1994-12-31

    Attempts to use artificially lit cabinets to grow plants identical to those growing in sunlight have provided compelling evidence of the importance of light quality for plant growth. Changing the balance of red (R) to far-red (FR) radiation, but with a fixed photosynthetic input can shift the phytochrome photoequilibrium in a plant and generate large differences in plant growth. With FR enrichment the plants elongate, and may produce more leaf area and dry matter. Similar morphogenic responses are also obtained when light quality is altered only briefly (15-30 min) at the end-of-the-day. Conversely, for plants grown in natural conditions the response of plant form to selective spectral filtering has again shown that red and far-red wavebands are important as found by Kasperbauer and coworkers. Also, where photosynthetic photon flux densities (PPFD) of sunlight have been held constant, the removal of far-red alone alters plant growth. As shown for chrysanthemum, with FR depletion plants grown in sunlight are small, more branched and darker green. We examine the implications for plant growth and flowering when the far-red composition of incident radiation in plant growth chambers is manipulated.

  7. Assessing Morphological and Physiological Properties of Forest Species Using High Throughput Plant Phenotyping and Imaging Techniques

    Science.gov (United States)

    Mazis, A.; Hiller, J.; Morgan, P.; Awada, T.; Stoerger, V.

    2017-12-01

    High throughput plant phenotyping is increasingly being used to assess morphological and biophysical traits of economically important crops in agriculture. In this study, the potential application of this technique in natural resources management, through the characterization of woody plants regeneration, establishment, growth, and responses to water and nutrient manipulations was assessed. Two woody species were selected for this study, Quercus prinoides and Quercus bicolor. Seeds were collected from trees growing at the edge of their natural distribution in Nebraska and Missouri, USA. Seeds were germinated in the greenhouse and transferred to the Nebraska Innovation Campus Lemnatec3D High Throughput facility at the University of Nebraska-Lincoln. Seedlings subjected to water and N manipulations, were imaged twice or three times a week using four cameras (Visible, Fluorescence, Infrared and Hyperspectral), throughout the growing season. Traditional leaf to plant levels ecophysiological measurements were concurrently acquired to assess the relationship between these two techniques. These include gas exchange (LI 6400 and LI 6800, LICOR Inc., Lincoln NE), chlorophyll content, optical characteristics (Ocean Optics USB200), water and osmotic potentials, leaf area and weight and carbon isotope ratio. In the presentation, we highlight results on the potential use of high throughput plant phenotyping techniques to assess the morphology and physiology of woody species including responses to water availability and nutrient manipulation, and its broader application under field conditions and natural resources management. Also, we explore the different capabilities imaging provides us for modeling the plant physiological and morphological growth and how it can complement the current techniques

  8. Interactive effect of Brevibacillus brevis and Glomus mosseae, both isolated from Cd contaminated soil, on plant growth, physiological mycorrhizal fungal characteristics and soil enzymatic activities in Cd polluted soil

    International Nuclear Information System (INIS)

    Vivas, A.; Barea, J.M.; Azcon, R.

    2005-01-01

    The interaction between two autochthonous microorganisms (Brevibacillus brevis and Glomus mosseae) isolated from Cd amended soil increased plant growth, arbuscular mycorrhizal (AM) colonization and physiological characteristics of the AM infection (measured as SDH or ALP activities). The enhanced plant Cd tolerance after coinoculation with native microorganisms seemed to be a consequence of increased P and K acquisition and, simultaneously, of decreased concentration of Cd, Cr, Mn, Cu, Mo, Fe and Ni in plant tissue. Autochthonous microbial strains were more efficient for nutrient uptake, to immobilize metals and decrease their translocation to the shoot than reference G. mosseae (with or without bacteria). Indole acetic acid produced by B. brevis may be related to its ability for improving root growth, nodule production and AM fungal intra and extraradical development. Dehydrogenase, phosphatase and β-glucosidase activities, indicative of microbial metabolism and soil fertility, were maximized by the coinoculation of autochthonous microorganisms in cadmium polluted conditions. As a consequence, the use of native microorganisms may result very efficient in bioremediation. - Endemic isolates of bacteria and fungi were effective in bioremediation

  9. Response of Physiological Growth Indices and Bulb Dry Yield of Onion (Allium cepa L. Genotypes to Priming and Seed Size

    Directory of Open Access Journals (Sweden)

    M. Izadkhah

    2016-02-01

    Full Text Available Introduction Priming is one of the most common methods of improving seed quality, which significantly affects their storability. Seed priming is a seed treatment that allows imbibition and activation of the initial metabolic events associated with seed germination, but prevents radicle emergence and growth. In other words, phase one and two of seed water imbibition curve are passed, but seeds do not enter the third phase of water uptake. Then seeds are dried back to their original water content. Seed priming is a pre-sowing strategy for influencing seed germination and seedling development by modulating pre-germination metabolic activity prior to emergence of the radicle and generally enhances germination rate and plant performance. Naturally, when speed and percentage emergence of germinating seeds are being high, growing sources like light, water and nutrient will be more used. Another factor that can affect the seed germination and seedling establishment is the seed size. As generally known, among producing factors, seed as the first consumer store, plays an important role in the transfer of genetic characters and improvement of qualitative and quantitative traits of production. One of the most important factors in maximizing crop yield is planting high quality seed. Seed size is an important physical indicator of seed quality that affects vegetative growth and is frequently related to yield, market grade factors and harvest efficiency. In the present paper, effects of different pre-sowing treatments and seed size on physiological growth indices and bulb dry yield of onion cultivars were investigated. Materials and Methods In order to determine the response of physiological growth indices and bulb dry yield of onion to priming and seed size, a field experiment was conducted in 2012-2013 cropping season at Agriculture and Natural Resources Research Center of East, Azarbayjan, Iran. This experiment was a factorial experiment based on a

  10. Plant physiology in theory and practice: an analysis of the WBE model for vascular plants.

    Science.gov (United States)

    Petit, Giai; Anfodillo, Tommaso

    2009-07-07

    The theoretical model of West, Brown and Enquist (hereafter WBE) proposed the fractal geometry of the transport system as the origin of the allometric scaling laws observed in nature. The WBE model has either been criticized for some restrictive and biologically unrealistic constraints or its reliability debated on the evidence of empirical tests. In this work, we revised the structure of the WBE model for vascular plants, highlighting some critical assumptions and simplifications and discuss them with regard to empirical evidence from plant anatomy and physiology. We conclude that the WBE model had the distinct merit of shedding light on some important features such as conduit tapering. Nonetheless, it is over-simplistic and a revised model would be desirable with an ontogenetic perspective that takes some important phenomena into account, such as the transformation of the inner sapwood into heartwood and the effect of hydraulic constraints in limiting the growth in height.

  11. Physiological relevance of plant 2-Cys peroxiredoxin overoxidation level and oligomerization status.

    Science.gov (United States)

    Cerveau, Delphine; Ouahrani, Djelloul; Marok, Mohamed Amine; Blanchard, Laurence; Rey, Pascal

    2016-01-01

    Peroxiredoxins are ubiquitous thioredoxin-dependent peroxidases presumed to display, upon environmental constraints, a chaperone function resulting from a redox-dependent conformational switch. In this work, using biochemical and genetic approaches, we aimed to unravel the factors regulating the redox status and the conformation of the plastidial 2-Cys peroxiredoxin (2-Cys PRX) in plants. In Arabidopsis, we show that in optimal growth conditions, the overoxidation level mainly depends on the availability of thioredoxin-related electron donors, but not on sulfiredoxin, the enzyme reducing the 2-Cys PRX overoxidized form. We also observed that upon various physiological temperature, osmotic and light stress conditions, the overoxidation level and oligomerization status of 2-Cys PRX can moderately vary depending on the constraint type. Further, no major change was noticed regarding protein conformation in water-stressed Arabidopsis, barley and potato plants, whereas species-dependent up- and down-variations in overoxidation were observed. In contrast, both 2-Cys PRX overoxidation and oligomerization were strongly induced during a severe oxidative stress generated by methyl viologen. From these data, revealing that the oligomerization status of plant 2-Cys PRX does not exhibit important variation and is not tightly linked to the protein redox status upon physiologically relevant environmental constraints, the possible in planta functions of 2-Cys PRX are discussed. © 2015 John Wiley & Sons Ltd.

  12. Seventh workshop on seedling physiology and growth problems in oak plantings (abstracts); 1998 September 27-29; South Lake Tahoe, CA.

    Science.gov (United States)

    D.D. McCreary; J.G. Isebrands

    1999-01-01

    Research results and ongoing research activities in field performance of planted trees, seedling propagation, physiology, genetics, acorn germination, and natural regeneration for oaks are described in 17 abstracts.

  13. Host Plant Physiology and Mycorrhizal Functioning Shift across a Glacial through Future [CO2] Gradient.

    Science.gov (United States)

    Becklin, Katie M; Mullinix, George W R; Ward, Joy K

    2016-10-01

    Rising atmospheric carbon dioxide concentration ([CO 2 ]) may modulate the functioning of mycorrhizal associations by altering the relative degree of nutrient and carbohydrate limitations in plants. To test this, we grew Taraxacum ceratophorum and Taraxacum officinale (native and exotic dandelions) with and without mycorrhizal fungi across a broad [CO 2 ] gradient (180-1,000 µL L -1 ). Differential plant growth rates and vegetative plasticity were hypothesized to drive species-specific responses to [CO 2 ] and arbuscular mycorrhizal fungi. To evaluate [CO 2 ] effects on mycorrhizal functioning, we calculated response ratios based on the relative biomass of mycorrhizal (M Bio ) and nonmycorrhizal (NM Bio ) plants (R Bio = [M Bio - NM Bio ]/NM Bio ). We then assessed linkages between R Bio and host physiology, fungal growth, and biomass allocation using structural equation modeling. For T. officinale, R Bio increased with rising [CO 2 ], shifting from negative to positive values at 700 µL L -1 [CO 2 ] and mycorrhizal effects on photosynthesis and leaf growth rates drove shifts in R Bio in this species. For T. ceratophorum, R Bio increased from 180 to 390 µL L -1 and further increases in [CO 2 ] caused R Bio to shift from positive to negative values. [CO 2 ] and fungal effects on plant growth and carbon sink strength were correlated with shifts in R Bio in this species. Overall, we show that rising [CO 2 ] significantly altered the functioning of mycorrhizal associations. These symbioses became more beneficial with rising [CO 2 ], but nonlinear effects may limit plant responses to mycorrhizal fungi under future [CO 2 ]. The magnitude and mechanisms driving mycorrhizal-CO 2 responses reflected species-specific differences in growth rate and vegetative plasticity, indicating that these traits may provide a framework for predicting mycorrhizal responses to global change. © 2016 American Society of Plant Biologists. All Rights Reserved.

  14. [Review on application of plant growth retardants in medicinal plants cultivation].

    Science.gov (United States)

    Zhai, Yu-Yao; Guo, Bao-Lin; Cheng, Ming

    2013-09-01

    Plant growth retardants are widely used in cultivation of medicinal plant, but there is still lack of scientific guidance. In order to guide the use of plant growth retardants in medicinal plant cultivation efficiently and reasonably, this paper reviewed the mechanism, function characteristic, plant and soil residue of plant growth retardants, such as chlorocholine chloride, mepiquat chloride, paclobutrazol, unicnazle and succinic acid, and summarized the application of plant growth retardants in medicinal plants cultivation in recent years, with focus on the effect of growth and yield of the officinal organs and secondary metabolites.

  15. Improvement of the growth and yield of lettuce plants by elf sinusoidal non-uniform magnetic fields

    International Nuclear Information System (INIS)

    Souzal, A. De; Gonzalez, L.M.; Sueirol, L.; Peralta, O.; Liceal, L.; Porras, E.; Gilart, F.

    2008-01-01

    Influence of pre-sowing magnetic treatments on plant growth and final yield of lettuce (cv. Black Seeded Simpson) were studied under organoponic conditions. Lettuce seeds were exposed to full-wave rectified sinusoidal non-uniform magnetic fields (MFs) induced by an electromagnet at 120 mT(rms) for 3 min, 160 mT(rms) for 1 min and to 160 mT (rms) for 5 min. Non-treated seeds were considered as controls. Plants were grown in experimental stonemasons (25.2 m2) of an organoponic and cultivated according to standard agricultural practices. During nursery and vegetative growth stages, samples were collected at regular intervals for seedling growth assessment and growth rate analyses. At physiological maturity, the plants were harvested from each stonemason and the final yield and yield parameters were determined. In the nursery stage, the magnetic treatments induced a significant increase of root length and shoot height in plants derived from magnetically-treated seeds. In the vegetative stage, the relative growth rates of plants derived from magnetically-exposed seeds were greater than those shown by the control plants. At maturity stage, all magnetic treatments increased significantly (p<0.05) the plant height, the leaf area per plant, the final yield per area and the fresh mass per plant in comparison with the controls. Pre-sowing magnetic treatments would enhance the growth and final yield of lettuce crop

  16. Effect of Root-Zone Moisture Variations on Growth of Lettuce and Pea Plants

    Science.gov (United States)

    Ilieva, Iliana; Ivanova, Tania

    2008-06-01

    Variations in substrate moisture lead to changes in water and oxygen availability to plant roots. Ground experiments were carried out in the laboratory prototype of SVET-2 Space Greenhouse to study the effect of variation of root-zone moisture conditions on growth of lettuce and pea plants. The effect of transient increase (for 1 day) and drastic increase (waterlogging for 10 days) of substrate moisture was studied with 16-day old pea and 21-day old lettuce plants respectively. Pea height and fresh biomass accumulation were not affected by transient substrate moisture increase. Net photosynthetic rate (Pn) of pea plants showed fast response to substrate moisture variation, while chlorophyll content did not change. Drastic change of substrate moisture suppressed lettuce Pn, chlorophyll biosynthesis and plant growth. These parameters slowly recovered after termination of waterlogging treatment but lettuce yield was greatly affected. The results showed that the most sensitive physiological parameter to substrate moisture variations is photosynthesis.

  17. Beyond cellular detoxification: a plethora of physiological roles for MDR transporter homologs in plants

    Science.gov (United States)

    Remy, Estelle; Duque, Paula

    2014-01-01

    Higher plants possess a multitude of Multiple Drug Resistance (MDR) transporter homologs that group into three distinct and ubiquitous families—the ATP-Binding Cassette (ABC) superfamily, the Major Facilitator Superfamily (MFS), and the Multidrug And Toxic compound Extrusion (MATE) family. As in other organisms, such as fungi, mammals, and bacteria, MDR transporters make a primary contribution to cellular detoxification processes in plants, mainly through the extrusion of toxic compounds from the cell or their sequestration in the central vacuole. This review aims at summarizing the currently available information on the in vivo roles of MDR transporters in plant systems. Taken together, these data clearly indicate that the biological functions of ABC, MFS, and MATE carriers are not restricted to xenobiotic and metal detoxification. Importantly, the activity of plant MDR transporters also mediates biotic stress resistance and is instrumental in numerous physiological processes essential for optimal plant growth and development, including the regulation of ion homeostasis and polar transport of the phytohormone auxin. PMID:24910617

  18. Impact of ultraviolet-B radiation on growth and development of the plants - literature review

    International Nuclear Information System (INIS)

    Zuk-Golaszewska, K.

    2003-01-01

    Paper presents a review of the recent literature dealing with the UV-B radiation, its effect on physiological processes of plant growth and development, cellular changes, concentration of chemical compounds and changes in morphological plant traits. The reasons of increasing UV-B radiation level are rapidly developing civilization and decreasing of ozone layer. It was stated that the plant reaction to UV-B irradiation depends on plant species and environmental conditions. Destructive effects of UV-B radiation to plants may be - to some extent - neutralized by defence mechanisms, a form of specific plant adaptation to stress, however, under conditions of strong UV-B irradiation such mechanisms are not sufficient

  19. Soilless plant growth media influence the efficacy of phytohormones and phytohormone inhibitors.

    Science.gov (United States)

    Best, Norman B; Hartwig, Thomas; Budka, Joshua S; Bishop, Brandon J; Brown, Elliot; Potluri, Devi P V; Cooper, Bruce R; Premachandra, Gnanasiri S; Johnston, Cliff T; Schulz, Burkhard

    2014-01-01

    Plant growth regulators, such as hormones and their respective biosynthesis inhibitors, are effective tools to elucidate the physiological function of phytohormones in plants. A problem of chemical treatments, however, is the potential for interaction of the active compound with the growth media substrate. We studied the interaction and efficacy of propiconazole, a potent and specific inhibitor of brassinosteroid biosynthesis, with common soilless greenhouse growth media for rice, sorghum, and maize. Many of the tested growth media interacted with propiconazole reducing its efficacy up to a hundred fold. To determine the molecular interaction of inhibitors with media substrates, Fourier Transform Infrared Spectroscopy and sorption isotherm analysis was applied. While mica clay substrates absorbed up to 1.3 mg of propiconazole per g substrate, calcined clays bound up to 12 mg of propiconazole per g substrate. The efficacy of the gibberellic acid biosynthesis inhibitor, uniconazole, and the most active brassinosteroid, brassinolide, was impacted similarly by the respective substrates. Conversely, gibberellic acid showed no distinct growth response in different media. Our results suggest that the reduction in efficacy of propiconazole, uniconazole, and brassinolide in bioassays when grown in calcined clay is caused by hydrophobic interactions between the plant growth regulators and the growth media. This was further confirmed by experiments using methanol-water solvent mixes with higher hydrophobicity values, which reduce the interaction of propiconazole and calcined clay.

  20. Causes of Low and High Citation Potentials in Science: Citation Analysis of Biochemistry and Plant Physiology Journals.

    Science.gov (United States)

    Marton, Janos

    1983-01-01

    Citation data of 16 biochemistry and plant physiology journals show that reasons for lower citation potentials of plant physiology articles are: (1) readership is narrower for plant physiology journals; (2) plant physiologists can cite fewer thematically relevant new articles; and (3) plant physiology research fields are more isolated. References…

  1. Identification of water use strategies at early growth stages in durum wheat from shoot phenotyping and physiological measurements.

    Directory of Open Access Journals (Sweden)

    ALIREZA NAKHFOROOSH

    2016-08-01

    Full Text Available Modern imaging technology provides new approaches to plant phenotyping for traits relevant to crop yield and resource efficiency. Our objective was to investigate water use strategies at early growth stages in durum wheat genetic resources using shoot imaging at the ScreenHouse phenotyping facility combined with physiological measurements. 12 durum landraces from different pedoclimatic backgrounds were compared to three modern check cultivars in a greenhouse pot experiment under well watered (75 % plant available water, PAW and drought (25 % PAW conditions. Transpiration rate was analyzed for the underlying main morphological (leaf area duration and physiological (stomata conductance factors. Combining both morphological and physiological regulation of transpiration, four distinct water use types were identified. Most landraces had high transpiration rates either due to extensive leaf area (area types or both large leaf areas together with high stomata conductance (spender types. All modern cultivars were distinguished by high stomata conductance with comparatively compact canopies (conductance types. Only few landraces were water saver types with both small canopy and low stomata conductance. During early growth, genotypes with large leaf area had high dry-matter accumulation under both well watered and drought conditions compared to genotypes with compact stature. However, high stomata conductance was the basis to achieve high dry matter per unit leaf area, indicating high assimilation capacity as a key for productivity in modern cultivars. We conclude that the identified water use strategies based on early growth shoot phenotyping combined with stomata conductance provide an appropriate framework for targeted selection of distinct pre-breeding material adapted to different types of water limited environments.

  2. Identification of Water Use Strategies at Early Growth Stages in Durum Wheat from Shoot Phenotyping and Physiological Measurements

    Science.gov (United States)

    Nakhforoosh, Alireza; Bodewein, Thomas; Fiorani, Fabio; Bodner, Gernot

    2016-01-01

    Modern imaging technology provides new approaches to plant phenotyping for traits relevant to crop yield and resource efficiency. Our objective was to investigate water use strategies at early growth stages in durum wheat genetic resources using shoot imaging at the ScreenHouse phenotyping facility combined with physiological measurements. Twelve durum landraces from different pedoclimatic backgrounds were compared to three modern check cultivars in a greenhouse pot experiment under well-watered (75% plant available water, PAW) and drought (25% PAW) conditions. Transpiration rate was analyzed for the underlying main morphological (leaf area duration) and physiological (stomata conductance) factors. Combining both morphological and physiological regulation of transpiration, four distinct water use types were identified. Most landraces had high transpiration rates either due to extensive leaf area (area types) or both large leaf areas together with high stomata conductance (spender types). All modern cultivars were distinguished by high stomata conductance with comparatively compact canopies (conductance types). Only few landraces were water saver types with both small canopy and low stomata conductance. During early growth, genotypes with large leaf area had high dry-matter accumulation under both well-watered and drought conditions compared to genotypes with compact stature. However, high stomata conductance was the basis to achieve high dry matter per unit leaf area, indicating high assimilation capacity as a key for productivity in modern cultivars. We conclude that the identified water use strategies based on early growth shoot phenotyping combined with stomata conductance provide an appropriate framework for targeted selection of distinct pre-breeding material adapted to different types of water limited environments. PMID:27547208

  3. Deficiency and toxicity of boron: Alterations in growth, oxidative damage and uptake by citrange orange plants.

    Science.gov (United States)

    Shah, Asad; Wu, Xiuwen; Ullah, Abid; Fahad, Shah; Muhammad, Riaz; Yan, Lei; Jiang, Cuncang

    2017-11-01

    Boron (B) deficiency and toxicity are the major factors that affect plant growth and yield. The present study revealed the effect of B deficiency and toxicity on plant growth, morphology, physiology, and cell structure. A hydroponic culture experiment was conducted with five B levels, B deficient (B0), sufficient (B20, B10, B40) and toxic (B100). Our results show that both B deficient as well as excess level inhibit plant growth. In B deficiency, the major visible symptoms were appeared in roots, while B excess burned the leaf margin of older leaves. The antioxidant enzymes including superoxide dismutase (SOD), peroxidase (POD), catalase (CAT) and ascorbate peroxidase (APX) decreased at B deficiency and also decreased up to some extent at B excess, while in sufficient treatments, the higher antioxidant enzymes were found at B20. In addition, the MDA concentration decreased at B deficiency and increased with B concentration. Moreover, the photosynthetic rate, transpiration rate, stomatal conductance, leaf gas exchange and intercellular CO 2 were reduced at both B deficiency as well as excess and higher at sufficient B20 treatment significantly. The chlorophyll and carotenoid content increased at B20 treatment, while decreased at B deficiency and excess. The middle lamellae of cell wall were found thick at B excess and normal at B20. The current study revealed that B deficiency as well as excess concentration affect plant growth and various morpho-physiological processes. Copyright © 2017 Elsevier Inc. All rights reserved.

  4. Effect of salt stress on growth and physiology in amaranth and lettuce: Implications for bioregenerative life support system

    Science.gov (United States)

    Qin, Lifeng; Guo, Shuangsheng; Ai, Weidang; Tang, Yongkang; Cheng, Quanyong; Chen, Guang

    2013-02-01

    Growing plants can be used to clean waste water in bioregenerative life support system (BLSS). However, NaCl contained in the human urine always restricts plant growth and further reduces the degree of mass cycle closure of the system (i.e. salt stress). This work determined the effect of NaCl stress on physiological characteristics of plants for the life support system. Amaranth (Amaranthus tricolor L. var. Huahong) and leaf lettuce (Lactuca sativa L. var. Luoma) were cultivated at nutrient solutions with different NaCl contents (0, 1000, 5000 and 10,000 ppm, respectively) for 10 to 18 days after planted in the Controlled Ecological Life Support System Experimental Facility in China. Results showed that the two plants have different responses to the salt stress. The amaranth showed higher salt-tolerance with NaCl stress. If NaCl content in the solution is below 5000 ppm, the salt stress effect is insignificant on above-ground biomass output, leaf photosynthesis rate, Fv/Fm, photosynthesis pigment contents, activities of antioxidant enzymes, and inducing lipid peroxidation. On the other hand, the lettuce is sensitive to NaCl which significantly decreases those indices of growth and physiology. Notably, the lettuce remains high productivity of edible biomass in low NaCl stress, although its salt-tolerant limitation is lower than amaranth. Therefore, we recommended that amaranth could be cultivated under a higher NaCl stress condition (lettuce should be under a lower NaCl stress (<1000 ppm) for water cleaning in future BLSS.

  5. Effect of Planting Date on Physiological and MorphologicalCharacteristics of Four Canola Cultivars in Yasouj

    Directory of Open Access Journals (Sweden)

    M. H. Fallah Heki

    2012-08-01

    Full Text Available In order to study the physiological and morphological characteristics of canola cultivars at different planting dates, an experiment was carried out in 2008-2009 at the Agriculture Research Station of Yasouj. A factorial with Randomized Complete Block Design with four replications was conducted. Four planting dates (September 12, September 22, October 2 and October 12 and four cultivars (Zarfam, Okapi, Elite and SLM-046 were used in this study. Results showed that cultivars and planting dates had significant effects on more characteristics. In addition, interaction of planting date and cultivar was significant on plant height, height to lowest silique, number of branches, growth indices and grain yield. Zarfam and Elite cultivars had lower initial fluorescence (Fo and higher maximum fluorescence (Fm and photochemical capacity of photosystem II (Fv/Fm than Okapi and SLM-046 cultivars. Elite cultivar at September 12 planting date had the highest plant height (173 cm and height to lowest silique (87.5 cm and Okapi cultivar at October 12 planting date showed the lowest plant height (91 cm and height to lowest silique (43.7 cm. At September 12 planting date, Elite cultivar had the greatest leaf area index (5.21 and grain yield (5231 kg/ha. At other planting dates, Zarfam cultivar because of priority in leaf area index, crop growth rate and total dry matter have the greatest grain yield than other cultivars. In general, seems at September 12 planting date, Elite cultivar and for delayed sowing, Zarfam cultivar had better reaction than other cultivars.

  6. Growth and physiological response of tomato plants to different periods of nitrogen starvation and recovery

    NARCIS (Netherlands)

    Martinez, V.; Amor, del F.M.; Marcelis, L.F.M.

    2005-01-01

    Young, vegetative-state tomato plants, starved of N for 1, 3 or 7 d, followed, in each case, by a 7-d recovery period with nutrient solution containing N, were examined. Relative growth rate (RGR), leaf photosynthesis and leaf expansion were reduced after only 1 d of N starvation.Tissue N

  7. X-ray microanalysis in plant physiology

    International Nuclear Information System (INIS)

    Neumann, D.

    1979-01-01

    X-ray microanalysis represents a highly sensitive and modern method for the measurement of ions in the very small compartments of the cell. The limitations of X-ray microanalysis in biological objects exist in the preparation of the tissues and the quantitation of the results. In plant physiology this method has provided several surprising results and new insights for further investigations. (author)

  8. Resolving the role of plant glutamate dehydrogenase: II. Physiological characterization of plants overexpressing the two enzyme subunits individually or simultaneously.

    Science.gov (United States)

    Tercé-Laforgue, Thérèse; Bedu, Magali; Dargel-Grafin, Céline; Dubois, Frédéric; Gibon, Yves; Restivo, Francesco M; Hirel, Bertrand

    2013-10-01

    Glutamate dehydrogenase (GDH; EC 1.4.1.2) is able to carry out the deamination of glutamate in higher plants. In order to obtain a better understanding of the physiological function of GDH in leaves, transgenic tobacco (Nicotiana tabacum L.) plants were constructed that overexpress two genes from Nicotiana plumbaginifolia (GDHA and GDHB under the control of the Cauliflower mosiac virus 35S promoter), which encode the α- and β-subunits of GDH individually or simultaneously. In the transgenic plants, the GDH protein accumulated in the mitochondria of mesophyll cells and in the mitochondria of the phloem companion cells (CCs), where the native enzyme is normally expressed. Such a shift in the cellular location of the GDH enzyme induced major changes in carbon and nitrogen metabolite accumulation and a reduction in growth. These changes were mainly characterized by a decrease in the amount of sucrose, starch and glutamine in the leaves, which was accompanied by an increase in the amount of nitrate and Chl. In addition, there was an increase in the content of asparagine and a decrease in proline. Such changes may explain the lower plant biomass determined in the GDH-overexpressing lines. Overexpressing the two genes GDHA and GDHB individually or simultaneously induced a differential accumulation of glutamate and glutamine and a modification of the glutamate to glutamine ratio. The impact of the metabolic changes occurring in the different types of GDH-overexpressing plants is discussed in relation to the possible physiological function of each subunit when present in the form of homohexamers or heterohexamers.

  9. Alteration of plant physiology by glyphosate and its by-product aminomethylphosphonic acid: an overview.

    Science.gov (United States)

    Gomes, Marcelo P; Smedbol, Elise; Chalifour, Annie; Hénault-Ethier, Louise; Labrecque, Michel; Lepage, Laurent; Lucotte, Marc; Juneau, Philippe

    2014-09-01

    It is generally claimed that glyphosate kills undesired plants by affecting the 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) enzyme, disturbing the shikimate pathway. However, the mechanisms leading to plant death may also be related to secondary or indirect effects of glyphosate on plant physiology. Moreover, some plants can metabolize glyphosate to aminomethylphosphonic acid (AMPA) or be exposed to AMPA from different environmental matrices. AMPA is a recognized phytotoxin, and its co-occurrence with glyphosate could modify the effects of glyphosate on plant physiology. The present review provides an overall picture of alterations of plant physiology caused by environmental exposure to glyphosate and its metabolite AMPA, and summarizes their effects on several physiological processes. It particularly focuses on photosynthesis, from photochemical events to C assimilation and translocation, as well as oxidative stress. The effects of glyphosate and AMPA on several plant physiological processes have been linked, with the aim of better understanding their phytotoxicity and glyphosate herbicidal effects. © The Author 2014. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  10. Growth Chambers on the International Space Station for Large Plants

    Science.gov (United States)

    Massa, Gioia D.; Wheeler, Raymond M.; Morrow, Robert C.; Levine, Howard G.

    2016-01-01

    The International Space Station (ISS) now has platforms for conducting research on horticultural plant species under LED (Light Emitting Diodes) lighting, and those capabilities continue to expand. The Veggie vegetable production system was deployed to the ISS as an applied research platform for food production in space. Veggie is capable of growing a wide array of horticultural crops. It was designed for low power usage, low launch mass and stowage volume, and minimal crew time requirements. The Veggie flight hardware consists of a light cap containing red (630 nanometers), blue, (455 nanometers) and green (530 nanometers) LEDs. Interfacing with the light cap is an extendable bellowsbaseplate for enclosing the plant canopy. A second large plant growth chamber, the Advanced Plant Habitat (APH), is will fly to the ISS in 2017. APH will be a fully controllable environment for high-quality plant physiological research. APH will control light (quality, level, and timing), temperature, CO2, relative humidity, and irrigation, while scrubbing any cabin or plant-derived ethylene and other volatile organic compounds. Additional capabilities include sensing of leaf temperature and root zone moisture, root zone temperature, and oxygen concentration. The light cap will have red (630 nm), blue (450 nm), green (525 nm), far red (730 nm) and broad spectrum white LEDs (4100K). There will be several internal cameras (visible and IR) to monitor and record plant growth and operations. Veggie and APH are available for research proposals.

  11. Adaptive diversification of growth allometry in the plant Arabidopsis thaliana.

    Science.gov (United States)

    Vasseur, François; Exposito-Alonso, Moises; Ayala-Garay, Oscar J; Wang, George; Enquist, Brian J; Vile, Denis; Violle, Cyrille; Weigel, Detlef

    2018-03-27

    Seed plants vary tremendously in size and morphology; however, variation and covariation in plant traits may be governed, at least in part, by universal biophysical laws and biological constants. Metabolic scaling theory (MST) posits that whole-organismal metabolism and growth rate are under stabilizing selection that minimizes the scaling of hydrodynamic resistance and maximizes the scaling of resource uptake. This constrains variation in physiological traits and in the rate of biomass accumulation, so that they can be expressed as mathematical functions of plant size with near-constant allometric scaling exponents across species. However, the observed variation in scaling exponents calls into question the evolutionary drivers and the universality of allometric equations. We have measured growth scaling and fitness traits of 451 Arabidopsis thaliana accessions with sequenced genomes. Variation among accessions around the scaling exponent predicted by MST was correlated with relative growth rate, seed production, and stress resistance. Genomic analyses indicate that growth allometry is affected by many genes associated with local climate and abiotic stress response. The gene with the strongest effect, PUB4 , has molecular signatures of balancing selection, suggesting that intraspecific variation in growth scaling is maintained by opposing selection on the trade-off between seed production and abiotic stress resistance. Our findings suggest that variation in allometry contributes to local adaptation to contrasting environments. Our results help reconcile past debates on the origin of allometric scaling in biology and begin to link adaptive variation in allometric scaling to specific genes. Copyright © 2018 the Author(s). Published by PNAS.

  12. Manipulation of the hypocotyl sink activity by reciprocal grafting of two Raphanus sativus varieties: its effects on morphological and physiological traits of source leaves and whole-plant growth.

    Science.gov (United States)

    Sugiura, Daisuke; Betsuyaku, Eriko; Terashima, Ichiro

    2015-12-01

    To reveal whether hypocotyl sink activities are regulated by the aboveground parts, and whether physiology and morphology of source leaves are affected by the hypocotyl sink activities, we conducted grafting experiments using two Raphanus sativus varieties with different hypocotyl sink activities. Comet (C) and Leafy (L) varieties with high and low hypocotyl sink activities were reciprocally grafted and resultant plants were called by their scion and stock such as CC, LC, CL and LL. Growth, leaf mass per area (LMA), total non-structural carbohydrates (TNCs) and photosynthetic characteristics were compared among them. Comet hypocotyls in CC and LC grew well regardless of the scions, whereas Leafy hypocotyls in CL and LL did not. Relative growth rate was highest in LL and lowest in CC. Photosynthetic capacity was correlated with Rubisco (ribulose 1·5-bisphosphate carboxylase/oxygenase) content but unaffected by TNC. High C/N ratio and accumulation of TNC led to high LMA and structural LMA. These results showed that the hypocotyl sink activity was autonomously regulated by hypocotyl and that the down-regulation of photosynthesis was not induced by TNC. We conclude that the change in the sink activity alters whole-plant growth through the changes in both biomass allocation and leaf morphological characteristics in R. sativus. © 2015 John Wiley & Sons Ltd.

  13. Extraction of Plant Physiological Status from Hyperspectral Signatures Using Machine Learning Methods

    Directory of Open Access Journals (Sweden)

    Daniel Doktor

    2014-12-01

    Full Text Available The machine learning method, random forest (RF, is applied in order to derive biophysical and structural vegetation parameters from hyperspectral signatures. Hyperspectral data are, among other things, characterized by their high dimensionality and autocorrelation. Common multivariate regression approaches, which usually include only a limited number of spectral indices as predictors, do not make full use of the available information. In contrast, machine learning methods, such as RF, are supposed to be better suited to extract information on vegetation status. First, vegetation parameters are extracted from hyperspectral signatures simulated with the radiative transfer model, PROSAIL. Second, the transferability of these results with respect to laboratory and field measurements is investigated. In situ observations of plant physiological parameters and corresponding spectra are gathered in the laboratory for summer barley (Hordeum vulgare. Field in situ measurements focus on winter crops over several growing seasons. Chlorophyll content, Leaf Area Index and phenological growth stages are derived from simulated and measured spectra. RF performs very robustly and with a very high accuracy on PROSAIL simulated data. Furthermore, it is almost unaffected by introduced noise and bias in the data. When applied to laboratory data, the prediction accuracy is still good (C\\(_{ab}\\: \\(R^2\\ = 0.94/ LAI: \\(R^2\\ = 0.80/BBCH (Growth stages of mono-and dicotyledonous plants : \\(R^2\\ = 0.91, but not as high as for simulated spectra. Transferability to field measurements is given with prediction levels as high as for laboratory data (C\\(_{ab}\\: \\(R^2\\ = 0.89/LAI: \\(R^2\\ = 0.89/BBCH: \\(R^2\\ = \\(\\sim\\0.8. Wavelengths for deriving plant physiological status based on simulated and measured hyperspectral signatures are mostly selected from appropriate spectral regions (both field and laboratory: 700–800 nm regressing on C\\(_{ab}\\ and 800–1300

  14. Comparison of ALS functionality and plant growth in ALS-inhibitor susceptible and resistant Myosoton aquaticum L.

    Science.gov (United States)

    Liu, Weitang; Bai, Shuang; Jia, Sisi; Guo, Wenlei; Zhang, Lele; Li, Wei; Wang, Jinxin

    2017-10-01

    Herbicide target-site resistance mutations may cause pleiotropic effects on plant ecology and physiology. The effect of several known (Pro197Ser, Pro197Leu Pro197Ala, and Pro197Glu) target-site resistance mutations of the ALS gene on both ALS functionality and plant vegetative growth of weed Myosoton aquaticum L. (water chickweed) have been investigated here. The enzyme kinetics of ALS from four purified water chickweed populations that each homozygous for the specific target-site resistance-endowing mutations were characterized and the effect of these mutations on plant growth was assessed via relative growth rate (RGR) analysis. Plants homozygous for Pro197Ser and Pro197Leu exhibited higher extractable ALS activity than susceptible (S) plants, while all ALS mutations with no negative change in ALS kinetics. The Pro197Leu mutation increased ALS sensitivity to isoleucine and valine, and Pro197Glu mutation slightly increased ALS sensitivity to isoleucine. RGR results indicated that none of these ALS resistance mutations impose negative pleiotropic effects on relative growth rate. However, resistant (R) seeds had a lowed germination rate than S seeds. This study provides baseline information on ALS functionality and plant growth characteristics associated with ALS inhibitor resistance-endowing mutations in water chickweed. Copyright © 2017. Published by Elsevier Inc.

  15. Características fisiológicas e de crescimento de cafeeiro sombreado com guandu e cultivado a pleno sol Physiological characteristics and growth of coffee plants grown under shade of pigeonpea and unshaded

    Directory of Open Access Journals (Sweden)

    Heverly Morais

    2003-10-01

    Full Text Available O conhecimento dos efeitos do sombreamento sobre a fisiologia de cafeeiros é importante para se determinar níveis ótimos de radiação e temperatura, bem como para subsidiar estudos sobre o crescimento de plantas sombreadas, a fim de determinar a arquitetura ideal do cafeeiro que maximize a captura da radiação solar disponível em ambientes sombreados. O objetivo deste trabalho foi avaliar características fisiológicas e de crescimento de cafeeiros (Coffea arabica L. cultivados sob sombreamento denso com guandu (Cajanus cajan (L. Millsp. e a pleno sol. O baixo nível de radiação incidente sobre os cafeeiros sombreados com guandu resultou em decréscimos na taxa fotossintética e na transpiração, maior altura de planta, folhas maiores e com menor quantidade de matéria seca. Esses resultados indicam que o excesso de sombra afeta drasticamente a fisiologia e morfologia de C. arabica.The characterization of shade effects on the physiology of coffee is important to determine optimum levels of radiation and temperature, as well as to subsidize studies on growth of shaded plants aiming at determining the ideal coffee plant architecture that maximizes the capture of the available solar radiation in shaded environments. The objective of this work was to evaluate physiological and growth characteristics of coffee (Coffea arabica L. shaded with pigeonpea (Cajanus cajan (L. Millsp. and under full sun. The low level of incident radiation on the coffee shaded with pigeonpea caused decreases in the photosynthetic rate and transpiration, increased plant height and leaf size, but diminished leaf dry matter. These results indicate that the excess of shade drastically affects the physiology and morphology of C. arabica.

  16. Evaluating physiological responses of plants to salinity stress

    KAUST Repository

    Negrã o, Só nia; Schmö ckel, S. M.; Tester, Mark A.

    2016-01-01

    Background Because soil salinity is a major abiotic constraint affecting crop yield, much research has been conducted to develop plants with improved salinity tolerance. Salinity stress impacts many aspects of a plant’s physiology, making

  17. PLANT GROWTH IN MICROGRAVITY FOR BLSS: GENERAL ISSUES AND THE ITALIAN CONTRIBUTION

    Directory of Open Access Journals (Sweden)

    Veronica De Micco

    2012-06-01

    Full Text Available Plants are among key organisms in Bioregenerative Life Support Systems (BLSSs in Space because they have a role in the regeneration of resources and in the psychological support of the crew. The design of efficient BLSSs cannot be irrespective of the deep knowledge of the functioning of the vegetal systems under the effect of Space factors. Under an evolutionary perspective, reduced gravity can be considered one of the factors driving the evolution of plants in Space. In this paper, we outline the need for plant-based BLSSs to sustain exploratory-class manned missions in Space. After some evolutionary considerations about future plant development in Space, we also report a synthesis of the results of case studies performed by Italian research groups aiming to understand the effect of simulated or real microgravity on various aspects of plant growth and reproduction. We conclude emphasising how plant research in Space should be addressed to both improvement of the knowledge of basic biological processes and development of new agro-technologies. Efforts to have multidisciplinary approach to understand the effect of Space factors on plant growth are needed considering that such factors affect the biological systems contemporarily at molecular, biochemical, morphostructural and physiological levels.

  18. The correlation between plant growth and intercepted radiation: an interpretation in terms of optimal plant nitrogen content

    International Nuclear Information System (INIS)

    Dewar, R.C.

    1996-01-01

    Photosynthesis of leaves is commonly observed to have a saturating response to increases in their nitrogen (N) content, while the response of plant maintenance respiration is more nearly linear over the normal range of tissue N contents. Hence, for a given amount of foliage, net primary productivity (NPP) may have a maximum value with respect to variations in plant N content. Using a simple analytically-solvable model of NPP, this idea is formulated and its broad implications for plant growth are explored at the scale of a closed stand of vegetation. The maximum-NPP hypothesis implies that NPP is proportional to intercepted radiation, as commonly observed. The light utilization coefficient (ε), defined as the slope of this relationship, is predicted to be ε = αY g (1−λ) 2 , where α is the quantum yield, Y g is the biosynthetic efficiency, and λ is a dimensionless combination of physiological and environmental parameters of the model. The maximum-NPP hypothesis is also consistent with observations that whole-plant respiration (R) is an approximately constant proportion of gross canopy photosynthesis (A c ), and predicts their ratio to be R:A c = 1−Y g (1−λ). Using realistic parameter values, predicted values for ε and R:A c are typical of C 3 plants. ε is predicted to be independent of plant N supply, consistent with observations that long-term growth responses to N fertilization are dominated by increased light interception associated with increased growth allocation to leaf area. Observed acclimated responses of plants to atmospheric [CO 2 ], light and temperature are interpreted in terms of the model. (author)

  19. Effect of Salicylic Acid on the Growth and Physiological Characteristics of Maize under Stress Conditions

    International Nuclear Information System (INIS)

    Manzoor, K.; Ilyas, N.; Batool, N.; Arshad, M.; Ahmad, B.

    2015-01-01

    Salicylic acid (SA) is a naturally occurring signaling molecule and growth regulator that enhances plant growth particularly in stress conditions. The present study was planned to evaluate the effects of different levels of SA on maize growth under drought and salt stress conditions. An experiment was conducted to test the morphological, physiological and biochemical changes in two cultivar of maize D-1184 and TG-8250. Varying levels of salicylic acid, i.e. 5mM, 10mM and 15mM were applied through foliar method. Exogenous applications of salicylic acid were done after 20 days of germination of the maize plants. Salicylic acid significantly affects root and shoot dry matter under drought and salt stress. Foliar application of SA significantly increased proline concentration (11 percentage and 12 percentage), amino acid accumulation (25 percentage and 18 percentage), relative water (17 percentage and 14 percentage) and Chlorophyll content. Overall, it can be concluded that SA at lower concentration is effective to minimize the effect of stress conditions. Maize cultivar TG-8250 showed better tolerance under drought and salt stress condition as compared to D-1184 cultivar. (author)

  20. Physiological integration enhanced the tolerance of Cynodon dactylon to flooding.

    Science.gov (United States)

    Li, Z J; Fan, D Y; Chen, F Q; Yuan, Q Y; Chow, W S; Xie, Z Q

    2015-03-01

    Many flooding-tolerant species are clonal plants; however, the effects of physiological integration on plant responses to flooding have received limited attention. We hypothesise that flooding can trigger changes in metabolism of carbohydrates and ROS (reactive oxygen species) in clonal plants, and that physiological integration can ameliorate the adverse effects of stress, subsequently restoring the growth of flooded ramets. In the present study, we conducted a factorial experiment combining flooding to apical ramets and stolon severing (preventing physiological integration) between apical and basal ramets of Cynodon dactylon, which is a stoloniferous perennial grass with considerable flooding tolerance. Flooding-induced responses including decreased root biomass, accumulation of soluble sugar and starch, as well as increased activity of superoxide dismutase (SOD) and ascorbate peroxidase (APX) in apical ramets. Physiological integration relieved growth inhibition, carbohydrate accumulation and induction of antioxidant enzyme activity in stressed ramets, as expected, without any observable cost in unstressed ramets. We speculate that relief of flooding stress in clonal plants may rely on oxidising power and electron acceptors transferred between ramets through physiological integration. © 2014 German Botanical Society and The Royal Botanical Society of the Netherlands.

  1. Growth and physiological responses of canola (Brassica napus) to three components of global climate change: temperature, carbon dioxide and drought

    Energy Technology Data Exchange (ETDEWEB)

    Qaderi, M.M.; Kurepin, L.V.; Reid, D.M. [Univ. of Calgary, Dept. of Biological Sciences, Calgary, Alberta (Canada)

    2006-12-15

    Elevated CO{sub 2} appears to be a significant factor in global warming, which will likely lead to drought conditions in many areas. Few studies have considered the interactive effects of higher CO{sub 2}, temperature and drought on plant growth and physiology. We grew canola (Brassica napus cv. 45H72) plants under lower (22/18 deg. C) and higher (28/24 deg. C) temperature regimes in controlled-environment chambers at ambient (370 {mu}mol mol-1) and elevated (740 {mu}mol mol-1) CO{sub 2} levels. One half of the plants were watered to field capacity and the other half at wilting point. In three separate experiments, we determined growth, various physiological parameters and content of abscisic acid (ABA), indole-3-acetic acid and ethylene. Drought-stressed plants grown under higher temperature at ambient CO{sub 2} had decreased stem height and diameter, leaf number and area, dry matter, leaf area ratio, shoot/root weight ratio, net CO{sub 2} assimilation and chlorophyll fluorescence. However, these plants had increased specific leaf weight, leaf weight ratio and chlorophyll concentration. Elevated CO{sub 2} generally had the opposite effect. and partially reversed the inhibitory effects of higher temperature and drought on leaf dry weight accumulation. This study showed that higher temperature and drought inhibit many processes but elevated CO{sub 2} partially mitigate some adverse effects. As expected, drought stress increased ABA but higher temperature inhibited the ability of plants to produce ABA in response to drought. (au)

  2. Growth Analysis of Fenugreek (Trigonella foenum- graecum L. under Various Levels of Nitrogen and Plant Density

    Directory of Open Access Journals (Sweden)

    L Bazrkar-Khatibani

    2018-02-01

    Full Text Available Introduction Fenugreek (Trigonella foenum-graecum L. is a specific condiment crop mostly grown for its edible parts, and is used as a green fodder and fresh vegetable. The seeds have medicinal value solely against digestive disorders, whereas its leaves are rich source of minerals and nutrients. The growth and yield of fenugreek is particularly affected by the application of nitrogen fertilizer and planting arrangement. Plant growth is a process of biomass accumulation which in turn is derived out of the interaction of the respiration, photosynthesis, water relations, long-distance transport, and mineral nutrition processes. Growth is the most important process in predicting plant reactions to environment. Irradiance, temperature, soil-water potential, nutrient supply and enhanced concentrations of atmospheric carbon dioxide are among some external components influencing crop growth and development. Growth analysis is a useful tool in studying the complex interactions between plant growth and the environment, clarifying and interpreting physiological responses. Plants total dry matter (TDM production and accumulation can be appraised via relative growth rate (RGR and crop growth rate (CGR which are the most important growth indices. Leaf area index (LAI is a factor of crop growth analysis that accounts for the potential of the crop to assimilate light energy and is a determinant component in understanding the function of many crop management practices. Materials and Methods A field investigation was conducted in a paddy field at Shaft County (Guilan Province for eight consecutive months (from November 2009 to June 2010, to study the effect of four levels of nitrogen fertilizer (0, 25, 50 and 75 Kg N ha-1 and four levels of planting density (60, 80,100, and 120 plants m-2 on the growth indices of fenugreek (Trigonella foenum graecum L. crop. The soil for the experiment was loam in texture and strongly acidic in reaction (pH 4.5. Sixteen treatment

  3. C4 plants use fluctuating light less efficiently than do C3 plants: a study of growth, photosynthesis and carbon isotope discrimination.

    Science.gov (United States)

    Kubásek, Jiří; Urban, Otmar; Šantrůček, Jiří

    2013-12-01

    Plants in the field are commonly exposed to fluctuating light intensity, caused by variable cloud cover, self-shading of leaves in the canopy and/or leaf movement due to turbulence. In contrast to C3 plant species, only little is known about the effects of dynamic light (DL) on photosynthesis and growth in C4 plants. Two C4 and two C3 monocot and eudicot species were grown under steady light or DL conditions with equal sum of daily incident photon flux. We measured leaf gas exchange, plant growth and dry matter carbon isotope discrimination to infer CO2 bundle sheath leakiness in C4 plants. The growth of all species was reduced by DL, despite only small changes in steady-state gas exchange characteristics, and this effect was more pronounced in C4 than C3 species due to lower assimilation at light transitions. This was partially attributed to increased bundle sheath leakiness in C4 plants under the simulated lightfleck conditions. We hypothesize that DL leads to imbalances in the coordination of C4 and C3 cycles and increasing leakiness, thereby decreasing the quantum efficiency of photosynthesis. In addition to their other constraints, the inability of C4 plants to efficiently utilize fluctuating light likely contributes to their absence in such environments as forest understoreys. © 2013 Scandinavian Plant Physiology Society.

  4. Tall or short? Slender or thick? A plant strategy for regulating elongation growth of roots by low concentrations of gibberellin.

    Science.gov (United States)

    Tanimoto, Eiichi

    2012-07-01

    Since the plant hormone gibberellin (GA) was discovered as a fungal toxin that caused abnormal elongation of rice shoots, the physiological function of GA has mainly been investigated in relation to the regulation of plant height. However, an indispensable role for GA in root growth has been elucidated by using severely GA-depleted plants, either with a gene mutation in GA biosynthesis or which have been treated by an inhibitor of GA biosynthesis. The molecular sequence of GA signalling has also been studied to understand GA functions in root growth. This review addresses research progress on the physiological functions of GA in root growth. Concentration-dependent stimulation of elongation growth by GA is important for the regulation of plant height and root length. Thus the endogenous level of GA and/or the GA sensitivity of shoots and roots plays a role in determining the shoot-to-root ratio of the plant body. Since the shoot-to-root ratio is an important parameter for agricultural production, control of GA production and GA sensitivity may provide a strategy for improving agricultural productivity. The sequence of GA signal transduction has recently been unveiled, and some component molecules are suggested as candidate in planta regulatory sites and as points for the artificial manipulation of GA-mediated growth control. This paper reviews: (1) the breakthrough dose-response experiments that show that root growth is regulated by GA in a lower concentration range than is required for shoot growth; (2) research on the regulation of GA biosynthesis pathways that are known predominantly to control shoot growth; and (3) recent research on GA signalling pathways, including GA receptors, which have been suggested to participate in GA-mediated growth regulation. This provides useful information to suggest a possible strategy for the selective control of shoot and root growth, and to explain how GA plays a role in rosette and liana plants with tall or short, and slender

  5. Impact of physico-chemical parameters on the physiological growth ...

    African Journals Online (AJOL)

    Impact of physico-chemical parameters on the physiological growth of Arthrospira (Spirulina platensis) exogenous strain UTEXLB2340. Yahia Mustafa A Fagiri, Aisha Salleh, Saifeldin Ahmed F El-Nagerabi ...

  6. Lichen physiological traits and growth forms affect communities of associated invertebrates.

    Science.gov (United States)

    Bokhorst, Stef; Asplund, Johan; Kardol, Paul; Wardle, David A

    2015-09-01

    While there has been much interest in the relationships between traits of primary producers and composition of associated invertebrate consumer communities, our knowledge is largely based on studies from vascular plants, while other types of functionally important producers, such as lichens, have rarely been considered. To address how physiological traits of lichens drive community composition of invertebrates, we collected thalli from 27 lichen species from southern Norway and quantified the communities of associated springtails, mites, and nematodes. For each lichen species, we measured key physiological thallus traits and determined whether invertebrate communities were correlated with these traits. We also explored whether invertebrate communities differed among lichen groups, categorized according to nitrogen-fixing ability, growth form, and substratum. Lichen traits explained up to 39% of the variation in abundances of major invertebrate groups. For many invertebrate groups, abundance was positively correlated with lichen N and P concentrations, N:P ratio, and the percentage of water content on saturation (WC), but had few relationships with concentrations of carbon-based secondary compounds. Diversity and taxonomic richness of invertebrate groups were sometimes also correlated with lichen N and N:P ratios. Nitrogen-fixing lichens showed higher abundance and diversity of some invertebrate groups than did non-N-fixing lichens. However, this emerged in part because most N-fixing lichens have a foliose growth form that benefits invertebrates, through, improving the microclimate, independently of N concentration. Furthermore, invertebrate communities associated with terricolous lichens were determined more by their close proximity to the soil invertebrate pool than by lichen traits. Overall, our results reveal that differences between lichen species have a large impact on the invertebrate communities that live among the thalli. Different invertebrate groups show

  7. Evolutionary History Underlies Plant Physiological Responses to Global Change Since the Last Glacial Maximum

    Science.gov (United States)

    Becklin, K. M.; Medeiros, J. S.; Sale, K. R.; Ward, J. K.

    2014-12-01

    Assessing family and species-level variation in physiological responses to global change across geologic time is critical for understanding factors that underlie changes in species distributions and community composition. Ancient plant specimens preserved within packrat middens are invaluable in this context since they allow for comparisons between co-occurring plant lineages. Here we used modern and ancient plant specimens preserved within packrat middens from the Snake Range, NV to investigate the physiological responses of a mixed montane conifer community to global change since the last glacial maximum. We used a conceptual model to infer relative changes in stomatal conductance and maximum photosynthetic capacity from measures of leaf carbon isotopes, stomatal characteristics, and leaf nitrogen content. Our results indicate that most of the sampled taxa decreased stomatal conductance and/or photosynthetic capacity from glacial to modern times. However, plant families differed in the timing and magnitude of these physiological responses. Additionally, leaf-level responses were more similar within plant families than within co-occurring species assemblages. This suggests that adaptation at the level of leaf physiology may not be the main determinant of shifts in community composition, and that plant evolutionary history may drive physiological adaptation to global change over recent geologic time.

