WorldWideScience

Sample records for physiology plant

  1. Plant Physiology and Development

    DEFF Research Database (Denmark)

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

    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......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...

  2. 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.

  3. 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)

  4. Plant physiology for profitable pastures

    Science.gov (United States)

    A basic question of pasture-based livestock production is whether producers should manage pastures on the basis of what is best for the animal or what is best for the plant. Given that pastures are the principal and most economical source of feed, producers should carefully consider how they manage...

  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. 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.

  7. Physiological functions of plant cell coverings.

    Science.gov (United States)

    Hoson, Takayuki

    2002-08-01

    The cell coverings of plants have two important functions in plant life. Plant cell coverings are deeply involved in the regulation of the life cycle of plants: each stage of the life cycle, such as germination, vegetative growth, reproductive growth, and senescence, is strongly influenced by the nature of the cell coverings. Also, the apoplast, which consists of the cell coverings, is the field where plant cells first encounter the outer environment, and so becomes the major site of plant responses to the environment. In the regulation of each stage of the life cycle and the response to each environmental signal, some specific constituents of the cell coverings, such as xyloglucans in dicotyledons and 1,3,1,4-beta-glucans in Gramineae, act as the key component. The physiological functions of plant cell coverings are sustained by the metabolic turnover of these components. The components of the cell coverings are supplied from the symplast, but then they are modified or degraded in the apoplast. Thus, the metabolism of the cell coverings is regulated through the cross-talk between the symplast and the apoplast. The understanding of physiological functions of plant cell coverings will be greatly advanced by the use of genomic approaches. At the same time, we need to introduce nanobiological techniques for clarifying the minute changes in the cell coverings that occur in a small part within each cell.

  8. 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.

  9. 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.

  10. Physiological phenotyping of plants for crop improvement.

    Science.gov (United States)

    Ghanem, Michel Edmond; Marrou, Hélène; Sinclair, Thomas R

    2015-03-01

    Future progress in crop breeding requires a new emphasis in plant physiological phenotyping for specific, well-defined traits. Success in physiological phenotyping to identify parents for use in breeding efforts for improved cultivars has been achieved by employing a multi-tier screening approach with different levels of sophistication and trait resolution. Subsequently, cultivar development required an integrated mix of classical breeding approaches and one or more tiers of phenotyping to identify genotypes expressing the desired trait. The role of high throughput systems can be useful; here, we emphasize that this approach is likely to offer useful results at an initial tier of phenotyping and will need to be complemented with more directed tiers of phenotyping. Copyright © 2014 Elsevier Ltd. All rights reserved.

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

    African Journals Online (AJOL)

    Fatality of salt stress to plants: Morphological, physiological and biochemical aspects. ... African Journal of Biotechnology ... Soil salinity affects various physiological and biochemical processes which result in reduced biomass production.

  12. Morphological and Physiological Responses of Strawberry Plants to Water Stress

    OpenAIRE

    Krzysztof Klamkowski; Waldemar Treder

    2006-01-01

    The most of previous studies have been focused on the effect of water stress on plant yielding. However, the conditions in which plants grow from the moment of planting might affect their morphology and physiological response. The aim of this study was to examine the effect of water deficiency on growth and plant physiological response of strawberry (Fragaria x ananassa Duch. cv. ‘Salut’) under greenhouse conditions. The plants were grown in plastic containers filled with peat substratum. Wat...

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

    African Journals Online (AJOL)

    Physiological blockage in plants in response to postharvest stress. ... African Journal of Biotechnology. Journal Home · ABOUT ... However, ornamental plants are used in floral arrangements in vases and have limited shelf-life. Thus, this study ...

  14. 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

  15. Plant Sterols: Diversity, Biosynthesis, and Physiological Functions.

    Science.gov (United States)

    Valitova, J N; Sulkarnayeva, A G; Minibayeva, F V

    2016-08-01

    Sterols, which are isoprenoid derivatives, are structural components of biological membranes. Special attention is now being given not only to their structure and function, but also to their regulatory roles in plants. Plant sterols have diverse composition; they exist as free sterols, sterol esters with higher fatty acids, sterol glycosides, and acylsterol glycosides, which are absent in animal cells. This diversity of types of phytosterols determines a wide spectrum of functions they play in plant life. Sterols are precursors of a group of plant hormones, the brassinosteroids, which regulate plant growth and development. Furthermore, sterols participate in transmembrane signal transduction by forming lipid microdomains. The predominant sterols in plants are β-sitosterol, campesterol, and stigmasterol. These sterols differ in the presence of a methyl or an ethyl group in the side chain at the 24th carbon atom and are named methylsterols or ethylsterols, respectively. The balance between 24-methylsterols and 24-ethylsterols is specific for individual plant species. The present review focuses on the key stages of plant sterol biosynthesis that determine the ratios between the different types of sterols, and the crosstalk between the sterol and sphingolipid pathways. The main enzymes involved in plant sterol biosynthesis are 3-hydroxy-3-methylglutaryl-CoA reductase, C24-sterol methyltransferase, and C22-sterol desaturase. These enzymes are responsible for maintaining the optimal balance between sterols. Regulation of the ratios between the different types of sterols and sterols/sphingolipids can be of crucial importance in the responses of plants to stresses.

  16. 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.

  17. Electrical signals and their physiological significance in plants.

    Science.gov (United States)

    Fromm, Jörg; Lautner, Silke

    2007-03-01

    Electrical excitability and signalling, frequently associated with rapid responses to environmental stimuli, are well known in some algae and higher plants. The presence of electrical signals, such as action potentials (AP), in both animal and plant cells suggested that plant cells, too, make use of ion channels to transmit information over long distances. In the light of rapid progress in plant biology during the past decade, the assumption that electrical signals do not only trigger rapid leaf movements in 'sensitive' plants such as Mimosa pudica or Dionaea muscipula, but also physiological processes in ordinary plants proved to be correct. Summarizing recent progress in the field of electrical signalling in plants, the present review will focus on the generation and propagation of various electrical signals, their ways of transmission within the plant body and various physiological effects.

  18. 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

    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...... phenotype. We chose three bacterial strains that differed in predicted metabolic capabilities, plant hormone production and metabolism, and secondary metabolite synthesis. We inoculated each bacterial strain on a single genotype of Populus trichocarpa and measured the response of plant growth related traits...... (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...

  19. Potential physiological role of plant glycosidase inhibitors

    DEFF Research Database (Denmark)

    Bellincampi, D.; Carmadella, L.; Delcour, J.A.;

    2004-01-01

    Carbohydrate-active enzymes including glycosidases, transglycosidases, glycosyltransferases, polysaccharide lyases and carbohydrate esterases are responsible for the enzymatic processing of carbohydrates in plants. A number of carbohydrate-active enzymes are produced by microbial pathogens...... applications....

  20. 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…

  1. Physiological response of soybean genotypes to plant density

    NARCIS (Netherlands)

    Gan, Y.; Stulen, H.; Keulen, van H.; Kuiper, P.J.C.

    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 g

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

    Directory of Open Access Journals (Sweden)

    Jeremiah A. Henning

    2016-11-01

    Full Text Available 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 phenotype. We chose three bacterial strains that differed in predicted metabolic capabilities, plant hormone production and metabolism, and secondary metabolite synthesis. We inoculated each bacterial strain on a single genotype of Populus trichocarpa and measured the response of plant growth related traits (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 not significantly increase plant carbon fixation and biomass, but their presence altered where and how carbon was being allocated in the plant host.

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

    OpenAIRE

    de Esch,, Hubert P. L.; 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 in the Dutch journal Onder Glas and the international edition In Greenhouses, written by Ep Heuvelink and Tijs Kierkels.

  4. 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.

  5. Morphological and Physiological Responses of Strawberry Plants to Water Stress

    Directory of Open Access Journals (Sweden)

    Krzysztof Klamkowski

    2006-12-01

    Full Text Available The most of previous studies have been focused on the effect of water stress on plant yielding. However, the conditions in which plants grow from the moment of planting might affect their morphology and physiological response. The aim of this study was to examine the effect of water deficiency on growth and plant physiological response of strawberry (Fragaria x ananassa Duch. cv. ‘Salut’ under greenhouse conditions. The plants were grown in plastic containers filled with peat substratum. Water stress was imposed by reducing the irrigation according to substratum moisture readings. Water stressed plants had the lowest values of water potential and showed strong decrease in gas exchange rate. Also, biomass and leaf area were the lowest in this group of plants. No differences in the length of root system were observed between control and water stressed plants. The lack of water in growing medium resulted also in a decrease of density and reduction of dimensions of stomata on plant leaves. These changes contribute to optimizing the use of assimilates and water use efficiency in periods when water availability is decreased.

  6. Morphological and Physiological Responses of Strawberry Plants to Water Stress

    Directory of Open Access Journals (Sweden)

    Krzysztof Klamkowski

    2006-01-01

    Full Text Available The most of previous studies have been focused on the effect of water stress on plant yielding. However, the conditions in which plants grow from the moment of planting might affect their morphology and physiological response. The aim of this study was to examine the effect of water deficiency on growth and plant physiological response of strawberry (Fragaria x ananassa Duch. cv. ‘Salut’ under greenhouse conditions. The plants were grown in plastic containers filled with peat substratum. Water stress was imposed by reducing the irrigation according to substratum moisture readings. Water stressed plants had the lowest values of water potential and showed strong decrease in gas exchange rate. Also, biomass and leaf area were the lowest in this group of plants. No differences in the length of root system were observed between control and water stressed plants. The lack of water in growing medium resulted also in a decrease of density and reduction of dimensions of stomata on plant leaves.These changes contribute to optimizing the use of assimilates and water use efficiency in periods when water availability is decreased.

  7. Natural selection on plant physiological traits in an urban environment

    Science.gov (United States)

    Lambrecht, Susan C.; Mahieu, Stephanie; Cheptou, Pierre-Olivier

    2016-11-01

    Current rates of urbanization are creating new opportunities for studying urban plant ecology, but our knowledge of urban plant physiology lags behind that of other ecosystems. Moreover, higher temperatures, elevated CO2, and increased inorganic nitrogen deposition along with altered moisture regimes of urban as compared to rural areas creates a compelling analog for studying adaptations of plants to climate change. We grew plants under common conditions in a greenhouse to determine whether populations of Crepis sancta (Asteraceae) differed in phenological, morphological, and physiological traits. We also used a field experiment to test for natural selection on these traits in urban Montpellier, France. Urban plants flowered and senesced later than rural plants, and natural selection favored later phenology in the urban habitat. Natural selection also favored larger plants with more leaves, and increased photosynthesis and leaf nitrogen concentration. Ours is the first study to document selection on plant functional traits in an urban habitat and, as such, advances our understanding of urban plant ecology and possible adaptations to climate change.

  8. 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.

  9. Physiological and ecological significance of biomineralization in plants.

    Science.gov (United States)

    He, Honghua; Veneklaas, Erik J; Kuo, John; Lambers, Hans

    2014-03-01

    Biomineralization is widespread in the plant kingdom. The most common types of biominerals in plants are calcium oxalate crystals, calcium carbonate, and silica. Functions of biominerals may depend on their shape, size, abundance, placement, and chemical composition. In this review we highlight advances in understanding physiological and ecological significance of biomineralization in plants. We focus on the functions of biomineralization in regulating cytoplasmic free calcium levels, detoxifying aluminum and heavy metals, light gathering and scattering to optimize photosynthesis, aiding in pollen release, germination, and tube growth, the roles it plays in herbivore deterrence, biogeochemical cycling of carbon, calcium, and silicon, and sequestering atmospheric CO2. Copyright © 2013 Elsevier Ltd. All rights reserved.

  10. Physiological roles of plastid terminal oxidase in plant stress responses

    Indian Academy of Sciences (India)

    Xin Sun; Tao Wen

    2011-12-01

    The plastid terminal oxidase (PTOX) is a plastoquinol oxidase localized in the plastids of plants. It is able to transfer electrons from plastoquinone (PQ) to molecular oxygen with the formation of water. Recent studies have suggested that PTOX is beneficial for plants under environmental stresses, since it is involved in the synthesis of photoprotective carotenoids and chlororespiration, which could potentially protect the chloroplast electron transport chain (ETC) from over-reduction. The absence of PTOX in plants usually results in photo-bleached variegated leaves and impaired adaptation to environment alteration. Although PTOX level and activity has been found to increase under a wide range of stress conditions, the functions of plant PTOX in stress responses are still disputed now. In this paper, the possible physiological roles of PTOX in plant stress responses are discussed based on the recent progress.

  11. 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.