  8. Effect of coastal eutrophication on growth and physiology of Spartina alterniflora Loisel

    Science.gov (United States)

    Zhang, Yu; Cui, Baoshan; Xie, Tian; Wang, Qing; Yan, Jiaguo

    2018-02-01

    Coastal eutrophication has become a driver of coastal wetlands loss. Eutrophication caused by the increase of nitrogen content was one of the most main reasons. We analyzed that exogenous ammonium nitrogen (EAN) of different concentration influenced on the growth and physiology of Spartina alterniflora Loisel (S. alterniflora) through simulated conditions. The results showed that growth of the root system largely depended on the environment conditions around S. alterniflora. Higher nitrogen concentration promoted aboveground biomass and increased plant height. On the other hand, as the increase of growth period, higher nitrogen concentration could inhibit the elongation growth of root and reduce the underground biomass. We showed that activity of POD, SOD and MDA content changed in an upward trend along with the increased nitrogen level. There was a significant positive correlation between H+ flux and NO3- flux (r = 0.601, P < 0.01), and a significant negative correlation between H+ flux and NH4+ flux (r = -0.713, P < 0.01) within 1.5 mm from the root tip of S. alterniflora. Efflux and influx of ions were associated with changes of nitrogen levels. This research will provide data supporting for coastal wetland restoration of biodiversity reduction caused by coastal eutrophication.

  9. Changes in the physiological activity of soybean (Glycine max L. Merr. under the influence of exogenous growth regulators

    Directory of Open Access Journals (Sweden)

    Anna Nowak

    2015-07-01

    Full Text Available In a two-year pot experiment (2008–2009 conducted at the Vegetation Hall, West Pomeranian University of Technology in Szczecin, we investigated the influence of exogenous growth regulators, i.e. indole-3-butyric acid (IBA and 6-benzylaminopurine (BAP and their mixture, on the activity of gas exchange and selected physiological features of soybeans (Glycine max L. Merr.. The experimental factors included the following Polish soybean cultivars: ‘Aldana’, ‘Progres’ and ‘Jutro’. During plant growth, CO2 assimilation (A, transpiration rate (E, stomatal conductance (gs, and substomatal CO2 concentration (ci were determined. Two soybean cultivars, i.e. ‘Jutro’ and ‘Progres’, showed a significant increase in the intensity of assimilation and transpiration after using all kinds of growth regulators as compared with the control plants. It was found that the ‘Jutro’ cultivar, after using a mixture of growth regulators (IBA + BAP, was characterized by the significantly highest CO2 assimilation (A and transpiration (E as well as the highest stomatal conductance (gs. The ‘Aldana’ cultivar, on the other hand, responded by a significant reduction in the transpiration rate, stomatal conductance and subsomatal CO2 concentration. The spraying of the plants with exogenous growth regulators had a significant influence on the increase in the number of stomata and stomatal pore length, mostly on the lower epidermis of the lamina. It was also found that plants from the ‘Jutro’ and ‘Aldana’ cultivars sprayed with IBA and IBA + BAP were characterized by the highest yield, as compared with the control plants. In the case of the ‘Jutro’ cultivar, after using the growth regulators, a positive correlation was observed between the assimilation and transpiration rates and the length of stomata, which in consequence produced increased yields.

  10. Associative bacteria influence maize (Zea mays L.) growth, physiology and root anatomy under different nitrogen levels.

    Science.gov (United States)

    Calzavara, Anderson Kikuchi; Paiva, Pedro Henrique Godoy; Gabriel, Lorrant Cavanha; de Oliveira, André Luiz Martinez; Milani, Karina; Oliveira, Halley Caixeta; Bianchini, Edmilson; Pimenta, José Antonio; de Oliveira, Maria Cristina Neves; Dias-Pereira, Jaqueline; Stolf-Moreira, Renata

    2018-05-15

    Despite the great diversity of plant growth-promoting bacteria (PGPB) with potential to partially replace the use of N-fertilizers in agriculture, few PGPB are explored for the production of commercial inoculants, reinforcing the importance of identifying positive plant-bacteria interactions. Aiming to better understand the influence of PGPB inoculation in plant development, two PGPB species with distant phylogenetic relationship were inoculated in maize. Maize seeds were inoculated with Bacillus sp. or Azospirillum brasilense. After germinating, the plants were subjected to two nitrogen treatments: full (N+) and limiting (N-) nitrogen supply. Then, anatomical, biometric and physiological analyses were performed. Both PGPB species modified the anatomical pattern of roots, as verified by the higher metaxylem vessel elements (MVE) number. Bacillus sp. also increased the MVE area in maize roots. Under N+ condition, both PGPB decreased the leaf protein content and led to the development of shorter roots; however, Bacillus sp. increased root and shoot dry weight, whereas A. brasilense increased photosynthesis rate and leaf nitrate content. In plants subjected to N limitation (N-), photosynthesis rate and photosystem II efficiency increased in those inoculated with Bacillus sp., whilst A. brasilense led to higher ammonium, amino acids and total soluble sugars contents in the leaves, compared to control. Plant developmental and metabolical patterns were switched by the inoculation, regardless the inoculant bacteria used, producing similar as well as distinct modifications on the parameters studied. These results indicatie that even non-diazotrophic inoculant strains can improve the plant N-status as result of the morpho-anatomical and physiological modifications produced by the PGPB. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  11. A Brief History of Bacterial Growth Physiology

    Directory of Open Access Journals (Sweden)

    Moselio eSchaechter

    2015-04-01

    Full Text Available Arguably, microbial physiology started when Leeuwenhoek became fascinated by observing a Vorticella beating its cilia, my point being that almost any observation of microbes has a physiological component. With the advent of modern microbiology in the mid 19th century, the field became recognizably distinctive with such discoveries as anaerobiosis, fermentation as a biological phenomenon, and the nutritional requirements of microbes. Soon came the discoveries of Winogradsky and his followers of the chemical changes in the environment that result from microbial activities. Later, during the first half of the 20th century, microbial physiology became the basis for much of the elucidation of central metabolism.Bacterial physiology then became a handmaiden of molecular biology and was greatly influenced by the discovery of cellular regulatory mechanisms. Microbial growth, which had come of age with the early work of Hershey, Monod, and others, was later pursued by studies on a whole cell level by what became known as the Copenhagen School. During this time, the exploration of physiological activities became coupled to modern inquiries into the structure of the bacterial cell.Recent years have seen the development of a further phase in microbial physiology, one seeking a deeper quantitative understanding of phenomena on a whole cell level. This pursuit is exemplified by the emergence of systems biology, which is made possible by the development of technologies that permit the gathering of information in huge amounts. As has been true through history, the research into microbial physiology continues to be guided by the development of new methods of analysis. Some of these developments may well afford the possibility of making stunning breakthroughs.

  12. Plant Growth-Promoting Rhizobacteria Stimulate Vegetative Growth and Asexual Reproduction of Kalanchoe daigremontiana.

    Science.gov (United States)

    Park, Yong-Soon; Park, Kyungseok; Kloepper, Joseph W; Ryu, Choong-Min

    2015-09-01

    Certain bacterial species associate with plant roots in soil. The plant growth-promoting rhizobacteria (PGPR) stimulate plant growth and yield in greenhouse and field. Here, we examined whether application of known bacilli PGPR strains stimulated growth and asexual reproduction in the succulent plant Kalanchoe daigremontiana. Four PGPR strains B. amyloliquefaciens IN937a, B. cereus BS107, B. pumilus INR7, and B. subtilis GB03 were applied to young plantlets by soil-drenching, and plant growth and development was monitored for three months. Aerial growth was significantly stimulated in PGPR-inoculated plants, which was observed as increases in plant height, shoot weight, and stem width. The stimulated growth influenced plant development by increasing the total number of leaves per plant. Treatment with bacilli also increased the total root biomass compared with that of control plants, and led to a 2-fold increase in asexual reproduction and plantlet formation on the leaf. Collectively, our results firstly demonstrate that Bacillus spp. promote vegetative development of K. daigremontiana, and the enhanced growth stimulates asexual reproduction and plantlet formation.

  13. Plant Growth-Promoting Rhizobacteria Stimulate Vegetative Growth and Asexual Reproduction of Kalanchoe daigremontiana

    Directory of Open Access Journals (Sweden)

    Yong-Soon Park

    2015-09-01

    Full Text Available Certain bacterial species associate with plant roots in soil. The plant growth-promoting rhizobacteria (PGPR stimulate plant growth and yield in greenhouse and field. Here, we examined whether application of known bacilli PGPR strains stimulated growth and asexual reproduction in the succulent plant Kalanchoe daigremontiana. Four PGPR strains B. amyloliquefaciens IN937a, B. cereus BS107, B. pumilus INR7, and B. subtilis GB03 were applied to young plantlets by soil-drenching, and plant growth and development was monitored for three months. Aerial growth was significantly stimulated in PGPR-inoculated plants, which was observed as increases in plant height, shoot weight, and stem width. The stimulated growth influenced plant development by increasing the total number of leaves per plant. Treatment with bacilli also increased the total root biomass compared with that of control plants, and led to a 2-fold increase in asexual reproduction and plantlet formation on the leaf. Collectively, our results firstly demonstrate that Bacillus spp. promote vegetative development of K. daigremontiana, and the enhanced growth stimulates asexual reproduction and plantlet formation.

  14. Plant Growth Promoting Rhizobacteria in Amelioration of Salinity Stress: A Systems Biology Perspective

    Directory of Open Access Journals (Sweden)

    Gayathri Ilangumaran

    2017-10-01

    Full Text Available Salinity affects plant growth and is a major abiotic stress that limits crop productivity. It is well-understood that environmental adaptations and genetic traits regulate salinity tolerance in plants, but imparting the knowledge gained towards crop improvement remain arduous. Harnessing the potential of beneficial microorganisms present in the rhizosphere is an alternative strategy for improving plant stress tolerance. This review intends to elucidate the understanding of salinity tolerance mechanisms attributed by plant growth promoting rhizobacteria (PGPR. Recent advances in molecular studies have yielded insights into the signaling networks of plant–microbe interactions that contribute to salt tolerance. The beneficial effects of PGPR involve boosting key physiological processes, including water and nutrient uptake, photosynthesis, and source-sink relationships that promote growth and development. The regulation of osmotic balance and ion homeostasis by PGPR are conducted through modulation of phytohormone status, gene expression, protein function, and metabolite synthesis in plants. As a result, improved antioxidant activity, osmolyte accumulation, proton transport machinery, salt compartmentalization, and nutrient status reduce osmotic stress and ion toxicity. Furthermore, in addition to indole-3-acetic acid and 1-aminocyclopropane-1-carboxylic acid deaminase biosynthesis, other extracellular secretions of the rhizobacteria function as signaling molecules and elicit stress responsive pathways. Application of PGPR inoculants is a promising measure to combat salinity in agricultural fields, thereby increasing global food production.

  15. Martian Soil Plant Growth Experiment: The Effects of Adding Nitrogen, Bacteria, and Fungi to Enhance Plant Growth

    Science.gov (United States)

    Kliman, D. M.; Cooper, J. B.; Anderson, R. C.

    2000-01-01

    Plant growth is enhanced by the presence of symbiotic soil microbes. In order to better understand how plants might prosper on Mars, we set up an experiment to test whether symbiotic microbes function to enhance plant growth in a Martian soil simulant.

  16. Host Plant Physiology and Mycorrhizal Functioning Shift across a Glacial through Future [CO2] Gradient1[OPEN

    Science.gov (United States)

    Mullinix, George W.R.; Ward, Joy K.

    2016-01-01

    Rising atmospheric carbon dioxide concentration ([CO2]) may modulate the functioning of mycorrhizal associations by altering the relative degree of nutrient and carbohydrate limitations in plants. To test this, we grew Taraxacum ceratophorum and Taraxacum officinale (native and exotic dandelions) with and without mycorrhizal fungi across a broad [CO2] gradient (180–1,000 µL L−1). Differential plant growth rates and vegetative plasticity were hypothesized to drive species-specific responses to [CO2] and arbuscular mycorrhizal fungi. To evaluate [CO2] effects on mycorrhizal functioning, we calculated response ratios based on the relative biomass of mycorrhizal (MBio) and nonmycorrhizal (NMBio) plants (RBio = [MBio − NMBio]/NMBio). We then assessed linkages between RBio and host physiology, fungal growth, and biomass allocation using structural equation modeling. For T. officinale, RBio increased with rising [CO2], shifting from negative to positive values at 700 µL L−1. [CO2] and mycorrhizal effects on photosynthesis and leaf growth rates drove shifts in RBio in this species. For T. ceratophorum, RBio increased from 180 to 390 µL L−1 and further increases in [CO2] caused RBio to shift from positive to negative values. [CO2] and fungal effects on plant growth and carbon sink strength were correlated with shifts in RBio in this species. Overall, we show that rising [CO2] significantly altered the functioning of mycorrhizal associations. These symbioses became more beneficial with rising [CO2], but nonlinear effects may limit plant responses to mycorrhizal fungi under future [CO2]. The magnitude and mechanisms driving mycorrhizal-CO2 responses reflected species-specific differences in growth rate and vegetative plasticity, indicating that these traits may provide a framework for predicting mycorrhizal responses to global change. PMID:27573369

  17. Comparative effects of cobalt, nickel and copper on plant growth

    Energy Technology Data Exchange (ETDEWEB)

    Brenchley, W E

    1938-11-01

    An account is given of the present position of our knowledge with regard to the distribution and the physiological importance of nickel and cobalt, in relation to plants and animals. Experiments on barley and broad beans were carried out in water cultures with the sulfates and chlorides of cobalt, nickel and copper. In every case a range of low concentrations did little or no damage, but toxic action occurred abruptly above a concentration which varied with the species and with the compound. With barley, copper was the most poisonous element in either compound, but the differences were not striking. Low concentrations of the sulfate were innocuous, but parallel low strengths of the chloride caused a slight, significant depression in growth. With broad beans, cobalt was much more poisonous than either nickel or copper, particularly with the sulfate. No slight depression with low concentrations of the chloride was noticeable with this species. The morphological response to toxicity varied with the element concerned. Copper, in poisonous strengths, caused shortening and bunching of barley roots, whereas nickel and cobalt permitted the growth of elongated roots of a very attenuated nature. The individuality of plant response to poison was frequently shown by the great variation in growth in the borderline concentrations just below those which caused marked depression of growth.

  18. Abscinazole-F1, a conformationally restricted analogue of the plant growth retardant uniconazole and an inhibitor of ABA 8'-hydroxylase CYP707A with no growth-retardant effect.

    Science.gov (United States)

    Todoroki, Yasushi; Kobayashi, Kyotaro; Shirakura, Minaho; Aoyama, Hikaru; Takatori, Kokichi; Nimitkeatkai, Hataitip; Jin, Mei-Hong; Hiramatsu, Saori; Ueno, Kotomi; Kondo, Satoru; Mizutani, Masaharu; Hirai, Nobuhiro

    2009-09-15

    To develop a specific inhibitor of abscisic acid (ABA) 8'-hydroxylase, a key enzyme in the catabolism of ABA, a plant hormone involved in stress tolerance, seed dormancy, and other various physiological events, we designed and synthesized conformationally restricted analogues of uniconazole (UNI), a well-known plant growth retardant, which inhibits a biosynthetic enzyme (ent-kaurene oxidase) of gibberellin as well as ABA 8'-hydroxylase. Although most of these analogues were less effective than UNI in inhibition of ABA 8'-hydroxylase and rice seedling growth, we found that a lactol-bridged analogue with an imidazole is a potent inhibitor of ABA 8'-hydroxylase but not of plant growth. This compound, abscinazole-F1, induced drought tolerance in apple seedlings upon spray treatment with a 10 microM solution.

  19. Effect of Planting Date and Biological and Chemical Fertilizers on Phenology and Physiological Indices of Peanuts

    Directory of Open Access Journals (Sweden)

    A Sepehri

    2017-06-01

    Full Text Available Introduction Peanut (Arachis hypogaea L. is an annual herbaceous plant in Fabaceae which grown in tropical to temperate regions worldwide for extracting its seed oil and nut consumption. Select the optimum planting date is one of the most important agricultural techniques that comply with the seed yield is maximized . For instance, delay planting date can reduce the number of fertile nodes and the number of pods per plant. The delay in planting date reduces total dry matter (TDM, leaf area index (LAI, crop growth rate (CGR and yield in bean (Phaseolus vulgaris L.. Daneshian et al., (2008 reported that the delay in planting date reduced sunflower (Helianthus annuus yield due to high temperatures in early growth which shortened flowering time and reduced solar radiation. On the other hand, due to increase importance of environmental issues has been attending biofertilizers to replace chemical fertilizers. Biofertilizers has formed by beneficial bacteria and fungi that each of them are produced for a specific purpose, such as nitrogen fixation, release of phosphate, potassium and iron ions of insoluble compound. The use of nitrogen fertilizer with slow-releasing ability stimulated shoot growth in soybean (Glycine max and be created more LAI in the reproductive process, particularly during grain filling stage and finally increased seed yield . Therefore, this study was conducted in order to evaluate the interaction of biological and chemical fertilizers in the purpose of achieving sustainable agriculture with emphasis of the effects of various planting dates on physiological parameters and growth of peanut in Hamadan. Materials and Methods In order to investigate the effects of planting date on important physiological indices of peanuts (Arachis hypogaea L. under the influence of biological and chemical fertilizers. A field experiment was conducted in the research farm of Bu-Ali Sina University, Hamedan during 2013 growing season. This study was

  20. Growth and physiological responses of maize (Zea mays L.) to porous silica nanoparticles in soil

    Energy Technology Data Exchange (ETDEWEB)

    Suriyaprabha, R.; Karunakaran, G.; Yuvakkumar, R.; Prabu, P.; Rajendran, V., E-mail: veerajendran@gmail.com [K. S. Rangasamy College of Technology, Centre for Nano Science and Technology (India); Kannan, N. [K. S. Rangasamy College of Arts and Science, Department of Biotechnology (India)

    2012-12-15

    The present study aims to explore the effect of high surface area (360.85 m{sup 2} g{sup -1}) silica nanoparticles (SNPs) (20-40 nm) extracted from rice husk on the physiological and anatomical changes during maize growth in sandy loam soil at four concentrations (5-20 kg ha{sup -1}) in comparison with bulk silica (15-20 kg ha{sup -1}). The plant responses to nano and bulk silica treatments were analyzed in terms of growth characteristics, phyto compounds such as total protein, chlorophyll, and other organic compounds (gas chromatography-mass spectroscopy), and silica accumulation (high-resolution scanning electron microscopy). Growth characteristics were much influenced with increasing concentration of SNPs up to 15 kg ha{sup -1} whereas at 20 kg ha{sup -1}, no significant increments were noticed. Silica accumulation in leaves was high at 10 and 15 kg ha{sup -1} (0.57 and 0.82 %) concentrations of SNPs. The observed physiological changes show that the expression of organic compounds such as proteins, chlorophyll, and phenols favored to maize treated with nanosilica especially at 15 kg ha{sup -1} compared with bulk silica and control. Nanoscale silica regimes at 15 kg ha{sup -1} has a positive response of maize than bulk silica which help to improve the sustainable farming of maize crop as an alternative source of silica fertilizer.

  1. Comparative Methods of Application of Wild Plant Parts on Growth and in the Control of Root Rot Fungi of Leguminous Crops

    International Nuclear Information System (INIS)

    Ikram, N.; Dawae, S.

    2016-01-01

    Present research work was carried out for the management of root rot fungi with wild plant part capsules and pellets formulation in soil. When application of pellets and capsules was carried out with Prosopis juliflora stem, leaves and flowers showed significant reduction in disease incidence and enhancement in growth and physiological parameters. Colonization of Fusarium spp., Macrophomina phaseolina and Rhizoctonia solani was completely suppressed when P. juliflora leaves pellets incorporated in soil. Physiological parameters such as chlorophyll a and b and protein were significantly increased when leaves pellets incorporated in soil at the rate of 1 percent w/w so P. juliflora leaves pellets were most effective in the control of root rot fungi and enhanced the growth of crop plants. (author)

  2. Plant growth inhibitors isolated from sugarcane (Saccharum officinarum) straw.

    Science.gov (United States)

    Sampietro, Diego Alejandro; Vattuone, Marta Amelia; Isla, María Ines

    2006-07-01

    Several compounds related with plant defense and pharmacological activities have been isolated from sugarcane. Straw phytotoxins and their possible mechanisms of growth inhibition are largely unknown. A bioassay-guided fractionation of the phytotoxic constituents leachated from a sugarcane straw led to the isolation of trans-ferulic (trans-FA), cis-ferulic (cis-FA), vanillic (VA) and syringic (SA) acids. The straw leachates and their identified constituents significantly inhibited root growth of lettuce and four weeds. VA was more phytotoxic to root elongation than FA and SA. The identified phenolic compounds significantly increased leakage of root cell constituents, inhibited dehydrogenase activity and reduced chlorophyll content in lettuce. VA and FA inhibited mitotic index while SA increased cell division. Additive (VA-FA and FA-SA) and synergistic (VA-SA) interactions on root growth were observed at the response level of EC(25). Although the isolated compounds differed in their relative phytotoxic activities, the observed physiological responses suggest that they have a common mode of action. HPLC analysis indicated that sugarcane straw can potentially release 1.43 (ratio 2:1, trans:cis), 1.14 and 0.14mmolkg(-1) (straw dry weight) of FA, VA and SA, respectively. As phenolic acids are often found spatially concentrated in the top soil layers under plant straws, further studies are needed to establish the impact of these compounds in natural settings.

  3. Effect of methyl salicylate (MeSA), an elicitor on growth, physiology and pathology of resistant and susceptible rice varieties.

    Science.gov (United States)

    Kalaivani, Kandaswamy; Kalaiselvi, Marimuthu Maruthi; Senthil-Nathan, Sengottayan

    2016-10-11

    Methyl salicylate (MeSA) is a volatile organic compound synthesized from salicylic acid (SA) a plant hormone that helps to fight against plant disease. Seed treatment with MeSA, is an encouraging method to the seed industry to produce more growth and yield. The aim of our study is to find out the growth, development and disease tolerance of rice seed treated with different concentrations of MeSA. Also the seed treatments were studied to determine whether they directly influenced seedling emergence and growth in rice (Oryza sativa L) cultivars 'IR 20, IR 50, IR 64, ASD 16, ASD 19 and ADT 46' under greenhouse condition. MeSA seed treatments at 25, 50, 75 and 100 mg/L significantly increased seedling emergence. Effects were stronger in IR 50, and IR 64 and the effects were dose dependent, although the relationship between dose and effect was not always linear. MeSA seed treated rice plant against bacterial blight were analyzed. Bacterial blight was more effectively controlled by the seed treated with 100 mg/L than others. These results suggest that seed treatment with MeSA alters plant physiology in ways that may be useful for crop production as well as protection.

  4. PHYSIOLOGICAL RESPONSES OF DWARF COCONUT PLANTS UNDER WATER DEFICIT IN SALT - AFFECTED SOILS

    Directory of Open Access Journals (Sweden)

    ALEXANDRE REUBER ALMEIDA DA SILVA

    2017-01-01

    Full Text Available The objective of this study was to characterize the physiological acclimation responses of young plants of the dwarf coconut cultivar ̳Jiqui Green‘ associated with tolerance to conditions of multiple abiotic stresses (drought and soil salinity, acting either independently or in combination. The study was conducted under controlled conditions and evaluated the following parameters: leaf gas exchange, quantum yield of chlorophyll a fluorescence, and relative contents of total chlorophyll (SPAD index. The experiment was conducted under a randomized block experimental design, in a split plot arrangement. In the plots, plants were exposed to different levels of water stress, by imposing potential crop evapotranspiration replacement levels equivalent to 100%, 80%, 60%, 40%, and 20%, whereas in subplots, plants were exposed to different levels of soil salinity (1.72, 6.25, 25.80, and 40.70 dS m - 1 . Physiological mechanisms were effectively limited when water deficit and salinity acted separately and/or together. Compared with soil salinity, water stress was more effective in reducing the measured physiological parameters. The magnitudes of the responses of plants to water supply and salinity depended on the intensity of stress and evaluation period. The physiological acclimation responses of plants were mainly related to stomatal regulation. The coconut tree has a number of physiological adjustment mechanisms that give the species partial tolerance to drought stress and/or salt, thereby enabling it to revegetate salinated areas, provided that its water requirements are at least partially met.

  5. Research Progress on the use of Plant Allelopathy in Agriculture and the Physiological and Ecological Mechanisms of Allelopathy.

    Science.gov (United States)

    Cheng, Fang; Cheng, Zhihui

    2015-01-01

    Allelopathy is a common biological phenomenon by which one organism produces biochemicals that influence the growth, survival, development, and reproduction of other organisms. These biochemicals are known as allelochemicals and have beneficial or detrimental effects on target organisms. Plant allelopathy is one of the modes of interaction between receptor and donor plants and may exert either positive effects (e.g., for agricultural management, such as weed control, crop protection, or crop re-establishment) or negative effects (e.g., autotoxicity, soil sickness, or biological invasion). To ensure sustainable agricultural development, it is important to exploit cultivation systems that take advantage of the stimulatory/inhibitory influence of allelopathic plants to regulate plant growth and development and to avoid allelopathic autotoxicity. Allelochemicals can potentially be used as growth regulators, herbicides, insecticides, and antimicrobial crop protection products. Here, we reviewed the plant allelopathy management practices applied in agriculture and the underlying allelopathic mechanisms described in the literature. The major points addressed are as follows: (1) Description of management practices related to allelopathy and allelochemicals in agriculture. (2) Discussion of the progress regarding the mode of action of allelochemicals and the physiological mechanisms of allelopathy, consisting of the influence on cell micro- and ultra-structure, cell division and elongation, membrane permeability, oxidative and antioxidant systems, growth regulation systems, respiration, enzyme synthesis and metabolism, photosynthesis, mineral ion uptake, protein and nucleic acid synthesis. (3) Evaluation of the effect of ecological mechanisms exerted by allelopathy on microorganisms and the ecological environment. (4) Discussion of existing problems and proposal for future research directions in this field to provide a useful reference for future studies on plant

  6. Research progress on the use of plant allelopathy in agriculture and the physiological and ecological mechanisms of allelopathy

    Directory of Open Access Journals (Sweden)

    Fang eCheng

    2015-11-01

    Full Text Available Allelopathy is a common biological phenomenon by which one organism produces biochemicals that influence the growth, survival, development, and reproduction of other organisms. These biochemicals are known as allelochemicals and have beneficial or detrimental effects on target organisms. Plant allelopathy is one of the modes of interaction between receptor and donor plants and may exert either positive effects (e.g., for agricultural management, such as weed control, crop protection, or crop re-establishment or negative effects (e.g., autotoxicity, soil sickness, or biological invasion. To ensure sustainable agricultural development, it is important to exploit cultivation systems that take advantage of the stimulatory / inhibitory influence of allelopathic plants to regulate plant growth and development and to avoid allelopathic autotoxicity. Allelochemicals can potentially be used as growth regulators, herbicides, insecticides and antimicrobial crop protection products. Here, we reviewed the plant allelopathy management practices applied in agriculture and the underlying allelopathic mechanisms described in the literature. The major points addressed are as follows: (1 Description of management practices related to allelopathy and allelochemicals in agriculture. (2 Discussion of the progress regarding the mode of action of allelochemicals and the physiological mechanisms of allelopathy, consisting of the influence on cell micro- and ultra-structure, cell division and elongation, membrane permeability, oxidative and antioxidant systems, growth regulation systems, respiration, enzyme synthesis and metabolism, photosynthesis, mineral ion uptake, protein and nucleic acid synthesis. (3 Evaluation of the effect of ecological mechanisms exerted by allelopathy on microorganisms and the ecological environment. (4 Discussion of existing problems and proposal for future research directions in this field to provide a useful reference for future studies on

  7. Was dinosaurian physiology inherited by birds? Reconciling slow growth in archaeopteryx.

    Directory of Open Access Journals (Sweden)

    Gregory M Erickson

    2009-10-01

    Full Text Available Archaeopteryx is the oldest and most primitive known bird (Avialae. It is believed that the growth and energetic physiology of basalmost birds such as Archaeopteryx were inherited in their entirety from non-avialan dinosaurs. This hypothesis predicts that the long bones in these birds formed using rapidly growing, well-vascularized woven tissue typical of non-avialan dinosaurs.We report that Archaeopteryx long bones are composed of nearly avascular parallel-fibered bone. This is among the slowest growing osseous tissues and is common in ectothermic reptiles. These findings dispute the hypothesis that non-avialan dinosaur growth and physiology were inherited in totality by the first birds. Examining these findings in a phylogenetic context required intensive sampling of outgroup dinosaurs and basalmost birds. Our results demonstrate the presence of a scale-dependent maniraptoran histological continuum that Archaeopteryx and other basalmost birds follow. Growth analysis for Archaeopteryx suggests that these animals showed exponential growth rates like non-avialan dinosaurs, three times slower than living precocial birds, but still within the lowermost range for all endothermic vertebrates.The unexpected histology of Archaeopteryx and other basalmost birds is actually consistent with retention of the phylogenetically earlier paravian dinosaur condition when size is considered. The first birds were simply feathered dinosaurs with respect to growth and energetic physiology. The evolution of the novel pattern in modern forms occurred later in the group's history.

  8. Chemical Control of Plant Growth.

    Science.gov (United States)

    Agricultural Research Center (USDA), Beltsville, MD.

    Seven experiments are presented in this Science Study Aid to help students investigate the control of plant growth with chemicals. Plant growth regulators, weed control, and chemical pruning are the topics studied in the experiments which are based on investigations that have been and are being conducted at the U. S. Agricultural Research Center,…

  9. Sex-related differences in stress tolerance in dioecious plants: a critical appraisal in a physiological context.

    Science.gov (United States)

    Juvany, Marta; Munné-Bosch, Sergi

    2015-10-01

    Sex-related differences in reproductive effort can lead to differences in vegetative growth and stress tolerance. However, do all dioecious plants show sex-related differences in stress tolerance? To what extent can the environmental context and modularity mask sex-related differences in stress tolerance? Finally, to what extent can physiological measurements help us understand secondary sexual dimorphism? This opinion paper aims to answer these three basic questions with special emphasis on developments in research in this area over the last decade. Compelling evidence indicates that dimorphic species do not always show differences in stress tolerance between sexes; and when sex-related differences do occur, they seem to be highly species-specific, with greater stress tolerance in females than males in some species, and the opposite in others. The causes of such sex-related species-specific differences are still poorly understood, and more physiological studies and diversity of plant species that allow comparative analyses are needed. Furthermore, studies performed thus far demonstrate that the expression of dioecy can lead to sex-related differences in physiological traits-from leaf gas exchange to gene expression-but the biological significance of modularity and sectoriality governing such differences has been poorly investigated. Future studies that consider the importance of modularity and sectoriality are essential for unravelling the mechanisms underlying stress adaptation in male and female plants growing in their natural habitat. © The Author 2015. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  10. PLANT-MICROBIAL INTERACTIONS IN THE RHIZOSPHERE – STRATEGIES FOR PLANT GROWTH-PROMOTION

    Directory of Open Access Journals (Sweden)

    Marius Stefan

    2012-03-01

    Full Text Available Plant growth-promoting rhizobacteria (PGPR are a group of bacteria that can actively colonize plant rootsand enhance plant growth using different mechanisms: production of plant growth regulators like indoleacetic acid,gibberellic acid, cytokinins and ethylene(Zahir et al., 2003, providing the host plant with fixed nitrogen, solubilizationof soil phosphorus, enhance Fe uptake, biocontrol, reducing the concentration of heavy metals. PGPR are perfectcandidates to be used as biofertilizers – eco-friendly alternative to common applied chemical fertilizer in today’sagriculture. The most important benefit of PGPR usage is related to the reduction of environmental pollution in conditionof increasing crop yield. This review presents the main mechanisms involved in PGPR promotion of plant growth.

  11. Physiological response of lovage (levisticum officinale, koch) plant to gamma radiation and organic fertilizers

    International Nuclear Information System (INIS)

    Taha, A.T.A.

    2009-01-01

    The main objective of this work is to study physiological response of lovage plant to gamma radiation and organic fertilizers.Two field experiments were conduct under conditions of newly reclaimed soil (sandy loam soil) during two successive seasons (2003/2004 and 2004/2005) in experimental farm , NRC,AEA Inshas. lovage fruits were irradiated before sowing with gamma rays at 0,20,40,60 and 80 Gy. Before planting farm yard manure (FYM) at rates of 0,20,30 and 40 m 3 /fed. Was applied to soil in combination with gamma doses in the first experiment, in the second one, chicken manure at 0,10,15 and 20 m 3 /fed. was added to soil before planting in combination with the same used gamma doses in first experiment. Growth of lovage plants was considerably stimulated by irradiating fruits before sowing with low gamma doses, in particularly at 60 Gy, which greatly increased plant height, number of branches/plant, stem thickness and dry matter yield of shoots. Similar trend was also observed with leaf chlorophyll content which increased due to low gamma doses . Low gamma doses markedly encouraged nutrients uptake by lovage plants which increased levels and total contents of N, P, K, Fe,Zn and Mn in plant shoots. Fruits yield, volatile oil % and oil yield and fruits index value were increased by low gamma doses particularly at 60 Gy.

  12. Plant-pathogen interactions: leaf physiology alterations in poplars infected with rust (Melampsora medusae).

    Science.gov (United States)

    Gortari, Fermín; Guiamet, Juan José; Graciano, Corina

    2018-01-23

    Rust produced by Melampsora sp. is considered one of the most relevant diseases in poplar plantations. Growth reduction in poplar plantations takes place because rust, like other pathogens, alters leaf physiology. There is not a complete evaluation of several of the physiological traits that can be affected by rust at leaf level. Therefore, the aim of this work was to evaluate, in an integrative way and in the same pathosystem, which physiological processes are affected when Populus deltoides Bartr. ex Marsh. leaves are infected by rust (Melampsora medusae Thümen). Leaves of two clones with different susceptibility to rust were analyzed. Field and pot experiments were performed, and several physiological traits were measured in healthy and infected leaves. We conclude that rust affects leaf mesophyll integrity, and so water movement in the leaf in liquid phase is affected. As a consequence, gas exchange is reduced, affecting both carbon fixation and transpiration. However, there is an increase in respiration rate, probably due to plant and fungal respiration. The increase in respiration rate is important in the reduction of net photosynthetic rate, but also some damage in the photosynthetic apparatus limits leaf capacity to fix carbon. The decrease in chlorophyll content would start later and seems not to explain the reduction in net photosynthetic rate. Both clones, although they have different susceptibility to rust, are affected in the same physiological mechanisms. © The Author(s) 2018. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  13. Identification of drought-responsive miRNAs and physiological characterization of tea plant (Camellia sinensis L.) under drought stress.

    Science.gov (United States)

    Guo, Yuqiong; Zhao, Shanshan; Zhu, Chen; Chang, Xiaojun; Yue, Chuan; Wang, Zhong; Lin, Yuling; Lai, Zhongxiong

    2017-11-21

    Drought stress is one of the major natural challenges in the main tea-producing regions of China. The tea plant (Camellia sinensis) is a traditional beverage plant whose growth status directly affects tea quality. Recent studies have revealed that microRNAs (miRNAs) play key functions in plant growth and development. Although some miRNAs have been identified in C. sinensis, little is known about their roles in the drought stress response of tea plants. Physiological characterization of Camellia sinensis 'Tieguanyin' under drought stress showed that the malondialdehyde concentration and electrical conductivity of leaves of drought-stressed plants increased when the chlorophyll concentration decreased under severe drought stress. We sequenced four small-RNA (sRNA) libraries constructed from leaves of plants subjected to four different treatments, normal water supply (CK); mild drought stress (T1); moderate drought stress (T2) and severe drought stress (T3). A total of 299 known mature miRNA sequences and 46 novel miRNAs were identified. Gene Ontology enrichment analysis revealed that most of the differentially expressed-miRNA target genes were related to regulation of transcription. Kyoto Encyclopedia of Genes and Genomes analysis revealed that the most highly enriched pathways under drought stress were D-alanine metabolism, sulfur metabolism, and mineral absorption pathways. Real-time quantitative PCR (qPCR) was used to validate the expression patterns of 21 miRNAs (2 up-regulated and 19 down-regulated under drought stress). The observed co-regulation of the miR166 family and their targets ATHB-14-like and ATHB-15-like indicate the presence of negative feedback regulation in miRNA pathways. Analyses of drought-responsive miRNAs in tea plants showed that most of differentially expressed-miRNA target genes were related to regulation of transcription. The results of study revealed that the expressions of phase-specific miRNAs vary with morphological, physiological, and

  14. Effects of elevated CO₂, warming and precipitation change on plant growth, photosynthesis and peroxidation in dominant species from North China grassland.

    Science.gov (United States)

    Xu, Zhenzhu; Shimizu, Hideyuki; Ito, Shoko; Yagasaki, Yasumi; Zou, Chunjing; Zhou, Guangsheng; Zheng, Yuanrun

    2014-02-01

    Warming, watering and elevated atmospheric CO₂-concentration effects have been extensively studied separately; however, their combined impact on plants is not well understood. In the current research, we examined plant growth and physiological responses of three dominant species from the Eurasian Steppe with different functional traits to a combination of elevated CO₂, high temperature, and four simulated precipitation patterns. Elevated CO₂ stimulated plant growth by 10.8-41.7 % for a C₃ leguminous shrub, Caragana microphylla, and by 33.2-52.3 % for a C₃ grass, Stipa grandis, across all temperature and watering treatments. Elevated CO₂, however, did not affect plant biomass of a C₄ grass, Cleistogenes squarrosa, under normal or increased precipitation, whereas a 20.0-69.7 % stimulation of growth occurred with elevated CO₂ under drought conditions. Plant growth was enhanced in the C₃ shrub and the C₄ grass by warming under normal precipitation, but declined drastically with severe drought. The effects of elevated CO₂ on leaf traits, biomass allocation and photosynthetic potential were remarkably species-dependent. Suppression of photosynthetic activity, and enhancement of cell peroxidation by a combination of warming and severe drought, were partly alleviated by elevated CO₂. The relationships between plant functional traits and physiological activities and their responses to climate change were discussed. The present results suggested that the response to CO₂ enrichment may strongly depend on the response of specific species under varying patterns of precipitation, with or without warming, highlighting that individual species and multifactor dependencies must be considered in a projection of terrestrial ecosystem response to climatic change.

  15. Plant Physiology: Out in the Midday Sun, Plants Keep Their Cool.

    Science.gov (United States)

    Ezer, Daphne; Wigge, Philip A

    2017-01-09

    Plants use context-dependent information to calibrate growth responses to temperature signals. A new study shows that plants modulate their sensitivity to temperature depending on whether or not they are in direct sunlight. This enables them to make adaptive decisions in a complex natural environment. Copyright © 2017. Published by Elsevier Ltd.

  16. Evaluation of the Effects of Biological and Chemical Fertilizers on Some Physiological and Growth Characteristics of Fenugreek (Trigonella foenum-graecum

    Directory of Open Access Journals (Sweden)

    Samira Menbari

    2017-12-01

    Full Text Available Nowadays, the use of soil-born microorganisms as biological fertilizers is considered to be a natural and most desirable solution to maintain sustainability of agricultural soil system. Potassium releasing bacteria, nitrogen fixing and phosphorus dissolving bacteria make mentioned elements available to plants. In order to evaluate the effects of bio-fertilizers Potabarvar 2, Sinorhizobium meliloti, as well as urea fertilizer on physiological properties and yield of Fenugreek, an experiment as complete randomized block design was conducted with five treatments and three replications. Treatments included biofertilizer Potabarvar 2, S. meliloti, inoculation with a mixture of Sinorhizobium+Potabarvar 2, positive control (based on soil analysis and negative control (no fertilization and inoculation.The results showed that all morphological traits were significant at 1%. Most physiological traits except for carotenoid were significantly affected by S. meliloti, and a mixture of Sinorhizobium+Potabarvar 2. Seed inoculation with biofertilizer Sinorhizobium meliloti and Potabarvar 2 lead to increase in growth and eventually shoot yield. Separate application of these biofertilizers led to better results than the integrated application. Symbiotic relationship of Sinorhizobium with Fenugreek increased physiological indices data, especially the absorption of nitrogen and phosphorus, as well as the amount of phenolic antioxidant have been significantly affected. In general, application of S. meliloti resulted in better and more effective increase in yield, quality and plant growth than fertilizer Potabarvar 2 and a mixture of Sinorhizobium+Potabarvar 2.

  17. Physiological factors influencing capillary growth.

    Science.gov (United States)

    Egginton, S

    2011-07-01

    (1) Angiogenesis (growth of new capillaries from an existing capillary bed) may result from a mismatch in microvascular supply and metabolic demand (metabolic error signal). Krogh examined the distribution and number of capillaries to explore the correlation between O(2) delivery and O(2) consumption. Subsequently, the heterogeneity in angiogenic response within a muscle has been shown to reflect either differences in fibre type composition or mechanical load. However, local control leads to targetted angiogenesis in the vicinity of glycolytic fibre types following muscle stimulation, or oxidative fibres following endurance training, while heterogeneity of capillary spacing is maintained during ontogenetic growth. (2) Despite limited microscopy resolution and lack of specific markers, Krogh's interest in the structure of the capillary wall paved the way for understanding the mechanisms of capillary growth. Angiogenesis may be influenced by the response of perivascular or stromal cells (fibroblasts, macrophages and pericytes) to altered activity, likely acting as a source for chemical signals modulating capillary growth such as vascular endothelial growth factor. In addition, haemodynamic factors such as shear stress and muscle stretch play a significant role in adaptive remodelling of the microcirculation. (3) Most indices of capillarity are highly dependent on fibre size, resulting in possible bias because of scaling. To examine the consequences of capillary distribution, it is therefore helpful to quantify the area of tissue supplied by individual capillaries. This allows the spatial limitations inherent in most models of tissue oxygenation to be overcome generating an alternative approach to Krogh's tissue cylinder, the capillary domain, to improve descriptions of intracellular oxygen diffusion. © 2010 The Author. Acta Physiologica © 2010 Scandinavian Physiological Society.

  18. Understanding the physiology of Lactobacillus plantarum at zero growth

    NARCIS (Netherlands)

    Goffin, P.; van de Bunt, B.; Giovane, M.; Leveau, J.H.J.; Höppener-Ogawa, S.; Teusink, B.; Hugenholtz, J.

    2010-01-01

    Situations of extremely low substrate availability, resulting in slow growth, are common in natural environments. To mimic these conditions, Lactobacillus plantarum was grown in a carbon-limited retentostat with complete biomass retention. The physiology of extremely slow-growing L. plantarum—as

  19. Elevated CO2, warmer temperatures and soil water deficit affect plant growth, physiology and water use of cotton (Gossypium hirsutum L.)

    Science.gov (United States)

    Changes in temperature, atmospheric [CO2] and precipitation under the scenarios of projected climate change present a challenge to crop production, and may have significant impacts on the physiology, growth and yield of cotton (Gossypium hirsutum L.). A glasshouse experiment explored the early growt...

  20. Was Dinosaurian Physiology Inherited by Birds? Reconciling Slow Growth in Archaeopteryx

    Science.gov (United States)

    Erickson, Gregory M.; Rauhut, Oliver W. M.; Zhou, Zhonghe; Turner, Alan H.; Inouye, Brian D.; Hu, Dongyu; Norell, Mark A.

    2009-01-01

    Background Archaeopteryx is the oldest and most primitive known bird (Avialae). It is believed that the growth and energetic physiology of basalmost birds such as Archaeopteryx were inherited in their entirety from non-avialan dinosaurs. This hypothesis predicts that the long bones in these birds formed using rapidly growing, well-vascularized woven tissue typical of non-avialan dinosaurs. Methodology/Principal Findings We report that Archaeopteryx long bones are composed of nearly avascular parallel-fibered bone. This is among the slowest growing osseous tissues and is common in ectothermic reptiles. These findings dispute the hypothesis that non-avialan dinosaur growth and physiology were inherited in totality by the first birds. Examining these findings in a phylogenetic context required intensive sampling of outgroup dinosaurs and basalmost birds. Our results demonstrate the presence of a scale-dependent maniraptoran histological continuum that Archaeopteryx and other basalmost birds follow. Growth analysis for Archaeopteryx suggests that these animals showed exponential growth rates like non-avialan dinosaurs, three times slower than living precocial birds, but still within the lowermost range for all endothermic vertebrates. Conclusions/Significance The unexpected histology of Archaeopteryx and other basalmost birds is actually consistent with retention of the phylogenetically earlier paravian dinosaur condition when size is considered. The first birds were simply feathered dinosaurs with respect to growth and energetic physiology. The evolution of the novel pattern in modern forms occurred later in the group's history. PMID:19816582

  1. Correlation between plant physiology and CO2 removable

    Science.gov (United States)

    Leman, A. M.; Shamsuri, Mohd Mahathir Suhaimi; Hariri, Azian; Kadir, Aeslina Abdul; Idris, Ahmad Fu'ad; Afandi, Azizi

    2017-09-01

    Certain plants that are able to live in the building are known as indoor plants. Plants have tolerance with indoor environment in order to survive. Usually these plants are able to improve indoor air quality (IAQ). Absorption of carbon dioxide (CO2) by plants is one of the indicators that plants are still alive during photosynthesis process. The possibility of plants structure (plant physiology) to affect CO2 absorption had been the concerns of former researchers. This research intends to study the significant of plant structure (leaf area, fresh weight, and dry weight) that leads to reducing the concentration of CO2 by seven plant species (Anthurium, Dumb Cane, Golden Pothos, Kadaka Fern, Prayer Plants, Spider Plants, and Syngonium). The data of CO2 reduction by plants has been obtained from previous studies. Based on results show that, the leaf area is the most contributing the significant effect to the plant absorb CO2 compare to fresh weight and dry weight. It can be prove by Pearson Correlation, where only the value of leaf area is more than 0.5 for every four conditions. This study can be conclude that the leaf area is quite plays an important role to the plant treat air from CO2, while concentration of light and CO2 will become catalytic factor for the plants improve their photosynthesis process.

  2. Nursery inoculation with the arbuscular mycorrhizal fungus Glomus viscosum and its effect on the growth and physiology of hybrid artichoke seedlings

    Directory of Open Access Journals (Sweden)

    Angela Campanelli

    2011-09-01

    Full Text Available Most nurseries operating in Italy adopt high technologies and produce transplants that well suit and satisfy the grower’s need to produce high value crops. Mycorrhizas are discussed as a tool for improving and developing plant production in the nursery. Much research has been carried out on mycorrhizal symbiosis and we now know more about the symbiontic relationship between fungi and host plants. Plants receive numerous benefits from this symbiosis which are more macroscopic the earlier in the ontogenetic cycle this symbiosis is established. Therefore, it appears that the most effective period in which the inoculum should be made corresponds to the in-nursery growing stage. The earlier the plant is inoculated, the more evident the effect will be. In this study, several aspects related to the physiological foundations of arbuscular mycorrhiza in artichoke plants are presented. The main goal was to study the effects of mycorrhiza on the growth and physiological parameters of three hybrids of artichokes growing in the nursery. The experimental 3¥2 design included two treatments (with or without arbuscular mycorrhizal fungi and three hybrids of artichokes marketed by Nunhems (Opal F1, Madrigal F1, Concerto F1. Mycorrhizal plants have greater shoot length, leaf area, shoot and root fresh and dry mass, and root density. This also corresponded with increased photosynthetic rates and stomatal conductance of mycorrhizal plants. Mycorrhizal colonization improves relative water content and increases proline concentration in vegetal tissue. Inoculation produced the most beneficial effect on hybrid Madrigal F1 and on hybrid Opal F1; the best mycorrhizal affinity was enhanced when compared to hybrid Concerto F1. The results showed that mycorrhizal symbiosis stimulated the growth of inoculated seedlings providing a qualitatively good propagation material.

  3. Nursery inoculation with the arbuscular mycorrhizal fungus Glomus viscosum and its effect on the growth and physiology of hybrid artichoke seedlings

    Directory of Open Access Journals (Sweden)

    Angela Campanelli

    2011-07-01

    Full Text Available Most nurseries operating in Italy adopt high technologies and produce transplants that well suit and satisfy the grower’s need to produce high value crops. Mycorrhizas are discussed as a tool for improving and developing plant production in the nursery. Much research has been carried out on mycorrhizal symbiosis and we now know more about the symbiontic relationship between fungi and host plants. Plants receive numerous benefits from this symbiosis which are more macroscopic the earlier in the ontogenetic cycle this symbiosis is established. Therefore, it appears that the most effective period in which the inoculum should be made corresponds to the in-nursery growing stage. The earlier the plant is inoculated, the more evident the effect will be. In this study, several aspects related to the physiological foundations of arbuscular mycorrhiza in artichoke plants are presented. The main goal was to study the effects of mycorrhiza on the growth and physiological parameters of three hybrids of artichokes growing in the nursery. The experimental 3¥2 design included two treatments (with or without arbuscular mycorrhizal fungi and three hybrids of artichokes marketed by Nunhems (Opal F1, Madrigal F1, Concerto F1. Mycorrhizal plants have greater shoot length, leaf area, shoot and root fresh and dry mass, and root density. This also corresponded with increased photosynthetic rates and stomatal conductance of mycorrhizal plants. Mycorrhizal colonization improves relative water content and increases proline concentration in vegetal tissue. Inoculation produced the most beneficial effect on hybrid Madrigal F1 and on hybrid Opal F1; the best mycorrhizal affinity was enhanced when compared to hybrid Concerto F1. The results showed that mycorrhizal symbiosis stimulated the growth of inoculated seedlings providing a qualitatively good propagation material.

  4. Effects of Three Fire-Suppressant Foams on the Germination and Physiological Responses of Plants

    Science.gov (United States)

    Song, Uhram; Mun, Saeromi; Waldman, Bruce; Lee, Eun Ju

    2014-10-01

    Suppressant foams used to fight forest fires may leave residual effects on surviving biota that managers need to consider prior to using them. We examined how three fire-suppressant foams (FSFs) (Forexpan S, Phos-Chek-WD881, and Silv-ex) affected seed germination and physiological responses of three plant species. Exposure to FSFs, whether in diluted concentrations or those typical in the field, reduced final germination percentages of seeds grown in petri dishes and within growth chambers. However, the FSFs did not cause total germination failure in any treatment. Inhibition of germination increased with longer exposure times, but only to diluted FSF solutions. Unlike in the laboratory experiments, none of the three FSFs affected seedling emergence when tested in field conditions. Further, we found no evidence of long-term phytotoxic effects on antioxidant enzyme activity nor chlorophyll content of the plant saplings. Therefore, although the three FSFs showed evidence of phytotoxicity to plants in laboratory tests, their actual impact on terrestrial ecosystems may be minimal. We suggest that the benefits of using these FSFs to protect plants in threatened forest ecosystems outweigh their minor risks.

  5. THE RESURRECTION PLANT TRIPOGON SPICATUS (POACEAE HARBORS A DIVERSITY OF PLANT GROWTH PROMOTING BACTERIA IN NORTHEASTERN BRAZILIAN CAATINGA

    Directory of Open Access Journals (Sweden)

    Paulo Ivan Fernandes-Júnior

    2015-08-01

    Full Text Available Plant species that naturally occur in the Brazilian Caatinga(xeric shrubland adapt in several ways to these harsh conditions, and that can be exploited to increase crop production. Among the strategic adaptations to confront low water availability, desiccation tolerance stands out. Up to now, the association of those species with beneficial soil microorganisms is not well understood. The aim of this study was to characterize Tripogon spicatusdiazotrophic bacterial isolates from the Caatingabiome and evaluate their ability to promote plant growth in rice. Sixteen bacterial isolates were studied in regard to their taxonomic position by partial sequencing of the 16S rRNA gene, putative diazotrophic capacity, in vitro indole-acetic acid (IAA production and calcium phosphate solubilization, metabolism of nine different C sources in semi-solid media, tolerance to different concentrations of NaCl to pHs and intrinsic resistance to nine antibiotics. Finally, the ability of the bacterial isolates to promote plant growth was evaluated using rice (Oryza sativa as a model plant. Among the 16 isolates evaluated, eight of them were classified as Enterobacteriaceae members, related to Enterobacter andPantoeagenera. Six other bacteria were related toBacillus, and the remaining two were related toRhizobiumand Stenotrophomonas.The evaluation of total N incorporation into the semi-solid medium indicated that all the bacteria studied have putative diazotrophic capacity. Two bacteria were able to produce more IAA than that observed for the strain BR 11175Tof Herbaspirillum seropedicae.Bacterial isolates were also able to form a microaerophilic pellicle in a semi-solid medium supplemented with different NaCl concentrations up to 1.27 mol L-1. Intrinsic resistance to antibiotics and the metabolism of different C sources indicated a great variation in physiological profile. Seven isolates were able to promote rice growth, and two bacteria were more efficient than the

  6. Effects of Cadmium on the Growth and Physiological Characteristics ...

    African Journals Online (AJOL)

    Administrator

    2011-11-09

    Nov 9, 2011 ... The effects of cadmium (Cd) stress on the growth and physiological characteristics were studied in 3 sorghum species viz., sweet sorghum [Sorghum bicolor (L.) Moench. cv. Hunnigreen], sorghum hybrid sudangrass (Sorghum bicolor × Sorghum sudanense, cv. Everlush) and sudangrass [Sorghum.

  7. Timing Effects of Heat-Stress on Plant Ecophysiological Characteristics and Growth.

    Science.gov (United States)

    Wang, Dan; Heckathorn, Scott A; Mainali, Kumar; Tripathee, Rajan

    2016-01-01

    Heat-waves with higher intensity and frequency and longer durations are expected in the future due to global warming, which could have dramatic impacts in agriculture, economy and ecology. This field study examined how plant responded to heat-stress (HS) treatment at different timing in naturally occurring vegetation. HS treatment (5 days at 40.5°C) were applied to 12 1 m 2 plots in restored prairie vegetation dominated by a warm-season C 4 grass, Andropogon gerardii , and a warm-season C 3 forb, Solidago canadensis , at different growing stages. During and after each heat stress (HS) treatment, temperature were monitored for air, canopy, and soil; net CO 2 assimilation ( A net ), quantum yield of photosystem II (Φ PSII ), stomatal conductance ( g s ), and internal CO 2 level ( C i ), specific leaf area (SLA), and chlorophyll content of the dominant species were measured. One week after the last HS treatment, all plots were harvested and the biomass of above-ground tissue and flower weight of the two dominant species were determined. HS decreased physiological performance and growth for both species, with S. canadensis being affected more than A. gerardii , indicated by negative HS effect on both physiological and growth responses for S. canadensis . There were significant timing effect of HS on the two species, with greater reductions in the net photosynthetic rate and productivity occurred when HS was applied at later-growing season. The reduction in aboveground productivity in S. canadensis but not A. gerardii could have important implications for plant community structure by increasing the competitive advantage of A. gerardii in this grassland. The present experiment showed that HS, though ephemeral, may promote long-term effects on plant community structure, vegetation dynamics, biodiversity, and ecosystem functioning of terrestrial biomes when more frequent and severe HS occur in the future.

  8. Physiological Actions of Fibroblast Growth Factor-23

    Directory of Open Access Journals (Sweden)

    Reinhold G. Erben

    2018-05-01

    Full Text Available Fibroblast growth factor-23 (FGF23 is a bone-derived hormone suppressing phosphate reabsorption and vitamin D hormone synthesis in the kidney. At physiological concentrations of the hormone, the endocrine actions of FGF23 in the kidney are αKlotho-dependent, because high-affinity binding of FGF23 to FGF receptors requires the presence of the co-receptor αKlotho on target cells. It is well established that excessive concentrations of intact FGF23 in the blood lead to phosphate wasting in patients with normal kidney function. Based on the importance of diseases associated with gain of FGF23 function such as phosphate-wasting diseases and chronic kidney disease, a large body of literature has focused on the pathophysiological consequences of FGF23 excess. Less emphasis has been put on the role of FGF23 in normal physiology. Nevertheless, during recent years, lessons we have learned from loss-of-function models have shown that besides the paramount physiological roles of FGF23 in the control of 1α-hydroxylase expression and of apical membrane expression of sodium-phosphate co-transporters in proximal renal tubules, FGF23 also is an important stimulator of calcium and sodium reabsorption in distal renal tubules. In addition, there is an emerging role of FGF23 as an auto-/paracrine regulator of alkaline phosphatase expression and mineralization in bone. In contrast to the renal actions of FGF23, the FGF23-mediated suppression of alkaline phosphatase in bone is αKlotho-independent. Moreover, FGF23 may be a physiological suppressor of differentiation of hematopoietic stem cells into the erythroid lineage in the bone microenvironment. At present, there is little evidence for a physiological role of FGF23 in organs other than kidney and bone. The purpose of this mini-review is to highlight the current knowledge about the complex physiological functions of FGF23.

  9. Influence of PGPR Bacteria and Arbuscular Mycorrhizal Fungi on Growth and some Physiological Parameters of Onopordon acanthium in a Cd-Contaminated Soil

    Directory of Open Access Journals (Sweden)

    MirHassan Rasouli-Sadaghiani

    2017-02-01

    Full Text Available Introduction: Heavy metals (HMs are serious threat for environment due to their dangerous effects. These metals as contaminants that can be accumulated in soil and after absorption by plants, finally will be found in food chains. Cadmium (Cd is one of the dangerous HMs that threats the health of plants, living organisms and human. Physicochemical remediation methods may cause large changes in different characteristics of soils . Recently environmental-friendly strategies including phytoremediation have been emphasized by researchers. Phytoremediation that refers to the use of plants and their assistance with microorganisms for remediation of contaminated soils is an effective and low cost method for reclamation of heavy metals polluted soils. The most important limitation of phytoremediation is low availability of heavy metals and sensitivity of plants to contamination. There are evidences that soil microbes can help to overcome these limitations through several ways. Plant growth promoting rhizobacteria (PGPR and arbuscular mycorrhizal fungi (AMF are known to enhance plant growth and survival in heavy metal contaminated soils through different mechanisms including producing promoting metabolites, auxin, siderophore and antibiotics. In this study the role of some strains of PGPR (a mixture of Pseudomonas species including P. putida, P. fluorescens, and P. aeruginosa and AMF (a mixture of Glomus species including G. intraradices, G. mosseae and G. fasciculatum, on uptake and accumulation of Cd, Fe, Zn and Cu as well as some physiological properties of Onopordon (Onopordon acanthium L were evaluated. Materials and Methods:This study was carried out under greenhouse condition as a factorial experiment based on a randomized complete block design with two factors including Cd concentration (four levels and microbial treatment (three levels in three replications. Consequently, a soil was selected and spiked uniformly with different concentrations of

  10. Helical growth trajectories in plant roots interacting with stiff barriers

    Science.gov (United States)

    Gerbode, Sharon; Noar, Roslyn; Harrison, Maria

    2009-03-01

    Plant roots successfully navigate heterogeneous soil environments with varying nutrient and water concentrations, as well as a variety of stiff obstacles. While it is thought that the ability of roots to penetrate into a stiff lower soil layer is important for soil erosion, little is known about how a root actually responds to a rigid interface. We have developed a laser sheet imaging technique for recording the 3D growth dynamics of plant roots interacting with stiff barriers. We find that a root encountering an angled interface does not grow in a straight line along the surface, but instead follows a helical trajectory. These experiments build on the pioneering studies of roots grown on a tilted 2D surface, which reported ``root waving,'' a similar curved pattern thought to be caused by the root's sensitivity to both gravity and the rigid surface on which it is grown. Our measurements extend these results to the more physiologically relevant case of 3D growth, where the spiral trajectory can be altered by tuning the relative strengths of the gravity and touch stimuli, providing some intuition for the physical mechanism driving it.

  11. Effects of cadmium on the growth and physiological characteristics ...

    African Journals Online (AJOL)

    The effects of cadmium (Cd) stress on the growth and physiological characteristics were studied in 3 sorghum species viz., sweet sorghum [Sorghum bicolor (L.) Moench. cv. Hunnigreen], sorghum hybrid sudangrass (Sorghum bicolor × Sorghum sudanense, cv. Everlush) and sudangrass [Sorghum sudanense (Piper) Stapf ...

  12. Physiological measurements of coffee young plants coexisting with sourgrass

    Directory of Open Access Journals (Sweden)

    Pedro Luis da Costa Aguiar Alves

    2012-03-01

    Full Text Available Coffee is an important crop planted in Brazil and commonly infested by sourgrass plants. Crescent densities of sourgrass growing with coffee young plants were maintained up to weed full flowering when physiological measurements were performed in the crop to evaluate photosynthetic coffee plant responses to increasing of weed competition. Experiments were arranged in a completely randomized design with seven replicates. The concentration of CO2 within the leaf, the leaf transpiration, the stomatal conductance, the CO2 assimilation rate, and the ratio Fv/Fm of coffee plants were not affected by increasing of sourgrass density. On the other hand, relative content of total chlorophyll was reduced by 13.9% in the density of 8 sourgrass plants. Gas exchange and fluorescence of chlorophyll of young coffee plants were not dependent on increasing of the intensity of competition while an opposite response occurred for chlorophyll content.

  13. Simple and robust determination of the activity signature of key carbohydrate metabolism enzymes for physiological phenotyping in model and crop plants

    DEFF Research Database (Denmark)

    Jammer, Alexandra; Gasperl, Anna; Luschin-Ebengreuth, Nora

    2015-01-01

    The analysis of physiological parameters is important to understand the link between plant phenotypes and their genetic bases, and therefore is needed as an important element in the analysis of model and crop plants. The activities of enzymes involved in primary carbohydrate metabolism have been...... shown to be strongly associated with growth performance, crop yield, and quality, as well as stress responses. A simple, fast, and cost-effective method to determine activities for 13 key enzymes involved in carbohydrate metabolism has been established, mainly based on coupled spectrophotometric kinetic...

  14. Error estimation in plant growth analysis

    Directory of Open Access Journals (Sweden)

    Andrzej Gregorczyk

    2014-01-01

    Full Text Available The scheme is presented for calculation of errors of dry matter values which occur during approximation of data with growth curves, determined by the analytical method (logistic function and by the numerical method (Richards function. Further formulae are shown, which describe absolute errors of growth characteristics: Growth rate (GR, Relative growth rate (RGR, Unit leaf rate (ULR and Leaf area ratio (LAR. Calculation examples concerning the growth course of oats and maize plants are given. The critical analysis of the estimation of obtained results has been done. The purposefulness of joint application of statistical methods and error calculus in plant growth analysis has been ascertained.

  15. Growth and other physiological responses of bivalves in laboratory experiments

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Milford lab maintains data sets relating to a variety of growth and physiology trials. These include husbandry techniques (i.e. stocking density, container size,...

  16. Morphology and physiology of the epiphyseal growth plate.

    Directory of Open Access Journals (Sweden)

    Robert Klepacz

    2009-05-01

    Full Text Available The epiphyseal growth plate develops from the cartilaginous-orientated mesenchymal cells that express SOX family genes. This multilayer structure is formed by the proliferation and hypertrophy of cells that synthesize the extracellular matrix composed of collagen (mainly type II, IX, X, XI and proteoglycans (aggrecan, decorin, annexin II, V and VI. The resting zone is responsible for protein synthesis and maintaining a germinal structure. In the proliferative zone, cells rapidly duplicate. The subsequent morphological changes take place in the transformation zone, divided into the upper and lower hypertrophic layers. In the degenerative zone, the mineralization process becomes intensive due to increased release of alkaline phosphate, calcium and matrix vesicles by terminally differentiated chondrocytes and some other factors e.g., metaphyseal ingrowth vessels. At this level, as well as in the primary and secondary spongiosa zones, chondrocytes undergo apoptosis and are physiologically eliminated. Unlike adult cartilage, in fetal and early formed growth plates, unusual forms such as authophagal bodies, paralysis and dark chondrocytes were also observed. Their ultrastructure differs greatly from apoptotic and normal cartilage cells. Chondrocyte proliferation and differentiation are regulated by various endocrine, paracrine, and autocrine agents such as growth, thyroid and sex hormones, beta-catenin, bone morphogenetic proteins, insulin-like growth factor, iodothyronine deiodinase, leptin, nitric oxide, transforming growth factor beta and vitamin D metabolites. However, the most significant factor is parathyroid hormone-related protein (PTHrP which is synthesized in the perichondrium by terminally differentiated chondrocytes. Secondary to activation of PTH/PTHrP receptors, PTHrP stimulates cell proliferation by G protein activation and delays their transformation into prehypertrophic and hypertrophic chondrocytes. When proliferation is completed

  17. Modelling asymmetric growth in crowded plant communities

    DEFF Research Database (Denmark)

    Damgaard, Christian

    2010-01-01

    A class of models that may be used to quantify the effect of size-asymmetric competition in crowded plant communities by estimating a community specific degree of size-asymmetric growth for each species in the community is suggested. The model consists of two parts: an individual size......-asymmetric growth part, where growth is assumed to be proportional to a power function of the size of the individual, and a term that reduces the relative growth rate as a decreasing function of the individual plant size and the competitive interactions from other plants in the neighbourhood....

  18. Plants and men in space - A new field in plant physiology

    Science.gov (United States)

    Andre, M.; Macelroy, R. D.

    1990-01-01

    Results are presented on a comparison of nutritional values of and human psychological responses to algae and of higher plants considered for growth as food on long-term missions in space, together with the technological complexities of growing these plants. The comparison shows the advantages of higher plants, with results suggesting that a high level of material recycling can be obtained. It is noted that the issue of space gravity may be not a major problem for plants because of the possibility that phototropism can provide an alternative sense of direction. Problems of waste recycling can be solved in association with plant cultivation, and a high degree of autonomy of food production can be obtained.

  19. Physiological blockage in plants in response to postharvest stress

    African Journals Online (AJOL)

    Marcos

    2013-03-13

    Mar 13, 2013 ... response of the plant to cut stem (Ichimura et al., 1999). When the vessel is blocked, ... E-mail: m.r.s.v@hotmail.com. of complex physiological ... of cells which protrude into the vessel lumen xylem whose shape is similar to a.

  20. Growth and physiological aspects of bell pepper ( Capsicum annuum )

    African Journals Online (AJOL)

    This study aimed to evaluate growth and physiological aspects of 'All Big' bell pepper, under saline stress and exogenous application of proline on the leaves. The research was conducted in pots adapted as drainage lysimeters under greenhouse conditions, using sandy-loam eutrophic Regolithic Neosol, in the ...

  1. Effects of planting date and plant density on crop growth of cut chrysanthemum

    NARCIS (Netherlands)

    Lee, J.H.; Heuvelink, E.; Challa, H.

    2002-01-01

    The effects of planting date (season) and plant density (32, 48 or 64 plants m-2) on growth of cut chrysanthemum (Chrysanthemum (Indicum group)) were investigated in six greenhouse experiments, applying the expolinear growth equation. Final plant fresh and dry mass and number of flowers per plant

  2. Inter-annual changes in detritus-based food chains can enhance plant growth response to elevated atmospheric CO2.

    Science.gov (United States)

    Hines, Jes; Eisenhauer, Nico; Drake, Bert G

    2015-12-01

    Elevated atmospheric CO2 generally enhances plant growth, but the magnitude of the effects depend, in part, on nutrient availability and plant photosynthetic pathway. Due to their pivotal role in nutrient cycling, changes in abundance of detritivores could influence the effects of elevated atmospheric CO2 on essential ecosystem processes, such as decomposition and primary production. We conducted a field survey and a microcosm experiment to test the influence of changes in detritus-based food chains on litter mass loss and plant growth response to elevated atmospheric CO2 using two wetland plants: a C3 sedge (Scirpus olneyi) and a C4 grass (Spartina patens). Our field study revealed that organism's sensitivity to climate increased with trophic level resulting in strong inter-annual variation in detritus-based food chain length. Our microcosm experiment demonstrated that increased detritivore abundance could not only enhance decomposition rates, but also enhance plant growth of S. olneyi in elevated atmospheric CO2 conditions. In contrast, we found no evidence that changes in the detritus-based food chains influenced the growth of S. patens. Considered together, these results emphasize the importance of approaches that unite traditionally subdivided food web compartments and plant physiological processes to understand inter-annual variation in plant production response to elevated atmospheric CO2. © 2015 John Wiley & Sons Ltd.

  3. Plant growth enhancement and associated physiological responses are coregulated by ethylene and gibberellin in response to harpin protein Hpa1

    OpenAIRE

    Li, Xiaojie; Han, Bing; Xu, Manyu; Han, Liping; Zhao, Yanying; Liu, Zhilan; Dong, Hansong; Zhang, Chunling

    2014-01-01

    The harpin protein Hpa1 produced by the bacterial blight pathogen of rice induces several growth-promoting responses in plants, activating the ethylene signaling pathway, increasing photosynthesis rates and EXPANSIN (EXP) gene expression levels, and thereby enhancing the vegetative growth. This study was attempted to analyze any mechanistic connections among the above and the role of gibberellin in these responses. Hpa1-induced growth enhancement was evaluated in Arabidopsis, tomato, and rice...

  4. Effect of metal tolerant plant growth promoting bacteria on growth and metal accumulation in Zea mays plants grown in fly ash amended soil.

    Science.gov (United States)

    Kumar, Kalpna V; Patra, D D

    2013-01-01

    The present study was undertaken to examine the effect of the application of fly ash (FA) into Garden soil (GS), with and without inoculation of plant growth promoting bacteria (PGPB), on the growth and metal uptake by Zea mays plants. Three FA tolerant PGPB strains, Pseudomonas sp. PS5, PS14, and Bacillus sp. BC29 were isolated from FA contaminated soils and assessed for their plant growth promoting features on the Z. mays plants. All three strains were also examined for their ability to solubilize phosphate and to produce Indole Acetic Acid (IAA), siderophores, and hydrogencynide acid (HCN) production. Although inoculation of all strains significantly enhanced the growth of plants at both the concentration of FA but maximum growth was observed in plants inoculated with BC29 and PS14 at low level (25%) of FA concentration. The experimental results explored the plant growth promoting features of selected strains which not only enhanced growth and biomass of plants but also protected them from toxicity of FA.

  5. Salt tolerance of precocious-dwarf cashew rootstocks: physiological and growth indexes

    Directory of Open Access Journals (Sweden)

    Carneiro Paulo Torres

    2004-01-01

    Full Text Available The cashew crop (Anacardium occiedentale L. is of great economic and social importance for Northeast Brazil, a region usually affected by water and soil salinity. The present study was conducted in a greenhouse to evaluate the effects of four salinity levels established through electrical conductivity of irrigation water (ECw: 0.7, 1.4, 2.1 and 2.8 dS m-1, at 25ºC, on growth and physiological indexes of five rootstocks of dwarf-precocious cashew varieties CCP06, CCP09, CCP1001, EMBRAPA50, and EMBRAPA51. Plant height, leaf area, dry weight of root, shoot and total; water content of leaves, root/shoot ratio, leaf area ratio, absolute and relative growth rates and rate of net assimilation were evaluated. The majority of the evaluated variables were found to be affected by ECw and the effects varied among clones; however, no significant interactive effects were observed for factors. The value of ECw = 1.39 dS m-1 was considered as a threshold tolerance for the precocious cashew rootstocks used in this study. The dwarf-precocious cashew is moderately sensible to soil salinity during the formation phase of rootstock. Clones EMBRAPA51 and EMBRAPA50 presented, respectively, the least and the best development indexes.

  6. Isolation, purification and studies on radiation induced biochemical and physiological changes of bovine growth hormone in animal

    International Nuclear Information System (INIS)

    Abdel-Salam, H.M.S.

    1997-01-01

    Growth hormone has a great importance in the field of animal physiology. Bovine growth hormone was extracted by alteration of the hydrogen ion concentration of phosphate buffer extract of frozen pituitary glands. The extracted bovine growth hormone has similar absorption peaks at UV and infrared spectra, bands of the same location on polyacrylamide gel electrophoresis plate and had a molecular weight exactly as the standard bovine growth hormone and equal to 20.9 KD. Labelling of bovine growth hormone with 131 I was carried out with fast and least expensive method. The biological and physiological effects of labelled and non labelled bovine growth hormone were studied on rabbits. The labelled bovine growth hormone decreased the biological and physiological effects of the hormone. Bovine growth hormone (unlabelled) and different effects on growth performance traits, body chemical composition (water, fat,protein and ash), and also on the serum biochemical parameters. We conclude that the bovine growth hormone affects on the biological and physiological properties but this depends on the dose, type of delivery of hormone, time of treatment, and the diet content of the animal. 6 tabs., 13.2 figs., 110 refs

  7. Crosstalk between sugarcane and a plant-growth promoting Burkholderia species

    Science.gov (United States)

    Paungfoo-Lonhienne, Chanyarat; Lonhienne, Thierry G. A.; Yeoh, Yun Kit; Donose, Bogdan C.; Webb, Richard I.; Parsons, Jeremy; Liao, Webber; Sagulenko, Evgeny; Lakshmanan, Prakash; Hugenholtz, Philip; Schmidt, Susanne; Ragan, Mark A.

    2016-01-01

    Bacterial species in the plant-beneficial-environmental clade of Burkholderia represent a substantial component of rhizosphere microbes in many plant species. To better understand the molecular mechanisms of the interaction, we combined functional studies with high-resolution dual transcriptome analysis of sugarcane and root-associated diazotrophic Burkholderia strain Q208. We show that Burkholderia Q208 forms a biofilm at the root surface and suppresses the virulence factors that typically trigger immune response in plants. Up-regulation of bd-type cytochromes in Burkholderia Q208 suggests an increased energy production and creates the microaerobic conditions suitable for BNF. In this environment, a series of metabolic pathways are activated in Burkholderia Q208 implicated in oxalotrophy, microaerobic respiration, and formation of PHB granules, enabling energy production under microaerobic conditions. In the plant, genes involved in hypoxia survival are up-regulated and through increased ethylene production, larger aerenchyma is produced in roots which in turn facilitates diffusion of oxygen within the cortex. The detected changes in gene expression, physiology and morphology in the partnership are evidence of a sophisticated interplay between sugarcane and a plant-growth promoting Burkholderia species that advance our understanding of the mutually beneficial processes occurring in the rhizosphere. PMID:27869215

  8. Relationship between Hexokinase and the Aquaporin PIP1 in the Regulation of Photosynthesis and Plant Growth

    Science.gov (United States)

    Kelly, Gilor; Sade, Nir; Attia, Ziv; Secchi, Francesca; Zwieniecki, Maciej; Holbrook, N. Michele; Levi, Asher; Alchanatis, Victor; Moshelion, Menachem; Granot, David

    2014-01-01

    Increased expression of the aquaporin NtAQP1, which is known to function as a plasmalemma channel for CO2 and water, increases the rate of both photosynthesis and transpiration. In contrast, increased expression of Arabidopsis hexokinase1 (AtHXK1), a dual-function enzyme that mediates sugar sensing, decreases the expression of photosynthetic genes and the rate of transpiration and inhibits growth. Here, we show that AtHXK1 also decreases root and stem hydraulic conductivity and leaf mesophyll CO2 conductance (g m). Due to their opposite effects on plant development and physiology, we examined the relationship between NtAQP1 and AtHXK1 at the whole-plant level using transgenic tomato plants expressing both genes simultaneously. NtAQP1 significantly improved growth and increased the transpiration rates of AtHXK1-expressing plants. Reciprocal grafting experiments indicated that this complementation occurs when both genes are expressed simultaneously in the shoot. Yet, NtAQP1 had only a marginal effect on the hydraulic conductivity of the double-transgenic plants, suggesting that the complementary effect of NtAQP1 is unrelated to shoot water transport. Rather, NtAQP1 significantly increased leaf mesophyll CO2 conductance and enhanced the rate of photosynthesis, suggesting that NtAQP1 facilitated the growth of the double-transgenic plants by enhancing mesophyll conductance of CO2. PMID:24498392

  9. Relationship between hexokinase and the aquaporin PIP1 in the regulation of photosynthesis and plant growth.

    Directory of Open Access Journals (Sweden)

    Gilor Kelly

    Full Text Available Increased expression of the aquaporin NtAQP1, which is known to function as a plasmalemma channel for CO₂ and water, increases the rate of both photosynthesis and transpiration. In contrast, increased expression of Arabidopsis hexokinase1 (AtHXK1, a dual-function enzyme that mediates sugar sensing, decreases the expression of photosynthetic genes and the rate of transpiration and inhibits growth. Here, we show that AtHXK1 also decreases root and stem hydraulic conductivity and leaf mesophyll CO₂ conductance (g(m. Due to their opposite effects on plant development and physiology, we examined the relationship between NtAQP1 and AtHXK1 at the whole-plant level using transgenic tomato plants expressing both genes simultaneously. NtAQP1 significantly improved growth and increased the transpiration rates of AtHXK1-expressing plants. Reciprocal grafting experiments indicated that this complementation occurs when both genes are expressed simultaneously in the shoot. Yet, NtAQP1 had only a marginal effect on the hydraulic conductivity of the double-transgenic plants, suggesting that the complementary effect of NtAQP1 is unrelated to shoot water transport. Rather, NtAQP1 significantly increased leaf mesophyll CO₂ conductance and enhanced the rate of photosynthesis, suggesting that NtAQP1 facilitated the growth of the double-transgenic plants by enhancing mesophyll conductance of CO₂.

  10. Soil Contamination With Heavy Metals and Its Effect on Growth, Yield and Physiological Responses of Vegetable Crop Plants (Turnip and Lettuce)

    OpenAIRE

    Raifa Ahmed Hassanein; Hanan Ahmed Hashem; Mohamed Hashem El-Deep; Ahmed Shouman

    2013-01-01

    The present study was conducted to investigate the impact of irrigation with industrial wastewater on soil and plant. For these purpose turnip and lettuce plants were cultivated in soil irrigated with wastewater then heavy metals content of the soil, plant growth, yield and the subsequent changes in biochemical constituents of plant were examined. Irrigation with wastewater was found to load the soil with heavy metals (Pb, Co, Ni and Cd) that were not detected in soil before irrig...

  11. Development of sensors for monitoring oxygen and free radicals in plant physiology

    Science.gov (United States)

    Chaturvedi, Prachee

    Oxygen plays a critical role in the physiology of photosynthetic organisms, including bioenergetics, metabolism, development, and stress response. Oxygen levels affect photosynthesis, respiration, and alternative oxidase pathways. Likewise, the metabolic rate of spatially distinct plant cells (and therefore oxygen flux) is known to be affected by biotic stress (e.g., herbivory) and environmental stress (e.g., salt/nutrient stress). During aerobic metabolism, cells produce reactive oxygen species (ROS) as a by product. Plants also produce ROS during adaptation to stress (e.g., abscisic acid (ABA) mediated stress responses). If stress conditions are prolonged, ROS levels surpass the capacity of detoxifying mechanisms within the cell, resulting in oxidative damage. While stress response pathways such as ABA-mediated mechanisms have been well characterized (e.g., water stress, inhibited shoot growth, synthesis of storage proteins in seeds), the connection between ROS production, oxygen metabolism and stress response remains unknown. In part, this is because details of oxygen transport at the interface of cell(s) and the surrounding microenvironment remains nebulous. The overall goal of this research was to develop oxygen and Free radical sensors for studying stress signaling in plants. Recent developments in nanomaterials and data acquisition systems were integrated to develop real-time, non-invasive oxygen and Free radical sensors. The availability of these sensors for plant physiologists is an exciting opportunity to probe the functional realm of cells and tissues in ways that were not previously possible.

  12. Growth of fluoride treated Kalanchoe pinnata plants

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, H N; Applegate, H G

    1962-01-01

    Kalanchoe pinnata plants can absorb fluoride through roots. The absorption is related to the amount of fluoride applied to the soil. There appeared to be a relationship between the amount of fluoride adsorbed and the subsequent growth of the plants. Plants which adsorbed the largest amounts of fluoride had the greatest increase in growth.

  13. Environmental effects of nanosilver: impact on castor seed germination, seedling growth, and plant physiology.

    Science.gov (United States)

    Yasur, Jyothsna; Rani, Pathipati Usha

    2013-12-01

    Increasing use of nanoparticles in daily products is of great concern today, especially when their positive and negative impact on environment is not known. Hence, in current research, we have studied the impact of silver nanoparticle (AgNPs) and silver nitrate (AgNO3) application on seed germination, root, and shoot length of castor bean, Ricinus communis L. plant. Silver nanoparticles had no significant effects on seedling growth even at higher concentration of 4,000 mg L(-1), while the silver in bulk form as AgNO3 applied on the castor bean seeds inhibited the seed germination. Silver uptake in seedlings of the castor seeds on treatment with both the forms of silver was confirmed through atomic absorption spectroscopy studies. The silver nanoparticle and silver nitrate application to castor seeds also caused an enhanced enzymatic activity of ROS enzymes and phenolic content in castor seedlings. High-performance liquid chromatography analysis of individual phenols indicated enhanced content of parahydroxy benzoic acid. These kinds of studies are of great interest in order to unveil the movement and accumulation of nanoparticles in plant tissues for assessing future applications in the field or laboratory.

  14. Plant growth-promoting bacteria: mechanisms and applications.

    Science.gov (United States)

    Glick, Bernard R

    2012-01-01

    The worldwide increases in both environmental damage and human population pressure have the unfortunate consequence that global food production may soon become insufficient to feed all of the world's people. It is therefore essential that agricultural productivity be significantly increased within the next few decades. To this end, agricultural practice is moving toward a more sustainable and environmentally friendly approach. This includes both the increasing use of transgenic plants and plant growth-promoting bacteria as a part of mainstream agricultural practice. Here, a number of the mechanisms utilized by plant growth-promoting bacteria are discussed and considered. It is envisioned that in the not too distant future, plant growth-promoting bacteria (PGPB) will begin to replace the use of chemicals in agriculture, horticulture, silviculture, and environmental cleanup strategies. While there may not be one simple strategy that can effectively promote the growth of all plants under all conditions, some of the strategies that are discussed already show great promise.

  15. Plant Growth-Promoting Bacteria: Mechanisms and Applications

    Directory of Open Access Journals (Sweden)

    Bernard R. Glick

    2012-01-01

    Full Text Available The worldwide increases in both environmental damage and human population pressure have the unfortunate consequence that global food production may soon become insufficient to feed all of the world's people. It is therefore essential that agricultural productivity be significantly increased within the next few decades. To this end, agricultural practice is moving toward a more sustainable and environmentally friendly approach. This includes both the increasing use of transgenic plants and plant growth-promoting bacteria as a part of mainstream agricultural practice. Here, a number of the mechanisms utilized by plant growth-promoting bacteria are discussed and considered. It is envisioned that in the not too distant future, plant growth-promoting bacteria (PGPB will begin to replace the use of chemicals in agriculture, horticulture, silviculture, and environmental cleanup strategies. While there may not be one simple strategy that can effectively promote the growth of all plants under all conditions, some of the strategies that are discussed already show great promise.

  16. Fatality of salt stress to plants: Morphological, physiological and ...

    African Journals Online (AJOL)

    GREGORY

    2010-08-23

    Aug 23, 2010 ... are difficult to establish in crops since salt stress may occur as a catastrophic episode, ... as well as cellular levels through osmotic and ionic adjustments that result in reduced biomass ... plant physiology such as increased respiration rate, ion toxicity ... eventually death of leaf cells and tissues (Marschner,.

  17. Physiological, vascular and nanomechanical assessment of hybrid poplar leaf traits in micropropagated plants and plants propagated from root cuttings: A contribution to breeding programs.

    Science.gov (United States)

    Ďurkovič, Jaroslav; Husárová, Hana; Javoříková, Lucia; Čaňová, Ingrid; Šuleková, Miriama; Kardošová, Monika; Lukáčik, Ivan; Mamoňová, Miroslava; Lagaňa, Rastislav

    2017-09-01

    Micropropagated plants experience significant stress from rapid water loss when they are transferred from an in vitro culture to either greenhouse or field conditions. This is caused both by inefficient stomatal control of transpiration and the change to a higher light intensity and lower humidity. Understanding the physiological, vascular and biomechanical processes that allow micropropagated plants to modify their phenotype in response to environmental conditions can help to improve both field performance and plant survival. To identify changes between the hybrid poplar [Populus tremula × (Populus × canescens)] plants propagated from in vitro tissue culture and those from root cuttings, we assessed leaf performance for any differences in leaf growth, photosynthetic and vascular traits, and also nanomechanical properties of the tracheary element cell walls. The micropropagated plants showed significantly higher values for leaf area, leaf length, leaf width and leaf dry mass. The greater leaf area and leaf size dimensions resulted from the higher transpiration rate recorded for this stock type. Also, the micropropagated plants reached higher values for chlorophyll a fluorescence parameters and for the nanomechanical dissipation energy of tracheary element cell walls which may indicate a higher damping capacity within the primary xylem tissue under abiotic stress conditions. The performance of the plants propagated from root cuttings was superior for instantaneous water-use efficiency which signifies a higher acclimation capacity to stressful conditions during a severe drought particularly for this stock type. Similarities were found among the majority of the examined leaf traits for both vegetative plant origins including leaf mass per area, stomatal conductance, net photosynthetic rate, hydraulic axial conductivity, indicators of leaf midrib vascular architecture, as well as for the majority of cell wall nanomechanical traits. This research revealed that

  18. Plant Growth Modeling Using L-System Approach and Its Visualization

    Directory of Open Access Journals (Sweden)

    Atris Suyantohadi

    2011-05-01

    Full Text Available The visualizationof plant growth modeling using computer simulation has rarely been conducted with Lindenmayer System (L-System approach. L-System generally has been used as framework for improving and designing realistic modeling on plant growth. It is one kind of tools for representing plant growth based on grammar sintax and mathematic formulation. This research aimed to design modeling and visualizing plant growth structure generated using L-System. The environment on modeling design used three dimension graphic on standart OpenGL format. The visualization on system design has been developed by some of L-System grammar, and the output graphic on three dimension reflected on plant growth as a virtual plant growth system. Using some of samples on grammar L-System rules for describing of the charaterictics of plant growth, the visualization of structure on plant growth has been resulted and demonstrated.

  19. Dominant role of plant physiology in trend and variability of gross primary productivity in North America

    Science.gov (United States)

    Zhou, Sha; Zhang, Yao; Ciais, Philippe; Xiao, Xiangming; Luo, Yiqi; Caylor, Kelly K.; Huang, Yuefei; Wang, Guangqian

    2017-02-01

    Annual gross primary productivity (GPP) varies considerably due to climate-induced changes in plant phenology and physiology. However, the relative importance of plant phenology and physiology on annual GPP variation is not clear. In this study, a Statistical Model of Integrated Phenology and Physiology (SMIPP) was used to evaluate the relative contributions of maximum daily GPP (GPPmax) and the start and end of growing season (GSstart and GSend) to annual GPP variability, using a regional GPP product in North America during 2000-2014 and GPP data from 24 AmeriFlux sites. Climatic sensitivity of the three indicators was assessed to investigate the climate impacts on plant phenology and physiology. The SMIPP can explain 98% of inter-annual variability of GPP over mid- and high latitudes in North America. The long-term trend and inter-annual variability of GPP are dominated by GPPmax both at the ecosystem and regional scales. During warmer spring and autumn, GSstart is advanced and GSend delayed, respectively. GPPmax responds positively to summer temperature over high latitudes (40-80°N), but negatively in mid-latitudes (25-40°N). This study demonstrates that plant physiology, rather than phenology, plays a dominant role in annual GPP variability, indicating more attention should be paid to physiological change under futher climate change.

  20. Silicon Regulates Potential Genes Involved in Major Physiological Processes in Plants to Combat Stress

    Directory of Open Access Journals (Sweden)

    Abinaya Manivannan

    2017-08-01

    Full Text Available Silicon (Si, the quasi-essential element occurs as the second most abundant element in the earth's crust. Biological importance of Si in plant kingdom has become inevitable particularly under stressed environment. In general, plants are classified as high, medium, and low silicon accumulators based on the ability of roots to absorb Si. The uptake of Si directly influence the positive effects attributed to the plant but Si supplementation proves to mitigate stress and recover plant growth even in low accumulating plants like tomato. The application of Si in soil as well as soil-less cultivation systems have resulted in the enhancement of quantitative and qualitative traits of plants even under stressed environment. Silicon possesses several mechanisms to regulate the physiological, biochemical, and antioxidant metabolism in plants to combat abiotic and biotic stresses. Nevertheless, very few reports are available on the aspect of Si-mediated molecular regulation of genes with potential role in stress tolerance. The recent advancements in the era of genomics and transcriptomics have opened an avenue for the determination of molecular rationale associated with the Si amendment to the stress alleviation in plants. Therefore, the present endeavor has attempted to describe the recent discoveries related to the regulation of vital genes involved in photosynthesis, transcription regulation, defense, water transport, polyamine synthesis, and housekeeping genes during abiotic and biotic stress alleviation by Si. Furthermore, an overview of Si-mediated modulation of multiple genes involved in stress response pathways such as phenylpropanoid pathway, jasmonic acid pathway, ABA-dependent or independent regulatory pathway have been discussed in this review.

  1. Physiology of in vitro culture

    Directory of Open Access Journals (Sweden)

    Maria Jesús Cañal

    2001-01-01

    Full Text Available The culture procedures described up to the eighties, did not made any mention to the environmental control of in vitro plant development. However, growth rate, development and many of the physiologic-morphologic features of the in vitro grown plants are influenced by the culture vessel. The increasing knowledge about the environmental control of culture vessels under sterile conditions, is helping to change micorpropagation procedures. The in vitro environment with lower rate ventilation, brings about low flow rates of matter and energy, with minimum variations of temperature, high relative humidity and large daily changes of the concentration of CO2 inside the culture vessel. The type of culture vessel (size, shape, fabric and closing system can influence the evolution of the atmosphere along the time of culture. Although submitted to different stresses factors plant can be grown in vitro, but plants can be faulty in their anatomy, morphology and physiology. As a consequence, these plants shown a phenotype unable to survive to ex vitro conditions. Different strategies can be used to control the atmosphere along the different phases of micropropagation, in heterotrophic, mixotrophic or autotrophic cultures. The election of the best strategy will be based on different factors as species, number of transplantes required, or quality-price relationship. enviromental control, tissue culture, micropropagation Keywords: in vitro enviromental, characteristic physiology,

  2. Physiological blockage in plants in response to postharvest stress ...

    African Journals Online (AJOL)

    Flowers have been designed primarily for cutting because of the diversity of shapes, colors and also durability. However, ornamental plants are used in floral arrangements in vases and have limited shelf-life. Thus, this study showed that one of the factors contributing to this limitation is the physiological blockage that occurs ...

  3. Molecular Physiology of Root System Architecture in Model Grasses

    Science.gov (United States)

    Hixson, K.; Ahkami, A. H.; Anderton, C.; Veličković, D.; Myers, G. L.; Chrisler, W.; Lindenmaier, R.; Fang, Y.; Yabusaki, S.; Rosnow, J. J.; Farris, Y.; Khan, N. E.; Bernstein, H. C.; Jansson, C.

    2017-12-01

    Unraveling the molecular and physiological mechanisms involved in responses of Root System Architecture (RSA) to abiotic stresses and shifts in microbiome structure is critical to understand and engineer plant-microbe-soil interactions in the rhizosphere. In this study, accessions of Brachypodium distachyon Bd21 (C3 model grass) and Setaria viridis A10.1 (C4 model grass) were grown in phytotron chambers under current and elevated CO2 levels. Detailed growth stage-based phenotypic analysis revealed different above- and below-ground morphological and physiological responses in C3 and C4 grasses to enhanced CO2 levels. Based on our preliminary results and by screening values of total biomass, water use efficiency, root to shoot ratio, RSA parameters and net assimilation rates, we postulated a three-phase physiological mechanism, i.e. RootPlus, BiomassPlus and YieldPlus phases, for grass growth under elevated CO2 conditions. Moreover, this comprehensive set of morphological and process-based observations are currently in use to develop, test, and calibrate biophysical whole-plant models and in particular to simulate leaf-level photosynthesis at various developmental stages of C3 and C4 using the model BioCro. To further link the observed phenotypic traits at the organismal level to tissue and molecular levels, and to spatially resolve the origin and fate of key metabolites involved in primary carbohydrate metabolism in different root sections, we complement root phenotypic observations with spatial metabolomics data using mass spectrometry imaging (MSI) methods. Focusing on plant-microbe interactions in the rhizosphere, six bacterial strains with plant growth promoting features are currently in use in both gel-based and soil systems to screen root growth and development in Brachypodium. Using confocal microscopy, GFP-tagged bacterial systems are utilized to study the initiation of different root types of RSA, including primary root (PR), coleoptile node axile root (CNR

  4. Comparative genomic analysis of four representative plant growth-promoting rhizobacteria in Pseudomonas

    Science.gov (United States)

    2013-01-01

    Background Some Pseudomonas strains function as predominant plant growth-promoting rhizobacteria (PGPR). Within this group, Pseudomonas chlororaphis and Pseudomonas fluorescens are non-pathogenic biocontrol agents, and some Pseudomonas aeruginosa and Pseudomonas stutzeri strains are PGPR. P. chlororaphis GP72 is a plant growth-promoting rhizobacterium with a fully sequenced genome. We conducted a genomic analysis comparing GP72 with three other pseudomonad PGPR: P. fluorescens Pf-5, P. aeruginosa M18, and the nitrogen-fixing strain P. stutzeri A1501. Our aim was to identify the similarities and differences among these strains using a comparative genomic approach to clarify the mechanisms of plant growth-promoting activity. Results The genome sizes of GP72, Pf-5, M18, and A1501 ranged from 4.6 to 7.1 M, and the number of protein-coding genes varied among the four species. Clusters of Orthologous Groups (COGs) analysis assigned functions to predicted proteins. The COGs distributions were similar among the four species. However, the percentage of genes encoding transposases and their inactivated derivatives (COG L) was 1.33% of the total genes with COGs classifications in A1501, 0.21% in GP72, 0.02% in Pf-5, and 0.11% in M18. A phylogenetic analysis indicated that GP72 and Pf-5 were the most closely related strains, consistent with the genome alignment results. Comparisons of predicted coding sequences (CDSs) between GP72 and Pf-5 revealed 3544 conserved genes. There were fewer conserved genes when GP72 CDSs were compared with those of A1501 and M18. Comparisons among the four Pseudomonas species revealed 603 conserved genes in GP72, illustrating common plant growth-promoting traits shared among these PGPR. Conserved genes were related to catabolism, transport of plant-derived compounds, stress resistance, and rhizosphere colonization. Some strain-specific CDSs were related to different kinds of biocontrol activities or plant growth promotion. The GP72 genome

  5. The Growth Hormone Receptor: Mechanism of Receptor Activation, Cell Signaling, and Physiological Aspects

    Directory of Open Access Journals (Sweden)

    Farhad Dehkhoda

    2018-02-01

    Full Text Available The growth hormone receptor (GHR, although most well known for regulating growth, has many other important biological functions including regulating metabolism and controlling physiological processes related to the hepatobiliary, cardiovascular, renal, gastrointestinal, and reproductive systems. In addition, growth hormone signaling is an important regulator of aging and plays a significant role in cancer development. Growth hormone activates the Janus kinase (JAK–signal transducer and activator of transcription (STAT signaling pathway, and recent studies have provided a new understanding of the mechanism of JAK2 activation by growth hormone binding to its receptor. JAK2 activation is required for growth hormone-mediated activation of STAT1, STAT3, and STAT5, and the negative regulation of JAK–STAT signaling comprises an important step in the control of this signaling pathway. The GHR also activates the Src family kinase signaling pathway independent of JAK2. This review covers the molecular mechanisms of GHR activation and signal transduction as well as the physiological consequences of growth hormone signaling.

  6. Transgenic plants with enhanced growth characteristics

    Energy Technology Data Exchange (ETDEWEB)

    Unkefer, Pat J.; Anderson, Penelope S.; Knight, Thomas J.

    2018-01-09

    The invention relates to transgenic plants exhibiting dramatically enhanced growth rates, greater seed and fruit/pod yields, earlier and more productive flowering, more efficient nitrogen utilization, increased tolerance to high salt conditions, and increased biomass yields. In one embodiment, transgenic plants engineered to over-express both glutamine phenylpyruvate transaminase (GPT) and glutamine synthetase (GS) are provided. The GPT+GS double-transgenic plants of the invention consistently exhibit enhanced growth characteristics, with T0 generation lines showing an increase in biomass over wild type counterparts of between 50% and 300%. Generations that result from sexual crosses and/or selfing typically perform even better, with some of the double-transgenic plants achieving an astounding four-fold biomass increase over wild type plants.

  7. Transgenic plants with enhanced growth characteristics

    Energy Technology Data Exchange (ETDEWEB)

    Unkefer, Pat J.; Anderson, Penelope S.; Knight, Thomas J.

    2016-09-06

    The invention relates to transgenic plants exhibiting dramatically enhanced growth rates, greater seed and fruit/pod yields, earlier and more productive flowering, more efficient nitrogen utilization, increased tolerance to high salt conditions, and increased biomass yields. In one embodiment, transgenic plants engineered to over-express both glutamine phenylpyruvate transaminase (GPT) and glutamine synthetase (GS) are provided. The GPT+GS double-transgenic plants of the invention consistently exhibit enhanced growth characteristics, with T0 generation lines showing an increase in biomass over wild type counterparts of between 50% and 300%. Generations that result from sexual crosses and/or selfing typically perform even better, with some of the double-transgenic plants achieving an astounding four-fold biomass increase over wild type plants.

  8. Effect of two different plant growth regulators on production traits of sunflower

    Directory of Open Access Journals (Sweden)

    Dávid ERNST

    2016-12-01

    Full Text Available The plant growth regulators (PGR are an organic compounds that modify plant physiological processes. PGR applied to the field crops promotes photosynthesis, stimulates plant growth, improves flowering and protects plants against unfavourable year weather conditions. Listed is an assumption to the yield of high quality. The effects of year weather conditions, biological material (hybrids and foliar application of two different PGR (Terra-Sorb® Foliar – containing free amino acids and Unicum® – containing Abiestins® on the yield-forming parameters, seed yield and the oil content in seeds of three selected hybrids of sunflower (NK Brio, NK Neoma, NK Ferti were studied in this paper. The field poly-factorial experiments were realized during two growing seasons of 2012 and 2013. The experimental area is situated in the maize-growing region (climatic region: warm; climatic sub-region: mild dry or dry; climatic zone: warm and dry, with mild winter and long sunshine and soil is silt loam Haplic Luvisol. The climatic conditions in chosen experimental years were different in quantities and distribution of precipitation at main growth period of sunflower plants (June to August and allows evaluating the yield stability between used hybrids and foliar treatments. The results showed that the application of selected PGR has contributed to an increase of sunflower seed yield, mainly through increase the weight of thousand seeds (rp = 0.761; P < 0.001. Similarly, oil content in seeds was significantly higher in treatments with PGR, especially with preparation Terra-Sorb® Foliar containing free amino acids. The study describes the relationship between quality (oil content in seeds and quantity (seed yield of sunflower production (rp = ‒0.41; P < 0.01. Results showed that PGR can be an important rationalization tool of the sunflower cultivation technology.

  9. Accumulation of cadmium, zinc, and copper by Helianthus annuus L.: impact on plant growth and uptake of nutritional elements.

    Science.gov (United States)

    Rivelli, Anna Rita; De Maria, Susanna; Puschenreiter, Markus; Gherbin, Piergiorgio

    2012-04-01

    We investigated the effects on physiological response, trace elements and nutrients accumulation of sunflower plants grown in soil contaminated with: 5 mg kg(-1) of Cd; 5 and 300 mg kg(-1) of Cd and Zn, respectively; 5, 300, and 400 mg kg(-1) of Cd, Zn, and Cu, respectively. Contaminants applied did not produce large effects on growth, except in Cd-Zn-Cu treatment in which leaf area and total dry matter were reduced, by 15%. The contamination with Cd alone did not affect neither growth nor physiological parameters, despite considerable amounts of Cd accumulated in roots and older leaves, with a high bioconcentration factor from soil to plant. By adding Zn and then Cu to Cd in soil, significant were the toxic effects on chlorophyll content and water relations due to greater accumulation of trace elements in tissues, with imbalances in nutrients uptake. Highly significant was the interaction between shoot elements concentration (Cd, Zn, Cu, Fe, Mg, K, Ca) and treatments. Heavy metals concentrations in roots always exceeded those in stem and leaves, with a lower translocation from roots to shoots, suggesting a strategy of sunflower to compartmentalise the potentially toxic elements in physiologically less active parts in order to preserve younger tissues.

  10. Plant phenology, growth and nutritive quality of Briza maxima: Responses induced by enhanced ozone atmospheric levels and nitrogen enrichment

    International Nuclear Information System (INIS)

    Sanz, J.; Bermejo, V.; Muntifering, R.; Gonzalez-Fernandez, I.; Gimeno, B.S.; Elvira, S.; Alonso, R.

    2011-01-01

    An assessment of the effects of tropospheric ozone (O 3 ) levels and substrate nitrogen (N) supplementation, singly and in combination, on phenology, growth and nutritive quality of Briza maxima was carried out. Two serial experiments were developed in Open-Top Chambers (OTC) using three O 3 and three N levels. Increased O 3 exposure did not affect the biomass-related parameters, but enhanced senescence, increased fiber foliar content (especially lignin concentration) and reduced plant life span; these effects were related to senescence acceleration induced by the pollutant. Added N increased plant biomass production and improved nutritive quality by decreasing foliar fiber concentration. Interestingly, the effects of N supplementation depended on meteorological conditions and plant physiological activity. N supplementation counteracted the O 3 -induced senescence but did not modifiy the effects on nutritive quality. Nutritive quality and phenology should be considered in new definitions of the O 3 limits for the protection of herbaceous vegetation. - Research highlights: → Forage quality (foliar protein and fiber content) and phenology are more O 3 -sensitive than growth parameters in the Mediterranean annual grass Briza maxima. → The effects of N supplementation depended on meteorological conditions and plant physiological activity. → Increase in nitrogen supplementation counterbalanced the O 3 -induced increase in senescence biomass. → Nutritive quality and phenology should be considered in new definitions of the O 3 limits for the protection of natural herbaceous vegetation. - Forage quality and phenology are more O 3 -sensitive than growth parameters in the Mediterranean annual grass Briza maxima.

  11. Effect of plant-biostimulant on cassava initial growth

    Directory of Open Access Journals (Sweden)

    João Emílio de Souza Magalhães

    2016-04-01

    Full Text Available ABSTRACT Biostimulants are complex substances that promote hormonal balance in plants, favor the genetic potential expression, and enhance growth of shoots and root system. The use of these plant growth promoters in crops can increase quantitatively and qualitatively crop production. Therefore, the aim of this study was to evaluate the effect of a commercial biostimulant on the initial growth of cassava. The experiment was arranged in a 2 x 5 factorial design, corresponding to two cassava cultivars (Cacau-UFV and Coimbra and five biostimulant concentrations (0, 4, 8, 12 and 16 mL L-1. At 90 days after planting, the characteristics leaf area, plant height, stem diameter, leaf number, total dry matter and dry matter of roots, stems and leaves were evaluated. The biostimulant promoted linear increases in plant height, leaf number, leaf area, total dry matter, dry matter of stems, leaves and roots. The cultivar Cacau-UFV had a higher growth rate than the cultivar Coimbra. The growth promoter stimulated the early growth of the cassava crop.

  12. Physiological characteristics of high yield under cluster planting: photosynthesis and canopy microclimate of cotton

    Directory of Open Access Journals (Sweden)

    Ting-ting Xie

    2016-01-01

    Full Text Available Cotton produces more biomass and economic yield when cluster planting pattern (three plants per hole than in a traditional planting pattern (one plant per hole, even at similar plant densities, indicating that individual plant growth is promoted by cluster planting. The causal factors for this improved growth induced by cluster planting pattern, the light interception, canopy microclimate and photosynthetic rate of cotton were investigated in an arid region of China. The results indicated that the leaf area index and light interception were higher in cluster planting, and significantly different from those in traditional planting during the middle and late growth stages. Cotton canopy humidity at different growth stages was increased but canopy temperatures were reduced by cluster planting. In the later growth stage of cluster planting, the leaf chlorophyll content was higher and the leaf net photosynthetic rate and canopy photosynthetic rate were significantly increased in comparing with traditional planting pattern. We concluded that differences in canopy light interception and photosynthetic rate were the primary factors responsible for increased biomass production and economic yield in cluster planting compared with the traditional planting of cotton.

  13. Influence of Pulsed Electromagnetic Field on Plant Growth, Nutrient Absorption and Yield of Durum Wheat

    Directory of Open Access Journals (Sweden)

    Nikolaos KATSENIOS

    2015-12-01

    Full Text Available Researchers have adopted the use of magnetic field as a new pre-sowing, environmental friendly technique. Enhancements on plant characteristics with economic impact on producer’s income could be the future of a modern, organic and sustainable agriculture. A field experiment was established at Soil Science Institute of Athens, Lycovrissi, Greece, in the winter of 2014. Two durum wheat cultivars were used. It was a pot experiment with 6 treatments (2 cultivars with 3 magnetic field time exposure. The seeds were treated using a PAPIMI electromagnetic field generator for 0, 30 and 45 minutes one day before planting. The experiment followed a completely randomized design with six treatments and 30 replications. The aim of this study was to evaluate the positive effect of magnetic field pre-sowing treatment in a wide range of plant measurements, including yield. The influence of pulsed electromagnetic field on two varieties of durum wheat seeds showed some statistically significant differences at the 0.05 level in growth measurements, physiological measurements and root growth measurements. Plant tissue analysis showed that magnetic field treatments had higher values than control in total nitrogen, phosphorus, potassium, magnesium, copper (only MF-45, zinc (only MF-30 and boron content, although values showed statistically significant differences only in total nitrogen. The results indicate that this innovative technique can increase the yield of durum wheat, through enhanced absorption of nutrients. Pre-sowing treatment of the seeds leads to vigorous plant growth that are more productive.

  14. Mechanisms and applications of plant growth promoting rhizobacteria: Current perspective

    Directory of Open Access Journals (Sweden)

    Munees Ahemad

    2014-01-01

    Full Text Available Plant growth promoting rhizobacteria are the soil bacteria inhabiting around/on the root surface and are directly or indirectly involved in promoting plant growth and development via production and secretion of various regulatory chemicals in the vicinity of rhizosphere. Generally, plant growth promoting rhizobacteria facilitate the plant growth directly by either assisting in resource acquisition (nitrogen, phosphorus and essential minerals or modulating plant hormone levels, or indirectly by decreasing the inhibitory effects of various pathogens on plant growth and development in the forms of biocontrol agents. Various studies have documented the increased health and productivity of different plant species by the application of plant growth promoting rhizobacteria under both normal and stressed conditions. The plant-beneficial rhizobacteria may decrease the global dependence on hazardous agricultural chemicals which destabilize the agro-ecosystems. This review accentuates the perception of the rhizosphere and plant growth promoting rhizobacteria under the current perspectives. Further, explicit outlooks on the different mechanisms of rhizobacteria mediated plant growth promotion have been described in detail with the recent development and research. Finally, the latest paradigms of applicability of these beneficial rhizobacteria in different agro-ecosystems have been presented comprehensively under both normal and stress conditions to highlight the recent trends with the aim to develop future insights.

  15. Plants growth, water relations and photosynthesis of two bean ...

    African Journals Online (AJOL)

    ... almost all physiological activities were suppressed. The superiority of the genotype Tema against Djadida genotype was attributed to quantitative rather than qualitative physiological response differences. Keywords: Salinity, fluridone, bean, growth, photosynthesis, stomatal conductance. African Journal of Biotechnology ...

  16. Prospecting cyanobacterial formulations as plant-growth-promoting ...

    African Journals Online (AJOL)

    Cyanobacteria represent environment-friendly inputs that can lead to savings of nitrogenous fertilisers, in addition to improving plant growth and soil fertility. The present investigation aimed to evaluate the potential of cyanobacteria inoculants as nutrient-management and plant-growth-promoting options for maize hybrids, ...

  17. Simulation of forest growth, applied to douglas fir stands in the Netherlands

    NARCIS (Netherlands)

    Mohren, G.M.J.

    1987-01-01

    Forest growth in relation to weather and soils is studied using a physiological simulation model. Growth potential depends on physiological characteristics of the plant species in combination with ambient weather conditions (mainly temperature and incoming radiation). For a given site, growth may be

  18. Ethylenediurea as a potential tool in evaluating ozone phytotoxicity: a review study on physiological, biochemical and morphological responses of plants.

    Science.gov (United States)

    Tiwari, Supriya

    2017-06-01

    Present-day climate change scenario has intensified the problem of continuously increasing ground-level ozone (O 3 ), which is responsible for causing deleterious effects on growth and development of plants. Studies involving use of ethylenediurea (EDU), a chemical with antiozonant properties, have given some promising results in evaluating O 3 injury in plants. The use of EDU is especially advantageous in developing countries which face a more severe problem of ground-level O 3 , and technical O 3 -induced yield loss assessment techniques like open-top chambers cannot be used. Recent studies have detected a hormetic response of EDU on plants; i.e. treatment with higher EDU concentrations may or may not show any adverse effect on plants depending upon the experimental conditions. Although the mode of action of EDU is still debated, it is confirmed that EDU remains confined in the apoplastic regions. Certain studies indicate that EDU significantly affects the electron transport chain and has positive impact on the antioxidant defence machinery of the plants. However, the mechanism of protecting the yield of plants without significantly affecting photosynthesis is still questionable. This review discusses in details the probable mode of action of EDU on the basis of available data along with the impact of EDU on physiological, biochemical, growth and yield response of plants under O 3 stress. Data regarding the effect of EDU on plant 'omics' is highly insufficient and can form an important aspect of future EDU research.