  12. RESTORATIVE ASPECT OF CASTOR PLANT ON MAMMALIAN PHYSIOLOGY: A REVIEW

    Directory of Open Access Journals (Sweden)

    Attila Kádasi

    2011-10-01

    Full Text Available The castor plant (Ricinus communis L. is a robust perennial shrub of Euphorbiaceae family and different parts of the plant are widely used by various communities and forest dwellers in many regions of the world for treating a variety of ailments. About 80% of world population is still dependent on traditional herbal medicines. The plant is documented to possess beneficial effects as anti-oxidant, antifertility, anti inflammatory, antimicrobial, central nervous system stimulant, anti diabetic, insecticidal and larvicidal and many other medicinal properties. The extracts or the isolated compounds of this plant have been found to have potent activity against various ailments. The aim of this paper is to scrutinize the available literature related to the restorative activity of the castor plant as a herbal medicine on mammalian physiology and to accumulate those scientifically valid data in a nut shell in the form of a mini review.

  13. Molecular and physiological strategies to increase aluminum resistance in plants.

    Science.gov (United States)

    Inostroza-Blancheteau, Claudio; Rengel, Zed; Alberdi, Miren; de la Luz Mora, María; Aquea, Felipe; Arce-Johnson, Patricio; Reyes-Díaz, Marjorie

    2012-03-01

    Aluminum (Al) toxicity is a primary limitation to plant growth on acid soils. Root meristems are the first site for toxic Al accumulation, and therefore inhibition of root elongation is the most evident physiological manifestation of Al toxicity. Plants may resist Al toxicity by avoidance (Al exclusion) and/or tolerance mechanisms (detoxification of Al inside the cells). The Al exclusion involves the exudation of organic acid anions from the root apices, whereas tolerance mechanisms comprise internal Al detoxification by organic acid anions and enhanced scavenging of free oxygen radicals. One of the most important advances in understanding the molecular events associated with the Al exclusion mechanism was the identification of the ALMT1 gene (Al-activated malate transporter) in Triticum aestivum root cells, which codes for a plasma membrane anion channel that allows efflux of organic acid anions, such as malate, citrate or oxalate. On the other hand, the scavenging of free radicals is dependent on the expression of genes involved in antioxidant defenses, such as peroxidases (e.g. in Arabidopsis thaliana and Nicotiana tabacum), catalases (e.g. in Capsicum annuum), and the gene WMnSOD1 from T. aestivum. However, other recent findings show that reactive oxygen species (ROS) induced stress may be due to acidic (low pH) conditions rather than to Al stress. In this review, we summarize recent findings regarding molecular and physiological mechanisms of Al toxicity and resistance in higher plants. Advances have been made in understanding some of the underlying strategies that plants use to cope with Al toxicity. Furthermore, we discuss the physiological and molecular responses to Al toxicity, including genes involved in Al resistance that have been identified and characterized in several plant species. The better understanding of these strategies and mechanisms is essential for improving plant performance in acidic, Al-toxic soils.

  14. Small plants, large plants: the importance of plant size for the physiological ecology of vascular epiphytes.

    Science.gov (United States)

    Zotz, G; Hietz, P; Schmidt, G

    2001-10-01

    Recently, a number of publications have reported that many physiological properties of vascular epiphytes are a function of plant size. This short review will summarize what is known to date about this phenomenon, describe the possible mechanism and will discuss the consequences for the present understanding of epiphyte biology. Size-related changes are also known from other plant groups and it is argued that close attention should be paid to the size of the organisms under study in order to understand the performance and survival of a species in the field. In the light of these findings, the results of many earlier studies on epiphyte ecophysiology are now difficult to interpret because essential information on the size of the specimens used is missing.

  15. 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.

  16. Flowering plant physiology triggered the expansion of tropical rainforest

    Science.gov (United States)

    Lee, J.; Boyce, C. K.

    2009-12-01

    Transpiration has long been known to feed precipitation, but unique hydraulic characteristics of flowering plants recently have been recognized to impart transpiration capacities dramatically higher than any other plants, living or extinct. Here we show through climate modeling that the replacement of angiosperm with non-angiosperm vegetation would result in a hotter, drier, and more seasonal Amazon basin—dry season length increases by 80 days over the eastern Amazon and overall area of everwet conditions decreases by a factor of five. Evolution of angiosperm physiology has uniquely facilitated spread of warm everwet forests and their enormous biodiversity, perhaps including their early Cenozoic expansion to extra-tropical latitudes. Divergent responses may be expected to general climate parameters and discrete environmental perturbations before and after evolution of angiosperm dominated ecosystems.

  17. Evaluating physiological responses of plants to salinity stress

    KAUST Repository

    Negrão, S.

    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.

  18. 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…

  19. Physiological parameters controlling plant-atmosphere ammonia exchange

    Science.gov (United States)

    Schjoerring, Jan K.; Husted, Søren; Mattsson, Marie

    Recent advances in characterizing the influence of different physiological and environmental parameters on NH 3 exchange between plants and the atmosphere are presented. A central parameter in controlling the rate and direction of NH 3 fluxes is the NH 3 compensation point. It may vary from below 1 to over 20 nmol NH 3 mol -1 air. High compensation points seem to be a result of high tissue N status, rapid absorption of NH +4 from the root medium and/or low activity of glutamine synthetase, a key enzyme in NH +4 assimilation. These conditions cause the NH +4 concentration in leaf apoplast and leaf cells to increase. The NH 3 compensation point also depends on plant developmental stage with peaks in NH 3 emission related to leaf senescence and N remobilization. The leaf temperature has a profound influence on the NH 3 compensation point: an increase in temperature from 15 to 30°C may cause a plant to switch from being a strong sink for atmospheric NH 3 to being a significant NH 3 source. Stomatal conductance for NH 3 relative to that of water vapour increases with tissue N status and with leaf senescence. At a given leaf temperature, the NH 3 compensation point can be successfully predicted on basis of the pH and NH +4 concentration in the apoplast of the mesophyll cells.

  20. What role does plant physiology play in limiting species distribution?

    Science.gov (United States)

    De Kauwe, M. G.; Medlyn, B. E.; Beaumont, L.; Duursma, R.; Baumgartner, J.

    2015-12-01

    To predict vulnerability of tree species to changes in climate, we need to understand what processes are currently limiting their distributions. Although the limits to distribution is among the most fundamental of ecological questions, there are few studies that determine quantitatively which processes can explain observed distributions. Focusing on two contrasting Eucalypt species, a fast-growing coastal species (E. saligna) and a slower-growing inland species (E. sideroxylon), we examined to what extent plant physiological characteristics limit species distributions. The ecophysiology of both species has been extensively characterised in both controlled and field environments. We parameterised an ecosystem model (GDAY, Generic Decomposition and Yield) for both species, using the best available experimental data. We then used the model to predict the spatial distribution of productivity for these species in eastern Australia, and compared these predictions with the actual distributions. The results of this comparison allow us to identify where the distributions of these species are limited by physiological constraints on productivity, and consequently their vulnerability to changes in climate.

  1. Physiological responses of plant leaves to atmospheric ammonia and ammonium

    Science.gov (United States)

    Pearson, J.; Soares, A.

    Misting of leaves of several plant species with 3 mM aqueous NH +4 at pH 5, or fumigation with 3000 μg m -3 gaseous NH 3 for 1 h, elicits similar biochemical and physiological changes in the species tested. The enzyme glutamine synthetase (GS) was shown to increase its activity in all species, while that of nitrate reductase (NR) was inhibited, at least in those species which possessed the ability to induce foliar NR. At the same time there were marked changes in organic anion concentrations, with malate and citrate in particular being reduced in concentration, following either NH +4 or NH 3 application to leaves. The changes in organic anions are also discussed in the light of pH regulation by the cell. A stimulation of photosynthesis was also evident when leaves were treated with either NH 3 or NH +4. It is argued that, because of the differences in solution chemistry of the two ammonia forms, the aqueous form applied at pH 5 and the gaseous form being an alkali in solution, these changes can only have occurred through the ability of the leaves to readily assimilate both forms of the ammonia. The biochemical changes might have potential as markers for the onset of physiological perturbation by atmospheric ammonia pollution, particularly changes in organic acid concentration; their use in an index of pollution stress is briefly discussed.

  2. Environmental Nanoparticles Interactions with Plants: Morphological, Physiological, and Genotoxic Aspects

    Directory of Open Access Journals (Sweden)

    C. Remédios

    2012-01-01

    Full Text Available Nanoparticles (NPs are characterized by their small size (less than 100 nm and large surface area, which confer specific physicochemical properties as strength, electrical, and optical features. NPs can be derived from natural or anthropic sources, such as engineered or unwanted/incidental NPs. The composition, dimension, and morphology of engineered NPs enable their use in a variety of areas, such as electronic, biomedical, pharmaceutical, cosmetic, energy, environmental, catalysis, and materials science. As nanotechnology is an innovative and scientific growth area with an exponential production, more information is needed concerning the impacts of these nanomaterials (NMs in the environment and, particularly, in animals/humans health and in plants performance. So, research on NPs as emerging contaminants is therefore a new field in environmental health. This minireview describes, briefly, the NPs characterization and their occurrence in the environment stating air, water, and soil. Finally, particular emphasis is given to the interaction of NPs with plants at different levels: morphology, physiology, and genotoxicity. By analyzing this compiled information, it is evident that research on NPs phytotoxicity is in the beginning, and more comprehensive studies are needed not only on NPs cytotoxicity and genotoxicity but also on the best and the most reliable methods of assessing NPs toxicity.

  3. 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.

  4. 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)

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

    Directory of Open Access Journals (Sweden)

    Richard eStrasser

    2014-07-01

    Full Text Available 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 beta1,2-xylose, core alpha1,3-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 signalling events. By 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.

  6. Regulation by arbuscular mycorrhizae of the integrated physiological response to salinity in plants: new challenges in physiological and molecular studies.

    Science.gov (United States)

    Ruiz-Lozano, Juan Manuel; Porcel, Rosa; Azcón, Charo; Aroca, Ricardo

    2012-06-01

    Excessive salt accumulation in soils is a major ecological and agronomical problem, in particular in arid and semi-arid areas. Excessive soil salinity affects the establishment, development, and growth of plants, resulting in important losses in productivity. Plants have evolved biochemical and molecular mechanisms that may act in a concerted manner and constitute the integrated physiological response to soil salinity. These include the synthesis and accumulation of compatible solutes to avoid cell dehydration and maintain root water uptake, the regulation of ion homeostasis to control ion uptake by roots, compartmentation and transport into shoots, the fine regulation of water uptake and distribution to plant tissues by the action of aquaporins, the reduction of oxidative damage through improved antioxidant capacity and the maintenance of photosynthesis at values adequate for plant growth. Arbuscular mycorrhizal (AM) symbiosis can help the host plants to cope with the detrimental effects of high soil salinity. There is evidence that AM symbiosis affects and regulates several of the above mentioned mechanisms, but the molecular bases of such effects are almost completely unknown. This review summarizes current knowledge about the effects of AM symbiosis on these physiological mechanisms, emphasizing new perspectives and challenges in physiological and molecular studies on salt-stress alleviation by AM symbiosis.

  7. Dewpoint - unstudied factor in ecology, physiology and plant introduction

    Directory of Open Access Journals (Sweden)

    Prokhorov Alexey

    2015-12-01

    Study of the mechanism of the condensation of atmospheric moisture on the surface of the plant and allow for modification of plant breeding with pronounced effect and reduce the temperature dependence on the least insolation. Such plants could be beneficial in reducing costs for irrigation of crops, and in the fight against desertification. The study of the mechanism of the phenomenon, allow for modification and selection of plants with the most pronounced effect of lowering the temperature and the lowest dependent on insolation. The plants, which are more efficient moisture capacitors can bring huge benefits in reducing costs for irrigation of crops, and in the fight against desertification.

  8. Impact of genomics approaches on plant genetics and physiology.

    Science.gov (United States)

    Tabata, Satoshi

    2002-08-01

    Comprehensive analysis of genetic information in higher plants is under way for several plants of biological and agronomical importance. Among them, Arabidopsis thaliana, a member of Brassica family, and Oryza sativa(rice) have been chosen as model plants most suitable for genome analysis. Sequencing of the genome of A. thaliana was completed in December 2000, and rice genome sequencing is in progress. The accumulated genome sequences, together with the hundreds of thousands of ESTs from several tens of plant species, have drastically changed the strategy of plant genetics. By utilizing the information on the genome and gene structures, comprehensive approaches for genome-wide functional analysis of the genes, including transcriptome analysis using microarray systems and a comprehensive analysis of a large number of insertion mutant lines, have been widely adopted. As a consequence, a large quantity of information on both the structure and function of genes in these model plants has been accumulated. However, other plant species may have their own characteristics and advantages to study individual phenomena. Application of knowledge from the model plants to other plant species and vice versa through the common language, namely the genome information, should facilitate understanding of the genetic systems underlying a variety of biological phenomena. Introduction of this common language may not be very simple, especially in the case of complex pathways such as a process of cell-covering formation. Nevertheless, it should be emphasized that genomics approaches are the most promising way to understand these processes.