  19. Molecular and Functional Characterization of a Wheat B2 Protein Imparting Adverse Temperature Tolerance and Influencing Plant Growth

    Directory of Open Access Journals (Sweden)

    akanksha esingh

    2016-05-01

    Full Text Available Genomic attempts were undertaken to elucidate the plant developmental responses to heat stress, and to characterize the roles of B2 protein in mediating those responses. A wheat EST for B2 protein was identified which was cloned and characterized to assess its functional relevance causing plant growth and development during stress adaptation. Here, we show that wheat B2 protein is highly expressed in root and shoot tissues as well as in developing seed tissues under high temperature stress conditions. Morphological studies of transgenic Arabidopsis overexpressing gene encoding wheat B2 protein and Δb2 mutant plants were studied at major developmental stages. The stunted growth phenotype of mutant plants, together with hypocotyl and root elongation analysis of transgenic plants showed that B2 protein exhibits a crucial role in plant growth and development. Additional physiological analyses highlights the role of B2 protein in increased tolerance to heat and cold stresses by maintaining high chlorophyll content, strong activity of photosystem II and less membrane damage of overexpression transgenics as compared with the wild-type. Furthermore, the constitutive overexpression of TaB2 in Arabidopsis resulted in ABA hypersensitivity. Taken together, these studies suggest a novel perspectives of B2 protein in plant development and in mediating the thermal stress tolerance.

  20. Plant growth promoting bacteria as an alternative strategy for salt tolerance in plants: A review.

    Science.gov (United States)

    Numan, Muhammad; Bashir, Samina; Khan, Yasmin; Mumtaz, Roqayya; Shinwari, Zabta Khan; Khan, Abdul Latif; Khan, Ajmal; Al-Harrasi, Ahmed

    2018-04-01

    Approximately 5.2 billion hectare agriculture land are affected by erosion, salinity and soil degradation. Salinity stress has significantly affecting the fertile lands, and therefore possesses a huge impact on the agriculture and economy of a country. Salt stress has severe effects on the growth and development of plants as well as reducing its yield. Plants are inherently equipped with stress tolerance ability to responds the specific type of stress. Plants retained specific mechanisms for salt stress mitigation, such as hormonal stimulation, ion exchange, antioxidant enzymes and activation of signaling cascades on their metabolic and genetic frontiers that sooth the stressed condition. Additional to the plant inherent mechanisms, certain plant growth promoting bacteria (PGPB) also have specialized mechanism that play key role for salt stress tolerance and plant growth promotion. These bacteria triggers plants to produce different plant growth hormones like auxin, cytokinine and gibberellin as well as volatile organic compounds. These bacteria also produces growth regulators like siderophore, which fix nitrogen, solubilize organic and inorganic phosphate. Considering the importance of PGPB in compensation of salt tolerance in plants, the present study has reviewed the different aspect and mechanism of bacteria that play key role in promoting plants growth and yield. It can be concluded that PGPB can be used as a cost effective and economical tool for salinity tolerance and growth promotion in plants. Copyright © 2018 Elsevier GmbH. All rights reserved.

  1. Modelling of tomato stem diameter growth rate based on physiological responses

    International Nuclear Information System (INIS)

    Li, L.; Tan, J.; Lv, T.

    2017-01-01

    The stem diameter is an important parameter describing the growth of tomato plant during vegetative growth stage. A stem diameter growth model was developed to predict the response of plant growth under different conditions. By analyzing the diurnal variations of stem diameter in tomato (Solanum lycopersicum L.), it was found that the stem diameter measured at 3:00 am was the representative value as the daily basis of tomato stem diameter. Based on the responses of growth rate in stem diameter to light and temperature, a linear regression relationship was applied to establish the stem diameter growth rate prediction model for the vegetative growth stage in tomato and which was further validated by experiment. The root mean square error (RMSE) and relative error (RE) were used to test the correlation between measured and modeled stem diameter variations. Results showed that the model can be used in prediction for stem diameter growth rate at vegetative growth stage in tomato. (author)

  2. The Effect of Drought Stress and Plant Density on Biochemical and Physiological Characteristics of Two Garlic (Allium sativum L. Ecotypes

    Directory of Open Access Journals (Sweden)

    Sh Akbari

    2017-03-01

    Full Text Available Introduction Drought stress is the most important growth limiting factor for crop production. Sugar accumulation under drought stress strengthens and stabilizes cell membranes and maintains the water absorption and turgid property. Under stress conditions, proline will also maintain the turgor pressure and decreased the damages caused to plant membrane. Although proline concentrations may have undesirable effects on plant growth, because of deflecting photosynthetic resources to the processes that are not involved in plant growth. Chloroplasts and its pigments are also affected by drought stress. Density is one of the factors that has a significant impact on plant growth. Garlic is one of the edible plants which has generated considerable interest throughout human history because of its pharmaceutical properties. This study aimed to determine the effects of drought stress and plant density on some biochemical and physiological treats of two garlic ecotypes and determining the more resistant ecotype. Materials and Methods The study was carried out in 2011-2012 in a farm land at the south east of Semnan city. The experimental layout was a split-plot factorial with a randomized complete block design in three replications. The treatments were comprised of three factors: irrigation regimes (60%, 80% and 100% of estimated crop evapotranspiration (ETC that were assigned as the main plot and the factorial combination of 3 levels of planting density (30, 40 and 50 plants. m-2 and two ecotypes (Tabas and Toroud made up the sub-plots. The water requirement was calculated based on FAO-56 crop water requirements instruction. FAO-56 Penman-Monteith equation was used to calculate evapotranspiration. To calculate the content of soluble sugar, proline and leaves pigment, the samples were collected in a random way from the youngest fully expended leaves one month before the final harvest. Relative water content was estimated by measuring dry weight, fresh weight

  3. State of the interface between conservation and physiology: a bibliometric analysis

    Science.gov (United States)

    Lennox, Robert; Cooke, Steven J.

    2014-01-01

    Contemporary conservation science benefits from the perspectives of a variety of different disciplines, including a recent synergy with physiology, an interface known as ‘conservation physiology’. To evaluate the degree of interaction between conservation and animal/plant physiology, we conducted three bibliometric analyses. We first pursued the use of the term ‘conservation physiology’ since its first definition in 2006 to determine how frequently it has been used and in which publications. Secondly, we evaluated the occurrence of conservation terms in animal and plant physiology journals, physiological terms in conservation journals, and a combination of terms in ecology journals. Thirdly, we explored trends in a subset of conservation physiology articles published between 2006 and 2012. We identified a surge in the use of the term ‘conservation physiology’ in 2012, after only a slow increase in usage between 2006 and 2011. Conservation journals tend to have been significantly more active in publishing conservation physiology than animal physiology, plant physiology or ecology journals. However, we found evidence that ecology and animal physiology journals began to incorporate more conservation physiology after 2006, while conservation- and plant physiology-themed journals did not. Among 299 conservation physiology articles that we identified, vertebrate taxa have been over-represented in conservation physiology compared with their relative taxonomic abundance, invertebrate taxa have been under-represented, and plants have been represented in proportion to their relative taxonomic abundance; however, those findings are reasonably consistent with publication trends in conservation biology. Diffuse distribution of conservation physiology papers throughout the literature may have been a barrier to the growth of the subdiscipline when the interface was emerging. The introduction of the focused journal Conservation Physiology in 2013 may address that

  4. Exploring plant growth-promotion actinomycetes from vermicompost and rhizosphere soil for yield enhancement in chickpea

    Science.gov (United States)

    Sreevidya, M.; Gopalakrishnan, S.; Kudapa, H.; Varshney, R.K.

    2016-01-01

    The main objective of the present study was to isolate and characterize actinomycetes for their plant growth-promotion in chickpea. A total of 89 actinomycetes were screened for their antagonism against fungal pathogens of chickpea by dual culture and metabolite production assays. Four most promising actinomycetes were evaluated for their physiological and plant growth-promotion properties under in vitro and in vivo conditions. All the isolates exhibited good growth at temperatures from 20 °C to 40 °C, pH range of 7–11 and NaCl concentrations up to 8%. These were also found highly tolerant to Bavistin, slightly tolerant to Thiram and Captan (except VAI-7 and VAI-40) but susceptible to Benlate and Ridomil at field application levels and were found to produce siderophore, cellulase, lipase, protease, chitinase (except VAI-40), hydrocyanic acid (except VAI-7 and VAI-40), indole acetic acid and β-1,3-glucanase. When the four actinomycetes were evaluated for their plant growth-promotion properties under field conditions on chickpea, all exhibited increase in nodule number, shoot weight and yield. The actinomycetes treated plots enhanced total N, available P and organic C over the un-inoculated control. The scanning electron microscope studies exhibited extensive colonization by actinomycetes on the root surface of chickpea. The expression profiles for indole acetic acid, siderophore and β-1,3-glucanase genes exhibited up-regulation for all three traits and in all four isolates. The actinomycetes were identified as Streptomyces but different species in the 16S rDNA analysis. It was concluded that the selected actinomycetes have good plant growth-promotion and biocontrol potentials on chickpea. PMID:26887230

  5. Exploring plant growth-promotion actinomycetes from vermicompost and rhizosphere soil for yield enhancement in chickpea

    Directory of Open Access Journals (Sweden)

    M. Sreevidya

    2016-03-01

    Full Text Available Abstract The main objective of the present study was to isolate and characterize actinomycetes for their plant growth-promotion in chickpea. A total of 89 actinomycetes were screened for their antagonism against fungal pathogens of chickpea by dual culture and metabolite production assays. Four most promising actinomycetes were evaluated for their physiological and plant growth-promotion properties under in vitro and in vivo conditions. All the isolates exhibited good growth at temperatures from 20 °C to 40 °C, pH range of 7–11 and NaCl concentrations up to 8%. These were also found highly tolerant to Bavistin, slightly tolerant to Thiram and Captan (except VAI-7 and VAI-40 but susceptible to Benlate and Ridomil at field application levels and were found to produce siderophore, cellulase, lipase, protease, chitinase (except VAI-40, hydrocyanic acid (except VAI-7 and VAI-40, indole acetic acid and β-1,3-glucanase. When the four actinomycetes were evaluated for their plant growth-promotion properties under field conditions on chickpea, all exhibited increase in nodule number, shoot weight and yield. The actinomycetes treated plots enhanced total N, available P and organic C over the un-inoculated control. The scanning electron microscope studies exhibited extensive colonization by actinomycetes on the root surface of chickpea. The expression profiles for indole acetic acid, siderophore and β-1,3-glucanase genes exhibited up-regulation for all three traits and in all four isolates. The actinomycetes were identified as Streptomyces but different species in the 16S rDNA analysis. It was concluded that the selected actinomycetes have good plant growth-promotion and biocontrol potentials on chickpea.

  6. Changes in Leaf Anatomical Traits Enhanced Photosynthetic Activity of Soybean Grown in Hydroponics with Plant Growth-Promoting Microorganisms.

    Science.gov (United States)

    Paradiso, Roberta; Arena, Carmen; De Micco, Veronica; Giordano, Maria; Aronne, Giovanna; De Pascale, Stefania

    2017-01-01

    The use of hydroponic systems for cultivation in controlled climatic conditions and the selection of suitable genotypes for the specific environment help improving crop growth and yield. We hypothesized that plant performance in hydroponics could be further maximized by exploiting the action of plant growth-promoting organisms (PGPMs). However, the effects of PGPMs on plant physiology have been scarcely investigated in hydroponics. Within a series of experiments aimed to identify the best protocol for hydroponic cultivation of soybean [ Glycine max (L.) Merr.], we evaluated the effects of a PGPMs mix, containing bacteria, yeasts, mycorrhiza and trichoderma beneficial species on leaf anatomy, photosynthetic activity and plant growth of soybean cv. 'Pr91m10' in closed nutrient film technique (NFT). Plants were grown in a growth chamber under semi-aseptic conditions and inoculated at seed, seedling and plant stages, and compared to non-inoculated (control) plants. Light and epi-fluorescence microscopy analyses showed that leaves of inoculated plants had higher density of smaller stomata (297 vs. 247 n/mm 2 ), thicker palisade parenchyma (95.0 vs. 85.8 μm), and larger intercellular spaces in the mesophyll (57.5% vs. 52.2%), compared to non-inoculated plants. The modifications in leaf functional anatomical traits affected gas exchanges; in fact starting from the reproductive phase, the rate of leaf net photosynthesis (NP) was higher in inoculated compared to control plants (8.69 vs. 6.13 μmol CO 2 m -2 s -1 at the beginning of flowering). These data are consistent with the better maximal PSII photochemical efficiency observed in inoculated plants (0.807 vs. 0.784 in control); conversely no difference in leaf chlorophyll content was found. The PGPM-induced changes in leaf structure and photosynthesis lead to an improvement of plant growth (+29.9% in plant leaf area) and seed yield (+36.9%) compared to control. Our results confirm that PGPMs may confer benefits in

  7. Changes in Leaf Anatomical Traits Enhanced Photosynthetic Activity of Soybean Grown in Hydroponics with Plant Growth-Promoting Microorganisms

    Directory of Open Access Journals (Sweden)

    Roberta Paradiso

    2017-05-01

    Full Text Available The use of hydroponic systems for cultivation in controlled climatic conditions and the selection of suitable genotypes for the specific environment help improving crop growth and yield. We hypothesized that plant performance in hydroponics could be further maximized by exploiting the action of plant growth-promoting organisms (PGPMs. However, the effects of PGPMs on plant physiology have been scarcely investigated in hydroponics. Within a series of experiments aimed to identify the best protocol for hydroponic cultivation of soybean [Glycine max (L. Merr.], we evaluated the effects of a PGPMs mix, containing bacteria, yeasts, mycorrhiza and trichoderma beneficial species on leaf anatomy, photosynthetic activity and plant growth of soybean cv. ‘Pr91m10’ in closed nutrient film technique (NFT. Plants were grown in a growth chamber under semi-aseptic conditions and inoculated at seed, seedling and plant stages, and compared to non-inoculated (control plants. Light and epi-fluorescence microscopy analyses showed that leaves of inoculated plants had higher density of smaller stomata (297 vs. 247 n/mm2, thicker palisade parenchyma (95.0 vs. 85.8 μm, and larger intercellular spaces in the mesophyll (57.5% vs. 52.2%, compared to non-inoculated plants. The modifications in leaf functional anatomical traits affected gas exchanges; in fact starting from the reproductive phase, the rate of leaf net photosynthesis (NP was higher in inoculated compared to control plants (8.69 vs. 6.13 μmol CO2 m-2 s-1 at the beginning of flowering. These data are consistent with the better maximal PSII photochemical efficiency observed in inoculated plants (0.807 vs. 0.784 in control; conversely no difference in leaf chlorophyll content was found. The PGPM-induced changes in leaf structure and photosynthesis lead to an improvement of plant growth (+29.9% in plant leaf area and seed yield (+36.9% compared to control. Our results confirm that PGPMs may confer benefits in

  8. Physiological quality of soybean seeds under different yield environments and plant density

    Directory of Open Access Journals (Sweden)

    Felipe A. Baron

    Full Text Available ABSTRACT Yield potential of agricultural fields associated with plant spatial arrangement could determine the physiological quality of soybean (Glycine max L. seeds. Thus, this study aimed to evaluate the physiological quality of soybean seeds from different yield environments and plant densities. Experiments were carried out in Boa Vista das Missões-RS, Brazil, during the 2014/2015 growing season. Yield environments were delineated by overlapping yield maps from the 2008, 2009/2010 and 2011/2012 growing seasons. The experimental design was a randomized complete block in a 2 x 5 factorial arrangement with two yield environments (low and high and five plant densities, with four replicates. Two varieties were tested: Brasmax Ativa RR (10, 15, 20, 25 and 30 plants m-1 and Nidera 5909 RR (5, 10, 15, 20 and 25 plants m-1. After harvested, the seeds were analysed as following: first count index, germination, abnormal seedlings, dead seeds, electrical conductivity, accelerate aging test, root length, hypocotyl length and seedling length. The spatial variability of seed vigor in the production field could be reduced by adjusting plant density, but the adjustment should consider the variety. Harvest according to yield environment is a strategy to separate lots of seeds with higher vigor, originated from high-yield environments.

  9. Foreign acquisition, plant survival, and employment growth

    DEFF Research Database (Denmark)

    Bandick, Roger; Görg, Holger

    This paper analyses the effect of foreign acquisition on survival probability and employment growth of target plant using data on Swedish manufacturing plants during the period 1993-2002.  An improvement over previous studies is that we take into account firm level heterogeneity by separating...... the lifetime of the acquired plants only if the plant was an exporter.  The effect differs depending on whether the acquisition is horizontal or vertical.  We also find robust positive employment growth effects only for exporters, and only if the takeover is vertical, not horizontal....

  10. Impacts of extreme winter warming events on plant physiology in a sub-Arctic heath community.

    Science.gov (United States)

    Bokhorst, Stef; Bjerke, Jarle W; Davey, Matthew P; Taulavuori, Kari; Taulavuori, Erja; Laine, Kari; Callaghan, Terry V; Phoenix, Gareth K

    2010-10-01

    Insulation provided by snow cover and tolerance of freezing by physiological acclimation allows Arctic plants to survive cold winter temperatures. However, both the protection mechanisms may be lost with winter climate change, especially during extreme winter warming events where loss of snow cover from snow melt results in exposure of plants to warm temperatures and then returning extreme cold in the absence of insulating snow. These events cause considerable damage to Arctic plants, but physiological responses behind such damage remain unknown. Here, we report simulations of extreme winter warming events using infrared heating lamps and soil warming cables in a sub-Arctic heathland. During these events, we measured maximum quantum yield of photosystem II (PSII), photosynthesis, respiration, bud swelling and associated bud carbohydrate changes and lipid peroxidation to identify physiological responses during and after the winter warming events in three dwarf shrub species: Empetrum hermaphroditum, Vaccinium vitis-idaea and Vaccinium myrtillus. Winter warming increased maximum quantum yield of PSII, and photosynthesis was initiated for E. hermaphroditum and V. vitis-idaea. Bud swelling, bud carbohydrate decreases and lipid peroxidation were largest for E. hermaphroditum, whereas V. myrtillus and V. vitis-idaea showed no or less strong responses. Increased physiological activity and bud swelling suggest that sub-Arctic plants can initiate spring-like development in response to a short winter warming event. Lipid peroxidation suggests that plants experience increased winter stress. The observed differences between species in physiological responses are broadly consistent with interspecific differences in damage seen in previous studies, with E. hermaphroditum and V. myrtillus tending to be most sensitive. This suggests that initiation of spring-like development may be a major driver in the damage caused by winter warming events that are predicted to become more

  11. Hpa1 harpin needs nitroxyl terminus to promote vegetative growth and leaf photosynthesis in Arabidopsis.

    Science.gov (United States)

    Li, Xiaojie; Han, Liping; Zhao, Yanying; You, Zhenzhen; Dong, Hansong; Zhang, Chunling

    2014-03-01

    Hpa1 is a harpin protein produced by Xanthomonas oryzae, an important bacterial pathogen of rice, and has the growth-promoting activity in plants. To understand the molecular basis for the function of Hpa1, we generated an inactive variant protein, Hpa1 delta NT, by deleting the nitroxyl-terminal region of the Hpa1 sequence and compared Hpa1 delta NT with the full-length protein in terms of the effects on vegetative growth and related physiological responses in Arabidopsis. When Hpa1 was applied to plants, it acted to enhance the vegetative growth but did not affect the floral development. Enhanced plant growth was accompanied by induced expression of growth-promoting genes in plant leaves. The growth-promoting activity of Hpa1 was further correlated with a physiological consequence shown as promoted leaf photosynthesis as a result of facilitated CO2 conduction through leaf stomata and mesophyll cells. On the contrary, plant growth, growth-promoting gene expression, and the physiological consequence changed little in response to the Hpa1 delta NT treatment. These analyses suggest that Hpa1 requires the nitroxyl-terminus to facilitate CO2 transport inside leaf cells and promote leaf photosynthesis and vegetative growth of the plant.

  12. Using the WOFOST plant growth model to built the data base of the terrestrial tritium and food chain modules in RODOS

    International Nuclear Information System (INIS)

    Melintescu, A.; Galeriu, D.; Marica, A.

    2003-01-01

    The European Commission Project RODOS implements a coherent methodology for a Real-time On-line Decision Support System for Nuclear Emergency across Europe. Within this system there is a special module to model the transfer of tritiated water from releases to terrestrial foods. In order to model the transfer of tritiated water from air to various plants, the conversion to organically bound tritium, and the migration to edible parts of the plant, both the mean dynamics of leaf area index and a physiological description of canopy photosynthesis are required. The WOFOST crop growth model has been selected as a basis for deriving tritium transfer dynamics to plants. Its ability to reproduce site-specific biomass growth of various plants (not only from Europe) is demonstrated in this paper, as well as its compatibility to other photosynthesis models. We have tested that this model can simulate limited fertilization situations via the adaptation of two important parameters. After adaptation of model parameters to site-specific plant growth data, multi-annual mean dynamics can be obtained using meteorological data for subsequent years. (authors)

  13. Thidiazuron: A multi-dimensional plant growth regulator | Guo ...

    African Journals Online (AJOL)

    Thidiazuron (TDZ) has gained a considerable attention during past decades due to its efficient role in plant cell and tissue culture. Wide array of physiological responses were observed in response to TDZapplication in different plant species. TDZ has shown both auxin and cytokinin like effects, although, chemically, it is ...

  14. Plant Growth Promoting Rhizobacteria

    Indian Academy of Sciences (India)

    IAS Admin

    known to improve plant growth in many ways when compared to ... roles in agricultural productivity. ... Sustainable agriculture: Sustainable agriculture involves the successful management of agricultural re- ... For the first time Kloepper et al.

  15. Plant growth and gas balance in a plant and mushroom cultivation system

    Science.gov (United States)

    Kitaya, Y.; Tani, A.; Kiyota, M.; Aiga, I.

    1994-11-01

    In order to obtain basic data for construction of a plant cultivation system incorporating a mushroom cultivation subsystem in the CELSS, plant growth and atmospheric CO2 balance in the system were investigated. The plant growth was promoted by a high level of CO2 which resulted from the respiration of the mushroom mycelium in the system. The atmospheric CO2 concentration inside the system changed significantly due to the slight change in the net photosynthetic rate of plants and/or the respiration rate of the mushroom when the plant cultivation system combined directly with the mushroom cultivation subsystem.

  16. Physiological and molecular alterations in plants exposed to high [CO2] under phosphorus stress.

    Science.gov (United States)

    Pandey, Renu; Zinta, Gaurav; AbdElgawad, Hamada; Ahmad, Altaf; Jain, Vanita; Janssens, Ivan A

    2015-01-01

    Atmospheric [CO2] has increased substantially in recent decades and will continue to do so, whereas the availability of phosphorus (P) is limited and unlikely to increase in the future. P is a non-renewable resource, and it is essential to every form of life. P is a key plant nutrient controlling the responsiveness of photosynthesis to [CO2]. Increases in [CO2] typically results in increased biomass through stimulation of net photosynthesis, and hence enhance the demand for P uptake. However, most soils contain low concentrations of available P. Therefore, low P is one of the major growth-limiting factors for plants in many agricultural and natural ecosystems. The adaptive responses of plants to [CO2] and P availability encompass alterations at morphological, physiological, biochemical and molecular levels. In general low P reduces growth, whereas high [CO2] enhances it particularly in C3 plants. Photosynthetic capacity is often enhanced under high [CO2] with sufficient P supply through modulation of enzyme activities involved in carbon fixation such as ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco). However, high [CO2] with low P availability results in enhanced dry matter partitioning towards roots. Alterations in below-ground processes including root morphology, exudation and mycorrhizal association are influenced by [CO2] and P availability. Under high P availability, elevated [CO2] improves the uptake of P from soil. In contrast, under low P availability, high [CO2] mainly improves the efficiency with which plants produce biomass per unit P. At molecular level, the spatio-temporal regulation of genes involved in plant adaptation to low P and high [CO2] has been studied individually in various plant species. Genome-wide expression profiling of high [CO2] grown plants revealed hormonal regulation of biomass accumulation through complex transcriptional networks. Similarly, differential transcriptional regulatory networks are involved in P

  17. Plants, plant pathogens, and microgravity--a deadly trio

    Science.gov (United States)

    Leach, J. E.; Ryba-White, M.; Sun, Q.; Wu, C. J.; Hilaire, E.; Gartner, C.; Nedukha, O.; Kordyum, E.; Keck, M.; Leung, H.; hide

    2001-01-01

    Plants grown in spaceflight conditions are more susceptible to colonization by plant pathogens. The underlying causes for this enhanced susceptibility are not known. Possibly the formation of structural barriers and the activation of plant defense response components are impaired in spaceflight conditions. Either condition would result from altered gene expression of the plant. Because of the tools available, past studies focused on a few physiological responses or biochemical pathways. With recent advances in genomics research, new tools, including microarray technologies, are available to examine the global impact of growth in the spacecraft on the plant's gene expression profile. In ground-based studies, we have developed cDNA subtraction libraries of rice that are enriched for genes induced during pathogen infection and the defense response. Arrays of these genes are being used to dissect plant defense response pathways in a model system involving wild-type rice plants and lesion mimic mutants. The lesion mimic mutants are ideal experimental tools because they erratically develop defense response-like lesions in the absence of pathogens. The gene expression profiles from these ground-based studies will provide the molecular basis for understanding the biochemical and physiological impacts of spaceflight on plant growth, development and disease defense responses. This, in turn, will allow the development of strategies to manage plant disease for life in the space environment.

  18. Wired to the roots: impact of root-beneficial microbe interactions on aboveground plant physiology and protection.

    Science.gov (United States)

    Kumar, Amutha Sampath; Bais, Harsh P

    2012-12-01

    Often, plant-pathogenic microbe interactions are discussed in a host-microbe two-component system, however very little is known about how the diversity of rhizospheric microbes that associate with plants affect host performance against pathogens. There are various studies, which specially direct the importance of induced systemic defense (ISR) response in plants interacting with beneficial rhizobacteria, yet we don't know how rhizobacterial associations modulate plant physiology. In here, we highlight the many dimensions within which plant roots associate with beneficial microbes by regulating aboveground physiology. We review approaches to study the causes and consequences of plant root association with beneficial microbes on aboveground plant-pathogen interactions. The review provides the foundations for future investigations into the impact of the root beneficial microbial associations on plant performance and innate defense responses.

  19. Physiological responses of planting frozen and thawed Douglas-fir seedlings

    Science.gov (United States)

    M. Anisul Islam; Kent G. Apostol; Douglass F. Jacobs; R. Kasten Dumroese

    2008-01-01

    We studied the short-term (7-day) physiological responses of planting thawed and frozen root plugs of Douglas-fir (Pseudotsuga menziesii) seedlings in 2 separate experiments under cool-moist and warm-dry growing conditions, respectively. Our results showed that shoot water potential, root hydraulic conductance, net photosynthesis (A), and...

  20. Effect of Different Arbuscular Mycorrhizal Fungi on Growth and Physiology of Maize at Ambient and Low Temperature Regimes

    Directory of Open Access Journals (Sweden)

    Xiaoying Chen

    2014-01-01

    Full Text Available The effect of four different arbuscular mycorrhizal fungi (AMF on the growth and lipid peroxidation, soluble sugar, proline contents, and antioxidant enzymes activities of Zea mays L. was studied in pot culture subjected to two temperature regimes. Maize plants were grown in pots filled with a mixture of sandy and black soil for 5 weeks, and then half of the plants were exposed to low temperature for 1 week while the rest of the plants were grown under ambient temperature and severed as control. Different AMF resulted in different root colonization and low temperature significantly decreased AM colonization. Low temperature remarkably decreased plant height and total dry weight but increased root dry weight and root-shoot ratio. The AM plants had higher proline content compared with the non-AM plants. The maize plants inoculated with Glomus etunicatum and G. intraradices had higher malondialdehyde and soluble sugar contents under low temperature condition. The activities of catalase (CAT and peroxidase of AM inoculated maize were higher than those of non-AM ones. Low temperature noticeably decreased the activities of CAT. The results suggest that low temperature adversely affects maize physiology and AM symbiosis can improve maize seedlings tolerance to low temperature stress.

  1. by recycled subirrigational supply of plant growth retardants

    African Journals Online (AJOL)

    STORAGESEVER

    2008-05-16

    May 16, 2008 ... an ebb and flow system on the growth and flowering of kalanchoe cultivar 'Gold Strike' was examined. Plants potted in 10 cm .... photoperiod during the first six weeks after pinching. .... stage and adverse influences on overall growth of the plants. ..... retardants on the growth and flowering in poinsettia. RDA.

  2. Growth, physiological response and phytoremoval capability of two willow clones exposed to ibuprofen under hydroponic culture.

    Science.gov (United States)

    Iori, Valentina; Zacchini, Massimo; Pietrini, Fabrizio

    2013-11-15

    Ibuprofen (IBU) is one of the most widespread pharmaceuticals in the aquatic ecosystem, despite the high removal rate that occurs in wastewater treatment plants. Phytoremediation represents a technology to improve the performance of existing wastewater treatment. This study was conducted under hydroponics to evaluate the ability of Salicaceae plants to tolerate and reduce IBU concentration in contaminated water. To this end, we combined growth, physiological and biochemical data to study the effects of different IBU concentrations on two clones of Salix alba L. Data demonstrated that clone SS5 was more tolerant and showed a higher ability to reduce IBU concentration in the solution than clone SP3. The high tolerance to IBU shown by SS5 was likely due to several mechanisms including the capacity to maintain an elevated photosynthetic activity and an efficient antioxidative defence. These results illustrate the remarkable potential of willow to phytoremediate IBU-contaminated waters in natural and constructed wetlands. Copyright © 2013 Elsevier B.V. All rights reserved.

  3. Non-linear effects of drought under shade: reconciling physiological and ecological models in plant communities.

    Science.gov (United States)

    Holmgren, Milena; Gómez-Aparicio, Lorena; Quero, José Luis; Valladares, Fernando

    2012-06-01

    The combined effects of shade and drought on plant performance and the implications for species interactions are highly debated in plant ecology. Empirical evidence for positive and negative effects of shade on the performance of plants under dry conditions supports two contrasting theoretical models about the role of shade under dry conditions: the trade-off and the facilitation hypotheses. We performed a meta-analysis of field and greenhouse studies evaluating the effects of drought at two or more irradiance levels on nine response variables describing plant physiological condition, growth, and survival. We explored differences in plant response across plant functional types, ecosystem types and methodological approaches. The data were best fit using quadratic models indicating a humped-back shape response to drought along an irradiance gradient for survival, whole plant biomass, maximum photosynthetic capacity, stomatal conductance and maximal photochemical efficiency. Drought effects were ameliorated at intermediate irradiance, becoming more severe at higher or lower light levels. This general pattern was maintained when controlling for potential variations in the strength of the drought treatment among light levels. Our quantitative meta-analysis indicates that dense shade ameliorates drought especially among drought-intolerant and shade-tolerant species. Wet tropical species showed larger negative effects of drought with increasing irradiance than semiarid and cold temperate species. Non-linear responses to irradiance were stronger under field conditions than under controlled greenhouse conditions. Non-linear responses to drought along the irradiance gradient reconciliate opposing views in plant ecology, indicating that facilitation is more likely within certain range of environmental conditions, fading under deep shade, especially for drought-tolerant species.

  4. Taxonomy, physiology and growth of Lactococcus lactis: a review

    Directory of Open Access Journals (Sweden)

    Dubravka Samaržija

    2001-01-01

    Full Text Available Lactococcus lactis species is one of the most important groups of lactic acid bacteria that are used in the dairy industry. The major functions of this species in dairy fermentation are the production of lactic acid from lactose, hydrolysis of casein and citric acid fermentation. Thus their metabolic end products and enzymes directly or indirectly have significant influence in determining the texture and flavour of the final products. In recent years, genetics and physiological properties of lactococci have considerable changed. Therefore, both for basic research and for application purposes in this paper the general view of the new taxonomic classification of Lactococcus lactis, the role of their plasmids and the physiology and nutritional requirements during growth are discussed.

  5. The Physiology of Microbial Symbionts in Fungus-Farming Termites

    DEFF Research Database (Denmark)

    Rodrigues da Costa, Rafael

    . The termites provide the fungus with optimal growth conditions (e.g., stable temperature and humidity), as well as with constant inoculation of growth substrate and protection against alien fungi. In reward, the fungus provides the termites with a protein-rich fungal biomass based diet. In addition...... with their symbionts are main decomposer of organic matter in Africa, and this is reflect of a metabolic complementarity to decompose plant biomass in the genome of the three organisms involved in this symbiosis. Many of the physiological aspects of this symbiosis remain obscure, and here I focus on physiology...... of microbial symbionts associated with fungus-growing termites. Firstly, by using a set of enzyme assays, plant biomass compositional analyses, and RNA sequencing we gained deeper understanding on what enzymes are produced and active at different times of the decomposition process. Our results show that enzyme...

  6. Spiral Growth in Plants: Models and Simulations

    Science.gov (United States)

    Allen, Bradford D.

    2004-01-01

    The analysis and simulation of spiral growth in plants integrates algebra and trigonometry in a botanical setting. When the ideas presented here are used in a mathematics classroom/computer lab, students can better understand how basic assumptions about plant growth lead to the golden ratio and how the use of circular functions leads to accurate…

  7. Plant ion channels: gene families, physiology, and functional genomics analyses.

    Science.gov (United States)

    Ward, John M; Mäser, Pascal; Schroeder, Julian I

    2009-01-01

    Distinct potassium, anion, and calcium channels in the plasma membrane and vacuolar membrane of plant cells have been identified and characterized by patch clamping. Primarily owing to advances in Arabidopsis genetics and genomics, and yeast functional complementation, many of the corresponding genes have been identified. Recent advances in our understanding of ion channel genes that mediate signal transduction and ion transport are discussed here. Some plant ion channels, for example, ALMT and SLAC anion channel subunits, are unique. The majority of plant ion channel families exhibit homology to animal genes; such families include both hyperpolarization- and depolarization-activated Shaker-type potassium channels, CLC chloride transporters/channels, cyclic nucleotide-gated channels, and ionotropic glutamate receptor homologs. These plant ion channels offer unique opportunities to analyze the structural mechanisms and functions of ion channels. Here we review gene families of selected plant ion channel classes and discuss unique structure-function aspects and their physiological roles in plant cell signaling and transport.

  8. Role of medicinal plants on growth performance and immune status in fish.

    Science.gov (United States)

    Awad, Elham; Awaad, Amani

    2017-08-01

    Disease outbreaks increase proportionally with increases in intensive aquaculture. Natural products including medicinal plants have been known from thousands of years for treating some human diseases. It is well known that many active compounds are responsible for potential bio-activities. For that reason, there has been considerable interest in the use of medicinal plants in aquaculture with a view to providing safe and eco-friendly compounds for replacing antibiotics and chemical compounds as well as to enhance immune status and control fish diseases. This article describes a wide range of medicinal plants such as herbs, seeds, and spices with different forms such as crude, extracts, mixed and active compounds, used as immunostimulants and resulting in a marked enhancement in the immune system of fish to prevent and control microbial diseases. Moreover, different activity was recorded from plant parts like seeds, roots, flowers and leaves. The mode of action of medicinal plants was stimulation of the cellular and humoral immune response which was monitored through elevation in immune parameters. Various levels of immune stimulation have been shown by medicinal plants at different concentrations through injection or immersion or oral administration. However, it is critically important to determine the optimal dose to enhance the immune system of fish and avoid the risk of immunosuppression. Some medicinal plants have been used to replace the protein in fishmeal as a cheap source of protein and proved to be efficient in this respect. Medicinal plants can act as a growth promoter and immunomodulator at the same time. Further investigations should be carried out to examine the influence of those plants on fish health (including physiological and histological parameters) as a preliminary step for use in large scale in aquaculture. The current review describes the role of medicinal plants and their derivatives on innate and adaptive immune status as well as growth

  9. Plant growth strategies are remodeled by spaceflight

    Directory of Open Access Journals (Sweden)

    Paul Anna-Lisa

    2012-12-01

    Full Text Available Abstract Background Arabidopsis plants were grown on the International Space Station within specialized hardware that combined a plant growth habitat with a camera system that can capture images at regular intervals of growth. The Imaging hardware delivers telemetric data from the ISS, specifically images received in real-time from experiments on orbit, providing science without sample return. Comparable Ground Controls were grown in a sister unit that is maintained in the Orbital Environment Simulator at Kennedy Space Center. One of many types of biological data that can be analyzed in this fashion is root morphology. Arabidopsis seeds were geminated on orbit on nutrient gel Petri plates in a configuration that encouraged growth along the surface of the gel. Photos were taken every six hours for the 15 days of the experiment. Results In the absence of gravity, but the presence of directional light, spaceflight roots remained strongly negatively phototropic and grew in the opposite direction of the shoot growth; however, cultivars WS and Col-0 displayed two distinct, marked differences in their growth patterns. First, cultivar WS skewed strongly to the right on orbit, while cultivar Col-0 grew with little deviation away from the light source. Second, the Spaceflight environment also impacted the rate of growth in Arabidopsis. The size of the Flight plants (as measured by primary root and hypocotyl length was uniformly smaller than comparably aged Ground Control plants in both cultivars. Conclusions Skewing and waving, thought to be gravity dependent phenomena, occur in spaceflight plants. In the presence of an orienting light source, phenotypic trends in skewing are gravity independent, and the general patterns of directional root growth typified by a given genotype in unit gravity are recapitulated on orbit, although overall growth patterns on orbit are less uniform. Skewing appears independent of axial orientation on the ISS – suggesting

  10. Improving growth and yield of cowpea by foliar application of ...

    African Journals Online (AJOL)

    Water stress impaired cowpea plant growth and decreased ion percentage and chlorophyll and carbohydrate concentration in the shoot as well as yield and its quality. Foliar-applied chitosan, in particular 250 mg/l, increased plant growth, yield and its quality as well as physiological constituents in plant shoot under stressed ...

  11. Post-fertilization physiology and growth performance of loblolly pine clones

    Science.gov (United States)

    N.T. King; J.R. Seiler; T.R. Fox; KurtH. Johnsen

    2008-01-01

    The physiological processes leading to enhanced growth of loblolly pine (Pinus taeda L.) following fertilization are not clearly understood. Part of the debate revolves around the temporal response of net photosynthetic rate (An) to fertilization and whether the An response is always positive. We measured light-saturated photosynthetic rate (Asat), dark respiration...

  12. Growth and Physiology of Senegalia senegal (L. Britton Seedlings as Influenced by Seed Origin and Salinity and Fertility Treatments

    Directory of Open Access Journals (Sweden)

    Mame Sokhna Sarr

    2017-10-01

    Full Text Available Multipurpose trees such as Senegalia senegal are widespread in arid and semi-arid lands that have natural or induced saline soils and poor soil fertility. Such environmental problems impact growth and have the potential to influence plant physiological adaptations. Identifying superior genotypes better adapted to these environmental stresses will be of great importance for tree selection for reclamation of degraded drylands. The main objective of this study was to examine the growth performance, and physiological and morphological adaptations to salinity, and fertility treatments of different Senegalia senegal families. We used five families (DB16, DB14, K4B19, K17B19, NB1 selected from 60 families of a Senegalia senegal progeny trial in Dahra, Senegal. Seedlings were grown under greenhouse conditions by watering all plants for three weeks and then stopping all watering for three more weeks. In a randomized complete block design, a two-level factorial combination was used for salinity (zero and 183.1 mM NaCl added and fertility (zero and 100 kg/ha N-P-K added treatments. A significant family × salt × fertilizer interaction was found for all biomass parameters (leaf dry matter, stem dry matter, root dry matter, and leaf area. The fertilizer application resulted in a significant increase of total biomass of all families, ranging from 63% to 237% for NB1 and K17B19, respectively. In contrast, salt only decreased total biomass of NB1 and K17B19 increased growth. Despite similar net photosynthetic rates before treatment started, fertilizer and salinity induced different effects between families. Prior to drought stress, fertilizer did not affect photosynthesis of DB16, while salt significantly decreased stomatal conductance of all families. DB16 and N1B1, despite significant differences of stomata size and density, significantly decreased transpiration, and thereby increased their intrinsic water use efficiency. Under drought, relative growth rate

  13. Genotypic variation in growth and physiological response to drought stress and re-watering reveals the critical role of recovery in drought adaptation in maize seedlings

    Directory of Open Access Journals (Sweden)

    Daoqian eChen

    2016-01-01

    Full Text Available Non-irrigated crops in temperate climates and irrigated crops in arid climates are subjected to continuous cycles of water stress and re-watering. Thus, fast and efficient recovery from water stress may be among the key determinants of plant drought adaptation. The present study was designed to comparatively analyze the roles of drought resistance and drought recovery in drought adaptation and to investigate the physiological basis of genotypic variation in drought adaptation in maize (Zea mays seedlings. As the seedlings behavior in growth associate with yield under drought, it could partly reflect the potential of drought adaptability. Growth and physiological responses to progressive drought stress and recovery were observed in seedlings of ten maize lines. The results showed that drought adaptability is closely related to drought recovery (r = 0.714**, but not to drought resistance (r = 0.332. Drought induced decreases in leaf water content, water potential, osmotic potential, gas exchange parameters, chlorophyll content, Fv/Fm and nitrogen content, and increased H2O2 accumulation and lipid peroxidation. After recovery, most of these physiological parameters rapidly returned to normal levels. The physiological responses varied between lines. Further correlation analysis indicated that the physiological bases of drought resistance and drought recovery are definitely different, and that maintaining higher chlorophyll content (r = 0.874*** and Fv/Fm (r = 0.626* under drought stress contributes to drought recovery. Our results suggest that both drought resistance and recovery are key determinants of plant drought adaptation, and that drought recovery may play a more important role than previously thought. In addition, leaf water potential, chlorophyll content and Fv/Fm could be used as efficient reference indicators in the selection of drought-adaptive genotypes.

  14. Regulating Intracellular Calcium in Plants: From Molecular Genetics to Physiology

    International Nuclear Information System (INIS)

    Sze, Heven

    2008-01-01

    To grow, develop, adapt, and reproduce, plants have evolved mechanisms to regulate the uptake, translocation and sorting of calcium ions into different cells and subcellular compartments. Yet how plants accomplish this remarkable feat is still poorly understood. The spatial and temporal changes in intracellular (Ca2+) during growth and during responses to hormonal and environmental stimuli indicate that Ca2+ influx and efflux transporters are diverse and tightly regulated in plants. The specific goals were to determine the biological roles of multiple Ca pumps (ECAs) in the model plant Arabidopsis thaliana. We had pioneered the use of K616 yeast strain to functionally express plant Ca pumps, and demonstrated two distinct types of Ca pumps in plants (Sze et al., 2000. Annu Rev Plant Biol. 51,433). ACA2 represented one type that was auto-inhibited by the N-terminal region and stimulated by calmodulin. ECA1 represented another type that was not sensitive to calmodulin and phylogenetically distinct from ACAs. The goal to determine the biological roles of multiple ECA-type Ca pumps in Arabidopsis has been accomplished. Although we demonstrated ECA1 was a Ca pump by functional expression in yeast, the in vivo roles of ECAs was unclear. A few highlights are described. ECA1 and/or ECA4 are Ca/Mn pumps localized to the ER and are highly expressed in all cell types. Using homozygous T-DNA insertional mutants of eca1, we demonstrated that the ER-bound ECA1 supports growth and confers tolerance of plants growing on medium low in Ca or containing toxic levels of Mn. This is the first genetic study to determine the in vivo function of a Ca pump in plants. A phylogenetically distinct ECA3 is also a Ca/Mn pump that is localized to endosome, such as post-Golgi compartments. Although it is expressed at lower levels than ECA1, eca3 mutants are impaired in Ca-dependent root growth and in pollen tube elongation. Increased secretion of wall proteins in mutants suggests that Ca and Mn

  15. The effects of rare earth elements on the growth and nutrition of plants

    International Nuclear Information System (INIS)

    Diatloff, E.; Asher, C.J.; Smith, F.W.

    1998-01-01

    Full text: The rare earth elements (REEs) have many and varied uses throughout the world. However, the large scale use of REEs in agriculture is confined to China where some beneficial effects of REEs have been reported. Very little is known about the basic physiological effects of REEs on plants. Such information is essential for an understanding of how these elements may influence agricultural crop production. In this paper we summarise results of experiments rigorously conducted over 3 years to examine the effects of lanthanum (La) and cerium (Ce) on the growth and mineral nutrition of plants. Lanthanum and Ce were applied to the foliage or roots of two plant species (Corn ( Zea mays) and mungbean ( Vigna radiata)) of agricultural importance in the sub-tropical and tropical areas of the world. A commercial REE fertiliser was obtained from China, chemically analysed and found to contain mainly La and Ce nitrates. This fertiliser and comparable synthetic REE solutions were applied at the recommended rates to the leaves of corn and mungbean plants grown on a low-REE medium under well-controlled environmental conditions. Foliar application of REEs did not significantly increase the shoot dry weight of corn or mungbean. Both REE sources applied at 0.5 and 1.0% produced symptoms of foliar damage and reduced shoot dry weight in both plant species. Damage symptoms and growth reductions of plants sprayed with pure La and Ce solutions were similar to those of plants sprayed with commercial REE fertiliser. When REEs were maintained in a soluble form in nutrient solutions comparable in composition to soil solutions, concentrations of La or Ce from 1 to 16 μM (0.1 - 2 ppm) were found to be toxic to the root elongation of corn and mungbean. Subsequently, when concentrations of La or Ce below 1.5 μM (<0.2 ppm) were accurately maintained in solution, concentrations as low as 0.2 μM (0.03 ppm) were shown to be toxic to mungbean. Thus Ce at 0.2 μM (0.03 ppm) reduced the total

  16. The effects of different nickel concentrations on some morpho-physiological characteristics of parsley (Petroselinum crispum

    Directory of Open Access Journals (Sweden)

    mitra khatib

    2009-06-01

    Full Text Available Nickel as a heavy metal is considered a fatal and toxic element for humans, animals and plants. However, some plants are known as hyper accumulator for nickel and sometimes seem to be useful for plant growth. Thus, investigation on the effect of nickel on plants' growth is an issue of importance. In this paper, we have studied the effect of different nickel concentrations on parsley growth and morph-physiological characteristics and its effect on absorption of some macro elements in this plant. Seeds of parsley were germinated in germinator and seedlings were transferred to hydroponics culture. The seedlings were grown in Hogland solution with different nickel concentrations (in form of nickel nitrate of: 0, 0.25, 0.5, 0.75, 1, 1.5, 2 and 4 ppm. A completely randomized design with 8 treatments and 7 replications per treatment was used. Twelve weeks after treatments, morph-physiological characteristics including SPAD number, plant biomass, length of shoot and root, leaf area, leaf number and stomatal resistance were measured. The amount of absorbed nickel in plant foliages and roots of different treatments were also measured. The results revealed that the application of different nickel concentrations were decreased SPAD number, plant biomass, leaf area and leaf number, but the stomatal resistance were increased. Increase of nickel concentration resulted increasing Ni concentrations of plant foliages and roots. Nickel with 0.75 ppm concentration or higher imposed a toxic effect on parsley as general wilting and significant reduction in most morph-physiological characteristics. Keywords: Hydroponics culture, parsley, Petroselinum crispum, Nickel.

  17. Tomato root growth and phosphorus absorption kinetics by tomato plants as affected by phosphorus concentration in nutrient solution

    International Nuclear Information System (INIS)

    Fontes, P.C.R.; Barber, S.A.

    1984-01-01

    To evaluate the effects P concentrations in nutrient solution on root growth and on root physiological characteristics involved in P uptake by tomato Lycopersicon esculentum Mill plants, six seedlings were grown in nutrient solution at initial concentrations of 48.5, 97, 194 and 388 μMP until one day before harvest. They were then transferred to solutions with P at 20 μM and 30 μM, and the depletion curves and Michaelis-Menten parameters were determined. The conclusions were that as P supply increased and as the plant P contents are sufficient for maximum growth, the rate of P uptake tends to be lower. The results also indicate that total P uptake by tomato seedlings depends on the amount of root surface area exposed to P. (M.A.C.) [pt

  18. Variation in relative growth rate and growth traits in wild and cultivated Capsicum accessions grown under different temperatures

    NARCIS (Netherlands)

    Swart, de E.A.M.; Marcelis, L.F.M.; Voorrips, R.E.

    2006-01-01

    Differences in environmental conditions are known to influence plant growth and growth-related traits. The aim of this study was to identify the variation in relative growth rate (RGR), and its underlying physiological and morphological traits, in a group of ten wild and cultivated Capsicum

  19. Increasing rice plant growth by Trichoderma sp.

    Science.gov (United States)

    Doni, Febri; Isahak, Anizan; Zain, Che Radziah Che Mohd; Sulaiman, Norela; Fathurahman, F.; Zain, Wan Nur Syazana Wan Mohd.; Kadhimi, Ahsan A.; Alhasnawi, Arshad Naji; Anhar, Azwir; Yusoff, Wan Mohtar Wan

    2016-11-01

    Trichoderma sp. is a plant growth promoting fungi in many crops. Initial observation on the ability to enhance rice germination and vigor have been reported. In this study, the effectiveness of a local isolate Trichoderma asprellum SL2 to enhance rice seedling growth was assessed experimentally under greenhouse condition using a completely randomized design. Results showed that inoculation of rice plants with Trichoderma asprellum SL2 significantly increase rice plants height, root length, wet weight, leaf number and biomass compared to untreated rice plants (control). The result of this study can serve as a reference for further work on the application of beneficial microorganisms to enhance rice production.

  20. Basic versus applied research: Julius Sachs (1832-1897) and the experimental physiology of plants.

    Science.gov (United States)

    Kutschera, Ulrich

    2015-01-01

    The German biologist Julius Sachs was the first to introduce controlled, accurate, quantitative experimentation into the botanical sciences, and is regarded as the founder of modern plant physiology. His seminal monograph Experimental-Physiologie der Pflanzen (Experimental Physiology of Plants) was published 150 y ago (1865), when Sachs was employed as a lecturer at the Agricultural Academy in Poppelsdorf/Bonn (now part of the University). This book marks the beginning of a new era of basic and applied plant science. In this contribution, I summarize the achievements of Sachs and outline his lasting legacy. In addition, I show that Sachs was one of the first biologists who integrated bacteria, which he considered to be descendants of fungi, into the botanical sciences and discussed their interaction with land plants (degradation of wood etc.). This "plant-microbe-view" of green organisms was extended and elaborated by the laboratory botanist Wilhelm Pfeffer (1845-1920), so that the term "Sachs-Pfeffer-Principle of Experimental Plant Research" appears to be appropriate to characterize this novel way of performing scientific studies on green, photoautotrophic organisms (embryophytes, algae, cyanobacteria).

  1. Physiological response of soybean and wheat to gamma radiation and gibberellin

    International Nuclear Information System (INIS)

    Maghraby, G. M.

    1997-01-01

    The main objective of this work is to study and evaluate physiological effects of gamma radiation and/or GA 3 on plant growth, nutritional status of plants, yield and some quality of seeds of soybean and wheat. Two field experiments were conducted under the condition of clay loam soil at kaliobia governorate during 1993 and 1994 and 1992/1993 and 1993/1994 for soybean and wheat, respectively. Growth of soybean and wheat plants was considerably stimulated by irradiation seeds before sowing with low gamma doses and/or concentration of Ga 3. Maximum growth of both plants was obtained by the combined treatment of 2 0 Gy x 25 ppm GA 3 and 1 0 Gy x 100 ppm GA 3 for soybean and wheat, respectively. On the contrary high gamma doses and/or high rates of GA 3 depressed growth of both plants. Low gamma doses and/or GA 3 at low concentration greatly encouraged nutrients uptake by soybean and wheat plants, i.e., N, Fe, Mn and Zn which seemed to be positively related to plant growth. Whereas, high doses and/or high concentrations of GA 3 reduced these nutrients in plant. 53 tabs., 5 figs., 91 refs

  2. Foreign acquisition, plant survival, and employment growth

    DEFF Research Database (Denmark)

    Bandick, Roger; Görg, Holger

    2010-01-01

    This paper analyzes the effect of foreign acquisition on survival and employment growth of targets using data on Swedish manufacturing plants.We separate targeted plants into those within Swedish MNEs, Swedish exporting non-MNEs, and purely domestic firms. The results, controlling for possible...... acquisitions. We find robust positive employment growth effects only for exporters and only if the takeover is vertical....

  3. The phytotronist and the phenotype: plant physiology, Big Science, and a Cold War biology of the whole plant.

    Science.gov (United States)

    Munns, David P D

    2015-04-01

    This paper describes how, from the early twentieth century, and especially in the early Cold War era, the plant physiologists considered their discipline ideally suited among all the plant sciences to study and explain biological functions and processes, and ranked their discipline among the dominant forms of the biological sciences. At their apex in the late-1960s, the plant physiologists laid claim to having discovered nothing less than the "basic laws of physiology." This paper unwraps that claim, showing that it emerged from the construction of monumental big science laboratories known as phytotrons that gave control over the growing environment. Control meant that plant physiologists claimed to be able to produce a standard phenotype valid for experimental biology. Invoking the standards of the physical sciences, the plant physiologists heralded basic biological science from the phytotronic produced phenotype. In the context of the Cold War era, the ability to pursue basic science represented the highest pinnacle of standing within the scientific community. More broadly, I suggest that by recovering the history of an underappreciated discipline, plant physiology, and by establishing the centrality of the story of the plant sciences in the history of biology can historians understand the massive changes wrought to biology by the conceptual emergence of the molecular understanding of life, the dominance of the discipline of molecular biology, and the rise of biotechnology in the 1980s. Copyright © 2015 Elsevier Ltd. All rights reserved.

  4. Graphene quantum dots as enhanced plant growth regulators: effects on coriander and garlic plants.

    Science.gov (United States)

    Chakravarty, Disha; Erande, Manisha B; Late, Dattatray J

    2015-10-01

    We report investigations on the use of graphene quantum dots for growth enhancement in coriander (Coriandrum sativam L.) and garlic (Allium sativum) plants. The as-received seeds of coriander and garlic were treated with 0.2 mg mL(-1) of graphene quantum dots for 3 h before planting. Graphene quantum dots enhanced the growth rate in coriander and garlic plants, including leaves, roots, shoots, flowers and fruits, when the seeds were treated with graphene quantum dots. Our investigations open up the opportunity to use graphene quantum dots as plant growth regulators that can be used in a variety of other food plants for high yield. © 2015 Society of Chemical Industry.