  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...

  10. 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

  11. Physiology

    Science.gov (United States)

    Kay, Ian

    2008-01-01

    Underlying recent developments in health care and new treatments for disease are advances in basic medical sciences. This edition of "Webwatch" focuses on sites dealing with basic medical sciences, with particular attention given to physiology. There is a vast amount of information on the web related to physiology. The sites that are included here…

  12. Air and the origin of the experimental plant physiology.

    Science.gov (United States)

    Pennazio, Sergio

    2005-01-01

    It is well known that oxygen and carbon dioxide are two chemicals which enter the plant metabolism as nutrients. The bases of this nowadays obvious statement were placed in the 18th century by means of the works of ingenious naturalists such as Robert Boyle, Stephen Hales, Joseph Priestley, Jam Ingenhousz, Lazzaro Spallanzani and Theodore De Saussure. Till the end of the 17th century, the atmospheric air was considered as an ineffable spirit, the function of which was of physical nature. Boyle was the first naturalist to admit the possibility that respiration were an exchange of vapours occurring in the blood. Stephen Hales realised that air could be fixed by plants under the influence of solar light. Priestley showed that plants could regenerate the bad air making it breathable. Ingenhousz demonstrated that the green parts of plants performed the complete purification of air only under the influence of the light. Spallanzani discovered that plants respire and guessed that the good air (oxygen) originated from the fixed air (carbon dioxide). Finally, Theodore De Saussure showed that plants were able to adsorb carbon dioxide and to release oxygen in a proportional air. All these discoveries benefited of the results coming from investigations of scholars of the so-called "pneumatic chemistry" (Boyle himself, George Ernst Stahl, Joseph Black, Priestley himself, and many more others. But among all the eminent scientists above mentioned stands out the genius of Antoine Laurent Lavoisier, who revolutionised the chemistry of the 18th century ferrying it towards the modern chemistry.

  13. 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.

  14. Physiological, biochemical, and molecular mechanisms of heat stress tolerance in plants.

    Science.gov (United States)

    Hasanuzzaman, Mirza; Nahar, Kamrun; Alam, Md Mahabub; Roychowdhury, Rajib; Fujita, Masayuki

    2013-05-03

    High temperature (HT) stress is a major environmental stress that limits plant growth, metabolism, and productivity worldwide. Plant growth and development involve numerous biochemical reactions that are sensitive to temperature. Plant responses to HT vary with the degree and duration of HT and the plant type. HT is now a major concern for crop production and approaches for sustaining high yields of crop plants under HT stress are important agricultural goals. Plants possess a number of adaptive, avoidance, or acclimation mechanisms to cope with HT situations. In addition, major tolerance mechanisms that employ ion transporters, proteins, osmoprotectants, antioxidants, and other factors involved in signaling cascades and transcriptional control are activated to offset stress-induced biochemical and physiological alterations. Plant survival under HT stress depends on the ability to perceive the HT stimulus, generate and transmit the signal, and initiate appropriate physiological and biochemical changes. HT-induced gene expression and metabolite synthesis also substantially improve tolerance. The physiological and biochemical responses to heat stress are active research areas, and the molecular approaches are being adopted for developing HT tolerance in plants. This article reviews the recent findings on responses, adaptation, and tolerance to HT at the cellular, organellar, and whole plant levels and describes various approaches being taken to enhance thermotolerance in plants.

  15. 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...... 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...... 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...

  16. Influence of plant architecture on maize physiology and yield in the Heilonggang River valley

    Directory of Open Access Journals (Sweden)

    Shoubing Huang

    2017-02-01

    Full Text Available The size and distribution of leaf area determine light interception in a crop canopy and influence overall photosynthesis and yield. Optimized plant architecture renders modern maize hybrids (Zea mays L. more productive, owing to their tolerance of high plant densities. To determine physiological and yield response to maize plant architecture, a field experiment was conducted in 2010 and 2011. With the modern maize hybrid ZD958, three plant architectures, namely triangle, diamond and original plants, were included at two plant densities, 60,000 and 90,000 plants ha−1. Triangle and diamond plants were derived from the original plant by spraying the chemical regulator Jindele (active ingredients, ethephon, and cycocel at different vegetative stages. To assess the effects of plant architecture, a light interception model was developed. Plant height, ear height, leaf size, and leaf orientation of the two regulated plant architectures were significantly reduced or altered compared with those of the original plants. On average across both plant densities and years, the original plants showed higher yield than the triangle and diamond plants, probably because of larger leaf area. The two-year mean grain yield of the original and diamond plants were almost the same at 90,000 plants ha−1 (8714 vs. 8798 kg ha−1. The yield increase (up to 5% of the diamonds plant at high plant densities was a result of increased kernel number per ear, which was likely a consequence of improved plant architecture in the top and middle canopy layers. The optimized light distribution within the canopy can delay leaf senescence, especially for triangle plants. The fraction of incident radiation simulated by the interception model successfully reflected plant architecture traits. Integration of canopy openness is expected to increase the simulation accuracy of the present model. Maize plant architecture with increased tolerance of high densities is probably

  17. 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.

  18. Paddy plants inoculated with PGPR show better growth physiology and nutrient content under saline condition

    Directory of Open Access Journals (Sweden)

    Yachana Jha

    2013-09-01

    Full Text Available The possible role of plant growth-promoting rhizobacteria (PGPR to alleviate salt stress during plant growth has been studied on paddy rice (Oryza sativa L. 'GJ-17' under greenhouse conditions; the study included growth parameters, mineral concentration, and antioxidant enzyme level. Salinity reduced plant growth, but PGPR inoculation reduced its harmful effect up to 1% salinity. Plants inoculated with PGPR under saline conditions showed 16% higher germination, 8% higher survival, 27% higher dry weight, and 31% higher plant height. Similarly, PGPR inoculated plants showed increased concentrations of N(26%, P (16%, K (31%, and reduced concentrations of Na (71% and Ca (36% as compared to non-inoculated control plants under saline conditions. Plants inoculated with PGPR under saline conditions also showed significant variations in antioxidant levels and growth physiology. Results suggested that inoculation with PGPR Bacillus pumilus and Pseudomonas pseudoalcaligenes in salt-stressed plants could help to alleviate salt stress in the paddy.

  19. Development of a portable multi-channel system for plant physiological signal recording

    Directory of Open Access Journals (Sweden)

    Ting Li

    2016-06-01

    Full Text Available Bioelectrical signals can reflect physiological state of organs or tissues in plants and have a significant potential value in research of plant stress tolerance. In order to study the relationship between environment factors and electrical signals in plant, a portable multi-channel physiological signal acquisition system which relevant in plant physiology research was developed. Environment parameters and electrical signals can be measured in different channels by the acquisition system simultaneously and the measurement data will be displayed in an embedded integrated touch screen which is the system processing core. The system was validated to be stable and reliable after the calibration and repeated experiments of recording electrical signals in Helianthus annuus L.

  20. Molecular and physiological mechanisms of plant tolerance to toxic metals

    Science.gov (United States)

    Plants have evolved a myriad of adaptive mechanisms based on a number of genes to deal with the different toxic metals they encounter in the soils worldwide. These genes encode a range of different metal and organic compound transporters and enzyme pathways for the synthesis of metal detoxifying lig...

  1. [Relationships between light and physiological characters of five climbing plants].

    Science.gov (United States)

    Huang, Chenglin; Fu, Songling; Liang, Shuyun; Ji, Yifan

    2004-07-01

    Studies on the photosynthetic and respiratory rates, light utilization efficiencies and light compensations of five climbing plants showed that the diurnal variations of photosynthetic rates presented double peak, the first peak was between 10:00 to 12:00, and the second was between 14:00 to 16:00. The phenomenon of "noon break" was obvious. The diurnal variations of respiration rates also presented double peak, the first peak was between 11:00 to 13:00, and the second was between 14:00 to 17:00. The light compensation point of Hedera nepatensis, H. helix, Parthenocissus tricuspidata, P. quinuefolia and Wisteria sinensis was 5.73, 5.07, 9.96, 6.40 and 18.93 micromol x m(-2) x s(-1), respectively, and the light utilization efficiency of W. sinensis was higher under strong light, P. quinuefolia was the second, but that of H. helix was higher under weak light. The results showed that Wisteria sinensis was a typical heliophytic plant, Parthenocissus tricuspidata and P. quinuefolia were neuter plants, and Hedera nepalensis and H. helix were typical sciophytic plants.

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

    Energy Technology Data Exchange (ETDEWEB)

    Heven Sze

    2008-06-22

    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

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

    Energy Technology Data Exchange (ETDEWEB)

    Heven Sze

    2008-06-22

    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

  4. 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.

  5. Physiological Response of Plants Grown on Porous Ceramic Tubes

    Science.gov (United States)

    Tsao, David; Okos, Martin

    1997-01-01

    This research involves the manipulation of the root-zone water potential for the purposes of discriminating the rate limiting step in the inorganic nutrient uptake mechanism utilized by higher plants. This reaction sequence includes the pathways controlled by the root-zone conditions such as water tension and gradient concentrations. Furthermore, plant based control mechanisms dictated by various protein productions are differentiated as well. For the nutrients limited by the environmental availability, the kinetics were modeled using convection and diffusion equations. Alternatively, for the nutrients dependent upon enzyme manipulations, the uptakes are modeled using Michaelis-Menten kinetics. In order to differentiate between these various mechanistic steps, an experimental apparatus known as the Porous Ceramic Tube - Nutrient Delivery System (PCT-NDS) was used. Manipulation of the applied suction pressure circulating a nutrient solution through this system imposes a change in the matric component of the water potential. This compensates for the different osmotic components of water potential dictated by nutrient concentration. By maintaining this control over the root-zone conditions, the rate limiting steps in the uptake of the essential nutrients into tomato plants (Lycopersicon esculentum cv. Cherry Elite) were differentiated. Results showed that the uptake of some nutrients were mass transfer limited while others were limited by the enzyme kinetics. Each of these were adequately modeled with calculations and discussions of the parameter estimations provided.

  6. Polyploidy in aspen alters plant physiology and drought sensitivity

    Science.gov (United States)

    Greer, B.; Still, C. J.; Brooks, J. R.; Meinzer, F. C.

    2015-12-01

    Polyploids of quaking aspen (Populus tremuloides) may be better suited to dry climatic conditions than diploids. However, the expression of diploid and polyploid functional traits, including water use efficiency, an important component of drought avoidance and tolerance, are not well understood in quaking aspen. In this study diploid and triploid aspen clones' leaf, ramet, and stand functional traits were measured near the Rocky Mountain Biological Laboratory in Gothic, Colorado. The physiology of diploid and triploid aspen, including leaf size, chlorophyll content, stomatal size and density and stomatal conductance, as well as growth rates and carbon isotope discrimination in response to climate (measured in tree rings), were found to be significantly different between ploidy levels. These findings demonstrate different sensitivities of diploid and triploid clones to drought related climate stressors which may impact strategies for aspen forest management and conservation.

  7. Century long assessment of herbaceous plants' physiological responses to climate change in Switzerland

    Science.gov (United States)

    Moreno-Gutierrez, Cristina; Kahmen, Ansgar

    2017-04-01

    The isotopic analysis of archived plant material offers the exceptional opportunity to reconstruct the physiological activity of plants over long time periods and thus, to assess plant responses to environmental changes during the last centuries. In addition, the stable isotope analysis of herbarium samples offers the opportunity to reconstruct the physiological processes of a large range of different plant species and from different environments. Interestingly, only few studies have to date assessed these archives. We will present a novel analysis of leaf nitrogen, oxygen and carbon isotope ratios of more than a thousand herbarium specimens collected since 1800 until present from the unique herbaria hold at the University of Basel. The objective of our study was to assess century-long physiological responses of herbaceous plant species from different plant functional groups and along an altitudinal gradient in Switzerland. The goal of our study was to determine with our investigations the long-term responses of plants to climate change. Such investigations are important as they allow to assess long-term processes of acclimation and adaptation in plants to global enviromental change. In our study we found that herbaceous plants have increased their intrinsic water use efficiency in response to increasing atmospheric CO2 concentration but this increment was higher in plants from higher altitudes, due to the higher efficiency of CO2 assimilation of alpine plants compared to plants from lowlands. There were also differences among functional groups, with grasses and forbs showing the highest increments. In addition, herbaceous plants showed a decreasing trend with time in their N isotopic composition, which may indicate progressive N limitation due to higher biological activity with increasing atmospheric CO2 concentration.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. Study on Effect of Plants in office on Human Physiological/Psychological Responses

    OpenAIRE

    2016-01-01

    Some offices have indoor environmental quality (IEQ) related problems such as space, indoor air quality (IAQ), office workers' thermal comfort, productivity and mental stress. As is well known, some foliage plants have effects of humidity control and VOC removal from indoor air, improvement of productivity and reducing workers' mental stress as well. The objective of this study is to examine the effect of indoor plants on physiological/psychological responses, and to demonstrate the mental he...