  5. Portraying mechanics of plant growth promoting rhizobacteria (PGPR: A review

    Directory of Open Access Journals (Sweden)

    Dweipayan Goswami

    2016-12-01

    Full Text Available Population growth and increase in food requirement is the global problem. It is inevitable to introduce new practices that help to increase agricultural productivity. Use of plant growth promoting rhizobacteria (PGPR has shown potentials to be a promising technique in the practice of sustainable agriculture. A group of natural soil microbial flora acquire dwelling in the rhizosphere and on the surface of the plant roots which impose beneficial effect on the overall well-being of the plant are categorized as PGPR. Researchers are actively involved in understanding plant growth promoting mechanics employed by PGPR. Broadly, these are divided into direct and indirect mechanics. Any mechanism that directly enhances plant growth either by providing nutrients or by producing growth regulators are portrayed as direct mechanics. Whereas, any mechanisms that protects plant from acquiring infections (biotic stress or helps plant to grow healthily under environmental stresses (abiotic stress are considered indirect mechanics. This review is focused to describe cogent mechanics employed by PGPR that assists plant to sustain healthy growth. Also, we emphasized on the PGPR-based products which have been commercially developed exploiting these mechanics of PGPR.

  6. Cadmium effects on growth and physiology of Ulva lactuca

    Energy Technology Data Exchange (ETDEWEB)

    Markham, J.W.; Kremer, B.P.; Sperling, K.R.

    1980-01-01

    The chlorophycean Ulva lactuca L. was grown in the laboratory in unialgal culture to sufficient size so that up to 70 discs, 24 mm in diameter, could be punched out of a single plant. Using such discs, U. lactuca was then tested with various concentrations of Cd under continuous-flow conditions. A concentration of 4.5 ppm Cd was lethal to U. lactuca within 6 days. Control discs in unpolluted water increased in diameter at a rate of 8 to 13% day/sup -1/ over a 6-day period. At sublethal concentration of Cd a sharp reduction in growth rate was observed at increasing concentrations up to approximately 0.3 ppm Cd, whereas from 0.3 ppm Cd to the lethal concentrations the reduction of the growth rate was significantly less. Reduction in photosynthetic performance corresponded closely to the recuction in growth rate. At ambient concentrations of 0.8 ppm Cd, the plants concentrated Cd by a factor of approximately 50 in 6 days. Much higher concentration factors were attained in lower ambient concentrations. After removal from Cd-polluted water into flow-through culture in unpolluted water, a subsequent loss of Cd was indicated and the plants recovered rapidly. Plants exposed up to 3 d to 0.7 ppm Cd recovered sufficiently to produce viable gametes 7 days after removal from Cd. Because it has a relatively short life span and apparently loses Cd subsequent to exposure to Cd-polluted water, Ulva lactuca is not recommended as an alga for monitoring in-situ environmental pollution.

  7. Polyamines in plant physiology

    Science.gov (United States)

    Galston, A. W.; Sawhney, R. K.

    1990-01-01

    The diamine putrescine, the triamine spermidine, and the tetramine spermine are ubiquitous in plant cells, while other polyamines are of more limited occurrence. Their chemistry and pathways of biosynthesis and metabolism are well characterized. They occur in the free form as cations, but are often conjugated to small molecules like phenolic acids and also to various macromolecules. Their titer varies from approximately micromolar to more than millimolar, and depends greatly on environmental conditions, especially stress. In cereals, the activity of one of the major polyamine biosynthetic enzymes, arginine decarboxylase, is rapidly and dramatically increased by almost every studied external stress, leading to 50-fold or greater increases in putrescine titer within a few hours. The physiological significance of this increase is not yet clear, although most recent work suggests an adaptive, protective role. Polyamines produced through the action of ornithine decarboxylase, by contrast, seem essential for DNA replication and cell division. The application of exogenous polyamines produces effects on patterns of senescence and morphogenesis, suggesting but not proving a regulatory role for polyamines in these processes. The evidence for such a regulatory role is growing.

  8. Assessment of Cadmium and Chromium Stress on Growth, Physiology and Metal Uptake Using Mirabilis Jalapa

    OpenAIRE

    S. A. Shahanaz Begum; Tharakeswar Yadamari; Kalyan Yakkala; Sreevani Parvathareddy; Ramakrishna Naidu Gurijala

    2015-01-01

    Phytoextraction potential of Mirabilis jalapa, with tuberous root having high ecological adoptability was studied in the present work . Different levels of cadmium and chromium stress on growth, physiology and metal uptake were studied using pot experiments. The experiment comprised of 5 dosages of cadmium and chromium with different test concentrations (TC) viz, TC1(0), TC2(25), TC3(50), TC4(75) and TC5(100) ppm, for the period of 45 days. Growth, physiological parameters and metal accumulat...

  9. Effect of plant growth-promoting bacteria on the growth and fructan production of Agave americana L.

    Directory of Open Access Journals (Sweden)

    Neyser De La Torre-Ruiz

    Full Text Available ABSTRACT The effect of plant growth-promoting bacteria inoculation on plant growth and the sugar content in Agave americana was assessed. The bacterial strains ACO-34A, ACO-40, and ACO-140, isolated from the A. americana rhizosphere, were selected for this study to evaluate their phenotypic and genotypic characteristics. The three bacterial strains were evaluated via plant inoculation assays, and Azospirillum brasilense Cd served as a control strain. Phylogenetic analysis based on the 16S rRNA gene showed that strains ACO-34A, ACO-40 and ACO-140 were Rhizobium daejeonense, Acinetobacter calcoaceticus and Pseudomonas mosselii, respectively. All of the strains were able to synthesize indole-3-acetic acid (IAA, solubilize phosphate, and had nitrogenase activity. Inoculation using the plant growth-promoting bacteria strains had a significant effect (p < 0.05 on plant growth and the sugar content of A. americana, showing that these native plant growth-promoting bacteria are a practical, simple, and efficient alternative to promote the growth of agave plants with proper biological characteristics for agroindustrial and biotechnological use and to increase the sugar content in this agave species.

  10. Efficiency of plant growth-promoting rhizobacteria (PGPR) for the ...

    African Journals Online (AJOL)

    Plant growth-promoting rhizobacteria (PGPR) are beneficial bacteria that colonize plant roots and enhance plant growth by a wide variety of mechanisms. The use of PGPR is steadily increasing in agriculture and offers an attractive way to replace chemical fertilizers, pesticides, and supplements. Here, we have isolated and ...

  11. Expert System Control of Plant Growth in an Enclosed Space

    Science.gov (United States)

    May, George; Lanoue, Mark; Bathel, Matthew; Ryan, Robert E.

    2008-01-01

    The Expert System is an enclosed, controlled environment for growing plants, which incorporates a computerized, knowledge-based software program that is designed to capture the knowledge, experience, and problem-solving skills of one or more human experts in a particular discipline. The Expert System is trained to analyze crop/plant status, to monitor the condition of the plants and the environment, and to adjust operational parameters to optimize the plant-growth process. This system is intended to provide a way to remotely control plant growth with little or no human intervention. More specifically, the term control implies an autonomous method for detecting plant states such as health (biomass) or stress and then for recommending and implementing cultivation and/or remediation to optimize plant growth and to minimize consumption of energy and nutrients. Because of difficulties associated with delivering energy and nutrients remotely, a key feature of this Expert System is its ability to minimize this effort and to achieve optimum growth while taking into account the diverse range of environmental considerations that exist in an enclosed environment. The plant-growth environment for the Expert System could be made from a variety of structures, including a greenhouse, an underground cavern, or another enclosed chamber. Imaging equipment positioned within or around the chamber provides spatially distributed crop/plant-growth information. Sensors mounted in the chamber provide data and information pertaining to environmental conditions that could affect plant development. Lamps in the growth environment structure supply illumination, and other additional equipment in the chamber supplies essential nutrients and chemicals.

  12. Plant growth-promoting bacteria for phytostabilization of mine tailings.

    Science.gov (United States)

    Grandlic, Christopher J; Mendez, Monica O; Chorover, Jon; Machado, Blenda; Maier, Raina M

    2008-03-15

    Eolian dispersion of mine tailings in arid and semiarid environments is an emerging global issue for which economical remediation alternatives are needed. Phytostabilization, the revegetation of these sites with native plants, is one such alternative. Revegetation often requires the addition of bulky amendments such as compost which greatly increases cost. We report the use of plant growth-promoting bacteria (PGPB) to enhance the revegetation of mine tailings and minimize the need for compost amendment. Twenty promising PGPB isolates were used as seed inoculants in a series of greenhouse studies to examine revegetation of an extremely acidic, high metal contenttailings sample previously shown to require 15% compost amendment for normal plant growth. Several isolates significantly enhanced growth of two native species, quailbush and buffalo grass, in tailings. In this study, PGPB/compost outcomes were plant specific; for quailbush, PGPB were most effective in combination with 10% compost addition while for buffalo grass, PGPB enhanced growth in the complete absence of compost. Results indicate that selected PGPB can improve plant establishment and reduce the need for compost amendment. Further, PGPB activities necessary for aiding plant growth in mine tailings likely include tolerance to acidic pH and metals.

  13. Paradigm shift in plant growth control.

    Science.gov (United States)

    Körner, Christian

    2015-06-01

    For plants to grow they need resources and appropriate conditions that these resources are converted into biomass. While acknowledging the importance of co-drivers, the classical view is still that carbon, that is, photosynthetic CO2 uptake, ranks above any other drivers of plant growth. Hence, theory and modelling of growth traditionally is carbon centric. Here, I suggest that this view is not reflecting reality, but emerged from the availability of methods and process understanding at leaf level. In most cases, poorly understood processes of tissue formation and cell growth are governing carbon demand, and thus, CO2 uptake. Carbon can only be converted into biomass to the extent chemical elements other than carbon, temperature or cell turgor permit. Copyright © 2015. Published by Elsevier Ltd.

  14. Is physiological performance a good predictor for fitness? Insights from an invasive plant species.

    Directory of Open Access Journals (Sweden)

    Marco A Molina-Montenegro

    Full Text Available Is physiological performance a suitable proxy of fitness in plants? Although, several studies have been conducted to measure some fitness-related traits and physiological performance, direct assessments are seldom found in the literature. Here, we assessed the physiology-fitness relationship using second-generation individuals of the invasive plant species Taraxacum officinale from 17 localities distributed in five continents. Specifically, we tested if i the maximum quantum yield is a good predictor for seed-output ii whether this physiology-fitness relationship can be modified by environmental heterogeneity, and iii if this relationship has an adaptive consequence for T. officinale individuals from different localities. Overall, we found a significant positive relationship between the maximum quantum yield and fitness for all localities evaluated, but this relationship decreased in T. officinale individuals from localities with greater environmental heterogeneity. Finally, we found that those individuals from localities where environmental conditions are highly seasonal performed better under heterogeneous environmental conditions. Contrarily, under homogeneous controlled conditions, those individuals from localities with low environmental seasonality performed much better. In conclusion, our results suggest that the maximum quantum yield seem to be good predictors for plant fitness. We suggest that rapid measurements, such as those obtained from the maximum quantum yield, could provide a straightforward proxy of individual's fitness in changing environments.

  15. PLANT GROWTH-PROMOTING MICROBIAL INOCULANT FOR Schizolobium parahyba pv. parahyba

    Directory of Open Access Journals (Sweden)

    Priscila Jane Romano de Oliveira Gonçalves

    2015-08-01

    Full Text Available ABSTRACTSchizolobium parahyba pv. amazonicum (Huber ex Ducke Barneby (paricá occurs naturally in the Amazon and is significant commercial importance due to its rapid growth and excellent performance on cropping systems. The aim of this paper was to evaluate a microbial inoculants such as arbuscular mycorrhiza fungi (AMF and Rhizobium sp. that promote plant growth. The inocula was 10 g of root colonized and spores of Glomus clarum and/or 1 mL of cell suspension (107 CFU/mL of Rhizobium sp. and/or 100 g of chemical fertilizer NPK 20-05-20 per planting hole. The experimental design was complete randomized blocks with five replications and eight treatments (n = 800. Plant height, stem diameter and plant survival were measured. The results were tested for normality and homogeneity of variances and analyzed by ANOVA and Tukey test (p < 0.05. Rhizobium sp and AM fungi showed no effect on plant growth. Environmental factors probably influenced the effectiveness of symbiosis of both microorganisms and plant growth. The chemical fertilizer increased S. parahyba growth. During the first 120 days plants suffered with drought and frost, and at 180 days plants inoculated with microorganism plus chemical fertilizer showed higher survival when compared with control. The results showed that the microbial inoculants used showed an important role on plant survival after high stress conditions, but not in plant growth. Also was concluded that the planting time should be between November to December to avoid the presence of young plants during winter time that is dry and cold.

  16. Symbiotic regulation of plant growth, development and reproduction

    Science.gov (United States)

    Russell J. Rodriguez; D. Carl Freeman; E. Durant McArthur; Yong Ok Kim; Regina S. Redman

    2009-01-01

    The growth and development of rice (Oryzae sativa) seedlings was shown to be regulated epigenetically by a fungal endophyte. In contrast to un-inoculated (nonsymbiotic) plants, endophyte colonized (symbiotic) plants preferentially allocated resources into root growth until root hairs were well established. During that time symbiotic roots expanded at...

  17. Diversity and Plant Growth Promoting Proerties of Rhizobacteria ...

    African Journals Online (AJOL)

    The purpose of this study was to evaluate and assess the plant growth promoting characteristics and diversity of major tef rhizosphere isolates from central Ethiopia. A total of 162 bacteria were isolated from rhizosphere of tef [Eragrostis tef (Zucc.) Trotter] and characterized. While screening using some plant growth ...

  18. The use of stable isotopes for studies on the physiology of plants

    International Nuclear Information System (INIS)

    Moyse, Alexis.

    1982-01-01

    The use of the stable isotopes 15 N, 18 O, 13 C for studies on the physiology of plants especially of plants grown under natural environment conditions is reviewed. Analysis of isotopic discrimination give estimates of the various patterns of carbon and nitrogen nutrition and of the rate of water circulation. The method can also be used for paleoclimatology and for the detection of frauds in food products [fr

  19. Potassium-modulated physiological performance of mango plants infected by Ceratocystis fimbriata

    Directory of Open Access Journals (Sweden)

    Isaias Severino Cacique

    2017-08-01

    Full Text Available ABSTRACT Mango wilt, caused by the fungus Ceratocystis fimbriata, is an important disease affecting mango production. In view of the beneficial effects of potassium (K in other profitable crops and the lack of information about the effect of macronutrients on mango wilt development, the present study aimed to evaluate how mango plants supplied with K respond physiologically when infected by C. fimbriata. Mango plants (» 3 years old from cultivar Ubá were grown in plastic pots containing 58 mg of K·dm−3 (original K level based on the chemical analysis of the substrate or in plastic pots with substrate amended with a solution of 0.5 M potassium chloride (KCl to achieve the rate of 240 mg K·dm−3. Disease symptoms were more pronounced in inoculated plants grown at the lower K level. Substantial declines in stomatal conductance, in line with decreases in the internal-to-ambient CO2 concentration ratio and the absence of detectable changes in the chlorophyll a fluorescence parameters, suggest that the decrease in the net carbon assimilation rate is due, at least initially, to stomatal limitations. High concentrations of K and manganese were found in the stem tissues of inoculated plants and supplied with the highest K rate, most likely due to the involvement of these tissues in the local development of defense mechanisms. The results of this study suggest that the supply of K favored the physiological performance of mango plants and their resistance against C. fimbriata infection.

  20. Fundaments of plant cybernetics.

    Science.gov (United States)

    Zucconi, F

    2001-01-01

    A systemic approach is proposed for analyzing plants' physiological organization and cybernesis. To this end, the plant is inspected as a system, starting from the integration of crown and root systems, and its impact on a number of basic epigenetic events. The approach proves to be axiomatic and facilitates the definition of the principles behind the plant's autonomous control of growth and reproduction.

  1. Design and construction of an inexpensive homemade plant growth chamber.

    Science.gov (United States)

    Katagiri, Fumiaki; Canelon-Suarez, Dario; Griffin, Kelsey; Petersen, John; Meyer, Rachel K; Siegle, Megan; Mase, Keisuke

    2015-01-01

    Plant growth chambers produce controlled environments, which are crucial in making reproducible observations in experimental plant biology research. Commercial plant growth chambers can provide precise controls of environmental parameters, such as temperature, humidity, and light cycle, and the capability via complex programming to regulate these environmental parameters. But they are expensive. The high cost of maintaining a controlled growth environment is often a limiting factor when determining experiment size and feasibility. To overcome the limitation of commercial growth chambers, we designed and constructed an inexpensive plant growth chamber with consumer products for a material cost of $2,300. For a comparable growth space, a commercial plant growth chamber could cost $40,000 or more. Our plant growth chamber had outside dimensions of 1.5 m (W) x 1.8 m (D) x 2 m (H), providing a total growth area of 4.5 m2 with 40-cm high clearance. The dimensions of the growth area and height can be flexibly changed. Fluorescent lights with large reflectors provided a relatively spatially uniform photosynthetically active radiation intensity of 140-250 μmoles/m2/sec. A portable air conditioner provided an ample cooling capacity, and a cooling water mister acted as a powerful humidifier. Temperature, relative humidity, and light cycle inside the chamber were controlled via a z-wave home automation system, which allowed the environmental parameters to be monitored and programmed through the internet. In our setting, the temperature was tightly controlled: 22.2°C±0.8°C. The one-hour average relative humidity was maintained at 75%±7% with short spikes up to ±15%. Using the interaction between Arabidopsis and one of its bacterial pathogens as a test experimental system, we demonstrate that experimental results produced in our chamber were highly comparable to those obtained in a commercial growth chamber. In summary, our design of an inexpensive plant growth chamber

  2. Design and construction of an inexpensive homemade plant growth chamber.

    Directory of Open Access Journals (Sweden)

    Fumiaki Katagiri

    Full Text Available Plant growth chambers produce controlled environments, which are crucial in making reproducible observations in experimental plant biology research. Commercial plant growth chambers can provide precise controls of environmental parameters, such as temperature, humidity, and light cycle, and the capability via complex programming to regulate these environmental parameters. But they are expensive. The high cost of maintaining a controlled growth environment is often a limiting factor when determining experiment size and feasibility. To overcome the limitation of commercial growth chambers, we designed and constructed an inexpensive plant growth chamber with consumer products for a material cost of $2,300. For a comparable growth space, a commercial plant growth chamber could cost $40,000 or more. Our plant growth chamber had outside dimensions of 1.5 m (W x 1.8 m (D x 2 m (H, providing a total growth area of 4.5 m2 with 40-cm high clearance. The dimensions of the growth area and height can be flexibly changed. Fluorescent lights with large reflectors provided a relatively spatially uniform photosynthetically active radiation intensity of 140-250 μmoles/m2/sec. A portable air conditioner provided an ample cooling capacity, and a cooling water mister acted as a powerful humidifier. Temperature, relative humidity, and light cycle inside the chamber were controlled via a z-wave home automation system, which allowed the environmental parameters to be monitored and programmed through the internet. In our setting, the temperature was tightly controlled: 22.2°C±0.8°C. The one-hour average relative humidity was maintained at 75%±7% with short spikes up to ±15%. Using the interaction between Arabidopsis and one of its bacterial pathogens as a test experimental system, we demonstrate that experimental results produced in our chamber were highly comparable to those obtained in a commercial growth chamber. In summary, our design of an inexpensive plant

  3. Plant neighbor identity influences plant biochemistry and physiology related to defense.

    Science.gov (United States)

    Broz, Amanda K; Broeckling, Corey D; De-la-Peña, Clelia; Lewis, Matthew R; Greene, Erick; Callaway, Ragan M; Sumner, Lloyd W; Vivanco, Jorge M

    2010-06-17

    Chemical and biological processes dictate an individual organism's ability to recognize and respond to other organisms. A small but growing body of evidence suggests that plants may be capable of recognizing and responding to neighboring plants in a species specific fashion. Here we tested whether or not individuals of the invasive exotic weed, Centaurea maculosa, would modulate their defensive strategy in response to different plant neighbors. In the greenhouse, C. maculosa individuals were paired with either conspecific (C. maculosa) or heterospecific (Festuca idahoensis) plant neighbors and elicited with the plant defense signaling molecule methyl jasmonate to mimic insect herbivory. We found that elicited C. maculosa plants grown with conspecific neighbors exhibited increased levels of total phenolics, whereas those grown with heterospecific neighbors allocated more resources towards growth. To further investigate these results in the field, we conducted a metabolomics analysis to explore chemical differences between individuals of C. maculosa growing in naturally occurring conspecific and heterospecific field stands. Similar to the greenhouse results, C. maculosa individuals accumulated higher levels of defense-related secondary metabolites and lower levels of primary metabolites when growing in conspecific versus heterospecific field stands. Leaf herbivory was similar in both stand types; however, a separate field study positively correlated specialist herbivore load with higher densities of C. maculosa conspecifics. Our results suggest that an individual C. maculosa plant can change its defensive strategy based on the identity of its plant neighbors. This is likely to have important consequences for individual and community success.

  4. Unraveling the effect of structurally different classes of insecticide on germination and early plant growth of soybean [Glycine max (L.) Merr].

    Science.gov (United States)

    Dhungana, Sanjeev Kumar; Kim, Il-Doo; Kwak, Hwa-Sook; Shin, Dong-Hyun

    2016-06-01

    Although a considerable number of studies about the effect of different insecticides on plant physiology and metabolism have been carried out, research work about the comparative action of structurally different classes of insecticide on physiological and biochemical properties of soybean seed germination and early growth has not been found. The objective of this study was to investigate the effect of different classes of insecticides on soybean seed germination and early plant growth. Soybean seeds of Bosuk cultivar were soaked for 24h in distilled water or recommended dose (2mLL(-1), 1mLL(-1), 0.5gL(-1), and 0.5gL(-1) water for insecticides Mepthion, Myungtaja, Actara, and Stonate, respectively) of pesticide solutions of four structurally different classes of insecticides - Mepthion (fenitrothion; organophosphate), Myungtaja (etofenprox; pyrethroid), Actara (thiamethoxam; neonicotinoid), and Stonate (lambda-cyhalothrin cum thiamethoxam; pyrethroid cum neonicotinoid) - which are used for controlling stink bugs in soybean crop. Insecticides containing thiamethoxam and lamda-cyhalothrin cum thiamethoxam showed positive effects on seedling biomass and content of polyphenol and flavonoid, however fenitrothion insecticide reduced the seed germination, seed and seedling vigor, and polyphenol and flavonoid contents in soybean. Results of this study reveal that different classes of insecticide have differential influence on physiologic and metabolic actions like germination, early growth, and antioxidant activities of soybean and this implies that yield and nutrient content also might be affected with the application of different types of insecticide. Copyright © 2015 Elsevier B.V. All rights reserved.

  5. Rhizosphere of rice plants harbor bacteria with multiple plant growth ...

    African Journals Online (AJOL)

    Rhizosphere of rice plants harbor bacteria with multiple plant growth promoting features. ... 45 (39.46%) isolates were capable of producing siderophore, the range of production being 4.50 to 223.26 μg mg-1 protein. Analysis of molecular diversity was made by amplified ribosomal DNA restriction analysis (ARDRA) and ...

  6. Crop growth, light utilization and yield of relay intercropped cotton as affected by plant density and a plant growth regulator

    NARCIS (Netherlands)

    Mao, L.; Zhang, L.; Zhao, X.; Liu, S.; Werf, van der W.; Zhang, S.; Spiertz, J.H.J.; Li, Z.

    2014-01-01

    Modern cotton cultivation requires high plant densities and compact plants. Here we study planting density and growth regulator effects on plant structure and production of cotton when the cotton is grown in a relay intercrop with wheat, a cultivation system that is widespread in China. Field

  7. How Will Global Environmental Changes Affect the Growth of Alien Plants?

    Directory of Open Access Journals (Sweden)

    Jujie Jia

    2016-11-01

    Full Text Available Global environmental changes can create novel habitats, promoting the growth of alien plants that often exhibit broad environmental tolerance and high phenotypic plasticity. However, the mechanisms underlying these growth promotory effects are unknown at present. Here, we conducted a phylogenetically controlled meta-analysis using data from 111 published studies encompassing the responses of 129 alien plants to global warming, increased precipitation, N deposition, and CO2 enrichment. We compared the differences in the responses of alien plants to the four global environmental change factors across six categories of functional traits between woody and non-woody life forms as well as C3 and C4 photosynthetic pathways. Our results showed that all four global change factors promote alien plant growth. Warming had a more positive effect on C4 than C3 plants. Although the effects of the four factors on the functional traits of alien plants were variable, plant growth was mainly promoted via an increase in growth rate and size. Our data suggest that potential future global environmental changes could further facilitate alien plant growth.

  8. GENETIC RELATIONSHIP BETWEEN PLANT GROWTH, SHOOT ...

    African Journals Online (AJOL)

    AISA

    2Department of Plant Sciences, North Dakota State University, Fargo, ND 58105, USA. ABSTRACT. Maize (Zea mays L.) ear vascular tissue transports nutrients that contribute to grain yield. To assess kernel heritabilities that govern ear development and plant growth, field studies were conducted to determine the combining ...

  9. Where have the organizers gone? - The growth control system as a foundation of physiology.

    Science.gov (United States)

    Li, Zhimin; Shang, Charles

    2017-01-01

    A model of growth control system suggests that the organizers in embryogenesis continue to exist and partially retain their function after embryogenesis. The organizers are the macroscopic singular points of the morphogen gradient and bioelectric fields. They have higher metabolic rate, higher density of gap junctions and stem cells than the surrounding tissue. The growth control model predicts that the organizers are likely to exist at the extreme points of surface or interface curvature of the body. Changes in bioelectric field at organizers precede the morphological and anatomical changes in morphogenesis and pathogenesis. Subtle perturbations at organizers can cause long lasting systemic effects. These features of organizers can be used for diagnostic and therapeutic purposes such as regenerative medicine. There is increasing evidence that acupuncture points are likely to have originated from organizers in embryogenesis. Many corollaries and predictions of the growth control model have been independently confirmed in developmental biology, physiology, as well as basic and clinical acupuncture research. This model set the first example of a truly integrative biological basis of acupuncture and conventional biomedical sciences which has met the gold standard of science with multiple confirmed predictions in both fields. The growth control system is embedded in various physiological systems and is part of the foundation of physiology and pathophysiology. Copyright © 2016 Elsevier Ltd. All rights reserved.

  10. EFFECT OF USING SOME MEDICINAL PLANTS (ANISE, CHAMOMILE AND GINGER) ON PRODUCTIVE AND PHYSIOLOGICAL PERFORMANCE OF JAPANESE QUAIL

    International Nuclear Information System (INIS)

    ABU TALEB, A.M.; HAMODI, S.J.; EL AFIFI, SH.F.

    2008-01-01

    This experiment was conducted to evaluate the effects of adding medicinal plants to Japanese quail diet on their performance and some metabolic functions. Four hundred, one day old, unsexed Japanese quails were used in this study. Quails were divided equally into four groups of 100 birds each according to medicinal plant additives. Group one was control (without additives, and the other groups contained 0.3% from anise (group 2), chamomile (group 3) and ginger (group 4). The end of the experiment was terminated when birds were 6 weeks old. Body weight, feed intake, some organs weight and some blood parameters were measured.The results indicated that addition of medicinal plants (anise, chamomile and ginger) improved growth rate, carcass and the relative weights of spleen, ovary and testis. Also, significant increases were observed in RBC, WBC, Hb, PCV, total protein and globulin. There was reduction in cholesterol in treated groups as compared to the control.The present results confirmed the beneficial effects of dietary medicinal plants (anise, chamomile and ginger) to improve the health condition as well as the productive and physiological characteristics of quails

  11. Effects of shade on growth, production and quality of coffee (Coffea arabica) in Ethiopia

    NARCIS (Netherlands)

    Bote, A.D.; Struik, P.C.

    2011-01-01

    The research work was conducted to evaluate the effect of shade on growth and production of coffee plants. To achieve this, growth and productivity of coffee plants growing under shade trees were compared with those of coffee plants growing under direct sun light. Different physiological,

  12. Isolation, Characterization, Screening, Formulation and Evaluation of Plant Growth Promoting Rhizobacteria

    Directory of Open Access Journals (Sweden)

    Puja Kumari

    2017-10-01

    Full Text Available Plant growth promoting rhizobacteria (PGPR are bioresources which may be viewed as a novel and potential tool for providing substantial benefits to the agriculture. Soil is the dynamic living matrix and the major source of food security providing various resources of plant growth and maintaining life processes. PGPR are originally defined as root- colonizing bacteria that cause either plant growth promotion or biological control of plant diseases. Chemical fertilizers are used for killing pathogens, increase crop yield but long term use of chemical fertilizers lead to adverse effect to the soil profile and is the reason for decrease in soil productivity, on the other hand PGPR promote plant growth directly by either facilitating resource acquisition (nitrogen, phosphorus and essential minerals or modulating plant hormone levels, or indirectly by decreasing the inhibitory effects of various pathogens on plant growth and development in the forms of biocontrol agents. PGPR is the indispensable part of rhizosphere biota that when grown in association with the host plants can stimulate the growth of the host. PGPR seemed as successful rhizobacteria in getting established in soil ecosystem due to their high adaptability in a wide variety of environments, faster growth rate and biochemical versatility to metabolize a wide range of natural and xenobiotic compounds. Isolated PGPRs from selective crop rizosphere soil were used for further growth promotion and biocontrol studies in the green house and field. Different studies have been carrying out to develop some new bioformulations and evaluate their efficacy in promoting crop seedlings growth characteristics. Field trials were performed to evaluate selective crops with formulations of several plants PGPR in a production system. The present review highlights the Plant growth promoting rhizobacteria as an alternative of chemical fertilizer for sustainable, environment friendly agriculture.

  13. Isolation of plant growth promoting rhizobacteria of guava plants (Psidium guajava

    Directory of Open Access Journals (Sweden)

    Blanca Estela Gómez Luna

    2012-09-01

    Full Text Available Guava production for 2008 in the state of Guanajuato was 177 ha in area planted and the same number of area harvested, production in 1,130.80 Ton. In traditional farming practices have made excessive use of mineral fertilizers, which, if it is true, ensure a good production are expensive and come to cause imbalances in agroecosystems by contamination of soil, water, and food. In this work we evaluated the effect of Bacillus subtilis strains as plant growth promoter rhizobacteria in guava plants under greenhouse conditions. We used three strains were inoculated potted plant with guava. We measured the height, number of branches and leaves. Guava orchards of 2 then display of soil were taken for the isolation andcharacterization of rhizobacteria. Selective medium was used with 1 - carboxylic acid, -1 - aminocyclopropane and selecting bacteria with ACC desaminase activity. For the isolates were determined antibiotic resistance, confrontation with fungal pathogens, plant growth tests in vitro and BIOLOG metabolic profiles. We found 30 isolates with ACC activities, 7 have the effect of biological control and 5 had effect on root development in vitro. The use of growth promotingrhizobacteria are an excellent alternative for improving the production of guavas, growing very little is known of themicroflora associated with the rhizosphere and the ecological role they have in the ground.

  14. Lemna minor exposed to fluoranthene: growth, biochemical, physiological and histochemical changes.

    Science.gov (United States)

    Zezulka, Stěpán; Kummerová, Marie; Babula, Petr; Váňová, Lucie

    2013-09-15

    Polycyclic aromatic hydrocarbons (PAHs) represent one of the major groups of organic contaminants in the aquatic environment. Duckweed (Lemna minor L.) is a common aquatic plant widely used in phytotoxicity tests for xenobiotic substances. The goal of this study was to assess the growth and the physiological, biochemical and histochemical changes in duckweed exposed for 4 and 10 days to fluoranthene (FLT, 0.1 and 1 mgL(-1)). Nonsignificant changes in number of plants, biomass production, leaf area size, content of chlorophylls a and b and carotenoids and parameters of chlorophyll fluorescence recorded after 4 and 10 days of exposure to FLT were in contrast with considerable changes at biochemical and histochemical levels. Higher occurrence of reactive oxygen species (ROS) caused by an exposure to FLT after 10 days as compared to control (hydrogen peroxide elevated by 13% in the 0.1 mgL(-1) and by 41% in the 1 mgL(-1) FLT; superoxide anion radical by 52% and 115% respectively) reflected in an increase in the activities of antioxidant enzymes (superoxide dismutase by 3% in both treatments, catalase by 9% and 1% respectively, ascorbate peroxidase by 21% and 5% respectively, guaiacol peroxidase by 12% in the 0.1 mgL(-1) FLT). Even the content of antioxidant compounds like ascorbate (by 20% in the 1 mgL(-1) FLT) or total thiols (reduced forms by 15% in the 0.1 mgL(-1) and 8% in the 1 mgL(-1) FLT, oxidized forms by 36% in the 0.1 mgL(-1) FLT) increased. Increased amount of ROS was followed by an increase in malondialdehyde content (by 33% in the 0.1 mgL(-1) and 79% in the 1 mgL(-1) FLT). Whereas in plants treated by the 0.1 mgL(-1) FLT the contents of total proteins and phenols increased by 15% and 25%, respectively, the 1 mgL(-1) FLT caused decrease of their contents by 32% and 7%. Microscopic observations of duckweed roots also confirmed the presence of ROS and related histochemical changes at the cellular and tissue levels. The assessment of phytotoxicity of organic

  15. Plant growth and resistance promoted by Streptomyces spp. in tomato.

    Science.gov (United States)

    Dias, Maila P; Bastos, Matheus S; Xavier, Vanessa B; Cassel, Eduardo; Astarita, Leandro V; Santarém, Eliane R

    2017-09-01

    Plant Growth Promoting Rhizobacteria (PGPR) represent an alternative to improve plant growth and yield as well as to act as agents of biocontrol. This study characterized isolates of Streptomyces spp. (Stm) as PGPR, determined the antagonism of these isolates against Pectobacterium carotovorum subsp. brasiliensis (Pcb), evaluated the ability of Stm on promoting growth and modulating the defense-related metabolism of tomato plants, and the potential of Stm isolates on reducing soft rot disease in this species. The VOC profile of Stm was also verified. Promotion of plant growth was assessed indirectly through VOC emission and by direct interaction with Stm isolates in the roots. Evaluation of soft rot disease was performed in vitro on plants treated with Stm and challenged with Pcb. Enzymes related to plant defense were then analyzed in plants treated with three selected isolates of Stm, and PM1 was chosen for further Pcb-challenging experiment. Streptomyces spp. isolates displayed characteristics of PGPR. PM3 was the isolate with efficient antagonism against Pcb by dual-culture. Most of the isolates promoted growth of root and shoot of tomato plants by VOC, and PM5 was the isolate that most promoted growth by direct interaction with Stm. Soft rot disease and mortality of plants were significantly reduced when plants were treated with StmPM1. Modulation of secondary metabolism was observed with Stm treatment, and fast response of polyphenoloxidases was detected in plants pretreated with StmPM1 and challenged with Pcb. Peroxidase was significantly activated three days after infection with Pcb in plants pretreated with StmPM1. Results suggest that Streptomyces sp. PM1 and PM5 have the potential to act as PGPR. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  16. Solar ultraviolet-B radiation affects seedling emergence, DNA integrity, plant morphology, growth rate, and attractiveness to herbivore insects in Datura ferox

    International Nuclear Information System (INIS)

    Ballare, C.L.; Scopel, A.L.; Stapleton, A.E.

    1996-01-01

    To study functional relationships between the effects of solar ultraviolet-B radiation (UV0B) on different aspects of the physiology of a wild plant, we carried out exclusion experiments in the field with the summer annual Datura ferrox L. Solar UV-B incident over Buenos Aires reduced daytime seedling emergence, inhibited stem elongation and leaf expansion, and tended to reduce biomass accumulation during early growth. However, UV-B had no effect on calculated net assimilation rate. Using a monoclonal antibody specific to the cyclobutane-pyrimidine dimer (CPD), we found that plants receiving full sunlight had more CPDs per unit of DNA than plants shielded from solar UV-B, but the positive correlation between UV-B and CPD burden tended to level off at high (near solar) UV-B levels. At our field site, Datura plants were consumed by leaf beetles (Coleoptera), and the proportion of plants attacked by insects declined with the amount of UV-B received during growth. Field experiments showed that plant exposure to solar UV-B reduced the likelihood of leaf beetle attack by one-half. Our results highlight the complexities associated with scaling plant responses to solar UV-B, because they show: (a) a lack of correspondence between UV-B effects on net assimilation rate and whole-plant growth rate, (b) nonlinear UV-B dose-response curves, and (c) UV-B effects of plant attractiveness to natural herbivores. 56 refs., 7 figs

  17. Functional plant types drive plant interactions in a Mediterranean mountain range

    Directory of Open Access Journals (Sweden)

    Petr eMacek

    2016-05-01

    Full Text Available Shrubs have both positive (facilitation and negative (competition effects on understory plants, the net interaction effect being modulated by abiotic conditions. Overall shrubs influence to great extent the structure of plant communities where they have significant presence. Interactions in a plant community are quite diverse but little is known about their variability and effects at community level. Here we checked the effects of co-occurring shrub species from different functional groups on a focal understory species, determining mechanisms driving interaction outcome, and tested whether effects measured on the focal species were a proxy for effects measured at the community level. Growth, physiological, and reproductive traits of Euphorbia nicaeensis, our focal species, were recorded on individuals growing in association with four dominant shrub species and in adjacent open areas. We also recorded community composition and environmental conditions in each microhabitat.Shrubs provided environmental conditions for plant growth, which contrasted with open areas, including moister soil, greater N content, higher air temperatures, and lower radiation. Shrub-associated individuals showed lower reproductive effort and greater allocation to growth, while most physiological traits remained unaffected. Euphorbia individuals were bigger and had more leaf N under N-fixing than under non-fixing species. Soil moisture was also higher under N-fixing shrubs; therefore soil conditions in the understory may counter reduced light conditions.There was a significant effect of species identity and functional types in the outcome of plant interactions with consistent effects at individual and community levels. The contrasting allocation strategies to reproduction and growth in Euphorbia plants, either associated or not with shrubs, showed high phenotypic plasticity and evidence its ability to cope with contrasting environmental conditions.

  18. Study of growth and development features of ten ground cover plants in Kish Island green space in warm season

    Directory of Open Access Journals (Sweden)

    S. Shooshtarian

    2016-05-01

    Full Text Available Having special ecological condition, Kish Island has a restricted range of native species of ornamental plants. Expansion of urban green space in this Island is great of importance due to its outstanding touristy position in the South of Iran. The purpose of this study was to investigate the growth and development of groundcover plants planted in four different regions of Kish Island and to recommend the most suitable and adaptable species for each region. Ten groundcover species included Festuca ovina L., Glaucium flavum Crantz., Frankenia thymifolia Desf., Sedum spurium Bieb., Sedum acre L., .Potentilla verna L., Carpobrotus acinaciformis (L. L. Bolus., Achillea millefolium L., Alternanthera dentata Moench. and Lampranthus spectabilis Haw. Evaluation of growth and development had been made by measurement of morphological characteristics such as height, covering area, leaf number and area, dry and fresh total weights and visual scoring. Physiological traits included proline and chlorophyll contents evaluated. This study was designed in factorial layout based on completely randomized blocks design with six replicates. Results showed that in terms of indices such as covering area, visual quality, height, total weight, and chlorophyll content, Pavioon and Sadaf plants had the most and the worst performances, respectively in comparison to other regions’ plants. Based on evaluated characteristics, C. acinaciformis, L. spectabilis and F. thymifolia had the most expansion and growth in all quadruplet regions and are recommend for planting in Kish Island and similar climates.

  19. Plant neighbor identity influences plant biochemistry and physiology related to defense

    Directory of Open Access Journals (Sweden)

    Callaway Ragan M

    2010-06-01

    Full Text Available Abstract Background Chemical and biological processes dictate an individual organism's ability to recognize and respond to other organisms. A small but growing body of evidence suggests that plants may be capable of recognizing and responding to neighboring plants in a species specific fashion. Here we tested whether or not individuals of the invasive exotic weed, Centaurea maculosa, would modulate their defensive strategy in response to different plant neighbors. Results In the greenhouse, C. maculosa individuals were paired with either conspecific (C. maculosa or heterospecific (Festuca idahoensis plant neighbors and elicited with the plant defense signaling molecule methyl jasmonate to mimic insect herbivory. We found that elicited C. maculosa plants grown with conspecific neighbors exhibited increased levels of total phenolics, whereas those grown with heterospecific neighbors allocated more resources towards growth. To further investigate these results in the field, we conducted a metabolomics analysis to explore chemical differences between individuals of C. maculosa growing in naturally occurring conspecific and heterospecific field stands. Similar to the greenhouse results, C. maculosa individuals accumulated higher levels of defense-related secondary metabolites and lower levels of primary metabolites when growing in conspecific versus heterospecific field stands. Leaf herbivory was similar in both stand types; however, a separate field study positively correlated specialist herbivore load with higher densities of C. maculosa conspecifics. Conclusions Our results suggest that an individual C. maculosa plant can change its defensive strategy based on the identity of its plant neighbors. This is likely to have important consequences for individual and community success.

  20. Enhanced performance of the microalga Chlorella sorokiniana remotely induced by the plant growth-promoting bacteria Azospirillum brasilense and Bacillus pumilus

    Science.gov (United States)

    Amavizca, Edgar; Bashan, Yoav; Ryu, Choong-Min; Farag, Mohamed A.; Bebout, Brad M.; de-Bashan, Luz E.

    2017-01-01

    Remote effects (occurring without physical contact) of two plant growth-promoting bacteria (PGPB) Azospirillum brasilense Cd and Bacilus pumilus ES4 on growth of the green microalga Chlorella sorokiniana UTEX 2714 were studied. The two PGPB remotely enhanced the growth of the microalga, up to six-fold, and its cell volume by about three-fold. In addition to phenotypic changes, both bacteria remotely induced increases in the amounts of total lipids, total carbohydrates, and chlorophyll a in the cells of the microalga, indicating an alteration of the microalga’s physiology. The two bacteria produced large amounts of volatile compounds, including CO2, and the known plant growth-promoting volatile 2,3-butanediol and acetoin. Several other volatiles having biological functions in other organisms, as well as numerous volatile compounds with undefined biological roles, were detected. Together, these bacteria-derived volatiles can positively affect growth and metabolic parameters in green microalgae without physical attachment of the bacteria to the microalgae. This is a new paradigm on how PGPB promote growth of microalgae which may serve to improve performance of Chlorella spp. for biotechnological applications. PMID:28145473

  1. Heterologous Expression of Secreted Bacterial BPP and HAP Phytases in Plants Stimulates Arabidopsis thaliana Growth on Phytate

    Directory of Open Access Journals (Sweden)

    Lia R. Valeeva

    2018-02-01

    Full Text Available Phytases are specialized phosphatases capable of releasing inorganic phosphate from myo-inositol hexakisphosphate (phytate, which is highly abundant in many soils. As inorganic phosphorus reserves decrease over time in many agricultural soils, genetic manipulation of plants to enable secretion of potent phytases into the rhizosphere has been proposed as a promising approach to improve plant phosphorus nutrition. Several families of biotechnologically important phytases have been discovered and characterized, but little data are available on which phytase families can offer the most benefits toward improving plant phosphorus intake. We have developed transgenic Arabidopsis thaliana plants expressing bacterial phytases PaPhyC (HAP family of phytases and 168phyA (BPP family under the control of root-specific inducible promoter Pht1;2. The effects of each phytase expression on growth, morphology and inorganic phosphorus accumulation in plants grown on phytate hydroponically or in perlite as the only source of phosphorus were investigated. The most enzymatic activity for both phytases was detected in cell wall-bound fractions of roots, indicating that these enzymes were efficiently secreted. Expression of both bacterial phytases in roots improved plant growth on phytate and resulted in larger rosette leaf area and diameter, higher phosphorus content and increased shoot dry weight, implying that these plants were indeed capable of utilizing phytate as the source of phosphorus for growth and development. When grown on phytate the HAP-type phytase outperformed its BPP-type counterpart for plant biomass production, though this effect was only observed in hydroponic conditions and not in perlite. Furthermore, we found no evidence of adverse side effects of microbial phytase expression in A. thaliana on plant physiology and seed germination. Our data highlight important functional differences between these members of bacterial phytase families and indicate

  2. Heterologous Expression of Secreted Bacterial BPP and HAP Phytases in Plants Stimulates Arabidopsis thaliana Growth on Phytate.

    Science.gov (United States)

    Valeeva, Lia R; Nyamsuren, Chuluuntsetseg; Sharipova, Margarita R; Shakirov, Eugene V

    2018-01-01

    Phytases are specialized phosphatases capable of releasing inorganic phosphate from myo -inositol hexakisphosphate (phytate), which is highly abundant in many soils. As inorganic phosphorus reserves decrease over time in many agricultural soils, genetic manipulation of plants to enable secretion of potent phytases into the rhizosphere has been proposed as a promising approach to improve plant phosphorus nutrition. Several families of biotechnologically important phytases have been discovered and characterized, but little data are available on which phytase families can offer the most benefits toward improving plant phosphorus intake. We have developed transgenic Arabidopsis thaliana plants expressing bacterial phytases PaPhyC (HAP family of phytases) and 168phyA (BPP family) under the control of root-specific inducible promoter Pht1;2 . The effects of each phytase expression on growth, morphology and inorganic phosphorus accumulation in plants grown on phytate hydroponically or in perlite as the only source of phosphorus were investigated. The most enzymatic activity for both phytases was detected in cell wall-bound fractions of roots, indicating that these enzymes were efficiently secreted. Expression of both bacterial phytases in roots improved plant growth on phytate and resulted in larger rosette leaf area and diameter, higher phosphorus content and increased shoot dry weight, implying that these plants were indeed capable of utilizing phytate as the source of phosphorus for growth and development. When grown on phytate the HAP-type phytase outperformed its BPP-type counterpart for plant biomass production, though this effect was only observed in hydroponic conditions and not in perlite. Furthermore, we found no evidence of adverse side effects of microbial phytase expression in A. thaliana on plant physiology and seed germination. Our data highlight important functional differences between these members of bacterial phytase families and indicate that future

  3. Heterologous Expression of Secreted Bacterial BPP and HAP Phytases in Plants Stimulates Arabidopsis thaliana Growth on Phytate

    Science.gov (United States)

    Valeeva, Lia R.; Nyamsuren, Chuluuntsetseg; Sharipova, Margarita R.; Shakirov, Eugene V.

    2018-01-01

    Phytases are specialized phosphatases capable of releasing inorganic phosphate from myo-inositol hexakisphosphate (phytate), which is highly abundant in many soils. As inorganic phosphorus reserves decrease over time in many agricultural soils, genetic manipulation of plants to enable secretion of potent phytases into the rhizosphere has been proposed as a promising approach to improve plant phosphorus nutrition. Several families of biotechnologically important phytases have been discovered and characterized, but little data are available on which phytase families can offer the most benefits toward improving plant phosphorus intake. We have developed transgenic Arabidopsis thaliana plants expressing bacterial phytases PaPhyC (HAP family of phytases) and 168phyA (BPP family) under the control of root-specific inducible promoter Pht1;2. The effects of each phytase expression on growth, morphology and inorganic phosphorus accumulation in plants grown on phytate hydroponically or in perlite as the only source of phosphorus were investigated. The most enzymatic activity for both phytases was detected in cell wall-bound fractions of roots, indicating that these enzymes were efficiently secreted. Expression of both bacterial phytases in roots improved plant growth on phytate and resulted in larger rosette leaf area and diameter, higher phosphorus content and increased shoot dry weight, implying that these plants were indeed capable of utilizing phytate as the source of phosphorus for growth and development. When grown on phytate the HAP-type phytase outperformed its BPP-type counterpart for plant biomass production, though this effect was only observed in hydroponic conditions and not in perlite. Furthermore, we found no evidence of adverse side effects of microbial phytase expression in A. thaliana on plant physiology and seed germination. Our data highlight important functional differences between these members of bacterial phytase families and indicate that future crop

  4. Differential growth responses of Brachypodium distachyon genotypes to inoculation with plant growth promoting rhizobacteria.

    Science.gov (United States)

    do Amaral, Fernanda P; Pankievicz, Vânia C S; Arisi, Ana Carolina M; de Souza, Emanuel M; Pedrosa, Fabio; Stacey, Gary

    2016-04-01

    Plant growth promoting rhizobacteria (PGPR) can associate and enhance the growth of important crop grasses. However, in most cases, the molecular mechanisms responsible for growth promotion are not known. Such research could benefit by the adoption of a grass model species that showed a positive response to bacterial inoculation and was amenable to genetic and molecular research methods. In this work we inoculated different genotypes of the model grass Brachypodium distachyon with two, well-characterized PGPR bacteria, Azospirillum brasilense and Herbaspirillum seropedicae, and evaluated the growth response. Plants were grown in soil under no nitrogen or with low nitrogen (i.e., 0.5 mM KNO3). A variety of growth parameters (e.g., shoot height, root length, number of lateral roots, fresh and dry weight) were measured 35 days after inoculation. The data indicate that plant genotype plays a very important role in determining the plant response to PGPR inoculation. A positive growth response was observed with only four genotypes grown under no nitrogen and three genotypes tested under low nitrogen. However, in contrast, relatively good root colonization was seen with most genotypes, as measured by drop plate counting and direct, microscopic examination of roots. In particular, the endophytic bacteria H. seropedicae showed strong epiphytic and endophytic colonization of roots.

  5. Isolation and selection of plant growth-promoting bacteria associated with sugarcane

    Directory of Open Access Journals (Sweden)

    Ariana Alves Rodrigues

    2016-06-01

    Full Text Available Microorganisms play a vital role in maintaining soil fertility and plant health. They can act as biofertilizers and increase the resistance to biotic and abiotic stress. This study aimed at isolating and characterizing plant growth-promoting bacteria associated with sugarcane, as well as assessing their ability to promote plant growth. Endophytic bacteria from leaf, stem, root and rhizosphere were isolated from the RB 867515 commercial sugarcane variety and screened for indole acetic acid (IAA production, ability to solubilize phosphate, fix nitrogen and produce hydrogen cyanide (HCN, ammonia and the enzymes pectinase, cellulase and chitinase. A total of 136 bacteria were isolated, with 83 of them presenting some plant growth mechanism: 47 % phosphate solubilizers, 26 % nitrogen fixers and 57 % producing IAA, 0.7 % HCN and chitinase, 45 % ammonia, 30 % cellulose and 8 % pectinase. The seven best isolates were tested for their ability to promote plant growth in maize. The isolates tested for plant growth promotion belong to the Enterobacteriaceae family and the Klebsiella, Enterobacter and Pantoea genera. Five isolates promoted plant growth in greenhouse experiments, showing potential as biofertilizers.

  6. Mycorrhizal association between the desert truffle Terfezia boudieri and Helianthemum sessiliflorum alters plant physiology and fitness to arid conditions.

    Science.gov (United States)

    Turgeman, Tidhar; Ben Asher, Jiftach; Roth-Bejerano, Nurit; Kagan-Zur, Varda; Kapulnik, Yoram; Sitrit, Yaron

    2011-10-01

    The host plant Helianthemum sessiliflorum was inoculated with the mycorrhizal desert truffle Terfezia boudieri Chatin, and the subsequent effects of the ectomycorrhizal relationship on host physiology were determined. Diurnal measurements revealed that mycorrhizal (M) plants had higher rates of photosynthesis (35%), transpiration (18%), and night respiration (49%) than non-mycorrhizal (NM) plants. Consequently, M plants exhibited higher biomass accumulation, higher shoot-to-root ratios, and improved water use efficiency compared to NM plants. Total chlorophyll content was higher in M plants, and the ratio between chlorophyll a to chlorophyll b was altered in M plants. The increase in chlorophyll b content was significantly higher than the increase in chlorophyll a content (2.58- and 1.52-fold, respectively) compared to control. Calculation of the photosynthetic activation energy indicated lower energy requirements for CO(2) assimilation in M plants than in NM plants (48.62 and 61.56 kJ mol(-1), respectively). Continuous measurements of CO(2) exchange and transpiration in M plants versus NM plants provided a complete picture of the daily physiological differences brought on by the ectomycorrhizal relationships. The enhanced competence of M plants to withstand the harsh environmental conditions of the desert is discussed in view of the mycorrhizal-derived alterations in host physiology. © Springer-Verlag 2011

  7. Effects of ultraviolet-B radiation on the growth, physiology and cannabinoid production of Cannabis sativa L

    International Nuclear Information System (INIS)

    Lydon, J.

    1986-01-01

    The concentration of cannabinoids in Cannabis sativa L. is correlated with high ultraviolet-B (UV-B) radiation environments. Δ 9 -Tetrahydrocannabinolic acid and cannabidiolic acid, both major secondary products of C. sativa, absorb UV-B radiation and may function as solar screens. The object of this study was to test the effects of UV-B radiation on the physiology and cannabinoid production of C. sativa. Drug and fiber-type C. sativa were irradiated with three levels of UV-B radiation for 40 days in greenhouse experiments. Physiological measurements on leaf tissues were made by infra-red gas analysis. Drug and fiber-type control plants had similar CO 2 assimilation rates from 26 to 32 0 C. Drug-type control plant had higher dark respiration rates and stomatal conductances than fiber-type control plants. The concentration of Δ 9 -THC, but not of other cannabinoids) in both vegetative and reproductive tissues increased with UV-B dose in drug-type plants. None of the cannabinoids in fiber-type plants were affected by UV-B radiation. The increased level of Δ 9 -THC found in leaves after irradiation may account for the physiological and morphological insensitivity to UV-B radiation in the drug-type plants. However, fiber plants showed no comparable change in the level of cannabidoil (CBD). Resin stripped form fresh fiber-type floral tissue by sonication was spotted on filter paper and irradiated continuously for 7 days. Cannabidiol (CBD) gradually decreased when irradiated but Δ 9 -THC and cannabichromene did not

  8. Effects of ultraviolet-B radiation on the growth, physiology and cannabinoid production of Cannabis sativa L

    Energy Technology Data Exchange (ETDEWEB)

    Lydon, J.

    1986-01-01

    The concentration of cannabinoids in Cannabis sativa L. is correlated with high ultraviolet-B (UV-B) radiation environments. ..delta../sup 9/-Tetrahydrocannabinolic acid and cannabidiolic acid, both major secondary products of C. sativa, absorb UV-B radiation and may function as solar screens. The object of this study was to test the effects of UV-B radiation on the physiology and cannabinoid production of C. sativa. Drug and fiber-type C. sativa were irradiated with three levels of UV-B radiation for 40 days in greenhouse experiments. Physiological measurements on leaf tissues were made by infra-red gas analysis. Drug and fiber-type control plants had similar CO/sub 2/ assimilation rates from 26 to 32/sup 0/C. Drug-type control plant had higher dark respiration rates and stomatal conductances than fiber-type control plants. The concentration of ..delta../sup 9/-THC, but not of other cannabinoids) in both vegetative and reproductive tissues increased with UV-B dose in drug-type plants. None of the cannabinoids in fiber-type plants were affected by UV-B radiation. The increased level of ..delta../sup 9/-THC found in leaves after irradiation may account for the physiological and morphological insensitivity to UV-B radiation in the drug-type plants. However, fiber plants showed no comparable change in the level of cannabidoil (CBD). Resin stripped form fresh fiber-type floral tissue by sonication was spotted on filter paper and irradiated continuously for 7 days. Cannabidiol (CBD) gradually decreased when irradiated but ..delta../sup 9/-THC and cannabichromene did not.