  14. 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

  15. The Effects of Salt Stress on Certain Physiological Parameters in Summer Savory (Satureja hortensis L. Plants

    Directory of Open Access Journals (Sweden)

    F.Najafi

    2010-04-01

    Full Text Available Savory plants were treated with different concentrations of NaCl. Plants were grown under controlled environment and harvested after 42 days for measurements of biochemical and physiological parameters. The essential oil of dryed aerial parts of treated plants were isolated and analyzed with GC/MS. The main essential oil compounds were determined as carvacrol (55.37% and g-terpinene (32.92% in control plants. In NaCl treated plants, with increasing NaCl, carvacrol content increased and g-terpinene decreased. In all the plants treated with NaCl, growth parameters, pigments contents and photosynthetic rate were decreased, while, proline and soluble sugars contents increased.Our results indicated that with increasing salinity, carvacrol amount increased which can be considered for medical usages.

  16. Plant physiological, morphological and yield-related responses to night temperature changes across different species and plant functional types

    Directory of Open Access Journals (Sweden)

    Panpan Jing

    2016-11-01

    Full Text Available Land surface temperature over the past decades has shown a faster warming trend during the night than during the day. Extremely low night temperatures have occurred frequently due to the influence of land-sea thermal difference, topography and climate change. This asymmetric night temperature change is expected to affect plant ecophysiology and growth, as the plant carbon consumption processes could be affected more than the assimilation processes because photosynthesis in most plants occurs during the daytime whereas plant respiration occurs throughout the day. The effects of high night temperature (HNT and low night temperature (LNT on plant ecophysiological and growing processes and how the effects vary among different plant functional types (PFTs have not been analyzed extensively. In this meta-analysis, we examined the effect of HNT and LNT on plant physiology and growth across different PFTs and experimental settings. Plant species were grouped according to their photosynthetic pathways (C3, C4 and CAM, growth forms (herbaceous, woody, and economic purposes (crop, non-crop. We found that HNT and LNT both had a negative effect on plant yield, but the effect of HNT on plant yield was primarily related to a reduction in biomass allocation to reproduction organs and the effect of LNT on plant yield was more related to a negative effect on total biomass. Leaf growth was stimulated at HNT and suppressed at LNT. HNT accelerated plants ecophysiological processes, including photosynthesis and dark respiration, while LNT slowed these processes. Overall, the results showed that the effects of night temperature on plant physiology and growth varied between HNT and LNT, among the response variables and PFTs, and depended on the magnitude of temperature change and experimental design. These findings suggest complexities and challenges in seeking general patterns of terrestrial plant growth in HNT and LNT. The PFT specific responses of plants are

  17. 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

  18. Photosynthetic, Physiological and Biochemical Responses of Tomato Plants to Polyethylene Glycol-Induced Water Deficit

    Institute of Scientific and Technical Information of China (English)

    Hatem ZGALLA(I); Kathy STEPPE; Raoul LEMEUR

    2005-01-01

    Polyethylene glycol (PEG 6000)-induced water deficit causes physiological as well as biochemical changes in plants. The present study reports on the results of such changes in hydroponically grown tomato plants (Lycopersicon esculentum Mill. cv. Nikita). Plants were subjected to moderate and severe levels of water stress (i.e. water potentials in the nutrient solution of-0.51 and -1.22 MPa, respectively).Water stress markedly affected the parameters of gas exchange. Net photosynthetic rate (Pn) decreased with the induction of water stress. Accordingly, a decrease in the transpiration rate (E) was observed. The ratio of both (Pn/E) resulted in a decrease in water use efficiency. One of the possible reasons for the reduction in Pn is structural damage to the thylakoids, which affects the photosynthetic transport of electrons. This was indicated by an increase in non-photochemical quenching and a reduction in the quantum yield of photosystem Ⅱ. Furthermore, a decrease in both leaf water potential and leaf osmotic potential was observed, which resulted in a significant osmotic adjustment during stress conditions. Analysis of the physiological responses was complemented with a study on changes in proline content. In stressed plants, a 10-fold increase in proline content was detected compared with control plants. It is clear that water stress tolerance is the result of a cumulative action of various physiological and biochemical processes, all of which were affected by PEG 6000-induced water stress.

  19. Detecting plant metabolic responses induced by ground shock using hyperspectral remote sensing and physiological contact measurements

    Energy Technology Data Exchange (ETDEWEB)

    Pickles, W.L.; Cater, G.A.

    1996-12-03

    A series of field experiments were done to determine if ground shock could have induced physiological responses in plants and if the level of the response could be observed. The observation techniques were remote sensing techniques and direct contact physiological measurements developed by Carter for detecting pre-visual plant stress. The remote sensing technique was similar to that used by Pickles to detect what appeared to be ground shock induced plant stress above the 1993 Non Proliferation Experiment`s underground chemical explosion. The experiment was designed to provide direct plant physiological measurements and remote sensing ratio images and from the same plants at the same time. The simultaneous direct and remote sensing measurements were done to establish a ground truth dataset to compare to the results of the hyperspectral remote sensing measurements. In addition, the experiment was designed to include data on what was thought to be the most probable interfering effect, dehydration. The experimental design included investigating the relative magnitude of the shock induced stress effects compared to dehydration effects.

  20. 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.

  1. The effect of differential growth rates across plants on spectral predictions of physiological parameters.

    Directory of Open Access Journals (Sweden)

    Tal Rapaport

    Full Text Available Leaves of various ages and positions in a plant's canopy can present distinct physiological, morphological and anatomical characteristics, leading to complexities in selecting a single leaf for spectral representation of an entire plant. A fortiori, as growth rates between canopies differ, spectral-based comparisons across multiple plants--often based on leaves' position but not age--becomes an even more challenging mission. This study explores the effect of differential growth rates on the reflectance variability between leaves of different canopies, and its implication on physiological predictions made by widely-used spectral indices. Two distinct irrigation treatments were applied for one month, in order to trigger the formation of different growth rates between two groups of grapevines. Throughout the experiment, the plants were physiologically and morphologically monitored, while leaves from every part of their canopies were spectrally and histologically sampled. As the control vines were constantly developing new leaves, the water deficit plants were experiencing growth inhibition, resulting in leaves of different age at similar nodal position across the treatments. This modification of the age-position correlation was characterized by a near infrared reflectance difference between younger and older leaves, which was found to be exponentially correlated (R(2 = 0.98 to the age-dependent area of intercellular air spaces within the spongy parenchyma. Overall, the foliage of the control plant became more spectrally variable, creating complications for intra- and inter-treatment leaf-based comparisons. Of the derived indices, the Structure-Insensitive Pigment Index (SIPI was found indifferent to the age-position effect, allowing the treatments to be compared at any nodal position, while a Normalized Difference Vegetation Index (NDVI-based stomatal conductance prediction was substantially affected by differential growth rates. As various

  2. Ecosystem services and plant physiological status during endophyte-assisted phytoremediation of metal contaminated soil.

    Science.gov (United States)

    Burges, Aritz; Epelde, Lur; Blanco, Fernando; Becerril, José M; Garbisu, Carlos

    2017-04-15

    Mining sites shelter a characteristic biodiversity with large potential for the phytoremediation of metal contaminated soils. Endophytic plant growth-promoting bacteria were isolated from two metal-(hyper)accumulator plant species growing in a metal contaminated mine soil. After characterizing their plant growth-promoting traits, consortia of putative endophytes were used to carry out an endophyte-assisted phytoextraction experiment using Noccaea caerulescens and Rumex acetosa (singly and in combination) under controlled conditions. We evaluated the influence of endophyte-inoculated plants on soil physicochemical and microbial properties, as well as plant physiological parameters and metal concentrations. Data interpretation through the grouping of soil properties within a set of ecosystem services was also carried out. When grown together, we observed a 41 and 16% increase in the growth of N. caerulescens and R. acetosa plants, respectively, as well as higher values of Zn phytoextraction and soil microbial biomass and functional diversity. Inoculation of the consortia of putative endophytes did not lead to higher values of plant metal uptake, but it improved the plants' physiological status, by increasing the content of chlorophylls and carotenoids by up to 28 and 36%, respectively, indicating a reduction in the stress level of plants. Endophyte-inoculation also stimulated soil microbial communities: higher values of acid phosphatase activity (related to the phosphate solubilising traits of the endophytes), bacterial and fungal abundance, and structural diversity. The positive effects of plant growth and endophyte inoculation on soil properties were reflected in an enhancement of some ecosystem services (biodiversity, nutrient cycling, water flow regulation, water purification and contamination control).

  3. 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.

  4. 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).

  5. 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.

  6. 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.

  7. 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

  8. Changes in morpho-physiological attributes of Eucalyptus globulus plants in response to different drought hardening treatments

    OpenAIRE

    Coopman, Rafael E.; Jara,Jorge C; Bravo,Leon A; Sáez,Katia L; Mella,Gloria R; Escobar,Rene

    2008-01-01

    Morpho-physiological attributes exhibited in response to drought hardening at the end of the growing season of Eucalyptus globulus Labill under nursery conditions were studied to evaluate the effect of three drought hardening treatments in morpho-physiological traits used as suitable indicators of drought hardiness, such as, plant growth, root growth potential, plant water relationships and survival. Freezing resistance of drought hardened plants was also studied in order to evaluate cross ha...

  9. Some Physiological Processes Related to Water Use Efficiency of Higher Plants

    Institute of Scientific and Technical Information of China (English)

    GUO Shi-wei; ZHOU Yi; SONG Na; SHEN Qi-rong

    2006-01-01

    Water use efficiency (WUE) of higher plants is of vital importance in the dry-land agricultural ecosystem in terms of the development of water-saving agriculture. Of all the approaches used to improve WUE, the intrinsic water use efficiency (WUET, the ratio of CO2 assimilation rate to transpiration rate) can be a right index, as the variation of WUET is correlated with the physiological and biochemical processes of higher plants. The measurements of leaf gas exchange and carbon isotope discrimination (D13C) are the two ways to detect the variation in WUET. This article reviewed some physiological processes related to WUET, including the relationship between CO2 assimilation and stomatal conductance and WUEr and water absorption. The relationship between WUE and aquaporin and the yield are discussed as well.

  10. Morphological, physiological and plant infectivity characterization of Frankia strains isolated from Casuarina’s nodules

    OpenAIRE

    Patrick Moritz; Kelly Campos Guerra P. de Goes; Souza,José Roberto P de; Letícia Trindade Ataíde; Diva Souza Andrade

    2007-01-01

    Frankia are soil microorganisms that form symbiosis with roots of tree species called actinorhizal plants and are capable of fixing atmospheric N2. This study was carried out to characterize morphologically, physiologically and to assess the nodulation of four Frankia reference strains (HFPCcI3, JCT287, KB5 and F59) and 12 (IPRF) isolated from root nodules of Casuarina plants. All strains (Reference and IPRF) were characterized as Gram-positive and 50% as acid-fast. The Frankia strains produc...

  11. Emerging technologies for non-invasive quantification of physiological oxygen transport in plants.

    Science.gov (United States)

    Chaturvedi, P; Taguchi, M; Burrs, S L; Hauser, B A; Salim, W W A W; Claussen, J C; McLamore, E S

    2013-09-01

    Oxygen plays a critical role in plant metabolism, stress response/signaling, and adaptation to environmental changes (Lambers and Colmer, Plant Soil 274:7-15, 2005; Pitzschke et al., Antioxid Redox Signal 8:1757-1764, 2006; Van Breusegem et al., Plant Sci 161:405-414, 2001). Reactive oxygen species (ROS), by-products of various metabolic pathways in which oxygen is a key molecule, are produced during adaptation responses to environmental stress. While much is known about plant adaptation to stress (e.g., detoxifying enzymes, antioxidant production), the link between ROS metabolism, O2 transport, and stress response mechanisms is unknown. Thus, non-invasive technologies for measuring O2 are critical for understanding the link between physiological O2 transport and ROS signaling. New non-invasive technologies allow real-time measurement of O2 at the single cell and even organelle levels. This review briefly summarizes currently available (i.e., mainstream) technologies for measuring O2 and then introduces emerging technologies for measuring O2. Advanced techniques that provide the ability to non-invasively (i.e., non-destructively) measure O2 are highlighted. In the near future, these non-invasive sensors will facilitate novel experimentation that will allow plant physiologists to ask new hypothesis-driven research questions aimed at improving our understanding of physiological O2 transport.