  9. The influence of growth retardants and cytokinins on flowering of ornamental plants

    Directory of Open Access Journals (Sweden)

    Anna Pobudkiewicz

    2012-12-01

    Full Text Available Growth retardants are applied in order to obtain short and well compact plants. They usually inhibit stem elongation, but also can influence the flowering of plants. The aim of cytokinin application is to obtain well branched plants without removing the apical meristem. Cytokinins usually increase the number of axillary shoots but also can influence flowering. Growth retardants and cytokinins can affect flower size, pedicel length, number of flowers, flower longevity, abortion of flower buds and number of days from potting plants to the first open flower. Flowering of growth retardant and cytokinin treated plants might depend on the method of growth regulator used (foliar spray or soil drench, plant species or even a plant cultivar, but in the highest degree it depends on the growth regulator rate used. These growth regulators, when are applied at rates appropriate for height and habit control, very seldom influence flowering of ornamental plants, but applied at high rates can delay flowering, diminish flower diameter or flower pedicel length and also can decrease the number of flowers per plant. In cultivation of bulb plants, growth retardants, used at very high rates, also cause abortion of flower buds.

  10. Multifarious plant growth promotion by an entomopathogenic fungus Lecanicillium psalliotae.

    Science.gov (United States)

    Senthil Kumar, C M; Jacob, T K; Devasahayam, S; Thomas, Stephy; Geethu, C

    2018-03-01

    An entomopathogenic fungus, Lecanicillium psalliotae strain IISR-EPF-02 previously found infectious to cardamom thrips, Sciothrips cardamomi promoted plant growth in cardamom, Elettaria cardamomum. The isolate exhibited direct plant growth promoting traits by production of indole-3-acetic acid and ammonia and by solubilizing inorganic phosphate and zinc. It also showed indirect plant growth promoting traits by producing siderophores and cell wall-degrading enzymes like, α-amylases, cellulases and proteases. In pot culture experiments, application of the fungus at the root zone of cardamom seedlings significantly increased shoot and root length, shoot and root biomass, number of secondary roots and leaves and leaf chlorophyll content compared to untreated plants. This is the first report on the plant growth promoting traits of this fungus. The entomopathogenic and multifarious growth promoting traits of L. psalliotae strain IISR-EPF-02 suggest that it has great potential for exploitation in sustainable agriculture. Copyright © 2017 Elsevier GmbH. All rights reserved.

  11. Conifers, angiosperm trees, and lianas: growth, whole-plant water and nitrogen use efficiency, and stable isotope composition ({delta}13C and {delta}18O) of seedlings grown in a tropical environment.

    Science.gov (United States)

    Cernusak, Lucas A; Winter, Klaus; Aranda, Jorge; Turner, Benjamin L

    2008-09-01

    Seedlings of several species of gymnosperm trees, angiosperm trees, and angiosperm lianas were grown under tropical field conditions in the Republic of Panama; physiological processes controlling plant C and water fluxes were assessed across this functionally diverse range of species. Relative growth rate, r, was primarily controlled by the ratio of leaf area to plant mass, of which specific leaf area was a key component. Instantaneous photosynthesis, when expressed on a leaf-mass basis, explained 69% of variation in r (P physiological models of tropical forest trees.

  12. Growth and physiological responses of two phenotypically distinct accessions of centipedegrass (Eremochloa ophiuroides (Munro) Hack.) to salt stress.

    Science.gov (United States)

    Li, JianJian; Ma, Jingjing; Guo, Hailin; Zong, Junqin; Chen, Jingbo; Wang, Yi; Li, Dandan; Li, Ling; Wang, Jingjing; Liu, Jianxiu

    2018-05-01

    Salinity is one of the major abiotic environmental stress factors affecting plant growth and development. Centipedegrass (Eremochloa ophiuroides [Munro)] Hack.) is an important warm-season turfgrass species with low turf maintenance requirements, but is sensitive to salinity stress. To explore salt tolerant germplasms in centipedegrass and better understand the growth and physiological responses of centipedegrass to salinity, we conducted anatomic observation and phytochemical quantification, examined growth parameters, and investigated photosynthetic machinery and antioxidant system in two phenotypically distinct centipedegrass accessions under NaCl salt stress. The morphophenotypical difference of the stems in the two accessions mainly depends on whether or not a thickened epidermal horny layer with purple colour was formed, which was caused by anthocyanin accumulation in the tissue. Successive salinity treatment was found to result in an inhibition of leaf growth, a marked decrease in photosynthesis, chlorophyll contents, and the maximal photochemical efficiency of PSII (Fv/Fm). Under the same treatment, purple-stem accession (E092) showed a lower degree of inhibition or decrease than green-stem one (E092-1). With the exception of malondialdehyde level, both proline content and antioxidant enzymes were upregulated to a greater extent in E092 following exposure to salinity condition. Meanwhile, significant enhancements of anthocyanin accumulation and total protein synthesis were detected in E092 after salt treatment, but not in E092-1. These results demonstrated that E092 favor better accumulation of anthocyanins under salinity condition, which contribute to salt tolerance by adjusting physiological functions and osmotic balance, and better maintenance of high turf quality. Hence, genetic phenotype can be utilized as a key indicator in E. ophiuroides breeding for salt-tolerance. Copyright © 2018. Published by Elsevier Masson SAS.

  13. Physiological and gene expression responses of sunflower (Helianthus annuus L.) plants differ according to irrigation placement.

    Science.gov (United States)

    Aguado, Ana; Capote, Nieves; Romero, Fernando; Dodd, Ian C; Colmenero-Flores, José M

    2014-10-01

    To investigate effects of soil moisture heterogeneity on plant physiology and gene expression in roots and leaves, three treatments were implemented in sunflower plants growing with roots split between two compartments: a control (C) treatment supplying 100% of plant evapotranspiration, and two treatments receiving 50% of plant evapotranspiration, either evenly distributed to both compartments (deficit irrigation - DI) or unevenly distributed to ensure distinct wet and dry compartments (partial rootzone drying - PRD). Plants receiving the same amount of water responded differently under the two irrigation systems. After 3 days, evapotranspiration was similar in C and DI, but 20% less in PRD, concomitant with decreased leaf water potential (Ψleaf) and increased leaf xylem ABA concentration. Six water-stress responsive genes were highly induced in roots growing in the drying soil compartment of PRD plants, and their expression was best correlated with local soil water content. On the other hand, foliar gene expression differed significantly from that of the root and correlated better with xylem ABA concentration and Ψleaf. While the PRD irrigation strategy triggered stronger physiological and molecular responses, suggesting a more intense and systemic stress reaction due to local dehydration of the dry compartment of PRD plants, the DI strategy resulted in similar water savings without strongly inducing these responses. Correlating physiological and molecular responses in PRD/DI plants may provide insights into the severity and location of water deficits and may enable a better understanding of long-distance signalling mechanisms. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  14. Productivity growth patterns in US dairy products manufacturing plants

    NARCIS (Netherlands)

    Geylani, P.C.; Stefanou, S.E.

    2011-01-01

    We analyse the productivity growth patterns in the US dairy products industry using the Census Bureau's plant-level data set. We decompose Total Factor Productivity (TFP) growth into the scale and technical change components and analyse variability of plants' productivity by constructing transition

  15. Plant Growth Absorption Spectrum Mimicking Light Sources

    Directory of Open Access Journals (Sweden)

    Jwo-Huei Jou

    2015-08-01

    Full Text Available Plant factories have attracted increasing attention because they can produce fresh fruits and vegetables free from pesticides in all weather. However, the emission spectra from current light sources significantly mismatch the spectra absorbed by plants. We demonstrate a concept of using multiple broad-band as well as narrow-band solid-state lighting technologies to design plant-growth light sources. Take an organic light-emitting diode (OLED, for example; the resulting light source shows an 84% resemblance with the photosynthetic action spectrum as a twin-peak blue dye and a diffused mono-peak red dye are employed. This OLED can also show a greater than 90% resemblance as an additional deeper red emitter is added. For a typical LED, the resemblance can be improved to 91% if two additional blue and red LEDs are incorporated. The approach may facilitate either an ideal use of the energy applied for plant growth and/or the design of better light sources for growing different plants.

  16. Morphological, Physiological, and Taxonomic Characterization of Actinobacterial Isolates Living as Endophytes of Cacao Pods and Cacao Seeds.

    Science.gov (United States)

    Tchinda, Romaric Armel Mouafo; Boudjeko, Thaddée; Simao-Beaunoir, Anne-Marie; Lerat, Sylvain; Tsala, Éric; Monga, Ernest; Beaulieu, Carole

    2016-01-01

    Vascular plants are commonly colonized by endophytic actinobacteria. However, very little is known about the relationship between these microorganisms and cacao fruits. In order to determine the physiological and taxonomic relationships between the members of this community, actinobacteria were isolated from cacao fruits and seeds. Among the 49 isolates recovered, 11 morphologically distinct isolates were selected for further characterization. Sequencing of the 16S rRNA gene allowed the partition of the selected isolates into three phylogenetic clades. Most of the selected endophytic isolates belonged to the Streptomyces violaceusniger clade. Physiological characterization was carried out and a similarity index was used to cluster the isolates. However, clustering based on physiological properties did not match phylogenetic lineages. Isolates were also characterized for traits commonly associated with plant growth-promoting bacteria, including antibiosis and auxin biosynthesis. All isolates exhibited resistance to geldanamycin, whereas only two isolates were shown to produce this antibiotic. Endophytes were inoculated on radish seedlings and most isolates were found to possess plant growth-promoting abilities. These endophytic actinobacteria inhibited the growth of various plant pathogenic fungi and/or bacteria. The present study showed that S. violaceusniger clade members represent a significant part of the actinobacterial community living as endophytes in cacao fruits and seeds. While several members of this clade are known to be geldanamycin producers and efficient biocontrol agents of plant diseases, we herein established the endophytic lifestyle of some of these microorganisms, demonstrating their potential as plant health agents.

  17. Enhanced degradation of chlorpyrifos in rice (Oryza sativa L.) by five strains of endophytic bacteria and their plant growth promotional ability.

    Science.gov (United States)

    Feng, Fayun; Ge, Jing; Li, Yisong; He, Shuang; Zhong, Jianfeng; Liu, Xianjing; Yu, Xiangyang

    2017-10-01

    Endophytic bacteria reside in plant tissues, such as roots, stems, leaves and seeds. Most of them can stimulate plant growth or alleviate phytotoxicity of pollutants. There are handful species with dual functions stimulating plant growth and degrading pollutants have been reported. Five endophytic bacteria were isolated from chlorpyrifos (CP) treated rice plants and identified as Pseudomonas aeruginosa strain RRA, Bacillus megaterium strain RRB, Sphingobacterium siyangensis strain RSA, Stenotrophomonas pavanii strain RSB and Curtobacterium plantarum strain RSC according to morphological characteristics, physiological and biochemical tests, and 16S rDNA phylogeny. All of them possessed some plant growth promotional traits, including indole acetic acid and siderophore production, secretion of phosphate solubilization and 1-aminocyclopropane-1-carboxylate deaminase. The bacteria were marked with the green fluorescent protein (gfp) gene and successfully colonized into rice plants. All isolates were able to degrade CP in vitro and in vivo. The five isolates degraded more than 90% of CP in 24 h when the initial concentration was lower than 5 mg/L. CP degradation was significantly enhanced in the infested rice plants and rice grains. The final CP residual was reduced up to 80% in the infested rice grains compared to the controls. The results indicate that these isolates are promising bio-inoculants for the removal or detoxification of CP residues in rice plants and grains. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Fusarium oxysporum volatiles enhance plant growth via affecting auxin transport and signaling

    Directory of Open Access Journals (Sweden)

    Vasileios eBitas

    2015-11-01

    Full Text Available Volatile organic compounds (VOCs have well-documented roles in plant-plant communication and directing animal behavior. In this study, we examine the less understood roles of VOCs in plant-fungal relationships. Phylogenetically and ecologically diverse strains of Fusarium oxysporum, a fungal species complex that often resides in the rhizosphere of assorted plants, produce volatile compounds that augment shoot and root growth of Arabidopsis thaliana and tobacco. Growth responses of A. thaliana hormone signaling mutants and expression patterns of a GUS reporter gene under the auxin-responsive DR5 promoter supported the involvement of auxin signaling in F. oxysporum volatile-mediated growth enhancement. In addition, 1-naphthylthalamic acid, an inhibitor of auxin efflux, negated F. oxysporum volatile-mediated growth enhancement in both plants. Comparison of the profiles of volatile compounds produced by F. oxysporum strains that differentially affected plant growth suggests that the relative compositions of both growth inhibitory and stimulatory compounds may determine the degree of plant growth enhancement. Volatile-mediated signaling between fungi and plants may represent a potentially conserved, yet mostly overlooked, mechanism underpinning plant-fungus interactions and fungal niche adaption.

  19. Auxin-BR Interaction Regulates Plant Growth and Development

    Science.gov (United States)

    Tian, Huiyu; Lv, Bingsheng; Ding, Tingting; Bai, Mingyi; Ding, Zhaojun

    2018-01-01

    Plants develop a high flexibility to alter growth, development, and metabolism to adapt to the ever-changing environments. Multiple signaling pathways are involved in these processes and the molecular pathways to transduce various developmental signals are not linear but are interconnected by a complex network and even feedback mutually to achieve the final outcome. This review will focus on two important plant hormones, auxin and brassinosteroid (BR), based on the most recent progresses about these two hormone regulated plant growth and development in Arabidopsis, and highlight the cross-talks between these two phytohormones. PMID:29403511

  20. Physiological effects of climate warming on flowering plants and insect pollinators and potential consequences for their interactions

    Directory of Open Access Journals (Sweden)

    Victoria L. SCAVEN, Nicole E. RAFFERTY

    2013-06-01

    Full Text Available Growing concern about the influence of climate change on flowering plants, pollinators, and the mutualistic interactions between them has led to a recent surge in research. Much of this research has addressed the consequences of warming for phenological and distributional shifts. In contrast, relatively little is known about the physiological responses of plants and insect pollinators to climate warming and, in particular, how these responses might affect plant-pollinator interactions. Here, we summarize the direct physiological effects of temperature on flowering plants and pollinating insects to highlight ways in which plant and pollinator responses could affect floral resources for pollinators, and pollination success for plants, respectively. We also consider the overall effects of these responses on plant-pollinator interaction networks. Plant responses to warming, which include altered flower, nectar, and pollen production, could modify floral resource availability and reproductive output of pollinating insects. Similarly, pollinator responses, such as altered foraging activity, body size, and life span, could affect patterns of pollen flow and pollination success of flowering plants. As a result, network structure could be altered as interactions are gained and lost, weakened and strengthened, even without the gain or loss of species or temporal overlap. Future research that addresses not only how plant and pollinator physiology are affected by warming but also how responses scale up to affect interactions and networks should allow us to better understand and predict the effects of climate change on this important ecosystem service [Current Zoolo­gy 59 (3: 418–426, 2013].

  1. Effects of microgravity on growth hormone concentration and distribution in plants

    Science.gov (United States)

    Schulze, Aga; Jensen, Philip; Desrosiers, Mark; Bandurski, Robert S.

    1989-01-01

    On earth, gravity affects the distribution of the plant growth hormone, indole-3-acetic acid (IAA), in a manner such that the plant grows into a normal vertical orientation (shoots up, roots down). How the plant controls the amount and distribution of IAA is only partially understood and is currently under investigation in this laboratory. The question to be answered in the flight experiment concerns the effect of gravity on the concentration, turn over, and distribution of the growth hormone. The answer to this question will aid in understanding the mechanism by which plants control the amount and distribution of growth hormone. Such knowledge of a plant's hormonal metabolism may aid in the growth of plants in space and will lead to agronomic advances.

  2. Impact of Selenium Supplementation on Growth and Selenium Accumulation on Spinach (Spinacia oleracea L. Plants

    Directory of Open Access Journals (Sweden)

    Azadeh SAFFARYAZDI

    2012-11-01

    Full Text Available Selenium (Se has been proved to be an essential element for humans and animals. However, less is known about its effects on plants. A hydroponic experiment was carried out to investigate the effects of selenium on growth, selenium accumulation and some physiological characteristics of spinach (Spinacia oleracea L. cv. Missouri plants. Plants were grown in Hoagland nutrient solution amended with sodium selenite at 0 (control, 1, 2, 4, 6 and 10 mg.L-1 for 28 days. Growth parameters like shoot and root fresh weight, shoot and root dry weight, total dry weight, shoot and root length increased by 17, 15, 38, 19, 18 and 34 percent in response to the lowest concentration of Se (1 mg L-1, respectively over control. However, application of higher Se concentrations reduced these parameters as compared to control. Selenium up to 1 mg L-1 enhanced the levels of chlorophyll a and chlorophyll b by 87 and 165 percent, respectively, while higher levels of Se exert toxic effects. Total phenolic compounds in leaves increased directly by increasing the level of Se and plants treated with 10 mg. L-1 Se had the highest values. Selenium, sodium and calcium content increased, while potassium content decreased, by increasing selenium treatments. The highest amounts of Se in shoots (3.89 mg g-1 DW and roots (4.27 mg g-1 DW were obtained for the highest concentration of Se (10 mg L-1. The present results suggested the beneficial effects of Se on spinach growth and also its contribute ion to improving the nutritional value of spinach for livestock and human nutrition.

  3. Impact of Selenium Supplementation on Growth and Selenium Accumulation on Spinach (Spinacia oleracea L. Plants

    Directory of Open Access Journals (Sweden)

    Azadeh SAFFARYAZDI

    2012-11-01

    Full Text Available Selenium (Se has been proved to be an essential element for humans and animals. However, less is known about its effects on plants. A hydroponic experiment was carried out to investigate the effects of selenium on growth, selenium accumulation and some physiological characteristics of spinach (Spinacia oleracea L. cv. �Missouri� plants. Plants were grown in Hoagland nutrient solution amended with sodium selenite at 0 (control, 1, 2, 4, 6 and 10 mg.L-1 for 28 days. Growth parameters like shoot and root fresh weight, shoot and root dry weight, total dry weight, shoot and root length increased by 17, 15, 38, 19, 18 and 34 percent in response to the lowest concentration of Se (1 mg L-1, respectively over control. However, application of higher Se concentrations reduced these parameters as compared to control. Selenium up to 1 mg L-1 enhanced the levels of chlorophyll a and chlorophyll b by 87 and 165 percent, respectively, while higher levels of Se exert toxic effects. Total phenolic compounds in leaves increased directly by increasing the level of Se and plants treated with 10 mg. L-1 Se had the highest values. Selenium, sodium and calcium content increased, while potassium content decreased, by increasing selenium treatments. The highest amounts of Se in shoots (3.89 mg g-1 DW and roots (4.27 mg g-1 DW were obtained for the highest concentration of Se (10 mg L-1. The present results suggested the beneficial effects of Se on spinach growth and also its contribute ion to improving the nutritional value of spinach for livestock and human nutrition.

  4. Predictable 'meta-mechanisms' emerge from feedbacks between transpiration and plant growth and cannot be simply deduced from short-term mechanisms.

    Science.gov (United States)

    Tardieu, François; Parent, Boris

    2017-06-01

    Growth under water deficit is controlled by short-term mechanisms but, because of numerous feedbacks, the combination of these mechanisms over time often results in outputs that cannot be deduced from the simple inspection of individual mechanisms. It can be analysed with dynamic models in which causal relationships between variables are considered at each time-step, allowing calculation of outputs that are routed back to inputs for the next time-step and that can change the system itself. We first review physiological mechanisms involved in seven feedbacks of transpiration on plant growth, involving changes in tissue hydraulic conductance, stomatal conductance, plant architecture and underlying factors such as hormones or aquaporins. The combination of these mechanisms over time can result in non-straightforward conclusions as shown by examples of simulation outputs: 'over production of abscisic acid (ABA) can cause a lower concentration of ABA in the xylem sap ', 'decreasing root hydraulic conductance when evaporative demand is maximum can improve plant performance' and 'rapid root growth can decrease yield'. Systems of equations simulating feedbacks over numerous time-steps result in logical and reproducible emergent properties that can be viewed as 'meta-mechanisms' at plant level, which have similar roles as mechanisms at cell level. © 2016 John Wiley & Sons Ltd.

  5. Evaluating the influence of plant-specific physiological parameterizations on the partitioning of land surface energy fluxes

    Science.gov (United States)

    Sulis, Mauro; Langensiepen, Matthias; Shrestha, Prabhakar; Schickling, Anke; Simmer, Clemens; Kollet, Stefan

    2015-04-01

    Vegetation has a significant influence on the partitioning of radiative forcing, the spatial and temporal variability of soil water and soil temperature. Therefore plant physiological properties play a key role in mediating and amplifying interactions and feedback mechanisms in the soil-vegetation-atmosphere continuum. Because of the direct impact on latent heat fluxes, these properties may also influence weather generating processes, such as the evolution of the atmospheric boundary layer (ABL). In land surface models, plant physiological properties are usually obtained from literature synthesis by unifying several plant/crop species in predefined vegetation classes. In this work, crop-specific physiological characteristics, retrieved from detailed field measurements, are included in the bio-physical parameterization of the Community Land Model (CLM), which is a component of the Terrestrial Systems Modeling Platform (TerrSysMP). The measured set of parameters for two typical European mid-latitudinal crops (sugar beet and winter wheat) is validated using eddy covariance measurements (sensible heat and latent heat) over multiple years from three measurement sites located in the North Rhine-Westphalia region, Germany. We found clear improvements of CLM simulations, when using the crop-specific physiological characteristics of the plants instead of the generic crop type when compared to the measurements. In particular, the increase of latent heat fluxes in conjunction with decreased sensible heat fluxes as simulated by the two new crop-specific parameter sets leads to an improved quantification of the diurnal energy partitioning. These findings are cross-validated using estimates of gross primary production extracted from net ecosystem exchange measurements. This independent analysis reveals that the better agreement between observed and simulated latent heat using the plant-specific physiological properties largely stems from an improved simulation of the

  6. Tenth workshop on seedling physiology and growth problems in oak plantings

    Science.gov (United States)

    Brian Roy Lockhart; Emile S. Gardiner; Daniel C. Dey

    2008-01-01

    Research results and ongoing research activities in field performance of oak plantings, seedling propagation, genetics, acorn germination, and natural regeneration of oaks are described in 15 abstracts.

  7. Emerging use of gene expression microarrays in plant physiology.

    Science.gov (United States)

    Wullschleger, Stan D; Difazio, Stephen P

    2003-01-01

    Microarrays have become an important technology for the global analysis of gene expression in humans, animals, plants, and microbes. Implemented in the context of a well-designed experiment, cDNA and oligonucleotide arrays can provide highthroughput, simultaneous analysis of transcript abundance for hundreds, if not thousands, of genes. However, despite widespread acceptance, the use of microarrays as a tool to better understand processes of interest to the plant physiologist is still being explored. To help illustrate current uses of microarrays in the plant sciences, several case studies that we believe demonstrate the emerging application of gene expression arrays in plant physiology were selected from among the many posters and presentations at the 2003 Plant and Animal Genome XI Conference. Based on this survey, microarrays are being used to assess gene expression in plants exposed to the experimental manipulation of air temperature, soil water content and aluminium concentration in the root zone. Analysis often includes characterizing transcript profiles for multiple post-treatment sampling periods and categorizing genes with common patterns of response using hierarchical clustering techniques. In addition, microarrays are also providing insights into developmental changes in gene expression associated with fibre and root elongation in cotton and maize, respectively. Technical and analytical limitations of microarrays are discussed and projects attempting to advance areas of microarray design and data analysis are highlighted. Finally, although much work remains, we conclude that microarrays are a valuable tool for the plant physiologist interested in the characterization and identification of individual genes and gene families with potential application in the fields of agriculture, horticulture and forestry.

  8. Human pathogens in plant biofilms: Formation, physiology, and detection.

    Science.gov (United States)

    Ximenes, Eduardo; Hoagland, Lori; Ku, Seockmo; Li, Xuan; Ladisch, Michael

    2017-07-01

    Fresh produce, viewed as an essential part of a healthy life style is usually consumed in the form of raw or minimally processed fruits and vegetables, and is a potentially important source of food-borne human pathogenic bacteria and viruses. These are passed on to the consumer since the bacteria can form biofilms or otherwise populate plant tissues, thereby using plants as vectors to infect animal hosts. The life cycle of the bacteria in plants differs from those in animals or humans and results in altered physiochemical and biological properties (e.g., physiology, immunity, native microflora, physical barriers, mobility, and temperature). Mechanisms by which healthy plants may become contaminated by microorganisms, develop biofilms, and then pass on their pathogenic burden to people are explored in the context of hollow fiber microfiltration by which plant-derived microorganisms may be recovered and rapidly concentrated to facilitate study of their properties. Enzymes, when added to macerated plant tissues, hydrolyze or alter macromolecules that would otherwise foul hollow-fiber microfiltration membranes. Hence, microfiltration may be used to quickly increase the concentration of microorganisms to detectable levels. This review discusses microbial colonization of vegetables, formation and properties of biofilms, and how hollow fiber microfiltration may be used to concentrate microbial targets to detectable levels. The use of added enzymes helps to disintegrate biofilms and minimize hollow fiber membrane fouling, thereby providing a new tool for more time effectively elucidating mechanisms by which biofilms develop and plant tissue becomes contaminated with human pathogens. Biotechnol. Bioeng. 2017;114: 1403-1418. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  9. Ethylene production throughout growth and development of plants

    Science.gov (United States)

    Wheeler, Raymond M.; Peterson, Barbara V.; Stutte, Gary W.

    2004-01-01

    Ethylene production by 10 or 20 m2 stands of wheat, soybean, lettuce, potato, and tomato was monitored throughout growth and development in an atmospherically closed plant chamber. Chamber ethylene levels varied among species and rose during periods of canopy expansion and rapid growth for all species. Following this, ethylene levels either declined during seed fill and maturation for wheat and soybean, or remained relatively constant for potato and tomato (during flowering and early fruit development). Lettuce plants were harvested during rapid growth and peak ethylene production. Chamber ethylene levels increased rapidly during tomato ripening, reaching concentrations about 10 times that measured during vegetative growth. The highest ethylene production rates during vegetative growth ranged from 1.6 to 2.5 nmol m-2 d-1 during rapid growth of lettuce and wheat stands, or about 0.3 to 0.5 nmol g-1 fresh weight per hour. Estimates of stand ethylene production during tomato ripening showed that rates reached 43 nmol m-2 d-1 in one study and 93 nmol m-2 d-1 in a second study with higher lighting, or about 50x that of the rate during vegetative growth of tomato. In a related test with potato, the photoperiod was extended from 12 to 24 hours (continuous light) at 58 days after planting (to increase tuber yield), but this change in the environment caused a sharp increase in ethylene production from the basal rate of 0.4 to 6.2 nmol m-2 d-1. Following this, the photoperiod was changed back to 12 h at 61 days and ethylene levels decreased. The results suggest three separate categories of ethylene production were observed with whole stands of plants: 1) production during rapid vegetative growth, 2) production during climacteric fruit ripening, and 3) production from environmental stress.

  10. Cotransport of water and solutes in plant membranes: The molecular basis, and physiological functions

    Directory of Open Access Journals (Sweden)

    Lars H. Wegner

    2017-03-01

    Full Text Available Current concepts of plant membrane transport are based on the assumption that water and solutes move across membranes via separate pathways. According to this view, coupling between the fluxes is more or less exclusively constituted via the osmotic force that solutes exert on water transport. This view is questioned here, and experimental evidence for a cotransport of water and solutes is reviewed. The overview starts with ion channels that provide pathways for both ion and water transport, as exemplified for maxi K+ channels from cytoplasmic droplets of Chara corallina. Aquaporins are usually considered to be selective for water (just allowing for slippage of some other small, neutral molecules. Recently, however, a “dual function” aquaporin has been characterized from Arabidopsis thaliana (AtPIP2.1 that translocates water and at the same time conducts cations, preferentially Na+. By analogy with mammalian physiology, other candidates for solute-water flux coupling are cation-chloride cotransporters of the CCC type, and transporters of sugars and amino acids. The last part is dedicated to possible physiological functions that could rely on solute-water cotransport. Among these are the generation of root pressure, refilling of embolized xylem vessels, fast turgor-driven movements of leaves, cell elongation (growth, osmoregulation and adjustment of buoyancy in marine algae. This review will hopefully initiate further research in the field.

  11. ROS and RNS in plant physiology: an overview.

    Science.gov (United States)

    Del Río, Luis A

    2015-05-01

    The production of reactive oxygen species (ROS) is the unavoidable consequence of aerobic life. ROS is a collective term that includes both oxygen radicals, like superoxide (O 2. -) and hydroxyl (·OH) radicals, and other non-radicals such as hydrogen peroxide (H2O2), singlet oxygen ((1)O2 or (1)Δg), etc. In plants, ROS are produced in different cell compartments and are oxidizing species, particularly hydroxyl radicals and singlet oxygen, that can produce serious damage in biological systems (oxidative stress). However, plant cells also have an array of antioxidants which, normally, can scavenge the excess oxidants produced and so avoid deleterious effects on the plant cell bio-molecules. The concept of 'oxidative stress' was re-evaluated in recent years and the term 'oxidative signalling' was created. This means that ROS production, apart from being a potentially harmful process, is also an important component of the signalling network that plants use for their development and for responding to environmental challenges. It is known that ROS play an important role regulating numerous biological processes such as growth, development, response to biotic and environmental stresses, and programmed cell death. The term reactive nitrogen species (RNS) includes radicals like nitric oxide (NO· ) and nitric dioxide (NO2.), as well as non-radicals such as nitrous acid (HNO2) and dinitrogen tetroxide (N2O4), among others. RNS are also produced in plants although the generating systems have still not been fully characterized. Nitric oxide (NO·) has an important function as a key signalling molecule in plant growth, development, and senescence, and RNS, like ROS, also play an important role as signalling molecules in the response to environmental (abiotic) stress. Similarly, NO· is a key mediator, in co-operation with ROS, in the defence response to pathogen attacks in plants. ROS and RNS have been demonstrated to have an increasingly important role in biology and medicine

  12. Air pollutants and the cuticle: implications for plant physiology

    International Nuclear Information System (INIS)

    Riederer, M.; Jetter, R.; Markstaedter, C.; Schreiber, L.

    1994-01-01

    The physiologically most important function of the plant cuticle is to control the loss of water and of inorganic and organic constituents of plants via the surfaces of leaves and fruits. In a polluted environment, the cuticle may also affect the rates of uptake of extraneous chemicals. It will be shown how the essential transport properties of plant cuticles can be determined experimentally using intact leaves, isolated cuticles, and reconstituted cuticular waxes. The transport properties will be related to the physico-chemical properties of the permeants in order to achieve a general description of pollutant transport across the leaf/atmosphere interface and to assess the relative contributions of the cuticular and the stomatal pathways to the total flow rate. The correlation of the transport properties of cuticles with their chemical composition will be discussed and a model of the molecular structure of the transport-limiting barrier of the cuticle and of epicuticular waxes be presented. The effects of chemicals of anthropogenic and biogenic origin on cuticular permeability will be described quantitatively. (orig.)

  13. Study on growth-promotion of paddy plants treated with oligo chitosan

    International Nuclear Information System (INIS)

    Norhashidah Talip; Maznah Mahmud; Norzita Yacob; Kamaruddin Hashim; Khairul Zaman Mohd Dahlan

    2010-01-01

    Chitosan has been degraded to produced oligo chitosan with different molecular weight using gamma ray irradiation from a Co-60 source in solid state (powder form) and liquid state (aqueous solution). Study on growth promotion of paddy plants was done using oligo chitosan and conventional plant growth promoter as a comparison. Oligo chitosan was used with different molecular weight and different concentrations. Smaller molecular weight of oligo chitosan with smaller concentration showed better result than bigger molecular weight of oligo chitosan as a plant growth promoter. This study also showed that conventional growth promoter can be replaced with oligo chitosan as it is more effective as plant growth promoter as well as more environmental friendly. (author)

  14. Low nitrogen stress stimulating the indole-3-acetic acid biosynthesis of Serratia sp. ZM is vital for the survival of the bacterium and its plant growth-promoting characteristic.

    Science.gov (United States)

    Ouyang, Liming; Pei, Haiyan; Xu, Zhaohui

    2017-04-01

    Serratia sp. ZM is a plant growth-promoting (PGP) bacterial strain isolated from the rhizospheric soil of Populus euphratica in northwestern China. In this study, low nitrogen supply significantly stimulated the production of indole-3-acetic acid (IAA) in Serratia sp.ZM. The inoculation of the bacterium to wheat seedlings improved plant growth compared with the uninoculated group, and the stimulating effect was more prominent under low nitrogen stress. Inactivation of the predicted key gene in the IAA biosynthesis pathway impaired IAA production and significantly hampered mutant growth in poor medium. Furthermore, the IAA-deficient mutant lost the PGP effect under either normal or low nitrogen conditions in plant experiments. This study revealed the significant impact of environmental nitrogen levels on IAA production in the PGP strain and the vital effect of IAA on resistance physiology of both the bacterium and host plant. The characteristics of Serratia sp. ZM also indicated its application potential as a biofertilizer for plants, especially those suffering from poor nitrogen soil.

  15. Phytohormone profiles induced by trichoderma isolates correspond with their biocontrol and plant growth-promoting activity on melon plants.

    Science.gov (United States)

    Martínez-Medina, Ainhoa; Del Mar Alguacil, Maria; Pascual, Jose A; Van Wees, Saskia C M

    2014-07-01

    The application of Trichoderma strains with biocontrol and plant growth-promoting capacities to plant substrates can help reduce the input of chemical pesticides and fertilizers in agriculture. Some Trichoderma isolates can directly affect plant pathogens, but they also are known to influence the phytohormonal network of their host plant, thus leading to an improvement of plant growth and stress tolerance. In this study, we tested whether alterations in the phytohormone signature induced by different Trichoderma isolates correspond with their ability for biocontrol and growth promotion. Four Trichoderma isolates were collected from agricultural soils and were identified as the species Trichoderma harzianum (two isolates), Trichoderma ghanense, and Trichoderma hamatum. Their antagonistic activity against the plant pathogen Fusarium oxysporum f. sp. melonis was tested in vitro, and their plant growth-promoting and biocontrol activity against Fusarium wilt on melon plants was examined in vivo, and compared to that of the commercial strain T. harzianum T-22. Several growth- and defense-related phytohormones were analyzed in the shoots of plants that were root-colonized by the different Trichoderma isolates. An increase in auxin and a decrease in cytokinins and abscisic acid content were induced by the isolates that promoted the plant growth. Principal component analysis (PCA) was used to evaluate the relationship between the plant phenotypic and hormonal variables. PCA pointed to a strong association of auxin induction with plant growth stimulation by Trichoderma. Furthermore, the disease-protectant ability of the Trichoderma strains against F. oxysporum infection seems to be more related to their induced alterations in the content of the hormones abscisic acid, ethylene, and the cytokinin trans-zeatin riboside than to the in vitro antagonism activity against F. oxysporum.

  16. Gravity Plant Physiology Facility (GPPF) Team in the Spacelab Payload Operations Control Center (SL

    Science.gov (United States)

    1992-01-01

    The primary payload for Space Shuttle Mission STS-42, launched January 22, 1992, was the International Microgravity Laboratory-1 (IML-1), a pressurized manned Spacelab module. The goal of IML-1 was to explore in depth the complex effects of weightlessness of living organisms and materials processing. Around-the-clock research was performed on the human nervous system's adaptation to low gravity and effects of microgravity on other life forms such as shrimp eggs, lentil seedlings, fruit fly eggs, and bacteria. Materials processing experiments were also conducted, including crystal growth from a variety of substances such as enzymes, mercury iodide, and a virus. The Huntsville Operations Support Center (HOSC) Spacelab Payload Operations Control Center (SL POCC) at the Marshall Space Flight Center (MSFC) was the air/ground communication channel used between the astronauts and ground control teams during the Spacelab missions. Featured is the Gravity Plant Physiology Facility (GPPF) team in the SL POCC during the IML-1 mission.

  17. Virtual Plant Tissue: Building Blocks for Next-Generation Plant Growth Simulation

    Directory of Open Access Journals (Sweden)

    Dirk De Vos

    2017-05-01

    Full Text Available Motivation: Computational modeling of plant developmental processes is becoming increasingly important. Cellular resolution plant tissue simulators have been developed, yet they are typically describing physiological processes in an isolated way, strongly delimited in space and time.Results: With plant systems biology moving toward an integrative perspective on development we have built the Virtual Plant Tissue (VPTissue package to couple functional modules or models in the same framework and across different frameworks. Multiple levels of model integration and coordination enable combining existing and new models from different sources, with diverse options in terms of input/output. Besides the core simulator the toolset also comprises a tissue editor for manipulating tissue geometry and cell, wall, and node attributes in an interactive manner. A parameter exploration tool is available to study parameter dependence of simulation results by distributing calculations over multiple systems.Availability: Virtual Plant Tissue is available as open source (EUPL license on Bitbucket (https://bitbucket.org/vptissue/vptissue. The project has a website https://vptissue.bitbucket.io.

  18. Soil organic matter influences cerium translocation and physiological processes in kidney bean plants exposed to cerium oxide nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Majumdar, Sanghamitra [Department of Chemistry, The University of Texas at El Paso, 500 West University Ave., El Paso, TX 79968 (United States); University of California Center for Environmental Implications of Nanotechnology (UC CEIN), El Paso, TX (United States); Peralta-Videa, Jose R. [Department of Chemistry, The University of Texas at El Paso, 500 West University Ave., El Paso, TX 79968 (United States); Environmental Science and Engineering PhD Program, The University of Texas at El Paso, 500 West University Ave., El Paso, TX 79968 (United States); University of California Center for Environmental Implications of Nanotechnology (UC CEIN), El Paso, TX (United States); Trujillo-Reyes, Jesica [Department of Chemistry, The University of Texas at El Paso, 500 West University Ave., El Paso, TX 79968 (United States); Sun, Youping [Texas AgriLife Research Center at El Paso, Texas A& M University System, 1380 A & M Circle, El Paso, TX 79927 (United States); Barrios, Ana C. [Department of Chemistry, The University of Texas at El Paso, 500 West University Ave., El Paso, TX 79968 (United States); Niu, Genhua [Texas AgriLife Research Center at El Paso, Texas A& M University System, 1380 A & M Circle, El Paso, TX 79927 (United States); Margez, Juan P. Flores- [Autonomous University of Ciudad Juarez, Departamento de Química y Biología, Instituto de Ciencias Biomédicas, Anillo envolvente PRONAF y Estocolmo, Ciudad Juarez, Chihuahua 32310, México (Mexico); Gardea-Torresdey, Jorge L., E-mail: jgardea@utep.edu [Department of Chemistry, The University of Texas at El Paso, 500 West University Ave., El Paso, TX 79968 (United States); Environmental Science and Engineering PhD Program, The University of Texas at El Paso, 500 West University Ave., El Paso, TX 79968 (United States); University of California Center for Environmental Implications of Nanotechnology (UC CEIN), El Paso, TX (United States)

    2016-11-01

    Soil organic matter plays a major role in determining the fate of the engineered nanomaterials (ENMs) in the soil matrix and effects on the residing plants. In this study, kidney bean plants were grown in soils varying in organic matter content and amended with 0–500 mg/kg cerium oxide nanoparticles (nano-CeO{sub 2}) under greenhouse condition. After 52 days of exposure, cerium accumulation in tissues, plant growth and physiological parameters including photosynthetic pigments (chlorophylls and carotenoids), net photosynthesis rate, transpiration rate, and stomatal conductance were recorded. Additionally, catalase and ascorbate peroxidase activities were measured to evaluate oxidative stress in the tissues. The translocation factor of cerium in the nano-CeO{sub 2} exposed plants grown in organic matter enriched soil (OMES) was twice as the plants grown in low organic matter soil (LOMS). Although the leaf cover area increased by 65–111% with increasing nano-CeO{sub 2} concentration in LOMS, the effect on the physiological processes were inconsequential. In OMES leaves, exposure to 62.5–250 mg/kg nano-CeO{sub 2} led to an enhancement in the transpiration rate and stomatal conductance, but to a simultaneous decrease in carotenoid contents by 25–28%. Chlorophyll a in the OMES leaves also decreased by 27 and 18% on exposure to 125 and 250 mg/kg nano-CeO{sub 2}. In addition, catalase activity increased in LOMS stems, and ascorbate peroxidase increased in OMES leaves of nano-CeO{sub 2} exposed plants, with respect to control. Thus, this study provides clear evidence that the properties of the complex soil matrix play decisive roles in determining the fate, bioavailability, and biological transport of ENMs in the environment. - Highlights: • Ce translocation to leaves was facilitated by higher organic matter (OM) in soil. • Lower soil OM increased leaf cover area in nano-CeO{sub 2} exposed plants. • Nano-CeO{sub 2} effects on metabolic processes were more

  19. Morpho-physiological and productive biometry in semi-erect cultivars of the cowpea under different plant populations

    Directory of Open Access Journals (Sweden)

    Antônio Aécio de Carvalho Bezerra

    Full Text Available ABSTRACT The aim of this study was to evaluate morpho-physiological and productive characteristics in four semi-erect cultivars of the cowpea under five plant populations. The experiment was conducted in the experimental area of Embrapa Meio-Norte in Teresina in the State of Piauí, Brazil (PI. The experimental design was of randomised complete blocks with four replications, in a 4 x 5 factorial scheme, for evaluating four cultivars (BRS Guariba, BRS Novaera, BRS Potengi and BRS Tumucumaque and five plant populations (105, 2x105, 3x105, 4x105 and 5x105 plants ha-1. There were significant differences between cultivars for primary branch length (PBL, number of lateral branches (NLB, 100-grain weight (HGW, and dry-grain yield (GY. The maximum PBL of 58.5 cm was obtained with 300 thousand plants ha-1, corresponding to an increase of 11.5% when compared to 100 thousand plants ha-1. However, there was a reduction of 91.2% in NLB when compared to the populations of 100 and 500 thousand plants ha-1. The increases of 188% obtained in the leaf area index (LAI in the range of 100 to 500 thousand plants ha-1 explain the linear increase in the crop growth rate (CGR as being due to the greater production of leaf area; also, the decreases seen in the net assimilation rate (NAR, especially in the range of 100 to 300 thousand plants ha-1, are explained as due to the consequent self-shading, which was intensified in the larger populations. LAI, light interception, and CGR in the cultivars increase in response to higher densities. HGW and GY are not significantly affected by the different populations.

  20. LeMYC2 acts as a negative regulator of blue light mediated photomorphogenic growth, and promotes the growth of adult tomato plants

    Science.gov (United States)

    2014-01-01

    Background Arabidopsis ZBF1/MYC2bHLH transcription factor is a repressor of photomorphogenesis, and acts as a point of cross talk in light, abscisic acid (ABA) and jasmonic acid (JA) signaling pathways. MYC2 also functions as a positive regulator of lateral root development and flowering time under long day conditions. However, the function of MYC2 in growth and development remains unknown in crop plants. Results Here, we report the functional analyses of LeMYC2 in tomato (Lycopersicon esculentum). The amino acid sequence of LeMYC2 showed extensive homology with Arabidopsis MYC2, containing the conserved bHLH domain. To study the function of LeMYC2 in tomato, overexpression and RNA interference (RNAi) LeMYC2 tomato transgenic plants were generated. Examination of seedling morphology, physiological responses and light regulated gene expression has revealed that LeMYC2 works as a negative regulator of blue light mediated photomorphogenesis. Furthermore, LeMYC2 specifically binds to the G-box of LeRBCS-3A promoter. Overexpression of LeMYC2 has led to increased root length with more number of lateral roots. The tomato plants overexpressing LeMYC2 have reduced internode distance with more branches, and display the opposite morphology to RNAi transgenic lines. Furthermore, this study shows that LeMYC2 promotes ABA and JA responsiveness. Conclusions Collectively, this study highlights that working in light, ABA and JA signaling pathways LeMYC2 works as an important regulator for growth and development in tomato plants. PMID:24483714

  1. Biotechnological application and taxonomical distribution of plant growth promoting actinobacteria.

    Science.gov (United States)

    Hamedi, Javad; Mohammadipanah, Fatemeh

    2015-02-01

    Plant growth promoting (PGP) bacteria are involved in various interactions known to affect plant fitness and soil quality, thereby increasing the productivity of agriculture and stability of soil. Although the potential of actinobacteria in antibiotic production is well-investigated, their capacity to enhance plant growth is not fully surveyed. Due to the following justifications, PGP actinobacteria (PGPA) can be considered as a more promising taxonomical group of PGP bacteria: (1) high numbers of actinobacteria per gram of soil and their filamentous nature, (2) genome dedicated to the secondary metabolite production (~5 to 10 %) is distinctively more than that of other bacteria and (3) number of plant growth promoter genera reported from actinobacteria is 1.3 times higher than that of other bacteria. Mechanisms by which PGPA contribute to the plant growth by association are: (a) enhancing nutrients availability, (b) regulation of plant metabolism, (c) decreasing environmental stress, (d) control of phytopathogens and (e) improvement of soil texture. Taxonomical and chemical diversity of PGPA and their biotechnological application along with their associated challenges are summarized in this paper.

  2. Physiological factors into plant uptake models for pollutant

    International Nuclear Information System (INIS)

    Goncharova, N.; Kalinkevich, E.; Pytyrskaya, V.; Lopareva, E.; Suvorov, D.

    2002-01-01

    The main principles of biological control of the intensity of pollutant flow into system soil-plant have been analysed. It demonstrated that functional state of plants is so far significant factor in determination of rate of pollutant turn on trophic chains as physical-chemical property of mineral elements Most biosphere and contamination assessment models are based on uniform soil conditions,since single coefficients are used to describe the transfer of contaminants to the plant. The main pathway of the functional control intensity of pollutant flow such as possibility of plant to increase mobility of mineral elements into soil and change of ion's exchange characteristics of plant tissues, which determine the degree of attraction and capacity of accumulation of non biogenic elements by a plant have been considered. It is known that there are two groups of factors which determine the level of pollutant accumulation by plant. The first group is connected with determination of the level of biological availability of pollutants for a plant in soil, the second group of factors determine attractive of the higher plants and capacity of radionuclides and heavy metals accumulation in biomass. At the same time in accordance with modern eco physiological data, different alive organisms can play active part in processes of the mineral elements migration. Metabolites of the coil microorganisms and especially root excretion of higher plants. Our investigations carried out earlier demonstrated that there is high correlation between the level of Cs, Cu, Zn and Co accumulation and cation exchange capacity of the intact plant tissues and on the other hand similar changes of these characteristics in condition of the experimental modification of radionuclide and heavy metals accumulation by different environmental factors. These data suggest that namely cation exchange capacity may be one of the main 'driving force' and physiological characteristics in absorption of non biogenic

  3. Growth physiology and dimorphism of Mucor circinelloides (syn. racemosus) during submerged batch cultivation

    DEFF Research Database (Denmark)

    Mcintyre, Mhairi; Breum, J.; Arnau, J.

    2002-01-01

    Mucor circinelloides is being investigated as a possible host for the production of heterologous proteins. Thus, the environmental conditions defining the physiology and morphology of this dimorphic fungus have been investigated in submerged batch cultivation. The optimal conditions for growth...

  4. Increasing plant growth by modulating omega-amidase expression in plants

    Science.gov (United States)

    Unkefer, Pat J.; Anderson, Penelope S.; Knight, Thomas J.

    2015-06-30

    The present disclosure relates to compositions and methods for increasing the leaf-to-root ratio of the signal metabolite 2-oxoglutaramate and related proline molecules in plants by modulating levels of .omega.-amidase to increase nitrogen use efficiency, resulting in enhanced growth, faster growth rates, greater seed and fruit/pod yields, earlier and more productive flowering, increased tolerance to high salt conditions, and increased biomass yields.

  5. Growth of hydroxyapatite on physiologically clotted fibrin capped gold nanoparticles

    International Nuclear Information System (INIS)

    Sastry, T P; Sundaraseelan, J; Swarnalatha, K; Sobhana, S S Liji; Makheswari, M Uma; Sekar, S; Mandal, A B

    2008-01-01

    The growth of hydroxyapatite (HAp) on physiologically clotted fibrin (PCF)-gold nanoparticles is presented for the first time by employing a wet precipitation method. Fourier transform infrared (FTIR) spectroscopy confirmed the characteristic functionalities of PCF and HAp in the PCF-Au-HAp nanocomposite. Scanning electron microscopy (SEM) images have shown cuboidal nanostructures having a size in the range of 70-300 nm of HAp, whereas 2-50 nm sized particles were visualized in high-resolution transmission electron microscopy (TEM). Energy-dispersive x-ray (EDX) and x-ray diffraction (XRD) studies have confirmed the presence of HAp. These results show that gold nanoparticles with PCF acted as a matrix for the growth of HAp, and that PCF-Au-HAp nanocomposite is expected to have better osteoinductive properties

  6. Manipulation of the apoplastic pH of intact plants mimics stomatal and growth responses to water availability and microclimatic variation.

    Science.gov (United States)

    Wilkinson, Sally; Davies, William J

    2008-01-01

    The apoplastic pH of intact Forsythiaxintermedia (cv. Lynwood) and tomato (Solanum lycopersicum) plants has been manipulated using buffered foliar sprays, and thereby stomatal conductance (g(s)), leaf growth rate, and plant water loss have been controlled. The more alkaline the pH of the foliar spray, the lower the g(s) and/or leaf growth rate subsequently measured. The most alkaline pH that was applied corresponds to that measured in sap extracted from shoots of tomato and Forsythia plants experiencing, respectively, soil drying or a relatively high photon flux density (PFD), vapour pressure deficit (VPD), and temperature in the leaf microclimate. The negative correlation between PFD/VPD/temperature and g(s) determined in well-watered Forsythia plants exposed to a naturally varying summer microclimate was eliminated by spraying the plants with relatively alkaline but not acidic buffers, providing evidence for a novel pH-based signalling mechanism linking the aerial microclimate with stomatal aperture. Increasing the pH of the foliar spray only reduced g(s) in plants of the abscisic acid (ABA)-deficient flacca mutant of tomato when ABA was simultaneously sprayed onto leaves or injected into stems. In well-watered Forsythia plants exposed to a naturally varying summer microclimate (variable PFD, VPD, and temperature), xylem pH and leaf ABA concentration fluctuated but were positively correlated. Manipulation of foliar apoplastic pH also affected the response of g(s) and leaf growth to ABA injected into stems of intact Forsythia plants. The techniques used here to control physiology and water use in intact growing plants could easily be applied in a horticultural context.

  7. Physiological blockage in plants in response to postharvest stress

    African Journals Online (AJOL)

    Marcos

    2013-03-13

    Mar 13, 2013 ... response of the plant to cut stem (Ichimura et al., 1999). When the vessel is ... blockage due to microbial growth and blockage caused by formation of .... HQS) and chlorine, are used to assess its actions in the microorganisms ...

  8. Functional diversity supports the physiological tolerance hypothesis for plant species richness along climatic gradients

    Science.gov (United States)

    Spasojevic, Marko J.; Grace, James B.; Harrison, Susan; Damschen, Ellen Ingman

    2013-01-01

    1. The physiological tolerance hypothesis proposes that plant species richness is highest in warm and/or wet climates because a wider range of functional strategies can persist under such conditions. Functional diversity metrics, combined with statistical modeling, offer new ways to test whether diversity-environment relationships are consistent with this hypothesis. 2. In a classic study by R. H. Whittaker (1960), herb species richness declined from mesic (cool, moist, northerly) slopes to xeric (hot, dry, southerly) slopes. Building on this dataset, we measured four plant functional traits (plant height, specific leaf area, leaf water content and foliar C:N) and used them to calculate three functional diversity metrics (functional richness, evenness, and dispersion). We then used a structural equation model to ask if ‘functional diversity’ (modeled as the joint responses of richness, evenness, and dispersion) could explain the observed relationship of topographic climate gradients to species richness. We then repeated our model examining the functional diversity of each of the four traits individually. 3. Consistent with the physiological tolerance hypothesis, we found that functional diversity was higher in more favorable climatic conditions (mesic slopes), and that multivariate functional diversity mediated the relationship of the topographic climate gradient to plant species richness. We found similar patterns for models focusing on individual trait functional diversity of leaf water content and foliar C:N. 4. Synthesis. Our results provide trait-based support for the physiological tolerance hypothesis, suggesting that benign climates support more species because they allow for a wider range of functional strategies.

  9. Growth and phenolic compounds of Lactuca sativa L. grown in a closed-type plant production system with UV-A, -B, or -C lamp.

    Science.gov (United States)

    Lee, Min-Jeong; Son, Jung Eek; Oh, Myung-Min

    2014-01-30

    The production of high-quality crops based on phytochemicals is a strategy for accelerating the practical use of plant factories. Previous studies have demonstrated that ultraviolet (UV) light is effective in improving phytochemical production. This study aimed to determine the effect of various UV wavelengths on growth and phenolic compound accumulation in lettuce (Lactuca sativa L.) grown in a closed-type plant production system. Seven days, 1 day and 0.25 day were determined as the upper limit of the irradiation periods for UV-A, -B, and -C, respectively, in the lettuce based on physiological disorders and the fluorescence parameter F(v)/F(m). Continuous UV-A treatment significantly induced the accumulation of phenolic compounds and antioxidants until 4 days of treatment without growth inhibition, consistent with an increase in phenylalanine ammonia lyase (PAL) gene expression and PAL activity. Repeated or gradual UV-B exposure yielded approximately 1.4-3.6 times more total phenolics and antioxidants, respectively, than the controls did 2 days after the treatments, although both treatments inhibited lettuce growth. Repeated UV-C exposure increased phenolics but severely inhibited the growth of lettuce plants. Our data suggest that UV irradiation can improve the accumulation of phenolic compounds with antioxidant properties in lettuce cultivated in plant factories. © 2013 Society of Chemical Industry.