  12. 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.

  13. Physiological and growth response of rice plants (Oryza sativa L.) to Trichoderma spp. inoculants.

    Science.gov (United States)

    Doni, Febri; Isahak, Anizan; Che Mohd Zain, Che Radziah; Wan Yusoff, Wan Mohtar

    2014-01-01

    Trichoderma spp., a known beneficial fungus is reported to have several mechanisms to enhance plant growth. In this study, the effectiveness of seven isolates of Trichoderma spp. to promote growth and increase physiological performance in rice was evaluated experimentally using completely randomized design under greenhouse condition. This study indicated that all the Trichoderma spp. isolates tested were able to increase several rice physiological processes which include net photosynthetic rate, stomatal conductance, transpiration, internal CO2 concentration and water use efficiency. These Trichoderma spp. isolates were also able to enhance rice growth components including plant height, leaf number, tiller number, root length and root fresh weight. Among the Trichoderma spp. isolates, Trichoderma sp. SL2 inoculated rice plants exhibited greater net photosynthetic rate (8.66 μmolCO2 m(-2) s(-1)), internal CO2 concentration (336.97 ppm), water use efficiency (1.15 μmoCO2/mmoH2O), plant height (70.47 cm), tiller number (12), root length (22.5 cm) and root fresh weight (15.21 g) compared to the plants treated with other Trichoderma isolates tested. We conclude that beneficial fungi can be used as a potential growth promoting agent in rice cultivation.

  14. 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.

  15. 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.

  16. 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.

  17. A few aspects of the physiology of flowering in photoperiodic sensitive plants

    Directory of Open Access Journals (Sweden)

    E. G. Groenewald

    2003-09-01

    Full Text Available Three aspects of the physiology of flowering in photoperiodic sensitive plants are discussed. These are the florigen hypothesis, phytochrome and the time measurement mechanism of flowering and genetic-molecular studies involved in flowering. There is evidence that the hypothetical compound, florigen, occurs in plants, but it has never been characterised. There is a family of phytochromes discovered in plants and some of them are involved with the circadian clock and thus with the time measurement mechanism of flowering. The molecular networks that interact to control flowering are being elucidated, by means of genetic-molecular techniques although at an early stage. It has not yet been possible to pinpoint florigen by these methods, but the future looks promising.

  18. 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.

  19. 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

    2015-08-03

    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.

  20. Physiological highlights of manganese toxicity symptoms in soybean plants: Mn toxicity responses.

    Science.gov (United States)

    Santos, Elcio Ferreira; Kondo Santini, José Mateus; Paixão, Amanda Pereira; Júnior, Enes Furlani; Lavres, José; Campos, Marcelo; Reis, André Rodrigues Dos

    2017-04-01

    Manganese (Mn) is an essential element for plants; however, high concentrations in certain soil conditions can cause toxicity symptoms in the plant tissue. Here, we describe Mn toxicity symptoms and Mn toxicity responses in soybean plants. Soybean plants exposed to excess Mn showed reductions in the CO2 assimilation rate and stomatal conductance, which in turn resulted in decreased shoot biomass. Furthermore, peroxidase (POD), superoxide dismutase (SOD), and catalase (CAT) activity were higher in plants grown with the highest Mn concentration. The Mn doses increased the activity of antioxidant enzymes such as CAT, POD, and SOD. The toxicity symptoms presented by the leaves included hypertrophying of the adaxial epidermis and the formation of necrotic areas with purple-colored veins. Dramatic movement of calcium from the healthy region to the purple-colored necrotic region was observed, as was the exit of potassium from the necrotic area to the healthy region of the tissue. The high activities of POD and SOD in the presence of high Mn compartmented in the roots was the main physiological responses at high Mn uptake by soybean plants. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  1. 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.

  2. Drought tolerance acquisition in Eucalyptus globulus (Labill.): a research on plant morphology, physiology and proteomics.

    Science.gov (United States)

    Valdés, Ana Elisa; Irar, Sami; Majada, Juan P; Rodríguez, Ana; Fernández, Belén; Pagès, Montserrat

    2013-02-21

    Plants perceiving drought stress activate multiple responses to synchronise developmental and molecular activities aimed at improving survival. In this study we attained a multidisciplinary approach to examine the interplay among plant morphology, physiology and proteomics for understanding the mechanisms underlying the adaptive response to drought stress. The stress-related phenotype, the differential expression of putative members of the LEA family of proteins, the seed proteomic profile, and the endogenous content of free and conjugated abscisic acid (ABA and ABAGE) were analysed in two Eucalyptus globulus provenances with contrasting drought tolerance. Differences in morphology were noticeable, drought-tolerant genotypes displaying smaller seeds with higher desiccation in the mature state and a more developed root system that was not reduced under water stress treatments. From physiological and molecular points of view, the endogenous contents of ABA and ABAGE were also higher in the tolerant provenance, as well as the accumulation of proteins involved in abiotic stress tolerance processes. In addition, evidence of two immunologically-related proteins to the maize RAB17 and RAB28 proteins is first reported in Eucalyptus, showing similarities between species. Our results show that E. globulus displays simultaneous adjustments for acquiring drought tolerance that are expressed at physiological, developmental and molecular levels.

  3. 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.

  4. 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.

  5. 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.

  6. Root growth, mycorrhization and physiological effects of plants growing on oil tailing sands

    Science.gov (United States)

    Boldt-Burisch, Katja M.; Naeth, Anne M.; Schneider, Bernd Uwe; Hüttl, Reinhard F.

    2015-04-01

    Surface mining creates large, intense disturbances of soils and produces large volumes of by-products and waste materials. After mining processes these materials often provide the basis for land reclamation and ecosystem restoration. In the present study, tailing sands (TS) and processed mature fine tailings (pMFT) from Fort McMurray (Alberta, Canada) were used. They represent challenging material for ecosystem rebuilding because of very low nutrient contents of TS and oil residuals, high density of MFT material. In this context, little is known about the interactions of pure TS, respectively mixtures of TS and MFT and root growth, mycorrhization and plant physiological effects. Four herbaceous plant species (Elymus trachycaulus, Koeleria macrantha, Deschampsia cespitosa, Lotus corniculatus) were chosen to investigate root development, chlorophyll fluorescence and mycorrhization intensity with and without application of Glomus mosseae (arbuscular mycorrhizae) on mainly tailing sands. Surprisingly both, plants growing on pure TS and plants growing on TS with additional AM-application showed mycorrhization of roots. In general, the mycorrhization intensity was lower for plants growing on pure tailings sands, but it is an interesting fact that there is a potential for mycorrhization available in tailing sands. The mycorrhizal intensity strongly increased with application of G. mosseae for K. macrantha and L. corniculatus and even more for E. trachycaulus. For D. cespitosa similar high mycorrhiza infection frequency was found for both variants, with and without AM-application. By the application of G. mosseae, root growth of E. trachycaulus and K. macrantha was significantly positively influenced. Analysis of leaf chlorophyll fluorescence showed no significant differences for E. trachycaulus but significant positive influence of mycorrhizal application on the physiological status of L. corniculatus. However, this effect could not be detected when TS was mixed with MFT

  7. Physiological and biochemical action of SO/sub 2/ on plants

    Energy Technology Data Exchange (ETDEWEB)

    Jaeger, H.J.

    1977-06-10

    Needles of spruce and pea plants, exposed to SO/sub 2/, were investigated for their amount of free amino acids. Under the influence of SO/sub 2/, the plants tested synthesize increased amounts of glutamate which stimulates the formation of glutamine and other amino acids of the glutamate family. The enhanced formation of acidic amides may be a N-detoxification process. In spruce needles there is an obvious increase of the amount of the phenolic amino acid tyrosine. The total contents of the free amino acids investigated increased in both the SO/sub 2/-polluted plants. The activities of glutamate dehydrogenase (reductive amination) and glutamine synthetase are stimulated in SO/sub 2/-polluted plants, whereas the glutamic-oxaloacetic- and the glutamic-pyruvate-transaminase are inactivated. The mode of the stimulation of the glutamate dehydrogenase in SO/sub 2/-polluted plants is described. The physiological consequences of the alteration of the composition of the free amino acids are discussed. 17 references, 3 tables.

  8. Effects of foliage plants on human physiological and psychological responses at different temperatures

    Science.gov (United States)

    Jumeno, Desto; Matsumoto, Hiroshi

    2015-02-01

    Escalation of task demands and time pressures tends to make a worker run into work stress, which leads to mental fatigue and depression. The mental fatigue can be reduced when attention capacity is restored. Nature can serve as a source of fascination which can restore the attention capacity. People bring plants indoors so they can experience nature in their workplace. The stress and fatigue are also affected by air temperatures. The increase or decrease of temperatures from the comfort zone may induce the stress and fatigue. The objective of this study is to investigate the intervention of using foliage plants placed inside a building at different air temperature levels. The effects of foliage plants on human stress and fatigue were measured by human physiological responses such as heart rate, amylase level, electroencephalography (EEG), and the secondary task-reaction time. Several different tasks, namely typing, math and logical sequences are included in the investigation of these studies. Fifteen subjects, with the age ranged from 22 to 38 years old have participated in the study using within subject design. From the study, it is revealed that the presence of foliage plants at several temperatures have different effects on meditation, secondary task reaction time and typing accuracy. This study also revealed that the presence of plants on several types of tasks has different effects of attention which are useful for increasing work performance.

  9. Phytotoxicity: An Overview of the Physiological Responses of Plants Exposed to Fungicides

    Directory of Open Access Journals (Sweden)

    Maria Celeste Dias

    2012-01-01

    Full Text Available In the last decades, the use of fungicides in agriculture for fungi diseases control has become crucial. Fungicide research has produced a diverse range of products with novel modes of action. However, the extensive use of these compounds in the agriculture system raises public concern because of the harmful potential of such substances in the environment and human health. Moreover, the phytotoxic effects of some fungicides are already recognized but little is known about the impact of these compounds on the photosynthetic apparatus. This paper presents a comprehensive overview of the literature considering different classes of fungicides and their effects on plant physiology, with particular emphasis on photosynthesis.

  10. Plant sterols, cholesterol precursors and oxysterols: Minute concentrations-Major physiological effects.

    Science.gov (United States)

    Olkkonen, Vesa M; Gylling, Helena; Ikonen, Elina

    2017-05-01

    Non-cholesterol sterols are present in our body at very low concentrations as compared to cholesterol. Small changes in the structure of sterol molecules confer them highly distinct biological activities. The best-known example are steroid hormones derived from cholesterol. During the past decade, our knowledge of also other biomolecules related to or derived from cholesterol, particularly plant sterols, biosynthetic precursors of cholesterol, and oxysterols, has expanded rapidly. In this review article we recapitulate the latest insights into the properties and physiological activities of these non-cholesterol sterols, as well as their importance in disease processes and potential as diagnostic biomarkers. Copyright © 2015 Elsevier Ltd. All rights reserved.

  11. Effect of excess iron and copper on physiology of aquatic plant Spirodela polyrrhiza (L.) Schleid.

    Science.gov (United States)

    Xing, Wei; Huang, Wenmin; Liu, Guihua

    2010-04-01

    To elucidate effect of chemical reagents addition on growth of aquatic plants in restoration of aquatic ecosystem, Spirodela polyrrhiza (L.) Schleid was used to evaluate its physiological responses to excess iron (Fe(3+)) and copper (Cu(2+)) in the study. Results showed that accumulation of iron and copper both reached maximum at 100 mg L(-1) iron or copper after 24 h short-term stress, but excess iron and copper caused plants necrosis or death and colonies disintegration as well as roots abscission at excess metal concentrations except for 1 mg L(-1) iron. Significant differences in chlorophyll fluorescence (Fv/Fm) were observed at 1-100 mg L(-1) iron or copper. The synthesis of chlorophyll and protein as well as carbohydrate and the uptake of phosphate and nitrogen were inhibited seriously by excess iron and copper. Proline content decreased with increasing iron or copper concentration, however, MDA content increased with increasing iron or copper concentration.

  12. Aspects of the physiology and biochemistry of some plants existing under the influence of atmosphere pollution

    Energy Technology Data Exchange (ETDEWEB)

    Ionescu, A.; Grou, E.