  10. Monoclonal antibodies for the detection and quantitation of the endogenous plant growth regulator, abscisic acid

    Energy Technology Data Exchange (ETDEWEB)

    Mertens, R.; Weiler, E.W. (Bochum Univ. (Germany, F.R.). Lehrstuhl fuer Pflanzenphysiologie); Deus-Neumann, B. (Muenchen Univ. (Germany, F.R.). Inst. fuer pharmazeutische Biologie)

    1983-08-22

    Monoclonal antibodies (mAB) have been produced which recognize the physiologically active 2-cis-(S)-form of the endogenous plant growth regulator, abscisic acid (ABA). Cross-reaction with the ABA-catabolites, phaseic and dihydrophaseic acid, is negligible, and (R)-ABA, 2-trans-ABA, the ABA-conjugate, ABA-..beta..-D-glucopyranosyl ester, as well as the putative ABA precursor, xanthoxin, are totally unreactive. In addition to being very specific, the mAB exhibit high affinities for 2-cis-(S)-ABA; the K values were 7.9 x 10/sup 9/ l/mol and 3.7 x 10/sup 9/ l/mol for antibodies from two different clones. By mAB-radioimmunoassay (RIA), 4 pg of 2-cis-(S)-ABA (99.5% confidence level) can be detected. mAB-RIA can be used to quantitate ABA directly in unprocessed plant extracts.

  11. Monoclonal antibodies for the detection and quantitation of the endogenous plant growth regulator, abscisic acid

    International Nuclear Information System (INIS)

    Mertens, R.; Weiler, E.W.; Deus-Neumann, B.

    1983-01-01

    Monoclonal antibodies (mAB) have been produced which recognize the physiologically active 2-cis-(S)-form of the endogenous plant growth regulator, abscisic acid (ABA). Cross-reaction with the ABA-catabolites, phaseic and dihydrophaseic acid, is negligible, and (R)-ABA, 2-trans-ABA, the ABA-conjugate, ABA-β-D-glucopyranosyl ester, as well as the putative ABA precursor, xanthoxin, are totally unreactive. In addition to being very specific, the mAB exhibit high affinities for 2-cis-(S)-ABA; the K values were 7.9 x 10 9 l/mol and 3.7 x 10 9 l/mol for antibodies from two different clones. By mAB-radioimmunoassay (RIA), 4 pg of 2-cis-(S)-ABA (99.5% confidence level) can be detected. mAB-RIA can be used to quantitate ABA directly in unprocessed plant extracts. (Auth.)

  12. Growth is required for perception of water availability to pattern root branches in plants.

    Science.gov (United States)

    Robbins, Neil E; Dinneny, José R

    2018-01-23

    Water availability is a potent regulator of plant development and induces root branching through a process termed hydropatterning. Hydropatterning enables roots to position lateral branches toward regions of high water availability, such as wet soil or agar media, while preventing their emergence where water is less available, such as in air. The mechanism by which roots perceive the spatial distribution of water during hydropatterning is unknown. Using primary roots of Zea mays (maize) we reveal that developmental competence for hydropatterning is limited to the growth zone of the root tip. Past work has shown that growth generates gradients in water potential across an organ when asymmetries exist in the distribution of available water. Using mathematical modeling, we predict that substantial growth-sustained water potential gradients are also generated in the hydropatterning competent zone and that such biophysical cues inform the patterning of lateral roots. Using diverse chemical and environmental treatments we experimentally demonstrate that growth is necessary for normal hydropatterning of lateral roots. Transcriptomic characterization of the local response of tissues to a moist surface or air revealed extensive regulation of signaling and physiological pathways, some of which we show are growth-dependent. Our work supports a "sense-by-growth" mechanism governing hydropatterning, by which water availability cues are rendered interpretable through growth-sustained water movement. Copyright © 2018 the Author(s). Published by PNAS.

  13. Compatible bacterial mixture, tolerant to desiccation, improves maize plant growth.

    Science.gov (United States)

    Molina-Romero, Dalia; Baez, Antonino; Quintero-Hernández, Verónica; Castañeda-Lucio, Miguel; Fuentes-Ramírez, Luis Ernesto; Bustillos-Cristales, María Del Rocío; Rodríguez-Andrade, Osvaldo; Morales-García, Yolanda Elizabeth; Munive, Antonio; Muñoz-Rojas, Jesús

    2017-01-01

    Plant growth-promoting rhizobacteria (PGPR) increase plant growth and crop productivity. The inoculation of plants with a bacterial mixture (consortium) apparently provides greater benefits to plant growth than inoculation with a single bacterial strain. In the present work, a bacterial consortium was formulated containing four compatible and desiccation-tolerant strains with potential as PGPR. The formulation had one moderately (Pseudomonas putida KT2440) and three highly desiccation-tolerant (Sphingomonas sp. OF178, Azospirillum brasilense Sp7 and Acinetobacter sp. EMM02) strains. The four bacterial strains were able to adhere to seeds and colonize the rhizosphere of plants when applied in both mono-inoculation and multi-inoculation treatments, showing that they can also coexist without antagonistic effects in association with plants. The effects of the bacterial consortium on the growth of blue maize were evaluated. Seeds inoculated with either individual bacterial strains or the bacterial consortium were subjected to two experimental conditions before sowing: normal hydration or desiccation. In general, inoculation with the bacterial consortium increased the shoot and root dry weight, plant height and plant diameter compared to the non-inoculated control or mono-inoculation treatments. The bacterial consortium formulated in this work had greater benefits for blue maize plants even when the inoculated seeds underwent desiccation stress before germination, making this formulation attractive for future field applications.

  14. Compatible bacterial mixture, tolerant to desiccation, improves maize plant growth.

    Directory of Open Access Journals (Sweden)

    Dalia Molina-Romero

    Full Text Available Plant growth-promoting rhizobacteria (PGPR increase plant growth and crop productivity. The inoculation of plants with a bacterial mixture (consortium apparently provides greater benefits to plant growth than inoculation with a single bacterial strain. In the present work, a bacterial consortium was formulated containing four compatible and desiccation-tolerant strains with potential as PGPR. The formulation had one moderately (Pseudomonas putida KT2440 and three highly desiccation-tolerant (Sphingomonas sp. OF178, Azospirillum brasilense Sp7 and Acinetobacter sp. EMM02 strains. The four bacterial strains were able to adhere to seeds and colonize the rhizosphere of plants when applied in both mono-inoculation and multi-inoculation treatments, showing that they can also coexist without antagonistic effects in association with plants. The effects of the bacterial consortium on the growth of blue maize were evaluated. Seeds inoculated with either individual bacterial strains or the bacterial consortium were subjected to two experimental conditions before sowing: normal hydration or desiccation. In general, inoculation with the bacterial consortium increased the shoot and root dry weight, plant height and plant diameter compared to the non-inoculated control or mono-inoculation treatments. The bacterial consortium formulated in this work had greater benefits for blue maize plants even when the inoculated seeds underwent desiccation stress before germination, making this formulation attractive for future field applications.

  15. Plant adaptation to temperature and photoperiod

    Directory of Open Access Journals (Sweden)

    O. JUNTTILA

    2008-12-01

    Full Text Available Plants respond to environmental conditions both by adaptation and by acclimation. The ability of the plants to grow, reproduce and survive under changing climatic conditions depends on the efficiency of adaptation and acclimation. The adaptation of developmental processes in plants to temperature and photoperiod is briefly reviewed. In annual plants this adaptation is related to growth capacity and to the timing of reproduction. In perennial plants growing under northern conditions, adaptation of the annual growth cycle to the local climatic cycle is of primary importance. Examples of the role of photothermal conditions in regulation of these phenological processes are given and discussed. The genetic and physiological bases for climatic adaptation in plants are briefly examined.;

  16. Loblolly pine seedling growth after inoculation with plant growth-promoting rhizobacteria and ozone exposure

    Energy Technology Data Exchange (ETDEWEB)

    Estes, B.L.; Enebak, S.A.; Chappelka, A.H. [Auburn Univ., Auburn, AL (United States). School of Forestry and Wildlife Sciences

    2004-07-01

    The conifer tree species with the greatest economic importance in south eastern United States plantations is Loblolly pine. Plantations require intensive fertilization, pesticide application, and irrigation. In these cases growth-promoting rhizobacteria are useful in pest control. While it was once thought that ozone in the troposphere was limited to urban areas, it is now known that it is transported far from its place of origin. Ozone is known to impact plant growth negatively. There have been no previous studies on whether growth-promoting rhizobacteria can decrease the negative effects of ozone. In this study seedlings of Loblolly pine were inoculated with either Bacillus subtilis (Ehrenberg) Cohn or Paenibacillus macerans (Schardinger) Ash. These were exposed to controlled amounts of ozone for 8-12 weeks. All plants showed decreased biomass and increased foliar damage compared to plants that were not exposed to ozone. B. subtilis inoculated plants showed less foliar damage than un-inoculated ones and root dimensions were increased. The use of growth-promoting rhizobacteria is not ready for large-scale commercial application in forestry, but this demonstration of the possible beneficial effects on ozone exposure warrants further investigation. 44 refs., 3 tabs., 2 figs.

  17. Usage and control of solid-state lighting for plant growth

    Energy Technology Data Exchange (ETDEWEB)

    Pinho, P.

    2008-07-01

    The work begins with an introductory part in which the basic aspects related to the photosynthetic radiation, the photobiology of plants and the technology of light-emitting diodes (Leads) are overviewed. It is followed by a review of related research works that have been conducted during the last two decades, and by the main design issues of Led lumin aires for plant growth. The following part of the work reports the experimental growth tests performed. The effects of the radiation emitted by spectrally tailored Led lumin aires on plant growth have been investigated. A total of four growth tests using lettuce and radish cultivars were performed. Two basic approaches were used to investigate the effects and the future possibilities of the usage of solid-state lighting (SSL) in plant growth. The first approach evaluates the growth development of lettuce plants in real greenhouse conditions using LEDs as supplementary light sources to natural daylight. In the second approach the evaluation was carried out with a total absence of natural daylight by growing lettuce and radish plants in phytotron-chamber conditions. The effects of SSL treatments on the growth development and quality of crops were compared with reference lighting systems composed of conventional and well-established light-source technologies, such as fluorescent and high-pressure sodium lamps. During the process of the investigation, the need to coherently quantify and evaluate the spectral quality of the radiation in terms of its photosynthetic appetence arose. Different metrics are still been used indiscriminately to quantify radiation used by plants to perform photosynthesis. Therefore, the existing metrics are discussed and a new proposal for coherent systematization is presented. The proposed system is referred to phyllophotometric and it is developed using the average photosynthetic spectral quantum yield response curve of plants. The results of the growth tests showed that the usage of SSL in

  18. Growth and physiological responses to varied environments among populations of Pinus ponderosa

    Science.gov (United States)

    Jianwei Zhang; Bert M. Cregg

    2005-01-01

    We investigated population responses in physiology, morphology, and growth of mature Pinus ponderosa trees to an environmental gradient across Nebraska, USA. Ten populations from western Nebraska and eastern Wyoming were grown in three 26-year-old provenance tests from the warmest and wettest site in the east (Plattsmouth) to the intermediate site in...

  19. Physiological response of carnation to radiation and some other factors

    International Nuclear Information System (INIS)

    Abdel - Baky, M.M.

    1986-01-01

    This study was carried out to investigate the physiological response of carnation plant (Dianthus caryophyllus c v. William sim) to gamma rays irradiation and some other factors namely: gibberellic acid and alar (B - 9 or daminozide) as growth regulators and potassium and boron as nutrients. The obtained results would be summarized

  20. Role of Plant Growth Promoting Rhizobacteria in Agricultural Sustainability—A Review

    Directory of Open Access Journals (Sweden)

    Pravin Vejan

    2016-04-01

    Full Text Available Plant growth promoting rhizobacteria (PGPR shows an important role in the sustainable agriculture industry. The increasing demand for crop production with a significant reduction of synthetic chemical fertilizers and pesticides use is a big challenge nowadays. The use of PGPR has been proven to be an environmentally sound way of increasing crop yields by facilitating plant growth through either a direct or indirect mechanism. The mechanisms of PGPR include regulating hormonal and nutritional balance, inducing resistance against plant pathogens, and solubilizing nutrients for easy uptake by plants. In addition, PGPR show synergistic and antagonistic interactions with microorganisms within the rhizosphere and beyond in bulk soil, which indirectly boosts plant growth rate. There are many bacteria species that act as PGPR, described in the literature as successful for improving plant growth. However, there is a gap between the mode of action (mechanism of the PGPR for plant growth and the role of the PGPR as biofertilizer—thus the importance of nano-encapsulation technology in improving the efficacy of PGPR. Hence, this review bridges the gap mentioned and summarizes the mechanism of PGPR as a biofertilizer for agricultural sustainability.

  1. Role of Plant Growth Promoting Rhizobacteria in Agricultural Sustainability-A Review.

    Science.gov (United States)

    Vejan, Pravin; Abdullah, Rosazlin; Khadiran, Tumirah; Ismail, Salmah; Nasrulhaq Boyce, Amru

    2016-04-29

    Plant growth promoting rhizobacteria (PGPR) shows an important role in the sustainable agriculture industry. The increasing demand for crop production with a significant reduction of synthetic chemical fertilizers and pesticides use is a big challenge nowadays. The use of PGPR has been proven to be an environmentally sound way of increasing crop yields by facilitating plant growth through either a direct or indirect mechanism. The mechanisms of PGPR include regulating hormonal and nutritional balance, inducing resistance against plant pathogens, and solubilizing nutrients for easy uptake by plants. In addition, PGPR show synergistic and antagonistic interactions with microorganisms within the rhizosphere and beyond in bulk soil, which indirectly boosts plant growth rate. There are many bacteria species that act as PGPR, described in the literature as successful for improving plant growth. However, there is a gap between the mode of action (mechanism) of the PGPR for plant growth and the role of the PGPR as biofertilizer-thus the importance of nano-encapsulation technology in improving the efficacy of PGPR. Hence, this review bridges the gap mentioned and summarizes the mechanism of PGPR as a biofertilizer for agricultural sustainability.

  2. Effect of plant growth promoting rhizobacteria on root morphology of ...

    African Journals Online (AJOL)

    Jane

    2011-10-03

    Oct 3, 2011 ... Plant growth promoting rhizobacteria improve the plant growth by a variety of ways like ... preparing textile dye in the Far East, Central and. Northern Asia and ... The experiment was carried out in complete randomized design.

  3. Emerging Use of Gene Expression Microarrays in Plant Physiology

    Directory of Open Access Journals (Sweden)

    Stephen P. Difazio

    2006-04-01

    Full Text Available Microarrays have become an important technology for the global analysis of gene expression in humans, animals, plants, and microbes. Implemented in the context of a well-designed experiment, cDNA and oligonucleotide arrays can provide highthroughput, simultaneous analysis of transcript abundance for hundreds, if not thousands, of genes. However, despite widespread acceptance, the use of microarrays as a tool to better understand processes of interest to the plant physiologist is still being explored. To help illustrate current uses of microarrays in the plant sciences, several case studies that we believe demonstrate the emerging application of gene expression arrays in plant physiology were selected from among the many posters and presentations at the 2003 Plant and Animal Genome XI Conference. Based on this survey, microarrays are being used to assess gene expression in plants exposed to the experimental manipulation of air temperature, soil water content and aluminium concentration in the root zone. Analysis often includes characterizing transcript profiles for multiple post-treatment sampling periods and categorizing genes with common patterns of response using hierarchical clustering techniques. In addition, microarrays are also providing insights into developmental changes in gene expression associated with fibre and root elongation in cotton and maize, respectively. Technical and analytical limitations of microarrays are discussed and projects attempting to advance areas of microarray design and data analysis are highlighted. Finally, although much work remains, we conclude that microarrays are a valuable tool for the plant physiologist interested in the characterization and identification of individual genes and gene families with potential application in the fields of agriculture, horticulture and forestry.

  4. The Effect of Plant Density on Photosynthesis and Growth Indices of Henna (Lowsonia inermis L. Ecotypes

    Directory of Open Access Journals (Sweden)

    A Pasandi Pour

    2018-05-01

    Full Text Available Introduction One of the most important factors to obtain the maximum performance or yield in every climatic condition and for each plant varieties is determining the optimum plant density. Henna (Lowsonia inermis L. is a perennial plant with high value in terms of having medicinal properties and industrial applications. The dye which is derived from green leaves of henna is used for decorating the body with intricate designs and the principle coloring matter is lawsone, 2-hydroxy-1, 4-naphthoqunone. The main purpose of this study was to evaluate the agro-physiological reaction of different henna ecotypes to different planting densities in Kerman weather conditions. Materials and Methods The study was carried out as a factorial experiment based on complete randomized block design with three replications in Shahid Bahonar University in 2015. The experiment consisted of four plant densities (25, 33, 50 and 100 plants m-2 and three ecotypes (Shahdad, Roodbar and Bam. Due to its small seeds and germination problems the planting method used was transplanting. In this study, growth indices such as leaf area index (LAI, crop growth rate (CGR, relative growth rate (RGR, leaf area ratio (LAR, specific leaf area (SLA, specific leaf weight (SLW, leaf area duration (LAD and biomass duration (BMD were calculated. The net photosynthesis, stomatal conductance and transpiration rate were measured in the middle of growing period by photosynthesis meter (CI-340 model, CID Bio- Science companies, USA. At the end, the results were analyzed using the SAS v. 9.1 and MSTATC software’s and diagrams were drawn by Excel software. Results and Discussion The results showed that the studied ecotypes were significantly different in terms of CGR, RGR and stomatal conductance. The highest average of CGR belonged to Shahdad ecotype while there was no significant difference between Roodbar and Bam ecotypes in this case. Shahdad ecotype with the RGR of 0.018 g.g.day had the

  5. Laboratory study on influence of plant growth promoting ...

    African Journals Online (AJOL)

    Aghomotsegin

    2015-03-06

    Mar 6, 2015 ... promoting rhizobacteria (PGPR) on growth response and tolerance of Zea ... inoculating maize seeds with plant growth promoting rhizobacterial strains in a crude oil impacted medium. ..... Botany and Environmental Health.

  6. Cell physiology of plants growing in cold environments.

    Science.gov (United States)

    Lütz, Cornelius

    2010-08-01

    The life of plants growing in cold extreme environments has been well investigated in terms of morphological, anatomical, and ecophysiological adaptations. In contrast, long-term cellular or metabolic studies have been performed by only a few groups. Moreover, a number of single reports exist, which often represent just a glimpse of plant behavior. The review draws together the literature which has focused on tissue and cellular adaptations mainly to low temperatures and high light. Most studies have been done with European alpine plants; comparably well studied are only two phanerogams found in the coastal Antarctic. Plant adaptation in northern polar regions has always been of interest in terms of ecophysiology and plant propagation, but nowadays, this interest extends to the effects of global warming. More recently, metabolic and cellular investigations have included cold and UV resistance mechanisms. Low-temperature stress resistance in plants from cold environments reflects the climate conditions at the growth sites. It is now a matter of molecular analyses to find the induced genes and their products such as chaperones or dehydrins responsible for this resistance. Development of plants under snow or pollen tube growth at 0 degrees C shows that cell biology is needed to explain the stability and function of the cytoskeleton. Many results in this field are based on laboratory studies, but several publications show that it is not difficult to study cellular mechanisms with the plants adapted to a natural stress. Studies on high light and UV loads may be split in two parts. Many reports describe natural UV as harmful for the plants, but these studies were mainly conducted by shielding off natural UV (as controls). Other experiments apply additional UV in the field and have had practically no negative impact on metabolism. The latter group is supported by the observations that green overwintering plants increase their flavonoids under snow even in the absence of

  7. The Critical Role of Potassium in Plant Stress Response

    Directory of Open Access Journals (Sweden)

    Min Wang

    2013-04-01

    Full Text Available Agricultural production continues to be constrained by a number of biotic and abiotic factors that can reduce crop yield quantity and quality. Potassium (K is an essential nutrient that affects most of the biochemical and physiological processes that influence plant growth and metabolism. It also contributes to the survival of plants exposed to various biotic and abiotic stresses. The following review focuses on the emerging role of K in defending against a number of biotic and abiotic stresses, including diseases, pests, drought, salinity, cold and frost and waterlogging. The availability of K and its effects on plant growth, anatomy, morphology and plant metabolism are discussed. The physiological and molecular mechanisms of K function in plant stress resistance are reviewed. This article also evaluates the potential for improving plant stress resistance by modifying K fertilizer inputs and highlights the future needs for research about the role of K in agriculture.

  8. Evaluation of iodate toxicity (KIO3 on growth, morpho-physiological characteristics and mineral nutrients concentrations of potato (Solanum tuberosum L. cv. Agria

    Directory of Open Access Journals (Sweden)

    Ezatollah Esfandiari

    2015-08-01

    Full Text Available The current study was aimed to assess the effects of different iodate concentrations on morpho-physiological characteristics of potato. In this regard, a pot experiment was carried out during the spring and summer 2013. Five concentrations of KIO3 including control beside 10, 20, 40, and 80 mg/Kgsoil were applied through irrigation system. The results showed that all selected agronomical and morphological characteristics of potato except dry weight of stem (SDW and root (RDW were negatively affected by high iodate concentrations. The results showed that applying 80 mg KIO3/Kgsoil compared to control resulted in around 15, 86, 84, 41, 16, 25, 20, and 87% reductions in harvest index (HI, leaf dry weight (LDW, tuber dry weight (TDW, plant dry weight (PDW, stem length (SL, root length (RL, plant height (PH, and number of tuber per plant (NT, respectively. Iodate application (80 mg KIO3/Kgsoil vs. control also affected potato’s physiological characteristics including chlorophyll content (SPAD, relative water content (RWC, water use efficiency (WUE, evapo-transpiration efficiency (ETE, cell membrane stability index (CMSI and tolerance index (TI showing around 27, 12, 87, 39, 40, and 77% reductions for each one, respectively. Increasing iodate concentrations, although, showed no effect of Zn concentration of root and Fe and Mn concentrations of leaf, gradually decreased Zn concentration of leaf and increased Fe and Mn concentrations of root and Cu concentrations of root and leaf. Plants also showed several visible symptoms including stunting, chlorosis, browning of leaf tip and reduction in growth due to iodate toxicity.

  9. Residual effects of biochar on improving growth, physiology and yield of wheat under salt stress

    DEFF Research Database (Denmark)

    Akhtar, Saqib Saleem; Andersen, Mathias Neumann; Liu, Fulai

    2015-01-01

    Salinity is one of the major threats to global food security. Biochar amendment could alleviate the negative impacts of salt stress in crop in the season. However, its long-term residual effect on reducing Na+ uptake in latter crops remains unknown. A pot experiment with wheat was conducted...... in a greenhouse. The soil used was from an earlier experiment on potato where the plants were irrigated with tap water (S0), 25 mM (S1) and 50 mM (S2) NaCl solutions and with 0 and 5% (w/w) biochar amendment. At onset of the experiment, three different EC levels at S0, S1 and S2 were established in the non...... by transient Na+ binding due to its high adsorption capacity, decreasing osmotic stress by enhancing soil moisture content, and by releasing mineral nutrients (particularly K+, Ca++, Mg++) into the soil solution. Growth, physiology and yield of wheat were affected positively with biochar amendment...

  10. Nickel detoxification and plant growth promotion by multi metal resistant plant growth promoting Rhizobium species RL9.

    Science.gov (United States)

    Wani, Parvaze Ahmad; Khan, Mohammad Saghir

    2013-07-01

    Pollution of the biosphere by heavy metals is a global threat that has accelerated dramatically since the beginning of industrial revolution. The aim of the study is to check the resistance of RL9 towards the metals and to observe the effect of Rhizobium species on growth, pigment content, protein and nickel uptake by lentil in the presence and absence of nickel. The multi metal tolerant and plant growth promoting Rhizobium strain RL9 was isolated from the nodules of lentil. The strain not only tolerated nickel but was also tolerant o cadmium, chromium, nickel, lead, zinc and copper. The strain tolerated nickel 500 μg/mL, cadmium 300 μg/mL, chromium 400 μg/mL, lead 1,400 μg/mL, zinc 1,000 μg/mL and copper 300 μg/mL, produced good amount of indole acetic acid and was also positive for siderophore, hydrogen cyanide and ammonia. The strain RL9 was further assessed with increasing concentrations of nickel when lentil was used as a test crop. The strain RL9 significantly increased growth, nodulation, chlorophyll, leghaemoglobin, nitrogen content, seed protein and seed yield compared to plants grown in the absence of bioinoculant but amended with nickel The strain RL9 decreased uptake of nickel in lentil compared to plants grown in the absence of bio-inoculant. Due to these intrinsic abilities strain RL9 could be utilized for growth promotion as well as for the remediation of nickel in nickel contaminated soil.

  11. Differential effects of Pseudomonas mendocina and Glomus intraradices on lettuce plants physiological response and aquaporin PIP2 gene expression under elevated atmospheric CO2 and drought.

    Science.gov (United States)

    Alguacil, Maria Del Mar; Kohler, Josef; Caravaca, Fuensanta; Roldán, Antonio

    2009-11-01

    Arbuscular mycorrhizal (AM) symbiosis and plant-growth-promoting rhizobacterium (PGPR) can alleviate the effects of water stress in plants, but it is unknown whether these benefits can be maintained at elevated CO2. Therefore, we carried out a study where seedlings of Lactuca sativa were inoculated with the AM fungus (AMF) Glomus intraradices N.C. Schenk & G.S. Sm. or the PGPR Pseudomonas mendocina Palleroni and subjected to two levels of watering and two levels of atmospheric CO2 to ascertain their effects on plant physiological parameters and gene expression of one PIP aquaporin in roots. The inoculation with PGPR produced the greatest growth in lettuce plants under all assayed treatments as well as the highest foliar potassium concentration and leaf relative water content under elevated [CO2] and drought. However, under such conditions, the PIP2 gene expression remained almost unchanged. G. intraradices increased significantly the AMF colonization, foliar phosphorus concentration and leaf relative water content in plants grown under drought and elevated [CO2]. Under drought and elevated [CO2], the plants inoculated with G. intraradices showed enhanced expression of the PIP2 gene as compared to P. mendocina or control plants. Our results suggest that both microbial inoculation treatments could help to alleviate drought at elevated [CO2]. However, the PIP2 gene expression was increased only by the AMF but not by the PGPR under these conditions.

  12. Getting the ecology into the interactions between plants and the plant-growth promoting bacterium Pseudomonas fluorescens

    NARCIS (Netherlands)

    Hol, W.H.G.; Bezemer, T.M.; Biere, A.

    2013-01-01

    Plant growth-promoting rhizobacteria (PGPR) are increasingly appreciated for their contributions to primary productivity through promotion of growth and triggering of induced systemic resistance in plants. Here we focus on the beneficial effects of one particular species of PGPR (Pseudomonas

  13. Short-Chain Chitin Oligomers: Promoters of Plant Growth

    Directory of Open Access Journals (Sweden)

    Alexander J. Winkler

    2017-02-01

    Full Text Available Chitin is the second most abundant biopolymer in nature after cellulose, and it forms an integral part of insect exoskeletons, crustacean shells, krill and the cell walls of fungal spores, where it is present as a high-molecular-weight molecule. In this study, we showed that a chitin oligosaccharide of lower molecular weight (tetramer induced genes in Arabidopsis that are principally related to vegetative growth, development and carbon and nitrogen metabolism. Based on plant responses to this chitin tetramer, a low-molecular-weight chitin mix (CHL enriched to 92% with dimers (2mer, trimers (3mer and tetramers (4mer was produced for potential use in biotechnological processes. Compared with untreated plants, CHL-treated plants had increased in vitro fresh weight (10%, radicle length (25% and total carbon and nitrogen content (6% and 8%, respectively. Our data show that low-molecular-weight forms of chitin might play a role in nature as bio-stimulators of plant growth, and they are also a known direct source of carbon and nitrogen for soil biomass. The biochemical properties of the CHL mix might make it useful as a non-contaminating bio-stimulant of plant growth and a soil restorer for greenhouses and fields.

  14. Enhanced shoot investment makes invasive plants exhibit growth advantages in high nitrogen conditions.

    Science.gov (United States)

    Liu, X A; Peng, Y; Li, J J; Peng, P H

    2018-03-12

    Resource amendments commonly promote plant invasions, raising concerns over the potential consequences of nitrogen (N) deposition; however, it is unclear whether invaders will benefit from N deposition more than natives. Growth is among the most fundamental inherent traits of plants and thus good invaders may have superior growth advantages in response to resource amendments. We compared the growth and allocation between invasive and native plants in different N regimes including controls (ambient N concentrations). We found that invasive plants always grew much larger than native plants in varying N conditions, regardless of growth- or phylogeny-based analyses, and that the former allocated more biomass to shoots than the latter. Although N addition enhanced the growth of invasive plants, this enhancement did not increase with increasing N addition. Across invasive and native species, changes in shoot biomass allocation were positively correlated with changes in whole-plant biomass; and the slope of this relationship was greater in invasive plants than native plants. These findings suggest that enhanced shoot investment makes invasive plants retain a growth advantage in high N conditions relative to natives, and also highlight that future N deposition may increase the risks of plant invasions.

  15. High-yielding Wheat Varieties Harbour Superior Plant Growth Promoting-Bacterial Endophytes

    Directory of Open Access Journals (Sweden)

    Mehwish Yousaf

    2017-06-01

    Full Text Available Background and Objective: The purpose of this study was to compare the endophytic microbial flora of different wheat varieties to check whether a better yielding variety also harbours superior plant growth promoting bacteria. Such bacteria are helpful in food biotechnology as their application can enhance the yield of the crop.Material and Methods: Three wheat varieties (Seher, Faisalabad and Lasani were selected, Seher being the most superior variety. endophytic bacteria were isolated from the histosphere of the leaves and roots at different growth phases of the plants. The isolates were analyzed for plant growth promoting activities. Isolates giving best results were identified through 16S rRNA gene sequencing. Statistical analysis was done using Microsoft Excel 2013. All the experiments were conducted in triplicates.Results and Conclusion: The endophytes of Seher variety showed maximum plant growth promoting abilities. Among the shoot endophytes, the highest auxin production was shown by Seher isolate SHHP1-3 up to 51.9μg ml-1, whereas in the case of root endophytes, the highest auxin was produced by SHHR1-5 up to 36 μg ml-1. The bacteria showing significant plant growth promoting abilities were identified by 16S rRNA sequencing. Bacillus, Proteobacteria and Actinobacteria species were the dominant bacteria showing all the traits of plant growth promotion. It can be concluded that Seher variety harbours superior plant growth promoting endophytes that must be one of the reasons for its better growth and yield as compared to the other two varieties. The investigated results support possible utilization of the selected isolates in wheat growth promotion with respect to increase in agro-productivity. The application of such bacteria could be useful to enhance wheat yield and can help in food biotechnology.Conflict of interest: The authors declare no conflict of interest.

  16. Bacillus spp. from rainforest soil promote plant growth under limited nitrogen conditions.

    Science.gov (United States)

    Huang, X-F; Zhou, D; Guo, J; Manter, D K; Reardon, K F; Vivanco, J M

    2015-03-01

    The aim of this study was to evaluate effects of PGPR (plant growth-promoting rhizobacteria) isolated from rainforest soil on different plants under limited nitrogen conditions. Bacterial isolates from a Peruvian rainforest soil were screened for plant growth-promoting effects on Arabidopsis (Col-0). Four selected isolates including one Bacillus subtilis, two B. atrophaeus and one B. pumilus significantly promoted growth of Zea mays L. and Solanum lycopersicum under greenhouse conditions. Moreover, the PGPRs significantly promoted growth of S. lycopersicum in both low and nitrogen-amended soil conditions. These PGPR strains were further studied to obtain insights into possible mechanisms of plant growth promotion. Volatile chemicals from those isolates promoted Arabidopsis growth, and the expression of genes related to IAA production was induced in the Arabidopsis plants treated with PGPRs. Further, selected PGPR strains triggered induced systemic resistance (ISR) against Pseudomonas syringae pv tomato DC3000 in Arabidopsis. PGPR strains isolated from the rainforest soil promoted the plant growth of Arabidopsis, corn and tomato. New PGPR that have wider adaptability to different crops, soils and environmental conditions are needed to decrease our reliance on agricultural amendments derived from fossil-based fuels. The PGPRs isolated from a nonagricultural site constitute new plant growth-promoting strains that could be developed for agricultural uses. © 2014 The Society for Applied Microbiology.

  17. Effects of precipitation changes on switchgrass photosynthesis, growth, and biomass: A mesocosm experiment.

    Science.gov (United States)

    Hui, Dafeng; Yu, Chih-Li; Deng, Qi; Dzantor, E Kudjo; Zhou, Suping; Dennis, Sam; Sauve, Roger; Johnson, Terrance L; Fay, Philip A; Shen, Weijun; Luo, Yiqi

    2018-01-01

    Climate changes, including chronic changes in precipitation amounts, will influence plant physiology and growth. However, such precipitation effects on switchgrass, a major bioenergy crop, have not been well investigated. We conducted a two-year precipitation simulation experiment using large pots (95 L) in an environmentally controlled greenhouse in Nashville, TN. Five precipitation treatments (ambient precipitation, and -50%, -33%, +33%, and +50% of ambient) were applied in a randomized complete block design with lowland "Alamo" switchgrass plants one year after they were established from tillers. The growing season progression of leaf physiology, tiller number, height, and aboveground biomass were determined each growing season. Precipitation treatments significantly affected leaf physiology, growth, and aboveground biomass. The photosynthetic rates in the wet (+50% and +33%) treatments were significantly enhanced by 15.9% and 8.1%, respectively, than the ambient treatment. Both leaf biomass and plant height were largely increased, resulting in dramatically increases in aboveground biomass by 56.5% and 49.6% in the +50% and +33% treatments, respectively. Compared to the ambient treatment, the drought (-33% and -50%) treatments did not influence leaf physiology, but the -50% treatment significantly reduced leaf biomass by 37.8%, plant height by 16.3%, and aboveground biomass by 38.9%. This study demonstrated that while switchgrass in general is a drought tolerant grass, severe drought significantly reduces Alamo's growth and biomass, and that high precipitation stimulates its photosynthesis and growth.

  18. Physiological and Biochemical Responses of Saltmarsh Plant Spartina alterniflora to Long-term Wave Exposure

    Science.gov (United States)

    Zhou, W.

    2017-12-01

    In recent years, ecosystem-based flood defence, i.e., eco-shoreline or living shoreline, that is more sustainable and cost-effective than conventional coastal engineering structures has been brought into large-scale practice. Numerous laboratory experiments have been performed to explore the wave-attenuation effects of saltmarsh plants that are widely used in eco-shoreline, and yet no study has ever been conducted on the physiological and biochemical responses of saltmarsh plants to long-term wave exposure, presumably due to the constraint that traditional wave generator fails to provide long-term stable wave conditions necessary for physiological experiments. In this study, a long-term shallow water wave environment simulator using crank-yoke mechanism was built in the laboratory to address this gap. Experiments using the wave simulator were conducted for 8 weeks in a greenhouse and the temperature was maintained at 24-30°C. 5‰ artificial sea water was filled in the test tank, and the water was changed every week. After being acclimatized, nine S. alterniflora individual plants (initial height 30 cm) were planted in each of the three streamlined cuboid containers (12cm×12cm×20cm), which were partially submerged in a test tank, and undertook horizontal sinusoidal motion imposed by the crank-yoke mechanism to mimic plants exposed to shallow water waves. The substrate filled in the containers were soils collected from the Yellow River Delta, so were the S. alterniflora plants. A realistic stem density of 400 stems/m2 was tested, which corresponded to a grid spacing of 5.0 cm. Shallow water waves with six wave heights (H: 0.041, 0.055, 0.069, 0.033, 0.044 and 0.056m), one plants submerged depth (0.1m) and two wave periods (2s and 3s) were simulated in the experiments. A no wave condition was also tested as control. Key physiological and biochemical parameters, such as stem length, peroxidase activity, catalase, superoxide dismutase, ascorbate peroxidase, etc

  19. The role of endomembrane-localized VHA-c in plant growth.

    Science.gov (United States)

    Zhou, Aimin; Takano, Tetsuo; Liu, Shenkui

    2018-01-02

    In plant cells, the vacuolar-type H + -ATPase (V-ATPase), a large multis`ubunit endomembrane proton pump, plays an important role in acidification of subcellular organelles, pH and ion homeostasis, and endocytic and secretory trafficking. V-ATPase subunit c (VHA-c) is essential for V-ATPase assembly, and is directly responsible for binding and transmembrane transport of protons. In previous studies, we identified a PutVHA-c gene from Puccinellia tenuiflora, and investigated its function in plant growth. Subcellular localization revealed that PutVHA-c is mainly localized in endosomal compartments. Overexpression of PutVHA-c enhanced V-ATPase activity and promoted plant growth in transgenic Arabidopsis. Furthermore, the activity of V-ATPase affected intracellular transport of the Golgi-derived endosomes. Our results showed that endomembrane localized-VHA-c contributes to plant growth by influencing V-ATPase-dependent endosomal trafficking. Here, we discuss these recent findings and speculate on the VHA-c mediated molecular mechanisms involved in plant growth, providing a better understanding of the functions of VHA-c and V-ATPase.

  20. GROWTH, PHYSIOLOGY AND YIELD OF FORMOSA ‘PAPAYA’ CULTIVATED UNDER DIFFERENT DOSES OF COATED AND CONVENTIONAL UREA

    Directory of Open Access Journals (Sweden)

    GABRIEL BARBOSA DA SILVA JÚNIOR

    2016-01-01

    Full Text Available Mineral fertilizer management is one of the most important agronomic techniques applied in papaya cultivation, which generally extracts large amounts of nutrients from soil, especially nitrogen. This study aimed to assess the phytotechnical and physiological attributes and yield of „Formosa‟ papaya hybrid Caliman 01 as a function of different doses of coated and conventional urea in the region of Bom Jesus - PI, Brazil. The treatments were arranged in a factorial scheme (2 × 4 and distributed in a randomized block design with four replications, corresponding to 2 nitrogen sources (coated urea, 43% of N; and conventional urea, 45% of N and 4 doses nitrogen (350, 440, 530 and 620 g per plant. The N doses used corresponded to 80, 100, 120 and 140% of the nitrogen fertilization. It was used six plants per plot with two row borders, totaling 192 plants cultivated in the field. It was assessed the intercepted photosynthetically active radiation (int.PAR, radiation interception efficiency (PAREff., leaf area index (LAI, plant height, stem diameter and yield. The coated urea promotes a higher growth and yield of „Formosa‟ papaya compared to the conventional urea. The application of 1.0 g of coated N promotes the production of 2.87 g of fruit per hectare while the application of 1.0 g of conventional N produces only 1.89 g of fruit per hectare, showing that the source of polymerized N increases the use efficiency of N applied to soil.

  1. The vascular plants: open system of growth.

    Science.gov (United States)

    Basile, Alice; Fambrini, Marco; Pugliesi, Claudio

    2017-03-01

    What is fascinating in plants (true also in sessile animals such as corals and hydroids) is definitely their open and indeterminate growth, as a result of meristematic activity. Plants as well as animals are characterized by a multicellular organization, with which they share a common set of genes inherited from a common eukaryotic ancestor; nevertheless, circa 1.5 billion years of evolutionary history made the two kingdoms very different in their own developmental biology. Flowering plants, also known as angiosperms, arose during the Cretaceous Period (145-65 million years ago), and up to date, they count around 235,000 species, representing the largest and most diverse group within the plant kingdom. One of the foundations of their success relies on the plant-pollinator relationship, essentially unique to angiosperms that pushed large speciation in both plants and insects and on the presence of the carpel, the structure devoted to seed enclosure. A seed represents the main organ preserving the genetic information of a plant; during embryogenesis, the primary axis of development is established by two groups of pluripotent cells: the shoot apical meristem (SAM), responsible for gene rating all aboveground organs, and the root apical meristem (RAM), responsible for producing all underground organs. During postembryonic shoot development, axillary meristem (AM) initiation and outgrowth are responsible for producing all secondary axes of growth including inflorescence branches or flowers. The production of AMs is tightly linked to the production of leaves and their separation from SAM. As leaf primordia are formed on the flanks of the SAM, a region between the apex and the developing organ is established and referred to as boundary zone. Interaction between hormones and the gene network in the boundary zone is fundamental for AM initiation. AMs only develop at the adaxial base of the leaf; thus, AM initiation is also strictly associated with leaf polarity. AMs

  2. Abscisic Acid Regulation of Root Hydraulic Conductivity and Aquaporin Gene Expression Is Crucial to the Plant Shoot Growth Enhancement Caused by Rhizosphere Humic Acids.

    Science.gov (United States)

    Olaetxea, Maite; Mora, Verónica; Bacaicoa, Eva; Garnica, María; Fuentes, Marta; Casanova, Esther; Zamarreño, Angel M; Iriarte, Juan C; Etayo, David; Ederra, Iñigo; Gonzalo, Ramón; Baigorri, Roberto; García-Mina, Jose M

    2015-12-01

    The physiological and metabolic mechanisms behind the humic acid-mediated plant growth enhancement are discussed in detail. Experiments using cucumber (Cucumis sativus) plants show that the shoot growth enhancement caused by a structurally well-characterized humic acid with sedimentary origin is functionally associated with significant increases in abscisic acid (ABA) root concentration and root hydraulic conductivity. Complementary experiments involving a blocking agent of cell wall pores and water root transport (polyethylenglycol) show that increases in root hydraulic conductivity are essential in the shoot growth-promoting action of the model humic acid. Further experiments involving an inhibitor of ABA biosynthesis in root and shoot (fluridone) show that the humic acid-mediated enhancement of both root hydraulic conductivity and shoot growth depended on ABA signaling pathways. These experiments also show that a significant increase in the gene expression of the main root plasma membrane aquaporins is associated with the increase of root hydraulic conductivity caused by the model humic acid. Finally, experimental data suggest that all of these actions of model humic acid on root functionality, which are linked to its beneficial action on plant shoot growth, are likely related to the conformational structure of humic acid in solution and its interaction with the cell wall at the root surface. © 2015 American Society of Plant Biologists. All Rights Reserved.

  3. Salt-Stress effects on crop plants: Role of proline, glycinebetaine and calcium at whole-plant and cellular levels

    International Nuclear Information System (INIS)

    Akhtar, L.H.; Gorham, J.; Siddiqui, S.Z.; Jamil, M.; Arshad, M.

    2002-01-01

    Salinity affects the physiological and biochemical processes of the plants in a variety of ways. In this manuscript, variability in plant, with respect to salinity-tolerance and morphological adaptations in plants for salinity-tolerance, have been discussed. Salinity effects on growth of plants, cell membranes, proteins, sugars, nucleic acids, starch, cell sap, transpiration, stomatal conductance, pollen viability, Co/sub 2/ assimilation, chlorophyll, photosynthesis and enzymes have been reviewed. Proline and glycinebetaine accumulation, localisation in the cell and their physiological role under salt-stress has been presented. Cellular mechanism of salt-tolerance and role of calcium in salt-stress have been reviewed. The possible approaches to deal with all types of stresses have been suggested. (author)

  4. Characterization of Minnesota lunar simulant for plant growth

    Science.gov (United States)

    Oglesby, James P.; Lindsay, Willard L.; Sadeh, Willy Z.

    1993-01-01

    Processing of lunar regolith into a plant growth medium is crucial in the development of a regenerative life support system for a lunar base. Plants, which are the core of such a system, produce food and oxygen for humans and, at the same time, consume carbon dioxide. Because of the scarcity of lunar regolith, simulants must be used to infer its properties and to develop procedures for weathering and chemical analyses. The Minnesota Lunar Simulant (MLS) has been identified to date as the best available simulant for lunar regolith. Results of the dissolution studies reveal that appropriately fertilized MLS can be a suitable medium for plant growth. The techniques used in conducting these studies can be extended to investigate the suitability of actual lunar regolith as a plant growth medium. Dissolution experiments were conducted using the MLS to determine its nutritional and toxicity characteristics for plant growth and to develop weathering and chemical analysis techniques. Two weathering regimes, one with water and one with dilute organic acids simulating the root rhizosphere microenvironment, were investigated. Elemental concentrations were measured using inductively-coupled-plasma (ICP) emission spectrometry and ion chromatography (IC). The geochemical speciation model, MINTEQA2, was used to determine the major solution species and the minerals controlling them. Acidification was found to be a useful method for increasing cation concentrations to meaningful levels. Initial results indicate that MLS weathers to give neutral to slightly basic solutions which contain acceptable amounts of the essential elements required for plant nutrition (i.e., potassium, calcium, magnesium, sulfur, zinc, sodium, silicon, manganese, copper, chlorine, boron, molybdenum, and cobalt). Elements that need to be supplemented include carbon, nitrogen, and perhaps phosphorus and iron. Trace metals in solution were present at nontoxic levels.

  5. Field transcriptome revealed critical developmental and physiological transitions involved in the expression of growth potential in japonica rice

    Directory of Open Access Journals (Sweden)

    Kamatsuki Kaori

    2011-01-01

    Full Text Available Abstract Background Plant growth depends on synergistic interactions between internal and external signals, and yield potential of crops is a manifestation of how these complex factors interact, particularly at critical stages of development. As an initial step towards developing a systems-level understanding of the biological processes underlying the expression of overall agronomic potential in cereal crops, a high-resolution transcriptome analysis of rice was conducted throughout life cycle of rice grown under natural field conditions. Results A wide range of gene expression profiles based on 48 organs and tissues at various developmental stages identified 731 organ/tissue specific genes as well as 215 growth stage-specific expressed genes universally in leaf blade, leaf sheath, and root. Continuous transcriptome profiling of leaf from transplanting until harvesting further elucidated the growth-stage specificity of gene expression and uncovered two major drastic changes in the leaf transcriptional program. The first major change occurred before the panicle differentiation, accompanied by the expression of RFT1, a putative florigen gene in long day conditions, and the downregulation of the precursors of two microRNAs. This transcriptome change was also associated with physiological alterations including phosphate-homeostasis state as evident from the behavior of several key regulators such as miR399. The second major transcriptome change occurred just after flowering, and based on analysis of sterile mutant lines, we further revealed that the formation of strong sink, i.e., a developing grain, is not the major cause but is rather a promoter of this change. Conclusions Our study provides not only the genetic basis for functional genomics in rice but also new insight into understanding the critical physiological processes involved in flowering and seed development, that could lead to novel strategies for optimizing crop productivity.

  6. Mineral nutrition of plants: a short history of plant physiology.

    Science.gov (United States)

    Pennazio, Sergio

    2005-01-01

    . This principle benefited further research concerning the effects of states of deficiency on plant growth and development through investigation on the anatomical, histologic and biochemical nutritional disorders of plants.

  7. Possible effects of regulating hydroponic water temperature on plant ...

    African Journals Online (AJOL)

    Water temperature can affect many physiological processes during plant growth and development. Temperatures below or above optimum levels may influence plant metabolic activities positively or negatively. This may include accumulation of different metabolites such as phenolic compounds, reactive oxygen species ...

  8. Plant growth promoters and methods of using them

    KAUST Repository

    Al-Babili, Salim

    2017-01-01

    New plant growth regulators, including compounds and compositions, and methods of use including for promoting root growth. The compounds are carotenoid oxidation products, and a preferred example is 3-OH--β-apo-13-Carotenone. A method comprising

  9. Selenium promotes sulfur accumulation and plant growth in wheat (Triticum aestivum)

    Science.gov (United States)

    Selenium (Se) is an essential micronutrient for animals and humans and a target for biofortification in crops. Sulfur (S) is a crucial nutrient for plant growth. To gain better understanding of Se and S nutrition and interaction in plants, the effects of Se dosages and forms on plant growth as well ...

  10. Arabidopsis thaliana ggt1 photorespiratory mutants maintain leaf carbon/nitrogen balance by reducing RuBisCO content and plant growth.

    Science.gov (United States)

    Dellero, Younès; Lamothe-Sibold, Marlène; Jossier, Mathieu; Hodges, Michael

    2015-09-01

    Metabolic and physiological analyses of glutamate:glyoxylate aminotransferase 1 (GGT1) mutants were performed at the global leaf scale to elucidate the mechanisms involved in their photorespiratory growth phenotype. Air-grown ggt1 mutants showed retarded growth and development, that was not observed at high CO2 (3000 μL L(-1) ). When compared to wild-type (WT) plants, air-grown ggt1 plants exhibited glyoxylate accumulation, global changes in amino acid amounts including a decrease in serine content, lower organic acid levels, and modified ATP/ADP and NADP(+) /NADPH ratios. When compared to WT plants, their net CO2 assimilation rates (An ) were 50% lower and this mirrored decreases in ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCO) contents. High CO2 -grown ggt1 plants transferred to air revealed a rapid decrease of An and photosynthetic electron transfer rate while maintaining a high energetic state. Short-term (a night period and 4 h of light) transferred ggt1 leaves accumulated glyoxylate and exhibited low serine contents, while other amino acid levels were not modified. RuBisCO content, activity and activation state were not altered after a short-term transfer while the ATP/ADP ratio was lowered in ggt1 rosettes. However, plant growth and RuBisCO levels were both reduced in ggt1 leaves after a long-term (12 days) acclimation to air from high CO2 when compared to WT plants. The data are discussed with respect to a reduced photorespiratory carbon recycling in the mutants. It is proposed that the low An limits nitrogen-assimilation, this decreases leaf RuBisCO content until plants attain a new homeostatic state that maintains a constant C/N balance and leads to smaller, slower growing plants. © 2015 The Authors The Plant Journal © 2015 John Wiley & Sons Ltd.

  11. The physiological effect of fluorene on Triticum aestivum, Medicago sativa, and Helianthus annus

    Directory of Open Access Journals (Sweden)

    Seyed Yahya Salehi-Lisar

    2015-12-01

    Full Text Available Polycyclic aromatic hydrocarbons (PAHs are widespread pollutants and can negatively affect plants. Fluorene is a prevalent PAH in the contaminated environment. In this study, the effects of higher concentrations of fluorene in soil on rate of seed germination, growth, and the physiological parameters of wheat, sunflower, and alfalfa were studied. The results showed that the higher concentration of fluorene decreased rate of seed germination and seedlings growth of plants. Wheat showed the highest resistance at seed germination and seedlings growth phases, and sunflower was the most sensitive species at both stages. Therefore, it was concluded that higher resistance at seed germination could be followed by the higher resistance of seedlings. Fluorene toxicity also induced oxidative stress in plants as shown by MDA accumulation in the plants. There was a significant correlation between the lower activity of CAT and MDA accumulation in the studied plants. Therefore, CAT could be an important enzyme involved in detoxification of ROS and plants resistance to fluorene toxicity. Depending on plant species and fluorene concentration, photosynthetic pigments content was differently affected.

  12. Plant eco-physiological responses to multiple environmental and climate changes

    Energy Technology Data Exchange (ETDEWEB)

    Rost Albert, K.

    2009-03-15

    The current global changes of temperature, precipitation, atmospheric CO{sub 2} and UV-B radiation impact in concert ecosystems and processes in an unpredictable way. Therefore multifactor experimentation is needed to unravel the variability in strength of these drivers, whether the factors act additively or synergistically and to establish cause-effect relations between ecosystem processes. This thesis deals with heath plant responses to global change factors (the CLIMAITE project). In a Danish temperate heath ecosystem elevated CO{sub 2}, experimental summer drought, and passive nighttime warming was applied in all combinations (based on the scenario for Denmark anno 2075) and the responses after one year of treatment were investigated through a growing season in Hairgrass (Deschampsia flexousa) and Heather (Calluna vulgaris). In a high arctic heath ecosystem situated in NE-Greenland UV-B exclusion experiments were conducted on Salix arctica and Vaccinium uliginosum during six years. Responses of photosynthesis performance were characterized on the leaf scale by means of leaf gas-exchange (A/Ci curves), chlorophyll-a fluorescence, leaf nitrogen, carbon and delta13C and secondary compounds. The main findings were 1) The different growth strategies of the evergreen Calluna versus the opportunistic bi-phasic Deschampsia affects the photosynthesis response to drought and autumn warming; 2) Elevated CO{sub 2} and warming synergistically increase photosynthesis in spring and autumn; 3) Summer drought decreased photosynthesis in both species, but where Calluna maintained photosynthetic metabolism then major proportion of grass leaves wilted down; 4) Elevated CO{sub 2} did not decrease stomatal conductance, but the treatments affected soil water content positively, pointing to the complex water relations when plants of contrasting growth strategy co-occur; 5) Water availability affected the magnitude of photosynthesis to a higher degree than warming and elevated CO{sub 2

  13. Sugar signals and the control of plant growth and development

    NARCIS (Netherlands)

    Lastdrager, Jeroen|info:eu-repo/dai/nl/357520076; Hanson, Johannes|info:eu-repo/dai/nl/304822299; Smeekens, Sjef|info:eu-repo/dai/nl/072489995

    2014-01-01

    Sugars have a central regulatory function in steering plant growth. This review focuses on information presented in the past 2 years on key players in sugar-mediated plant growth regulation, with emphasis on trehalose 6-phosphate, target of rapamycin kinase, and Snf1-related kinase 1 regulatory

  14. Lactococcus lactis Metabolism and Gene Expression during Growth on Plant Tissues

    Science.gov (United States)

    Golomb, Benjamin L.

    2014-01-01

    Lactic acid bacteria have been isolated from living, harvested, and fermented plant materials; however, the adaptations these bacteria possess for growth on plant tissues are largely unknown. In this study, we investigated plant habitat-specific traits of Lactococcus lactis during growth in an Arabidopsis thaliana leaf tissue lysate (ATL). L. lactis KF147, a strain originally isolated from plants, exhibited a higher growth rate and reached 7.9-fold-greater cell densities during growth in ATL than the dairy-associated strain L. lactis IL1403. Transcriptome profiling (RNA-seq) of KF147 identified 853 induced and 264 repressed genes during growth in ATL compared to that in GM17 laboratory culture medium. Genes induced in ATL included those involved in the arginine deiminase pathway and a total of 140 carbohydrate transport and metabolism genes, many of which are involved in xylose, arabinose, cellobiose, and hemicellulose metabolism. The induction of those genes corresponded with L. lactis KF147 nutrient consumption and production of metabolic end products in ATL as measured by gas chromatography-time of flight mass spectrometry (GC-TOF/MS) untargeted metabolomic profiling. To assess the importance of specific plant-inducible genes for L. lactis growth in ATL, xylose metabolism was targeted for gene knockout mutagenesis. Wild-type L. lactis strain KF147 but not an xylA deletion mutant was able to grow using xylose as the sole carbon source. However, both strains grew to similarly high levels in ATL, indicating redundancy in L. lactis carbohydrate metabolism on plant tissues. These findings show that certain strains of L. lactis are well adapted for growth on plants and possess specific traits relevant for plant-based food, fuel, and feed fermentations. PMID:25384484

  15. Influence of Plant Growth Regulators (PGRs and Planting Method on Growth and Yield in Oil Pumpkin (Cucurbita pepo var. styriaca

    Directory of Open Access Journals (Sweden)

    Shirzad SURE

    2012-05-01

    Full Text Available The effect of plant growth regulators IBA (indole butyric acid, GA3 (gibberellin and ethylene (as ethephon in two methods of planting was investigated (each method was considered as a separate experiment on morphological characters and yield of medicinal pumpkin. The experiments were carried out in a factorial trial based on completely randomized block design, with four replicates. The treatments were combined with priming and spraying with the above PGRs. The first seed priming with control (water, IBA 100 ppm, GA3 25 ppm and ethephon 200 ppm, and when seedling developed to 4 leaf stage sprayed there with control (water, IBA 100 ppm, GA3 25 ppm and ethephon 200 ppm for three times. In both planting methods, there were all of these treatments. The result showed that PGRs and planting method had significant effects on vegetative, flowering and yield characteristics including: leaf area %DM plant, number of male and female flowers per plant, number of fruit/plant, fruits fresh weight, seeds length and width, number of seed per fruit, seed yield, % seeds oil and oil yield. Hence spraying with GA3 25 ppm in four leaf stage at trellis method could be a suitable treatment for enhancing growth and yield of medicinal pumpkin.