    1971-01-01

    The vegetation of the Copsa Mica(Romania) zone is often visibly affected by the noxious elements existing in the atmosphere, especially sulfur dioxide. Comparative investigations were undertaken to examine some physiological and biochemical processes in plants from polluted as well as control zones. Water content (total and fractions of free and bound water), stomata condition and hydrogen ion concentration in cellular sap were analyzed; the results of these analyses showed that at the level of all the studied processes, modifications occur, which are sometimes substantial. In laboratory experiments with Pelargonium plants grown in an atmosphere containing sulfur dioxide, a foliar symptomatology was obtained, as well as a chromatogram of free amino acids different to that of controls

  13. Plant nutrition between chemical and physiological limitations: is a sustainable approach possible?

    Directory of Open Access Journals (Sweden)

    Zeno Varanini

    2008-04-01

    Full Text Available The estimate of world population growth and the extent of malnutrition problems due to lack of food or to deficit of specific micronutrients bring to light the importance of plant nutrition in the context of a sustainable development. Beside these aspects, which force to use fertilizers, the topic of nutrient use efficiency of by plants is far from being solved: recent estimates of world cereals productions indicate that use efficiency of nitrogen fertilizers is not higher than 35%. These values are even smaller for phosphorus fertilizers (estimate of use efficiency between 10 and 30%, worsen by the fact that, with the present technology and on the basis of present knowledge, it is expected that the phosphorus reserves used for fertilizer production will be sufficient for less than 100 years. Efficiency problems have also been recently raised concerning the use of synthetic chelates to alleviate deficiency of micronutrients: these compounds have been shown to be extremely mobile along soil profile and to be only partially utilizable by plants. The low uptake efficiency of nutrients from soil is, in one hand, caused by several intrinsic characteristics of the biogeochemical cycle of nutrients, by the other, seems to be limited by biochemical and physiological aspects of nutrient absorption. Only recently, the complexity of these aspects has been apprehended and it has been realized that the programs of breeding had neglected these problematic. In this review aspects related to the acquisition of a macro- (N and a micro- (Fe nutrient, will be discussed. The aim is to show that improvements of mineral nutrient use efficiency can be achieved only through a scientific approach, considering the whole soil-plant system. Particularly emphasis will be put on aspect of molecular physiology relevant to the improvement of nutrient capture efficiency; furthermore, the role of naturally occurring organic molecules in optimizing the nutritional capacity of

  14. Plant nutrition between chemical and physiological limitations: is a sustainable approach possible?

    Directory of Open Access Journals (Sweden)

    Roberto Pinton

    2011-02-01

    Full Text Available The estimate of world population growth and the extent of malnutrition problems due to lack of food or to deficit of specific micronutrients bring to light the importance of plant nutrition in the context of a sustainable development. Beside these aspects, which force to use fertilizers, the topic of nutrient use efficiency of by plants is far from being solved: recent estimates of world cereals productions indicate that use efficiency of nitrogen fertilizers is not higher than 35%. These values are even smaller for phosphorus fertilizers (estimate of use efficiency between 10 and 30%, worsen by the fact that, with the present technology and on the basis of present knowledge, it is expected that the phosphorus reserves used for fertilizer production will be sufficient for less than 100 years. Efficiency problems have also been recently raised concerning the use of synthetic chelates to alleviate deficiency of micronutrients: these compounds have been shown to be extremely mobile along soil profile and to be only partially utilizable by plants. The low uptake efficiency of nutrients from soil is, in one hand, caused by several intrinsic characteristics of the biogeochemical cycle of nutrients, by the other, seems to be limited by biochemical and physiological aspects of nutrient absorption. Only recently, the complexity of these aspects has been apprehended and it has been realized that the programs of breeding had neglected these problematic. In this review aspects related to the acquisition of a macro- (N and a micro- (Fe nutrient, will be discussed. The aim is to show that improvements of mineral nutrient use efficiency can be achieved only through a scientific approach, considering the whole soil-plant system. Particularly emphasis will be put on aspect of molecular physiology relevant to the improvement of nutrient capture efficiency; furthermore, the role of naturally occurring organic molecules in optimizing the nutritional capacity of

  15. 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

  16. NaCl-induced physiological and biochemical adaptative mechanisms in the ornamental Myrtus communis L. plants.

    Science.gov (United States)

    Acosta-Motos, José Ramón; Diaz-Vivancos, Pedro; Álvarez, Sara; Fernández-García, Nieves; Sánchez-Blanco, María Jesús; Hernández, José Antonio

    2015-07-01

    Physiological and biochemical changes in Myrtus communis L. plants after being subjected to different solutions of NaCl (44, and 88 mM) for up to 30 days (Phase I) and after recovery from the salinity period (Phase II) were studied. Myrtle plants showed salinity tolerance by displaying a series of adaptative mechanisms to cope with salt-stress, including controlled ion homeostasis, the increase in root/shoot ratio, the reduction of water potentials and stomatal conductance to limit water loss. In addition, they displayed different strategies to protect the photosynthetic machinery, including limiting toxic ion accumulation in leaves, increase in chlorophyll content, and changes in chlorophyll fluorescence parameters, leaf anatomy and increases in catalase activity. Anatomical modifications in leaves, including a decrease in spongy parenchyma and increased intercellular spaces, allow CO2 diffusion in a situation of reduced stomatal aperture. In spite of all these changes, salinity produced oxidative stress in myrtle plants as monitored by increases in oxidative stress parameter values. The post-recovery period is perceived as a new stress situation, as observed through effects on plant growth and alterations in non-photochemical quenching parameters and lipid peroxidation values.

  17. Mechanisms and effective control of physiological browning phenomena in plant cell cultures.

    Science.gov (United States)

    Dong, Yan-Shan; Fu, Chun-Hua; Su, Peng; Xu, Xiang-Ping; Yuan, Jie; Wang, Sheng; Zhang, Meng; Zhao, Chun-Fang; Yu, Long-Jiang

    2016-01-01

    Browning phenomena are ubiquitous in plant cell cultures that severely hamper scientific research and widespread application of plant cell cultures. Up to now, this problem still has not been well controlled due to the unclear browning mechanisms in plant cell cultures. In this paper, the mechanisms were investigated using two typical materials with severe browning phenomena, Taxus chinensis and Glycyrrhiza inflata cells. Our results illustrated that the browning is attributed to a physiological enzymatic reaction, and phenolic biosynthesis regulated by sugar plays a decisive role in the browning. Furthermore, to confirm the specific compounds which participate in the enzymatic browning reaction, transcriptional profile and metabolites of T. chinensis cells, and UV scanning and high-performance liquid chromatography-mass spectrometry (HPLC-MS) profile of the browning compounds extracted from the brown-turned medium were analyzed, flavonoids derived from phenylpropanoid pathway were found to be the main compounds, and myricetin and quercetin were deduced to be the main substrates of the browning reaction. Inhibition of flavonoid biosynthesis can prevent the browning occurrence, and the browning is effectively controlled via blocking flavonoid biosynthesis by gibberellic acid (GA3 ) as an inhibitor, which further confirms that flavonoids mainly contribute to the browning. On the basis above, a model elucidating enzymatic browning mechanisms in plant cell cultures was put forward, and effective control approaches were presented.

  18. 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.

  19. Physiological, biochemical and molecular responses of the potato (Solanum tuberosum L.) plant to moderately elevated temperature.

    Science.gov (United States)

    Hancock, Robert D; Morris, Wayne L; Ducreux, Laurence J M; Morris, Jenny A; Usman, Muhammad; Verrall, Susan R; Fuller, John; Simpson, Craig G; Zhang, Runxuan; Hedley, Pete E; Taylor, Mark A

    2014-02-01

    Although significant work has been undertaken regarding the response of model and crop plants to heat shock during the acclimatory phase, few studies have examined the steady-state response to the mild heat stress encountered in temperate agriculture. In the present work, we therefore exposed tuberizing potato plants to mildly elevated temperatures (30/20 °C, day/night) for up to 5 weeks and compared tuber yield, physiological and biochemical responses, and leaf and tuber metabolomes and transcriptomes with plants grown under optimal conditions (22/16 °C). Growth at elevated temperature reduced tuber yield despite an increase in net foliar photosynthesis. This was associated with major shifts in leaf and tuber metabolite profiles, a significant decrease in leaf glutathione redox state and decreased starch synthesis in tubers. Furthermore, growth at elevated temperature had a profound impact on leaf and tuber transcript expression with large numbers of transcripts displaying a rhythmic oscillation at the higher growth temperature. RT-PCR revealed perturbation in the expression of circadian clock transcripts including StSP6A, previously identified as a tuberization signal. Our data indicate that potato plants grown at moderately elevated temperatures do not exhibit classic symptoms of abiotic stress but that tuber development responds via a diversity of biochemical and molecular signals.

  20. The impact of Ni on the physiology of a Mediterranean Ni-hyperaccumulating plant.

    Science.gov (United States)

    Roccotiello, Enrica; Serrano, Helena Cristina; Mariotti, Mauro Giorgio; Branquinho, Cristina

    2016-06-01

    High nickel (Ni) levels exert toxic effects on plant growth and plant water content, thus affecting photosynthesis. In a pot experiment, we investigated the effect of the Ni concentration on the physiological characteristics of the Ni hyperaccumulator Alyssoides utriculata when grown on a vermiculite substrate in the presence of different external Ni concentrations (0-500 mg Ni L(-1)). The results showed that the Ni concentration was higher in leaves than in roots, as evidenced by a translocation factor = 3 and a bioconcentration factor = 10. At the highest concentration tested (500 mg Ni L(-1)), A. utriculata accumulated 1100 mg Ni per kilogram in its leaves, without an effects on its biomass. Plant water content increased significantly with Ni accumulation. Ni treatment did not, or only slightly, affected chlorophyll fluorescence parameters. The photosynthetic efficiency (FV/FM) of A. utriculata was stable between Ni treatments (always ≥ 0.8) and the photosynthetic performance of the plant under Ni stress remained high (performance index = 1.5). These findings support that A. utriculata has several mechanisms to avoid severe damage to its photosynthetic apparatus, confirming the tolerance of this species to Ni under hyperaccumulation.

  1. 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.

  2. PPDB: A Tool for Investigation of Plants Physiology Based on Gene Ontology.

    Science.gov (United States)

    Sharma, Ajay Shiv; Gupta, Hari Om; Prasad, Rajendra

    2015-09-01

    Representing the way forward, from functional genomics and its ontology to functional understanding and physiological model, in a computationally tractable fashion is one of the ongoing challenges faced by computational biology. To tackle the standpoint, we herein feature the applications of contemporary database management to the development of PPDB, a searching and browsing tool for the Plants Physiology Database that is based upon the mining of a large amount of gene ontology data currently available. The working principles and search options associated with the PPDB are publicly available and freely accessible online ( http://www.iitr.ac.in/ajayshiv/ ) through a user-friendly environment generated by means of Drupal-6.24. By knowing that genes are expressed in temporally and spatially characteristic patterns and that their functionally distinct products often reside in specific cellular compartments and may be part of one or more multicomponent complexes, this sort of work is intended to be relevant for investigating the functional relationships of gene products at a system level and, thus, helps us approach to the full physiology.

  3. Mathematical literacy in Plant Physiology undergraduates: results of interventions aimed at improving students' performance

    Science.gov (United States)

    Vila, Francisca; Sanz, Amparo

    2013-09-01

    The importance of mathematical literacy in any scientific career is widely recognized. However, various studies report lack of numeracy and mathematical literacy in students from various countries. In the present work, we present a detailed study of the mathematical literacy of Spanish undergraduate students of Biology enrolled in a Plant Physiology course. We have performed individual analyses of results obtained during the period 2000-2011, for questions in the examinations requiring and not requiring mathematical skills. Additionally, we present the outcome of two interventions introduced with the aim of helping students improve their prospects for success in the course. Our results confirm previous research showing students' deficiencies in mathematical skills. However, the scores obtained for mathematical questions in the examinations are good predictors of the final grades attained in Plant Physiology, as there are strong correlations at the individual level between results for questions requiring and not requiring mathematical skills. The introduction of a laboratory session devoted to strengthening the application of students' previously acquired mathematical knowledge did not change significantly the results obtained for mathematical questions. Since mathematical abilities of students entering university have declined in recent years, this intervention may have helped to maintain students' performance to a level comparable to that of previous years. The outcome of self-assessment online tests indicates that although Mathematics anxiety is lower than during examinations, the poor results obtained for questions requiring mathematical skills are, at least in part, due to a lack of self-efficacy.