  16. Physiological Dose-Response of Coffee (Coffea arabica L. Plants to Glyphosate Depends on Growth Stage Respuesta Fisiológica de Plantas de Café (Coffea arabica L. a Glifosato Depende de la Etapa de Crecimiento

    Directory of Open Access Journals (Sweden)

    Leonardo Bianco de Carvalho

    2012-06-01

    Full Text Available Glyphosate is the main herbicide used in coffee (Coffea arabica L. plantations in Brazil. Problems with herbicide drift commonly occur in orchard fields due to non-adequate spraying conditions. A series of experiments was carried out aiming to evaluate physiological dose-response of C. arabica plants submitted to exposure to simulated glyphosate drift in two distinct plant growth stages. Glyphosate was applied at 0, 180, 360, and 720 g acid equivalent (AE ha-1 directly on coffee plants with 10 and 45 d after transplanting (DAT. Glyphosate doses in a range of 180-360 g AE ha-1 increased photosynthesis, transpiration and stomatal conductance in 10 DAT-plants up to 14 d after application (DAA while, in 45 DAT-plants, an increase was observed only up to 2 DAA, but this pattern was not persistent afterwards so that no difference in gas exchange was observed at 60 DAA in both plants. Macronutrient content was not affected by glyphosate application in both plants. Plant DM accumulation was not affected by glyphosate application at 10 DAT-plants, but an increase in plant growth was observed when glyphosate was applied in a range of 360-720 g AE ha-1 in 45 DAT-plants. Coffea arabica cv. Catuaí Vermelho IAC-144 responded differentially to glyphosate drift depending on plant growth stage, regarding on photosynthesis, transpiration, stomatal conductance, and plant growth, in spite of macronutrient nutrition was not affected.Glifosato es el principal herbicida utilizado en las plantaciones de café (Coffea arabica L. en Brasil. Problemas con la deriva de herbicidas comúnmente ocurren en los campos de cultivo debido a condiciones no adecuadas de pulverización. Una serie de experimentos se llevó a cabo con el objetivo de evaluar la relación dosis-respuesta fisiológica de plantas de C. arabica expuestas a situaciones simuladas de exposición a deriva de glifosato en dos etapas distintas de crecimiento de las plantas. El glifosato se aplicó en dosis de 0

  17. Biological consilience of hydrogen sulfide and nitric oxide in plants: Gases of primordial earth linking plant, microbial and animal physiologies.

    Science.gov (United States)

    Yamasaki, Hideo; Cohen, Michael F

    2016-05-01

    Hydrogen sulfide (H2S) is produced in the mammalian body through the enzymatic activities of cystathionine β-synthase (CBS), cystathionine γ-lyase (CSE) and 3-mercaptopyruvate sulfurtransferase (3MST). A growing number of studies have revealed that biogenic H2S produced in tissues is involved in a variety of physiological responses in mammals including vasorelaxation and neurotransmission. It is now evident that mammals utilize H2S to regulate multiple signaling systems, echoing the research history of the gaseous signaling molecules nitric oxide (NO) and carbon monoxide (CO) that had previously only been recognized for their cytotoxicity. In the human diet, meats (mammals, birds and fishes) and vegetables (plants) containing cysteine and other sulfur compounds are the major dietary sources for endogenous production of H2S. Plants are primary producers in ecosystems on the earth and they synthesize organic sulfur compounds through the activity of sulfur assimilation. Although plant H2S-producing activities have been known for a long time, our knowledge of H2S biology in plant systems has not been updated to the extent of mammalian studies. Here we review recent progress on H2S studies, highlighting plants and bacteria. Scoping the future integration of H2S, NO and O2 biology, we discuss a possible linkage between physiology, ecology and evolutional biology of gas metabolisms that may reflect the historical changes of the Earth's atmospheric composition. Copyright © 2016 Elsevier Inc. All rights reserved.

  18. Individualism in plant populations: using stochastic differential equations to model individual neighbourhood-dependent plant growth.

    Science.gov (United States)

    Lv, Qiming; Schneider, Manuel K; Pitchford, Jonathan W

    2008-08-01

    We study individual plant growth and size hierarchy formation in an experimental population of Arabidopsis thaliana, within an integrated analysis that explicitly accounts for size-dependent growth, size- and space-dependent competition, and environmental stochasticity. It is shown that a Gompertz-type stochastic differential equation (SDE) model, involving asymmetric competition kernels and a stochastic term which decreases with the logarithm of plant weight, efficiently describes individual plant growth, competition, and variability in the studied population. The model is evaluated within a Bayesian framework and compared to its deterministic counterpart, and to several simplified stochastic models, using distributional validation. We show that stochasticity is an important determinant of size hierarchy and that SDE models outperform the deterministic model if and only if structural components of competition (asymmetry; size- and space-dependence) are accounted for. Implications of these results are discussed in the context of plant ecology and in more general modelling situations.

  19. Screening and characterization of endophytic Bacillus and Paenibacillus strains from medicinal plant Lonicera japonica for use as potential plant growth promoters

    Directory of Open Access Journals (Sweden)

    Longfei Zhao

    2015-12-01

    Full Text Available Abstract A total of 48 endophytic bacteria were isolated from surface-sterilized tissues of the medicinal plant Lonicera japonica, which is grown in eastern China; six strains were selected for further study based on their potential ability to promote plant growth in vitro (siderophore and indoleacetic acid production. The bacteria were characterized by phylogenetically analyzing their 16S rRNA gene similarity, by examining their effect on the mycelial development of pathogenic fungi, by testing their potential plant growth-promoting characteristics, and by measuring wheat growth parameters after inoculation. Results showed that the number of endophytic bacteria in L. japonica varied among different tissues, but it remained relatively stable in the same tissues from four different plantation locations. Among the three endophytic strains, strains 122 and 124 both had high siderophore production, with the latter showing the highest phosphate solubilization activity (45.6 mg/L and aminocyclopropane-1-carboxylic acid deaminase activity (47.3 nmol/mg/h. Strain 170 had the highest indoleacetic acid (IAA production (49.2 mg/L and cellulase and pectinase activities. After inoculation, most of the six selected isolates showed a strong capacity to promote wheat growth. Compared with the controls, the increase in the shoot length, root length, fresh weight, dry weight, and chlorophyll content was most remarkable in wheat seedlings inoculated with strain 130. The positive correlation between enzyme (cellulose and pectinase activity and inhibition rate on Fusarium oxysporum, the IAA production, and the root length of wheat seedlings inoculated with each tested endophytic strain was significant in regression analysis. Deformity of pathogenic fungal mycelia was observed under a microscope after the interaction with the endophytic isolates. Such deformity may be directly related to the production of hydrolytic bacterial enzymes (cellulose and pectinase. The six

  20. Effect of plant-growth-promoting rhizobacteria inoculation on plant ...

    African Journals Online (AJOL)

    A field experiment was conducted in a wet season (Kharif) to study the effects of plant growth-promoting rhizobacteria(PGPR) inoculation on agronomic traits and productivity of Basmati rice (cv. 'Pusa Basmati 1401') in a randomized block with twelve treatments. We evaluated one bacterial (Providencia sp. PW5) and one ...

  1. Symbiotic regulation of plant growth, development and reproduction

    Science.gov (United States)

    Rodriguez, R.J.; Freeman, D. Carl; McArthur, E.D.; Kim, Y.-O.; Redman, R.S.

    2009-01-01

    The growth and development of rice (Oryzae sativa) seedlings was shown to be regulated epigenetically by a fungal endophyte. In contrast to un-inoculated (nonsymbiotic) plants, endophyte colonized (symbiotic) plants preferentially allocated resources into root growth until root hairs were well established. During that time symbiotic roots expanded at five times the rate observed in nonsymbiotic plants. Endophytes also influenced sexual reproduction of mature big sagebrush (Artemisia tridentata) plants. Two spatially distinct big sagebrush subspecies and their hybrids were symbiotic with unique fungal endophytes, despite being separated by only 380 m distance and 60 m elevation. A double reciprocal transplant experiment of parental and hybrid plants, and soils across the hybrid zone showed that fungal endophytes interact with the soils and different plant genotypes to confer enhanced plant reproduction in soil native to the endophyte and reduced reproduction in soil alien to the endophyte. Moreover, the most prevalent endophyte of the hybrid zone reduced the fitness of both parental subspecies. Because these endophytes are passed to the next generation of plants on seed coats, this interaction provides a selective advantage, habitat specificity, and the means of restricting gene flow, thereby making the hybrid zone stable, narrow and potentially leading to speciation. ?? 2009 Landes Bioscience.

  2. The effect of plant growth regulators, explants and cultivars on ...

    African Journals Online (AJOL)

    To achieve the best explants and media for spinach tissue culture, the effects of two different plant growth regulators, two explants and cultivars on adventitious shoot regeneration were tested. The Analysis of Variance (ANOVA) showed that the effects of plant growth regulators on spinach tissue culture were significant; ...

  3. Experiments on Growth and Variation of Spaceship Loaded Plant Seeds

    Energy Technology Data Exchange (ETDEWEB)

    Kang, S. Y.; Lee, G. J.; Kim, D. S.; Kim, J. B.

    2008-08-15

    This educational experiment was designed (1)to obtain the basic information on the effects of the space environments on plant growth and mutagenesis, (2)to evaluate plant germination and seedling growth under the effect of microgravity and light conditions and (3)to improve a child's scientific mind through the real-time observations of a seedling growth for two plants conducted both in space and on earth. This project was implemented?as one of the missions in the Korean Astronaut Program. Seeds of eleven plant species (rice, soybean, rape, radish, hot pepper, perilla, arabidopsis, orchids, dandelion, hibiscus, cosmos) was vacuum-sealed in aluminium bags. Those seeds was loaded in the 'Progress' spaceship in Feb. 2008, traveled in the 'Progress', placed in the Russian Sector-International Space Station (RS-ISS), and then was brought by the Korean astronaut from the RS-ISS, and handed over to us at Korea Atomic Energy Research Institute(KAERI). The germination rate, plant growth and mutation type/frequency of the returned plants are under testing in the lab and field in KAERI now. The first Korean astronaut, Dr. So-Yeon Yi, who had returned to earth on April 19, 2008 after successfully completing her scientific mission for 12 days in Space, performed the experiment of plant germination and seedling growth in the International Space Station (ISS), and a similarly designed experiment kit was distributed to conduct the experiment by student and adult volunteers in Korea at the same time. The experiment was to observe the effects of microgravity and light on a seedling growth for soybean and radish. We designed a growth kit that was an all-in-one package consisting of seeds (12 seeds in each chamber) and rock wool as a growing medium filled in four polycarbonate growing chambers in a light proof textile bag or carton paper. The bottom of the chamber was filled with a tightly-fitted rock wool which can hold water and provide moisture during a

  4. Experiments on Growth and Variation of Spaceship Loaded Plant Seeds

    International Nuclear Information System (INIS)

    Kang, S. Y.; Lee, G. J.; Kim, D. S.; Kim, J. B.

    2008-08-01

    This educational experiment was designed (1)to obtain the basic information on the effects of the space environments on plant growth and mutagenesis, (2)to evaluate plant germination and seedling growth under the effect of microgravity and light conditions and (3)to improve a child's scientific mind through the real-time observations of a seedling growth for two plants conducted both in space and on earth. This project was implemented?as one of the missions in the Korean Astronaut Program. Seeds of eleven plant species (rice, soybean, rape, radish, hot pepper, perilla, arabidopsis, orchids, dandelion, hibiscus, cosmos) was vacuum-sealed in aluminium bags. Those seeds was loaded in the 'Progress' spaceship in Feb. 2008, traveled in the 'Progress', placed in the Russian Sector-International Space Station (RS-ISS), and then was brought by the Korean astronaut from the RS-ISS, and handed over to us at Korea Atomic Energy Research Institute(KAERI). The germination rate, plant growth and mutation type/frequency of the returned plants are under testing in the lab and field in KAERI now. The first Korean astronaut, Dr. So-Yeon Yi, who had returned to earth on April 19, 2008 after successfully completing her scientific mission for 12 days in Space, performed the experiment of plant germination and seedling growth in the International Space Station (ISS), and a similarly designed experiment kit was distributed to conduct the experiment by student and adult volunteers in Korea at the same time. The experiment was to observe the effects of microgravity and light on a seedling growth for soybean and radish. We designed a growth kit that was an all-in-one package consisting of seeds (12 seeds in each chamber) and rock wool as a growing medium filled in four polycarbonate growing chambers in a light proof textile bag or carton paper. The bottom of the chamber was filled with a tightly-fitted rock wool which can hold water and provide moisture during a seedling growth. The

  5. Effect of sea salt irrigation on plant growth, yield potential and some biochemical attributes of carissa carandas

    International Nuclear Information System (INIS)

    Tayyab, A.

    2016-01-01

    Carissa carandas (varn. Karonda) is an edible and medicinal plant having ability to grow in saline and water deficit conditions, however, little is known about its salinity tolerance. Therefore, the effect of salinity on vegetative (height and volume), reproductive (number of flowers and number, size and weight of fruits) and some biochemical parameters (leaf pigments, ions, soluble sugars, proteins, and phenols) of C. carandas were studied. Plants were grown in drum pot culture and irrigated with non-saline or saline water of 0.6% and 0.8% sea salt concentrations, for a period of 30 months. Results showed that, plant height, and canopy volume decreased with increasing salinity. The chlorophyll contents and chlorophyll a/b ratio followed the similar trend as for growth, however, carotenoids increased at 0.6% sea salt and subsequently decreased in higher salinity. Unchanged soluble sugar and protein content at 0.6% sea salt, as compared to control, could be attributed to leaf osmotic adjustments which decreased with further increase in salinity. Linear increase in soluble phenols and carotenoid/chlorophyll ratio indicating a protective strategy of C. carandas to minimize photo-damage. Besides increasing Na+ and decreasing K+ contents, plant seemed to maintain K+/Na+ ratio (above 1), especially at 0.6 sea salt, which disturbed at higher salinity. Salinity adversely affected reproductive growth of C. carandas where, production of flowers, and fruits were significantly reduced. In addition, fresh and dry weights of fruits decreased with increasing salinity, but salinity did not affect fruit length and diameter. Present study provides basic information related to plant growth, fruit yield and some biochemical attributes, which suggest that C. carandas is moderately salt tolerant plant. This plant showed potential to grow on saline marginal lands using brackish water irrigation and provide biomass for edible and medicinal purposes. However, in-depth analysis of field and

  6. Effect of regulated deficit irrigation on growth, flowering and physiological responses of potted Syringa meyeri ‘Palibin’

    Directory of Open Access Journals (Sweden)

    Michał Koniarski

    2014-01-01

    Full Text Available The aim of this study was to analyze the physiological and morphological response of Syringa meyeri ‘Palibin’ to different levels of irrigation and to evaluate regulated deficit irrigation (RDI as a possible technique for saving water in nursery production and promoting of flowering. Plants were grown in 3 liter containers in an unheated greenhouse and were subjected to six irrigation treatments for 18 weeks from the be- ginning of June to mid-October 2011. A drip irrigation system was used. Irrigation treatments were established on the basis of evapotranspiration (ETp. Three constant irrigation treatments were used: 1 1 ETp; 2 0.75 ETp; 3 0.5 ETp, while the other three with irrigation varying between phases were as follows: 4 1–0.5–1; 5 1–0.25–1; and 6 0.5–1–0.5 ETp. The 0.75 ETp and 0.5 ETp irrigation regimes adversely affected the growth and visual quality index of plants as well as they resulted in reduced leaf conductance, transpiration, maximum quantum efficiency of photosystem II (Fv/Fm and CCI (chlorophyll content index. Plants grown under the 1–0.5–1 ETp regime had the same morphological parameters as plants grown under the 0.5 ETp treatment. A further reduction of water quantity supplied to plants in the 1–0.25–1 ETp regime resulted in further deterioration of the visual quality index of plants. In this study, the quality index of plants exposed to 0.5–1–0.5 ETp was similar to control plants (1 ETp. These plants were lower, more compact, and had smaller leaves than control plants. The irrigation regimes imposed in this study had no significant effect on the number of floral buds formed in relation to the control regime, except for 1–0.25–1 ETp where this number decreased.

  7. The microbiome of medicinal plants: diversity and importance for plant growth, quality and health.

    Science.gov (United States)

    Köberl, Martina; Schmidt, Ruth; Ramadan, Elshahat M; Bauer, Rudolf; Berg, Gabriele

    2013-12-20

    Past medicinal plant research primarily focused on bioactive phytochemicals, however, the focus is currently shifting due to the recognition that a significant number of phytotherapeutic compounds are actually produced by associated microbes or through interaction with their host. Medicinal plants provide an enormous bioresource of potential use in modern medicine and agriculture, yet their microbiome is largely unknown. The objective of this review is (i) to introduce novel insights into the plant microbiome with a focus on medicinal plants, (ii) to provide details about plant- and microbe-derived ingredients of medicinal plants, and (iii) to discuss possibilities for plant growth promotion and plant protection for commercial cultivation of medicinal plants. In addition, we also present a case study performed both to analyse the microbiome of three medicinal plants (Matricaria chamomilla L., Calendula officinalis L., and Solanum distichum Schumach. and Thonn.) cultivated on organically managed Egyptian desert farm and to develop biological control strategies. The soil microbiome of the desert ecosystem was comprised of a high abundance of Gram-positive bacteria of prime importance for pathogen suppression under arid soil conditions. For all three plants, we observed a clearly plant-specific selection of the microbes as well as highly specific diazotrophic communities that overall identify plant species as important drivers in structural and functional diversity. Lastly, native Bacillus spec. div. strains were able to promote plant growth and elevate the plants' flavonoid production. These results underline the numerous links between the plant-associated microbiome and the plant metabolome.

  8. A novel bZIP gene from Tamarix hispida mediates physiological responses to salt stress in tobacco plants.

    Science.gov (United States)

    Wang, Yucheng; Gao, Caiqiu; Liang, Yenan; Wang, Chao; Yang, Chuanping; Liu, Guifeng

    2010-02-15

    Basic leucine zipper proteins (bZIPs) are transcription factors that bind abscisic acid (ABA)-responsive elements (ABREs) and enable plants to withstand adverse environmental conditions. In the present study, a novel bZIP gene, ThbZIP1 was cloned from Tamarix hispida. Expression studies in T. hispida showed differential regulation of ThbZIP1 in response to treatment with NaCl, polyethylene glycol (PEG) 6000, NaHCO(3), and CdCl(2), suggesting that ThbZIP1 is involved in abiotic stress responses. To identify the physiological responses mediated by ThbZIP1, transgenic tobacco plants overexpressing exogenous ThbZIP1 were generated. Various physiological parameters related to salt stress were measured and compared between transgenic and wild type (WT) plants. Our results indicate that overexpression of ThbZIP1 can enhance the activity of both peroxidase (POD) and superoxide dismutase (SOD), and increase the content of soluble sugars and soluble proteins under salt stress conditions. These results suggest that ThbZIP1 contributes to salt tolerance by mediating signaling through multiple physiological pathways. Furthermore, ThbZIP1 confers stress tolerance to plants by enhancing reactive oxygen species (ROS) scavenging, facilitating the accumulation of compatible osmolytes, and inducing and/or enhancing the biosynthesis of soluble proteins. Copyright 2009 Elsevier GmbH. All rights reserved.

  9. Parasitic plants in agriculture: Chemical ecology of germination and host-plant location as targets for sustainable control: A review

    Science.gov (United States)

    Justin B. Runyon; John F. Tooker; Mark C. Mescher; Consuelo M. De Moraes

    2009-01-01

    Parasitic plants are among the most problematic pests of agricultural crops worldwide. Effective means of control are generally lacking, in part because of the close physiological connection between the established parasite and host plant hindering efficient control using traditional methods. Seed germination and host location are critical early-growth stages that...

  10. Physiological Roles of Plant Post-Golgi Transport Pathways in Membrane Trafficking.

    Science.gov (United States)

    Uemura, Tomohiro

    2016-10-01

    Membrane trafficking is the fundamental system through which proteins are sorted to their correct destinations in eukaryotic cells. Key regulators of this system include RAB GTPases and soluble N-ethylmaleimide sensitive factor attachment protein receptors (SNAREs). Interestingly, the numbers of RAB GTPases and SNAREs involved in post-Golgi transport pathways in plant cells are larger than those in animal and yeast cells, suggesting that plants have evolved unique and complex post-Golgi transport pathways. The trans-Golgi network (TGN) is an important organelle that acts as a sorting station in the post-Golgi transport pathways of plant cells. The TGN also functions as the early endosome, which is the first compartment to receive endocytosed proteins. Several endocytosed proteins on the plasma membrane (PM) are initially targeted to the TGN/EE, then recycled back to the PM or transported to the vacuole for degradation. The recycling and degradation of the PM localized proteins is essential for the development and environmental responses in plant. The present review describes the post-Golgi transport pathways that show unique physiological functions in plants. © The Author 2016. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  11. Trickle water and feeding system in plant culture and light-dark cycle effects on plant growth

    Science.gov (United States)

    Takano, T.; Inada, K.; Takanashi, J.

    1987-01-01

    Rockwool, as an inert medium covered or bagged with polyethylene film, can be effectively used for plant culture in space stations. The most important machine is the pump adjusting the dripping rate in the feeding system. Hydro-aeroponics may be adaptable to a space laboratory. The shortening of the light-dark cycles inhibits plant growth and induces an abnormal morphogenesis. A photoperiod of 12 hr dark may be needed for plant growth.

  12. Plant Tolerance: A Unique Approach to Control Hemipteran Pests.

    Science.gov (United States)

    Koch, Kyle G; Chapman, Kaitlin; Louis, Joe; Heng-Moss, Tiffany; Sarath, Gautam

    2016-01-01

    Plant tolerance to insect pests has been indicated to be a unique category of resistance, however, very little information is available on the mechanism of tolerance against insect pests. Tolerance is distinctive in terms of the plant's ability to withstand or recover from herbivore injury through growth and compensatory physiological processes. Because plant tolerance involves plant compensatory characteristics, the plant is able to harbor large numbers of herbivores without interfering with the insect pest's physiology or behavior. Some studies have observed that tolerant plants can compensate photosynthetically by avoiding feedback inhibition and impaired electron flow through photosystem II that occurs as a result of insect feeding. Similarly, the up-regulation of peroxidases and other oxidative enzymes during insect feeding, in conjunction with elevated levels of phytohormones can play an important role in providing plant tolerance to insect pests. Hemipteran insects comprise some of the most economically important plant pests (e.g., aphids, whiteflies), due to their ability to achieve high population growth and their potential to transmit plant viruses. In this review, results from studies on plant tolerance to hemipterans are summarized, and potential models to understand tolerance are presented.

  13. Colonization of Plant Growth Promoting Rhizobacteria (PGPR) on Two Different Root Systems

    International Nuclear Information System (INIS)

    Chaudhry, M. Z.; Naz, A. U.; Nawaz, A.; Nawaz, A.; Mukhtar, H.

    2016-01-01

    Phytohormones producing bacteria enhance the plants growth by positively affecting growth of the root. Plant growth promoting bacteria (PGPR) must colonize the plant roots to contribute to the plant's endogenous pool of phytohormones. Colonization of these plant growth promoting rhizobacteria isolated from rhizosplane and soil of different crops was evaluated on different root types to establish if the mechanism of host specificity exist. The bacteria were isolated from maize, wheat, rice, canola and cotton and phytohormone production was detected and quantified by HPLC. Bacteria were inoculated on surface sterilized seeds of different crops and seeds were germinated. After 7 days the bacteria were re-isolated from the roots and the effect of these bacteria was observed by measuring increase in root length. Bacteria isolated from one plant family (monocots) having fibrous root performed well on similar root system and failed to give significant results on other roots (tap root) of dicots. Some aggressive strains were able to colonize both root systems. The plant growth promoting activities of the bacteria were optimum on the same plant from whom roots they were isolated. The results suggest that bacteria adapt to the root they naturally inhabit and colonize the same plant root systems preferably. Although the observe trend indicate host specificity but some bacteria were aggressive colonizers which grew on all the plants used in experiment. (author)

  14. Introgression of physiological traits for a comprehensive improvement of drought adaptation in crop plants

    Science.gov (United States)

    Sreeman, Sheshshayee M.; Vijayaraghavareddy, Preethi; Sreevathsa, Rohini; Rajendrareddy, Sowmya; Arakesh, Smitharani; Bharti, Pooja; Dharmappa, Prathibha; Soolanayakanahally, Raju

    2018-04-01

    Burgeoning population growth, industrial demand and the predicted global climate change resulting in erratic monsoon rains are expected to severely limit fresh water availability for agriculture both in irrigated and rainfed ecosystems. In order to remain food and nutrient secure, agriculture research needs to focus on devising strategies to save water in irrigated conditions and to develop superior cultivars with improved water productivity to sustain yield under rainfed conditions. Recent opinions accruing in the scientific literature strongly favour the adoption of a “trait based” approach for increasing water productivity especially the traits associated with maintenance of positive tissue turgor and maintenance of increased carbon assimilation as the most relevant traits to improve crop growth rates under water limiting conditions and to enhance water productivity. The advent of several water saving agronomic practices notwithstanding, a genetic enhancement strategy of introgressing distinct physiological, morphological and cellular mechanisms on to a single elite genetic background is essential for achieving a comprehensive improvement in drought adaptation in crop plants. The significant progress made in genomics, though would provide the necessary impetus, a clear understanding of the “traits” to be introgressed is the most essential need of the hour. Water uptake by a better root architecture, water conservation by preventing unproductive transpiration is crucial for maintaining positive tissue water relations. Improved carbon assimilation associated with carboxylation capacity and mesophyll conductance is equally important in sustaining crop growth rates under water limited conditions. Besides these major traits, we summarized the available information in literature on classifying various drought adaptive traits. We provide evidences that water-use efficiency when introgressed with moderately higher transpiration, would significantly enhance

  15. Introgression of Physiological Traits for a Comprehensive Improvement of Drought Adaptation in Crop Plants

    Directory of Open Access Journals (Sweden)

    Sheshshayee M. Sreeman

    2018-04-01

    Full Text Available Burgeoning population growth, industrial demand, and the predicted global climate change resulting in erratic monsoon rains are expected to severely limit fresh water availability for agriculture both in irrigated and rainfed ecosystems. In order to remain food and nutrient secure, agriculture research needs to focus on devising strategies to save water in irrigated conditions and to develop superior cultivars with improved water productivity to sustain yield under rainfed conditions. Recent opinions accruing in the scientific literature strongly favor the adoption of a “trait based” crop improvement approach for increasing water productivity. Traits associated with maintenance of positive tissue turgor and maintenance of increased carbon assimilation are regarded as most relevant to improve crop growth rates under water limiting conditions and to enhance water productivity. The advent of several water saving agronomic practices notwithstanding, a genetic enhancement strategy of introgressing distinct physiological, morphological, and cellular mechanisms on to a single elite genetic background is essential for achieving a comprehensive improvement in drought adaptation in crop plants. The significant progress made in genomics, though would provide the necessary impetus, a clear understanding of the “traits” to be introgressed is the most essential need of the hour. Water uptake by a better root architecture, water conservation by preventing unproductive transpiration are crucial for maintaining positive tissue water relations. Improved carbon assimilation associated with carboxylation capacity and mesophyll conductance is important in sustaining crop growth rates under water limited conditions. Besides these major traits, we summarize the available information in literature on classifying various drought adaptive traits. We provide evidences that Water-Use Efficiency when introgressed with moderately higher transpiration, would

  16. Manipulation of plant ethylene balance by soil microbiota: a holobiont perspective to stress tolerance

    NARCIS (Netherlands)

    Ravanbakhsh, Mohammadhossein

    2018-01-01

    Plants continuously adjust their physiology and phenotype to stressors. Plant hormones and modulators mediate the adaptation of the plant to changing environmental conditions by allocating resources precisely between growth and stress tolerance. Plant responses to stressors are typically studied

  17. Nutrient leaching when soil is part of plant growth media

    Science.gov (United States)

    Soils can serve as sorbents for phosphorus (P) within plant growth media, negating the need for artificial sorbents. The purpose of this study was to compare soils with different properties, as part of plant growth media, for their effect on nutrient levels in effluent. Four soils were mixed with sa...

  18. Physiological Assessment of Water Stress in Potato Using Spectral Information.

    Science.gov (United States)

    Romero, Angela P; Alarcón, Andrés; Valbuena, Raúl I; Galeano, Carlos H

    2017-01-01

    Water stress in potato ( Solanum tuberosum L.) causes considerable losses in yield, and therefore, potato is often considered to be a drought sensitive crop. Identification of water deficit tolerant potato genotypes is an adaptation strategy to mitigate the climatic changes that are occurring in the Cundiboyacense region in Colombia. Previous studies have evaluated potato plants under water stress conditions using physiological analyses. However, these methodologies require considerable amounts of time and plant material to perform these measurements. This study evaluated and compared the physiological and spectral traits between two genotypes, Diacol Capiro and Perla Negra under two drought levels (10 and 15 days without irrigation from flowering). Reflectance information was used to calculate indexes which were associated with the physiological behavior in plants. The results showed that spectral information was correlated (ρ < 0.0001) with physiological variables such as foliar area (FA), total water content (H 2 Ot), relative growth rate of potato tubers (RGTtub), leaf area ratio (LAR), and foliar area index (AFI). In general, there was a higher concentration of chlorophyll under drought treatments. In addition, Perla Negra under water deficit treatments did not show significant differences in its physiological variables. Therefore, it could be considered a drought tolerant genotype because its physiological performance was not affected under water stress conditions. However, yield was affected in both genotypes after being subject to 15 days of drought. The results suggested that reflectance indexes are a useful and affordable approach for potato phenotyping to select parent and segregant populations in breeding programs.

  19. Physiological and Molecular Processes Associated with Long Duration of ABA Treatment

    Directory of Open Access Journals (Sweden)

    Mei Wang

    2018-02-01

    Full Text Available Plants need to respond to various environmental stresses such as abiotic stress for proper development and growth. The responses to abiotic stress can be biochemically demanding, resulting in a trade-off that negatively affects plant growth and development. Thus, plant stress responses must be fine-tuned depending on the stress severity and duration. Abscisic acid, a phytohormone, plays a key role in responses to abiotic stress. Here, we investigated time-dependent physiological and molecular responses to long-term ABA treatment in Arabidopsis as an approach to gain insight into the plant responses to long-term abiotic stress. Upon ABA treatment, the amount of cellular ABA increased to higher levels, reaching to a peak at 24 h after treatment (HAT, and then gradually decreased with time whereas ABA-GE was maintained at lower levels until 24 HAT and then abruptly increased to higher levels at 48 HAT followed by a gradual decline at later time points. Many genes involved in dehydration stress responses, ABA metabolism, chloroplast biogenesis, and chlorophyll degradation were strongly expressed at early time points with a peak at 24 or 48 HAT followed by gradual decreases in induction fold or even suppression at later time points. At the physiological level, long-term ABA treatment caused leaf yellowing, reduced chlorophyll levels, and inhibited chloroplast division in addition to the growth suppression whereas short-term ABA treatment did not affect chlorophyll levels. Our results indicate that the duration of ABA treatment is a crucial factor in determining the mode of ABA-mediated signaling and plant responses: active mobilization of cellular resources at early time points and suppressive responses at later time points.

  20. Termitarium-inhabiting Bacillus endophyticus TSH42 and Bacillus cereus TSH77 colonizing Curcuma longa L.: isolation, characterization, and evaluation of their biocontrol and plant-growth-promoting activities.

    Science.gov (United States)

    Chauhan, Ankit Kumar; Maheshwari, Dinesh Kumar; Kim, Kangmin; Bajpai, Vivek K

    2016-10-01

    Bacillus strains were isolated from termitarium soil and screened for their antifungal activity through the production of diffusible and volatile metabolites. Further, the bacterial strains that showed antifungal activity were evaluated for their biocontrol potential on the basis of their plant-growth-promoting attributes. Termitarium-inhabiting Bacillus strains TSH42 and TSH77 significantly reduced the growth of pathogenic fungus Fusarium solani, controlled the symptoms of rhizome rot in turmeric (Curcuma longa L.), and demonstrated various plant-growth-promoting traits in different in vitro assays. On the basis of morphological, physiological, biochemical, and 16S rDNA characteristics, isolates TSH42 and TSH77 were identified as Bacillus endophyticus (KT379993) and Bacillus cereus (KT379994), respectively. Through liquid chromatography - mass spectrometry analysis, acidified cell-free culture filtrate (CFCF) of B. cereus TSH77 was shown to contain surfactin and fengycin, while CFCF of B. endophyticus TSH42 contained iturin in addition to surfactin and fengycin. Treatment of the turmeric (C. longa L.) plants with TSH42 and TSH77 significantly reduced the percentage incidence of rhizome rot disease caused by F. solani. The same treatment also increased the fresh rhizome biomass and plant growth in greenhouse conditions.

  1. Influence of integrated phosphorus supply and plant growth ...

    African Journals Online (AJOL)

    To guarantee a sufficient phosphorus supply for plants, a rapid and permanent mobilization of phosphorus from the labile phosphorus fractions is necessary, because phosphorus concentrations in soil solution are generally low. Several plant growth-promoting rhizobacteria (PGPR) have shown potential to enhance ...

  2. Controlled ecological life support systems: Development of a plant growth module

    Science.gov (United States)

    Averner, Mel M.; Macelroy, Robert D.; Smernoff, David T.

    1987-01-01

    An effort was made to begin defining the scientific and technical requirements for the design and construction of a ground-based plant growth facility. In particular, science design criteria for the Plant Growth Module (PGM) of the Controlled Ecological Life Support System (CELSS) were determined in the following areas: (1) irradiation parameters and associated equipment affecting plant growth; (2) air flow; (3) planting, culture, and harvest techniques; (4) carbon dioxide; (5) temperature and relative humidity; (6) oxygen; (7) construction materials and access; (8) volatile compounds; (9) bacteria, sterilization, and filtration; (10) nutrient application systems; (11) nutrient monitoring; and (12) nutrient pH and conductivity.

  3. Growth physiology and fate of diatoms in the ocean: a review

    Science.gov (United States)

    Sarthou, Géraldine; Timmermans, Klaas R.; Blain, Stéphane; Tréguer, Paul

    2005-01-01

    Diatoms are a major component of phytoplankton community. They tend to dominate under natural high-nutrient concentrations, as well as during artificial Fe fertilisation experiments. They are main players in the biogeochemical cycle of carbon (C), as they can account for 40% of the total primary production in the Ocean and dominate export production, as well as in the biogeochemical cycles of the other macro-nutrients, nitrogen (N), phosphorus (P), and silicon (Si). Another important nutrient is Fe, which was shown to have a direct or indirect effect on nearly all the biogeochemical parameters of diatoms. In the present paper, an inventory is made of the growth, physiology and fate of many diatom species, including maximum growth rate, photosynthetic parameters (maximum specific rate of photosynthesis, photosynthetic efficiency and light adaptation parameter), nutrient limitation (half-saturation constant for growth/uptake), cellular elemental ratios, and loss terms (sinking rates, autolysis rates and grazing rates). This is a first step for improvement of the parameterisation of physiologically based phytoplankton growth and global 3D carbon models. This review is a synthesis of a large number of published laboratory experiments using monospecific cultures as well as field data. Our compilation confirms that size is an important factor explaining variations of biogeochemical parameters of diatoms (e.g. maximum growth rate, photosynthesis parameters, half-saturation constants, sinking rate, and grazing). Some variations of elemental ratios can be explained by adaptation of intracellular requirements or storage of Fe, and P, for instance. The important loss processes of diatoms pointed out by this synthesis are (i) sinking, as single cells as well as through aggregation which generally greatly increases sinking rate, (ii) cell autolysis, which can significantly reduce net growth rates, especially under nutrient limitation when gross growth rates are low, and (iii

  4. Salicylic acid promotes plant growth and salt-related gene expression in Dianthus superbus L. (Caryophyllaceae) grown under different salt stress conditions.

    Science.gov (United States)

    Zheng, Jian; Ma, Xiaohua; Zhang, Xule; Hu, Qingdi; Qian, Renjuan

    2018-03-01

    Salt stress is a critical factor that affects the growth and development of plants. Salicylic acid (SA) is an important signal molecule that mitigates the negative effects of salt stress on plants. To elucidate salt tolerance in large pink Dianthus superbus L. (Caryophyllaceae) and the regulatory mechanism of exogenous SA on D. superbus under different salt stresses, we conducted a pot experiment to evaluate leaf biomass, leaf anatomy, soluble protein and sugar content, and the relative expression of salt-induced genes in D. superbus under 0.3, 0.6, and 0.9% NaCl conditions with and without 0.5 mM SA. The result showed that exposure of D. superbus to salt stress lead to a decrease in leaf growth, soluble protein and sugar content, and mesophyll thickness, together with an increase in the expression of MYB and P5CS genes. Foliar application of SA effectively increased leaf biomass, soluble protein and sugar content, and upregulated the expression of MYB and P5CS in the D. superbus , which facilitated in the acclimation of D. superbus to moderate salt stress. However, when the plants were grown under severe salt stress (0.9% NaCl), no significant difference in plant physiological responses and relevant gene expression between plants with and without SA was observed. The findings of this study suggest that exogenous SA can effectively counteract the adverse effects of moderate salt stress on D. superbus growth and development.

  5. Elevated temperature is more effective than elevated [CO2 ] in exposing genotypic variation in Telopea speciosissima growth plasticity: implications for woody plant populations under climate change.

    Science.gov (United States)

    Huang, Guomin; Rymer, Paul D; Duan, Honglang; Smith, Renee A; Tissue, David T

    2015-10-01

    Intraspecific variation in phenotypic plasticity is a critical determinant of plant species capacity to cope with climate change. A long-standing hypothesis states that greater levels of environmental variability will select for genotypes with greater phenotypic plasticity. However, few studies have examined how genotypes of woody species originating from contrasting environments respond to multiple climate change factors. Here, we investigated the main and interactive effects of elevated [CO2 ] (CE ) and elevated temperature (TE ) on growth and physiology of Coastal (warmer, less variable temperature environment) and Upland (cooler, more variable temperature environment) genotypes of an Australian woody species Telopea speciosissima. Both genotypes were positively responsive to CE (35% and 29% increase in whole-plant dry mass and leaf area, respectively), but only the Coastal genotype exhibited positive growth responses to TE . We found that the Coastal genotype exhibited greater growth response to TE (47% and 85% increase in whole-plant dry mass and leaf area, respectively) when compared with the Upland genotype (no change in dry mass or leaf area). No intraspecific variation in physiological plasticity was detected under CE or TE , and the interactive effects of CE and TE on intraspecific variation in phenotypic plasticity were also largely absent. Overall, TE was a more effective climate factor than CE in exposing genotypic variation in our woody species. Our results contradict the paradigm that genotypes from more variable climates will exhibit greater phenotypic plasticity in future climate regimes. © 2015 John Wiley & Sons Ltd.

  6. Outline of research on plant physiological functions using Positron Emitting Tracer

    International Nuclear Information System (INIS)

    Kume, Tamikazu

    2000-01-01

    Application of Positron Emitting Tracer Imaging System (Pets) for the plant has been investigated under JAERI-Universities Joint Research Project. Five university groups are studying a dynamic image of plant transport or a static image of the result of tracer movement using 11 C (half-life 20 min), 13 N (10 min), 18 F (110 min), etc. The Pets consisted of two-dimensional block detectors (48 x 50 mm square) which were composed of a Bi 4 Ge 3 O 12 scintillator array coupled to a position sensitive photomultiplier tube. In the system, the plant samples are placed at the mid position between the two opposing detectors and annihilation γ-rays from the samples are detected in coincidence. The positron emitting tracer images are obtained by accumulating these signals. The spatial resolution was 2.4 mm and images with a good S/N ratio can be obtained in real time. Using TIARA AVF cyclotron, 13 NO 3 - , 13 NH 4 + , 18 F-water, 11 C-methionine, etc. were produced and supplied to the plants. The transport of these labeled compounds introduced into plants was followed dynamically by PETIS. The results show that the system is effective in observing the uptake and transport of nutrients in plants and is useful for the study of physiological functions of plants. (author)

  7. Pectin Methylesterification Impacts the Relationship between Photosynthesis and Plant Growth.

    Science.gov (United States)

    M Weraduwage, Sarathi; Kim, Sang-Jin; Renna, Luciana; C Anozie, Fransisca; D Sharkey, Thomas; Brandizzi, Federica

    2016-06-01

    Photosynthesis occurs in mesophyll cells of specialized organs such as leaves. The rigid cell wall encapsulating photosynthetic cells controls the expansion and distribution of cells within photosynthetic tissues. The relationship between photosynthesis and plant growth is affected by leaf area. However, the underlying genetic mechanisms affecting carbon partitioning to different aspects of leaf growth are not known. To fill this gap, we analyzed Arabidopsis plants with altered levels of pectin methylesterification, which is known to modulate cell wall plasticity and plant growth. Pectin methylesterification levels were varied through manipulation of cotton Golgi-related (CGR) 2 or 3 genes encoding two functionally redundant pectin methyltransferases. Increased levels of methylesterification in a line over-expressing CGR2 (CGR2OX) resulted in highly expanded leaves with enhanced intercellular air spaces; reduced methylesterification in a mutant lacking both CGR-genes 2 and 3 (cgr2/3) resulted in thin but dense leaf mesophyll that limited CO2 diffusion to chloroplasts. Leaf, root, and plant dry weight were enhanced in CGR2OX but decreased in cgr2/3. Differences in growth between wild type and the CGR-mutants can be explained by carbon partitioning but not by variations in area-based photosynthesis. Therefore, photosynthesis drives growth through alterations in carbon partitioning to new leaf area growth and leaf mass per unit leaf area; however, CGR-mediated pectin methylesterification acts as a primary factor in this relationship through modulation of the expansion and positioning of the cells in leaves, which in turn drive carbon partitioning by generating dynamic carbon demands in leaf area growth and leaf mass per unit leaf area. © 2016 American Society of Plant Biologists. All Rights Reserved.

  8. Materials and methods to increase plant growth and yield

    Science.gov (United States)

    Kirst, Matias

    2017-05-16

    The present invention relates to materials and methods for modulating growth rates, yield, and/or resistance to drought conditions in plants. In one embodiment, a method of the invention comprises increasing expression of an hc1 gene (or a homolog thereof that provides for substantially the same activity), or increasing expression or activity of the protein encoded by an hc1 gene thereof, in a plant, wherein expression of the hc1 gene or expression or activity of the protein encoded by an hc1 gene results in increased growth rate, yield, and/or drought resistance in the plant.

  9. Solid-support substrates for plant growth at a lunar base

    Science.gov (United States)

    Ming, D. W.; Galindo, C.; Henninger, D. L.

    1990-01-01

    Zeoponics is only in its developmental stages at the Johnson Space Center and is defined as the cultivation of plants in zeolite substrates that contain several essential plant growth cations on their exchange sites, and have minor amounts of mineral phases and/or anion-exchange resins that supply essential plant growth anions. Zeolites are hydrated aluminosilicates of alkali and alkaline earth cations with the ability to exchange most of their constituent exchange cations as well as hydrate/dehydrate without change to their structural framework. Because zeolites have extremely high cation exchange capabilities, they are very attractive media for plant growth. It is possible to partially or fully saturate plant-essential cations on zeolites. Zeoponic systems will probably have their greatest applications at planetary bases (e.g., lunar bases). Lunar raw materials will have to be located that are suited for the synthesis of zeolites and other exchange resings. Lunar 'soil' simulants have been or are being prepared for zeolite/smectite synthesis and 'soil' dissolution studies.

  10. Natural genetic variation in Arabidopsis for responsiveness to plant growth-promoting rhizobacteria

    NARCIS (Netherlands)

    Wintermans, Paul C A; Bakker, Peter A H M; Pieterse, Corné M J

    The plant growth-promoting rhizobacterium (PGPR) Pseudomonas simiae WCS417r stimulates lateral root formation and increases shoot growth in Arabidopsis thaliana (Arabidopsis). These plant growth-stimulating effects are partly caused by volatile organic compounds (VOCs) produced by the bacterium.

  11. Natural genetic variation in Arabidopsis for responsiveness to plant growth-promoting rhizobacteria

    NARCIS (Netherlands)

    Wintermans, P.C.A.; Bakker, P.A.H.M.; Pieterse, C.M.J.

    2016-01-01

    The plant growth-promoting rhizobacterium (PGPR) Pseudomonas simiae WCS417r stimulates lateral root formation and increases shoot growth in Arabidopsis thaliana (Arabidopsis). These plant growth-stimulating effects are partly caused by volatile organic compounds (VOCs) produced by the bacterium.

  12. Relationship between Aflatoxin Contamination and Physiological Responses of Corn Plants under Drought and Heat Stress

    Directory of Open Access Journals (Sweden)

    Nacer Bellaloui

    2012-11-01

    Full Text Available Increased aflatoxin contamination in corn by the fungus Aspergillus flavus is associated with frequent periods of drought and heat stress during the reproductive stages of the plants. The objective of this study was to evaluate the relationship between aflatoxin contamination and physiological responses of corn plants under drought and heat stress. The study was conducted in Stoneville, MS, USA under irrigated and non-irrigated conditions. Five commercial hybrids, P31G70, P33F87, P32B34, P31B13 and DKC63-42 and two inbred germplasm lines, PI 639055 and PI 489361, were evaluated. The plants were inoculated with Aspergillus flavus (K-54 at mid-silk stage, and aflatoxin contamination was determined on the kernels at harvest. Several physiological measurements which are indicators of stress response were determined. The results suggested that PI 639055, PI 489361 and hybrid DKC63-42 were more sensitive to drought and high temperature stress in the non-irrigated plots and P31G70 was the most tolerant among all the genotypes. Aflatoxin contamination was the highest in DKC63-42 and PI 489361 but significantly lower in P31G70. However, PI 639055, which is an aflatoxin resistant germplasm, had the lowest aflatoxin contamination, even though it was one of the most stressed genotypes. Possible reasons for these differences are discussed. These results suggested that the physiological responses were associated with the level of aflatoxin contamination in all the genotypes, except PI 639055. These and other physiological responses related to stress may help examine differences among corn genotypes in aflatoxin contamination.

  13. Relationship between aflatoxin contamination and physiological responses of corn plants under drought and heat stress.

    Science.gov (United States)

    Kebede, Hirut; Abbas, Hamed K; Fisher, Daniel K; Bellaloui, Nacer

    2012-11-20

    Increased aflatoxin contamination in corn by the fungus Aspergillus flavus is associated with frequent periods of drought and heat stress during the reproductive stages of the plants. The objective of this study was to evaluate the relationship between aflatoxin contamination and physiological responses of corn plants under drought and heat stress. The study was conducted in Stoneville, MS, USA under irrigated and non-irrigated conditions. Five commercial hybrids, P31G70, P33F87, P32B34, P31B13 and DKC63-42 and two inbred germplasm lines, PI 639055 and PI 489361, were evaluated. The plants were inoculated with Aspergillus flavus (K-54) at mid-silk stage, and aflatoxin contamination was determined on the kernels at harvest. Several physiological measurements which are indicators of stress response were determined. The results suggested that PI 639055, PI 489361 and hybrid DKC63-42 were more sensitive to drought and high temperature stress in the non-irrigated plots and P31G70 was the most tolerant among all the genotypes. Aflatoxin contamination was the highest in DKC63-42 and PI 489361 but significantly lower in P31G70. However, PI 639055, which is an aflatoxin resistant germplasm, had the lowest aflatoxin contamination, even though it was one of the most stressed genotypes. Possible reasons for these differences are discussed. These results suggested that the physiological responses were associated with the level of aflatoxin contamination in all the genotypes, except PI 639055. These and other physiological responses related to stress may help examine differences among corn genotypes in aflatoxin contamination.

  14. Characterisation of bacteria from Pinus sylvestris-Suillus luteus mycorrhizas and their effects on root-fungus interactions and plant growth.

    Science.gov (United States)

    Bending, Gary D; Poole, Elizabeth J; Whipps, John M; Read, David J

    2002-03-01

    Bacteria from Pinus sylvestris-Suillus luteus mycorrhizas were isolated, characterised, and their effects on P. sylvestris-S. luteus interactions and plant growth investigated in vitro. The isolates formed five distinct phenotypic and physiological groups. Two of the groups, accounting for 34 of the 55 isolates, consisted of Bacillus spp., with three subgroups represented. The other groups contained Burkholderia spp., Serratia spp. and Pseudomonas spp. Representatives from each bacterial group were used in microcosm experiments to investigate bacterial effects on P. sylvestris-S. luteus interactions. Most Bacillus isolates stimulated growth of S. luteus along the P. sylvestris root, while isolates of Pseudomonas and Serratia inhibited root colonisation by the fungus. Burkholderia and Serratia isolates inhibited ectomycorrhiza formation by 97 and 41% respectively, while a single Bacillus isolate doubled the formation of first order ectomycorrhizal roots. There were no clear relationships between effects of the bacteria on root colonisation by the fungus after 4 weeks, and chitinase production or subsequent ectomycorrhiza formation. However, isolates that inhibited ectomycorrhiza formation appeared to associate preferentially with ectomycorrhizal roots. Several isolates enhanced plant growth substantially, although these effects were unrelated to either root colonisation by the fungus or ectomycorrhiza formation.

  15. Phosphorus mobilizing consortium Mammoth P™ enhances plant growth

    Science.gov (United States)

    Bell, Colin; Mancini, Lauren M.; Lee, Melanie N.; Conant, Richard T.; Wallenstein, Matthew D.

    2016-01-01

    Phosphorus (P) is a critical nutrient used to maximize plant growth and yield. Current agriculture management practices commonly experience low plant P use efficiency due to natural chemical sorption and transformations when P fertilizer is applied to soils. A perplexing challenge facing agriculture production is finding sustainable solutions to deliver P more efficiently to plants. Using prescribed applications of specific soil microbial assemblages to mobilize soil bound—P to improve crop nutrient uptake and productivity has rarely been employed. We investigated whether inoculation of soils with a bacterial consortium developed to mobilize soil P, named Mammoth PTM, could increase plant productivity. In turf, herbs, and fruits, the combination of conventional inorganic fertilizer combined with Mammoth PTM increased productivity up to twofold compared to the fertilizer treatments without the Mammoth PTM inoculant. Jalapeño plants were found to bloom more rapidly when treated with either Mammoth P. In wheat trials, we found that Mammoth PTM by itself was able to deliver yields equivalent to those achieved with conventional inorganic fertilizer applications and improved productivity more than another biostimulant product. Results from this study indicate the substantial potential of Mammoth PTM to enhance plant growth and crop productivity. PMID:27326379

  16. New challenges in plant aquaporin biotechnology.

    Science.gov (United States)

    Martinez-Ballesta, Maria del Carmen; Carvajal, Micaela

    2014-03-01

    Recent advances concerning genetic manipulation provide new perspectives regarding the improvement of the physiological responses in herbaceous and woody plants to abiotic stresses. The beneficial or negative effects of these manipulations on plant physiology are discussed, underlining the role of aquaporin isoforms as representative markers of water uptake and whole plant water status. Increasing water use efficiency and the promotion of plant water retention seem to be critical goals in the improvement of plant tolerance to abiotic stress. However, newly uncovered mechanisms, such as aquaporin functions and regulation, may be essential for the beneficial effects seen in plants overexpressing aquaporin genes. Under distinct stress conditions, differences in the phenotype of transgenic plants where aquaporins were manipulated need to be analyzed. In the development of nano-technologies for agricultural practices, multiple-walled carbon nanotubes promoted plant germination and cell growth. Their effects on aquaporins need further investigation. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  17. Chemical diversity of microbial volatiles and their potential for plant growth and productivity

    Directory of Open Access Journals (Sweden)

    CHIDANANDA NAGAMANGALA KANCHISWAMY

    2015-03-01

    Full Text Available Microbial volatile organic compounds (MVOCs are produced by a wide array of microorganisms ranging from bacteria to fungi. A growing body of evidence indicates that MVOCs are ecofriendly and can be exploited as a cost-effective sustainable strategy for use in agricultural practice as agents that enhance plant growth, productivity and disease resistance. As naturally occurring chemicals, MVOCs have potential as possible alternatives to harmful pesticides, fungicides and bactericides as well as genetic modification. Recent studies performed under open field conditions demonstrate that efficiently adopting MVOCs may contribute to sustainable crop protection and production. We review here the chemical diversity of MVOCs and their potential physiological effects on crops and analyze potential and actual limitations for MVOC use as a sustainable strategy for improving productivity and reducing pesticide use.

  18. Ninth workshop on seedling physiology and growth problems in oak plantings (abstracts)

    Science.gov (United States)

    D.R. Weigel; J.W. Van Sambeek; C.H., eds. Michler

    2005-01-01

    Research results and ongoing research activities in field performance of oak plantings, seedling propagation, genetics, acorn germination, and natural regeneration of oaks are described in 26 abstracts.

  19. Plant phenomics and the need for physiological phenotyping across scales to narrow the genotype-to-phenotype knowledge gap

    Czech Academy of Sciences Publication Activity Database

    Grosskinsky, D. K.; Svensgaard, J.; Christensen, S.; Roitsch, Thomas

    2015-01-01

    Roč. 66, č. 18 (2015), s. 5429-5440 ISSN 0022-0957 Institutional support: RVO:67179843 Keywords : External phenotype * genome–environment–management interaction * genome–phenome map * internal phenotype * phenomics * physiological traits * physiology * plant phenotyping * predictors Subject RIV: EH - Ecology, Behaviour Impact factor: 5.677, year: 2015

  20. Physiological plant investigations for the purpose of growing smoke resistant conifers

    Energy Technology Data Exchange (ETDEWEB)

    Polster, H; Bortitz, S; Vogl, M

    1965-01-01

    Spruce and pine are the main commercial wood varieties used in East Germany. These are also the most sensitive to smoke. Usually replacement of the damaged trees is necessary. The Department of Smoke Research of the Institute for Plant Chemistry of the Dresden Institute of Technology has been able to develop conifers resistant to SO2. In order to select smoke resistant trees for breeding, the Institute for Forestry and Plant Physiology of the Institute of Forestry Breeding in Graupa, East Germany has developed a rapid selection test. It is based on subjecting a small branch to doses of SO2. A method of breeding smoke resistant conifers is given in detail. It takes approximately ten years to produce the seeds.