  4. Improving intercropping: a synthesis of research in agronomy, plant physiology and ecology.

    Science.gov (United States)

    Brooker, Rob W; Bennett, Alison E; Cong, Wen-Feng; Daniell, Tim J; George, Timothy S; Hallett, Paul D; Hawes, Cathy; Iannetta, Pietro P M; Jones, Hamlyn G; Karley, Alison J; Li, Long; McKenzie, Blair M; Pakeman, Robin J; Paterson, Eric; Schöb, Christian; Shen, Jianbo; Squire, Geoff; Watson, Christine A; Zhang, Chaochun; Zhang, Fusuo; Zhang, Junling; White, Philip J

    2015-04-01

    Intercropping is a farming practice involving two or more crop species, or genotypes, growing together and coexisting for a time. On the fringes of modern intensive agriculture, intercropping is important in many subsistence or low-input/resource-limited agricultural systems. By allowing genuine yield gains without increased inputs, or greater stability of yield with decreased inputs, intercropping could be one route to delivering ‘sustainable intensification’. We discuss how recent knowledge from agronomy, plant physiology and ecology can be combined with the aim of improving intercropping systems. Recent advances in agronomy and plant physiology include better understanding of the mechanisms of interactions between crop genotypes and species – for example, enhanced resource availability through niche complementarity. Ecological advances include better understanding of the context-dependency of interactions, the mechanisms behind disease and pest avoidance, the links between above- and below-ground systems, and the role of microtopographic variation in coexistence. This improved understanding can guide approaches for improving intercropping systems, including breeding crops for intercropping. Although such advances can help to improve intercropping systems, we suggest that other topics also need addressing. These include better assessment of the wider benefits of intercropping in terms of multiple ecosystem services, collaboration with agricultural engineering, and more effective interdisciplinary research.

  5. Joint control of terrestrial gross primary productivity by plant phenology and physiology.

    Science.gov (United States)

    Xia, Jianyang; Niu, Shuli; Ciais, Philippe; Janssens, Ivan A; Chen, Jiquan; Ammann, Christof; Arain, Altaf; Blanken, Peter D; Cescatti, Alessandro; Bonal, Damien; Buchmann, Nina; Curtis, Peter S; Chen, Shiping; Dong, Jinwei; Flanagan, Lawrence B; Frankenberg, Christian; Georgiadis, Teodoro; Gough, Christopher M; Hui, Dafeng; Kiely, Gerard; Li, Jianwei; Lund, Magnus; Magliulo, Vincenzo; Marcolla, Barbara; Merbold, Lutz; Montagnani, Leonardo; Moors, Eddy J; Olesen, Jørgen E; Piao, Shilong; Raschi, Antonio; Roupsard, Olivier; Suyker, Andrew E; Urbaniak, Marek; Vaccari, Francesco P; Varlagin, Andrej; Vesala, Timo; Wilkinson, Matthew; Weng, Ensheng; Wohlfahrt, Georg; Yan, Liming; Luo, Yiqi

    2015-03-03

    Terrestrial gross primary productivity (GPP) varies greatly over time and space. A better understanding of this variability is necessary for more accurate predictions of the future climate-carbon cycle feedback. Recent studies have suggested that variability in GPP is driven by a broad range of biotic and abiotic factors operating mainly through changes in vegetation phenology and physiological processes. However, it is still unclear how plant phenology and physiology can be integrated to explain the spatiotemporal variability of terrestrial GPP. Based on analyses of eddy-covariance and satellite-derived data, we decomposed annual terrestrial GPP into the length of the CO2 uptake period (CUP) and the seasonal maximal capacity of CO2 uptake (GPPmax). The product of CUP and GPPmax explained >90% of the temporal GPP variability in most areas of North America during 2000-2010 and the spatial GPP variation among globally distributed eddy flux tower sites. It also explained GPP response to the European heatwave in 2003 (r(2) = 0.90) and GPP recovery after a fire disturbance in South Dakota (r(2) = 0.88). Additional analysis of the eddy-covariance flux data shows that the interbiome variation in annual GPP is better explained by that in GPPmax than CUP. These findings indicate that terrestrial GPP is jointly controlled by ecosystem-level plant phenology and photosynthetic capacity, and greater understanding of GPPmax and CUP responses to environmental and biological variations will, thus, improve predictions of GPP over time and space.

  6. A meta-analysis of plant physiological and growth responses to temperature and elevated CO(2).

    Science.gov (United States)

    Wang, Dan; Heckathorn, Scott A; Wang, Xianzhong; Philpott, Stacy M

    2012-05-01

    Atmospheric carbon dioxide (CO(2)) and global mean temperature are expected to be significantly higher by the end of the 21st century. Elevated CO(2) (eCO(2)) and higher temperature each affect plant physiology and growth, but their interactive effects have not been reviewed statistically with respect to higher chronic mean temperatures and abrupt heat stress. In this meta-analysis, we examined the effect of CO(2) on the physiology and growth of plants subjected to different temperature treatments. The CO(2) treatments were categorized into ambient (560 ppm) levels, while temperature treatments were categorized into ambient temperature (AT), elevated temperature (ET; AT + 1.4-6°C), or heat stress (HS; AT + >8°C). Plant species were grouped according to photosynthetic pathways (C(3), C(4)), functional types (legumes, non-legumes), growth forms (herbaceous, woody), and economic purposes (crop, non-crop). eCO(2) enhanced net photosynthesis at AT, ET, and HS in C(3) species (especially at the HS level), but in C(4) species, it had no effect at AT, a positive effect at ET, and a negative effect at HS. The positive effect of eCO(2) on net photosynthesis was greater for legumes than for non-legumes at HS, for non-crops than crops at ET, and for woody than herbaceous species at ET and HS. Total (W (T)) and above- (W (AG)) and below-ground (W (BG)) biomass were increased by eCO(2) for most species groups at all temperatures, except for C(4) species and W (BG) of legumes at HS. Hence, eCO(2) × heat effects on growth were often not explained by effects on net photosynthesis. Overall, the results show that eCO(2) effects on plant physiology and growth vary under different temperature regimes, among functional groups and photosynthetic pathways, and among response variables. These findings have important implications for biomass accumulation and ecosystem functioning in the future when the CO(2) level is higher and climate extremes, such as heat waves, become more frequent.

  7. Effect of low dosage biochar amendment on plant physiology parameters of sunflowers

    Science.gov (United States)

    María De la Rosa, José; Paneque, Marina; Franco-Navarro, Juan D.; Colmenero-Flores, José Manuel; Knicker, Heike

    2017-04-01

    Four different biochars were used as organic ameliorants in a typical agricultural soil of the Mediterranean region a (Calcic Cambisol). This field study was performed with plants of sunflower (Helianthus annuus L.) at the experimental station "La Hampa", located in the Guadalquivir river valley (SW Spain). The soil was amended with doses equivalent to 1.5 and 15 t ha-1 of the four biochars in two independent plantations. In addition, un-amended plots were prepared for comparison purposes 1. This study showed that the amendment with 1.5 t biochar ha-1 did not modify significantly soil properties, or the agronomic productivity of sunflowers. However, in spite of this low dose of biochar, positive effects on plant physiology were observed. The efficiency of Photosystem-II (quantum yield (QYPSII)), is a stress marker, related to the water status of the plant, and is reduced under drought stress. The QYPSII values of the plants grown with 1.5 t biochar ha-1 were higher than in the control and ranged between 72 and 77%. Values between 70 and 80% correspond to non-stressed (well-watered) sunflower plants. Biochar reduced stomatal conductance (gs, leaf transpiration) in both treatments. Therefore, the dependence of agronomic productivity on biochar dose was not observed, since both doses resulted in similar gs reductions. In C3 plants, such as sunflower, an increase of leaf area (LA) is usually associated to a decrease of gs caused by a reduction of stomatal frequency and increases the water use efficiency and drought tolerance 2. However, here no clear correlation could be established between biochar-induced LA stimulation and gs response after application of biochar. Thus, gs reduction was evident but not a consequence of LA increase. We hypothesize that biochar addition to soils alters anatomical and/or physiological parameters of the plants that in turn reduces stomatal conductance and increases water use efficiency of sunflower plants. After the last rain, increasing

  8. Crop management as a driving force of plant growth promoting rhizobacteria physiology.

    Science.gov (United States)

    Melo, Juliana; Carolino, Manuela; Carvalho, Luís; Correia, Patrícia; Tenreiro, Rogério; Chaves, Sandra; Meleiro, Ana I; de Souza, Sávio B; Dias, Teresa; Cruz, Cristina; Ramos, Alessandro C

    2016-01-01

    Crop management systems influence plant productivity and nutrient use efficiency, as well as plant growth-promoting rhizobacteria (PGPR), which are known to influence the growth of plants via phytohormone production, phosphate solubilization, nitrogen (N) fixation and antimicrobial activity. The objective of this study was to compare the influence of two crop management system on microbial PGPR features. PGPR isolated from the rhizospheres of Carica papaya L. grown under two distinct management systems (conventional and organic) were identified and characterized. The 12 strains most efficient in solubilizing inorganic phosphate belonged to the genera Burkholderia, Klebsiella, and Leclercia. N fixation was observed in the strains B. vietnamiensis from the conventional farming system and B. vietnamiensis, B. cepacia and Leclercia sp. from the organic farming system. The B. vietnamiensis, B. cepacia, Klebsiella sp. and Klebsiella sp. isolates showed antifungal activity, while Leclercia sp. did not. The strains B. vietnamiensis and Enterobcter sp. (isolated from the conventional farming system) and Klebsiella sp. (isolated from the organic farming system) were efficient at solubilizing phosphate, producing phytohormones and siderophores, and inhibiting the mycelial growth of various phytopathogenic fungi (Botrytis cinerea, Pestalotia sp., Alternaria sp., Phoma sp., Fusarium culmorum, Geotrichum candidum). Physiological differences between the isolates from the two crop management regimes were distinguishable after 10 years of distinct management.

  9. Eco-physiological Effects of Atmospheric Ozone and Polycyclic Aromatic Hydrocarbons (PAHs) on Plants

    Science.gov (United States)

    Bandai, S.; Sakugawa, H. H.

    2012-12-01

    [Introduction] Tropospheric ozone is one of most concerned air pollutant, by causing damage to trees and crops. Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous contaminants found in various environmental compartments. Photo-induced toxicity of PAHs can be driven from formation of intracellular single oxygen and other reactive oxygen intermediates (ROI) leading to biological damages.(1) In the present study, we measured photosynthesis rate and other variables to investigate the effects of ozone and PAHs on the eco-physiological status of plants such as eggplant, common bean and strawberry. Plants treated with the single or combined air pollutants are expected to exhibit altered physiological, morphological and possibly growth changes. [Materials and Methods] We performed three exposure experiments. Exp.1. Eggplant (Solanum melongena) seedlings, were placed in the open-top chambers (n=6 plants/treatment). Treatment system was ozone (O)(120ppb), phenanthrene (P)(10μM), O+P, fluoranthene (F)(10μM), O+F, mannitol (M)(1mM) and the control (Milli-Q water)(C). P, F and M were sprayed three times weekly on the foliage part of eggplant. Average volume sprayed per seedling was 50mL. The treatment period was 30days and [AOT 40 (Accumulated exposure over a threshold of 40 ppb)]=28.8 ppmh. Exp.2, Common bean (Phaseolus vulgaris L.) seedlings were used (n=5 plants/treatment). The treatment system was the same as Exp.1. The treatment period was 40days and [AOT 40]=38.4ppmh. Exp.3. Strawberry (Fragaria L.) seedlings were used (n=5 plants/treatment). Treatment system was O (120ppb), F(10μM), O+F, F+M, O+M and C. The treatment period was 90days and [AOT 40]=86.4ppmh. Ecophysiological variables examined were photosynthesis rate measured at saturated irradiance (Amax), stomatal conductance to water vapour (gs), internal CO2 concentration (Ci), photochemical efficiency of PS2 in the dark (Fv/Fm), chlorophyll contents, visual symptom assessment and elemental composition in the

  10. 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.

  11. 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.

  12. 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

  13. Instrumentation enabling study of plant physiological response to elevated night temperature

    Directory of Open Access Journals (Sweden)

    Tarpley Lee

    2009-06-01

    Full Text Available Abstract Background Global climate warming can affect functioning of crops and plants in the natural environment. In order to study the effects of global warming, a method for applying a controlled heating treatment to plant canopies in the open field or in the greenhouse is needed that can accept either square wave application of elevated temperature or a complex prescribed diurnal or seasonal temperature regime. The current options are limited in their accuracy, precision, reliability, mobility or cost and scalability. Results The described system uses overhead infrared heaters that are relatively inexpensive and are accurate and precise in rapidly controlling the temperature. Remote computer-based data acquisition and control via the internet provides the ability to use complex temperature regimes and real-time monitoring. Due to its easy mobility, the heating system can randomly be allotted in the open field or in the greenhouse within the experimental setup. The apparatus has been successfully applied to study the response of rice to high night temperatures. Air temperatures were maintained within the set points ± 0.5°C. The incorporation of the combination of air-situated thermocouples, autotuned proportional integrative derivative temperature controllers and phase angled fired silicon controlled rectifier power controllers provides very fast proportional heating action (i.e. 9 ms time base, which avoids prolonged or intense heating of the plant material. Conclusion The described infrared heating system meets the utilitarian requirements of a heating system for plant physiology studies in that the elevated temperature can be accurately, precisely, and reliably controlled with minimal perturbation of other environmental factors.

  14. 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.

  15. A molecular physiological review of vegetative desiccation tolerance in the resurrection plant Xerophyta viscosa (Baker).

    Science.gov (United States)

    Farrant, Jill M; Cooper, Keren; Hilgart, Amelia; Abdalla, Kamal O; Bentley, Joanne; Thomson, Jennifer A; Dace, Halford J W; Peton, Nashied; Mundree, Sagadevan G; Rafudeen, Mohamed S

    2015-08-01

    Provides a first comprehensive review of integrated physiological and molecular aspects of desiccation tolerance Xerophyta viscosa. A synopsis of biotechnological studies being undertaken to improve drought tolerance in maize is given. Xerophyta viscosa (Baker) is a monocotyledonous resurrection plant from the family Vellociacea that occurs in summer-rainfall areas of South Africa, Lesotho and Swaziland. It inhabits rocky terrain in exposed grasslands and frequently experiences periods of water deficit. Being a resurrection plant it tolerates the loss of 95% of total cellular water, regaining full metabolic competency within 3 days of rehydration. In this paper, we review some of the molecular and physiological adaptations that occur during various stages of dehydration of X. viscosa, these being functionally grouped into early and late responses, which might be relevant to the attainment of desiccation tolerance. During early drying (to 55% RWC) photosynthesis is shut down, there is increased presence and activity of housekeeping antioxidants and a redirection of metabolism to the increased formation of sucrose and raffinose family oligosaccharides. Other metabolic shifts suggest water replacement in vacuoles proposed to facilitate mechanical stabilization. Some regulatory processes observed include increased presence of a linker histone H1 variant, a Type 2C protein phosphatase, a calmodulin- and an ERD15-like protein. During the late stages of drying (to 10% RWC) there was increased expression of several proteins involved in signal transduction, and retroelements speculated to be instrumental in gene silencing. There was induction of antioxidants not typically found in desiccation-sensitive systems, classical stress-associated proteins (HSP and LEAs), proteins involved in structural stabilization and those associated with changes in various metabolite pools during drying. Metabolites accumulated in this stage are proposed, inter alia, to facilitate subcellular

  16. Plant phenomics and the need for physiological phenotyping across scales to narrow the genotype-to-phenotype knowledge gap

    DEFF Research Database (Denmark)

    Grosskinsky, Dominik Kilian; Svensgaard, Jesper; Christensen, Svend

    2015-01-01

    Plants are affected by complex genome×environment×management interactions which determine phenotypic plasticity as a result of the variability of genetic components. Whereas great advances have been made in the cost-efficient and high-throughput analyses of genetic information and non-invasive......-throughput non-invasive phenotyping needs to be validated and verified across scales to be used as proxy for the underlying processes. Armed with this interdisciplinary and multidimensional phenomics approach, plant physiology, non-invasive phenotyping, and functional genomics will complement each other...... of the internal phenotype into high-throughput phenotyping of whole plants and canopies. By this means, complex traits can be broken down into individual components of physiological traits. Since the higher resolution of physiological phenotyping by ‘wet chemistry’ is inherently limited in throughput, high...

  17. Plant phenomics and the need for physiological phenotyping across scales to narrow the genotype-to-phenotype knowledge gap.

    Science.gov (United States)

    Großkinsky, Dominik K; Svensgaard, Jesper; Christensen, Svend; Roitsch, Thomas

    2015-09-01

    Plants are affected by complex genome×environment×management interactions which determine phenotypic plasticity as a result of the variability of genetic components. Whereas great advances have been made in the cost-efficient and high-throughput analyses of genetic information and non-invasive phenotyping, the large-scale analyses of the underlying physiological mechanisms lag behind. The external phenotype is determined by the sum of the complex interactions of metabolic pathways and intracellular regulatory networks that is reflected in an internal, physiological, and biochemical phenotype. These various scales of dynamic physiological responses need to be considered, and genotyping and external phenotyping should be linked to the physiology at the cellular and tissue level. A high-dimensional physiological phenotyping across scales is needed that integrates the precise characterization of the internal phenotype into high-throughput phenotyping of whole plants and canopies. By this means, complex traits can be broken down into individual components of physiological traits. Since the higher resolution of physiological phenotyping by 'wet chemistry' is inherently limited in throughput, high-throughput non-invasive phenotyping needs to be validated and verified across scales to be used as proxy for the underlying processes. Armed with this interdisciplinary and multidimensional phenomics approach, plant physiology, non-invasive phenotyping, and functional genomics will complement each other, ultimately enabling the in silico assessment of responses under defined environments with advanced crop models. This will allow generation of robust physiological predictors also for complex traits to bridge the knowledge gap between genotype and phenotype for applications in breeding, precision farming, and basic research. © The Author 2015. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please

  18. 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.

  19. Plastoquinone and Ubiquinone in Plants: Biosynthesis, Physiological Function and Metabolic Engineering

    Science.gov (United States)

    Liu, Miaomiao; Lu, Shanfa

    2016-01-01

    review, we summarize and discuss recent research progresses in the biosynthetic pathways of PQ and UQ and enzymes and their encoding genes involved in side chain elongation and in the second stage of PQ and UQ biosynthesis. Physiological functions of PQ and UQ played in plants as well as the practical application and metabolic engineering of PQ and UQ are also included. PMID:28018418

  20. Plastoquinone and ubiquinone in plants: biosynthesis, physiological function and metabolic engineering

    Directory of Open Access Journals (Sweden)

    Miaomiao Liu

    2016-12-01

    tested. In this review, we summarize and discuss recent research progresses in the biosynthetic pathways of PQ and UQ and enzymes and their encoding genes involved in side chain elongation and in the second stage of PQ and UQ biosynthesis. Physiological functions of PQ and UQ played in plants as well as the practical application and metabolic engineering of PQ and UQ are also included.

  1. Physiological Responses and Yield of Wheat Plants in Zinc-Mediated Alleviation of Drought Stress

    Directory of Open Access Journals (Sweden)

    Dongyun Ma

    2017-05-01

    Full Text Available To evaluate the physiological responses of wheat to zinc (Zn fertilizer application under drought stress, pot, and field experiments were conducted on wheat plants grown under different soil moistures and treated with soil and foliar Zn applications. Photosynthetic characteristics, antioxidant content, Zn element concentration, and the transcription level of genes involved in antioxidant biosynthesis were analyzed. Zn application increased SPAD and Fv/Fm of wheat flag leaves, while decreased lipid peroxidation levels and H2O2 content. Zn application increased the antioxidant content (ascorbate, reduced glutathione, total phenolic, and total flavonoid of wheat flag leaves, and enhanced the relative expression levels of two antioxidant enzyme genes, four ascorbate–glutathione cycle genes, and two flavonoid biosynthesis pathway genes under drought stress. Soil Zn application increased grain yield and Zn concentration by 10.5 and 15.8%, 22.6 and 9.7%, and 28.2 and 32.8% under adequate water supply, moderate drought, and severe drought, respectively. Furthermore, foliar application of Zn in the field increased grain yield and grain Zn concentration under both adequate water supply and rain-fed conditions. Zn plays a role in alleviating wheat plant drought stress by Zn-mediated increase in photosynthesis pigment and active oxygen scavenging substances, and reduction in lipid peroxidation. Furthermore, Zn fertilizer could regulate multiple antioxidant defense systems at the transcriptional level in response to drought.

  2. EDTA reduces the physiological damage of lead on cardoon plants grown hydroponically

    Science.gov (United States)

    Hernandez-Allica, J.; Barrutia, O.; Becerril, J. M.; Garbisu, C.

    2003-05-01

    Cardoon seedlings (Cynara cardunculus L.) were grown hydroponically in nutrient solution and exposed to lead (Pb^{2+}: ImM) in the presence of a range of different EDTA concentrations (EDTANa2: 0, 0.5, 1 or 2mM). Analyses were performed to establish whether the coordination of Pb^{2+} transport by EDTA enhances the mobility of this metal within the plant and to determine the toxic effects of these treatments during a phytoextraction process. Net photosynthesis, transpiration rate and stomatal conductance decreased dramatically in plants treated with Pb^{2+} or Pb-EDTA at doses below 1 mM. ln these treatments, most of the Pb^{2+} accumulated in the roots, alld only a very low amount of it was translocated to the shoots. Increasing the EDTA doses up to Pb^{2+} equimolarity, increased the Pb^{2+} shoot content more than 10-fold without any physiological evidence of toxicity. The treatment with higher doses of EDTA (Pb^{2+} 1 mM + EDTA 2 mM) did not show toxicity symptoms, but the Pb^{2+} concentration in the aboveground tissues decreased when compared with the equimolar treatment. The interaction with the absorption of some essential cations such as Ca^{2+} and phytotoxicity on chelated-assisted phytoextraction is discussed.

  3. Plant physiological ecology and the global changes Ecofisiologia vegetal e as mudanças globais

    Directory of Open Access Journals (Sweden)

    João Paulo Rodrigues Alves Delfino Barbosa

    2012-06-01

    Full Text Available The global changes are marked by alteration on the normal patterns of important biochemical and biophysical processes of the Earth. However, the real effects as well as the feedbacks of the global changes over vegetation are still unclear. Part of this uncertainty can be attributed to the inattention of stakeholders and scientists towards vegetation and its complex interrelations with the environment, which drive plant physiological processes in different space-time scales. Notwithstanding, some key subjects of the global changes could be better elucidated with a more plant physiological ecology approach. We discuss some issues related to this topic, going through some limitations of approaching vegetation as a static component of the biosphere as the other sub-systems of the Earth-system change. With this perspective, this review is an initial reflection towards the assessment of the role and place of vegetation structure and function in the global changes context. We reviewed the Earth-system and global changes terminology; attempted to illustrate key plant physiological ecology researches themes in the global changes context; consider approaching plants as complex systems in order to adequately quantify systems characteristics as sensibility, homeostasis, and vulnerability. Moreover, we propose insights that would allow vegetation studies and scaling procedures in the context of the Earth-system. We hope this review will assist researchers on their strategy to identify, understand and anticipate the potential effects of global changes over the most vulnerable vegetation processes from the leaf to the global levels.As mudanças globais englobam importantes alterações nos padrões normais de processos bioquímicos e biofísicos da Terra. Os reais efeitos e retroalimentações das mudanças globais sobre a vegetação ainda são incertos. Parte das incertezas pode ser atribuída à falta de atenção de cientistas e políticos para a vegeta

  4. Extreme climatic events: impacts of drought and high temperature on physiological processes in agronomically important plants

    Directory of Open Access Journals (Sweden)

    Urs eFeller

    2014-10-01

    Full Text Available Climate models predict more frequent and more severe extreme events (e.g. heat waves, extended drought periods, flooding in many regions for the next decades. The impact of adverse environmental conditions on crop plants is ecologically and economically relevant. This review is focused on drought and heat effects on physiological status and productivity of agronomically important plants. Stomatal opening represents an important regulatory mechanism during drought and heat stress since it influences simultaneously water loss via transpiration and CO2 diffusion into the leaf apoplast which further is utilized in photosynthesis. Along with the reversible short-term control of stomatal opening, stomata and leaf epidermis may produce waxy deposits and irreversibly down-regulate the stomatal conductance and non-stomatal transpiration. As a consequence photosynthesis will be negatively affected. Rubisco activase - a key enzyme in keeping the Calvin cycle functional – is heat-sensitive and may become a limiting factor at elevated temperature. The accumulated reactive oxygen species during stress represent an additional challenge under unfavorable conditions. Drought and heat cause accumulation of free amino acids which are partially converted into compatible solutes such as proline. This is accompanied by lower rates of both nitrate reduction and de novo amino acid biosynthesis. Protective proteins (e.g. dehydrins, chaperones, antioxidant enzymes or the key enzyme for proline biosynthesis play an important role in leaves and may be present at higher levels under water deprivation or high temperatures. On the whole plant level, effects on long-distance translocation of solutes via xylem and phloem and on leaf senescence (e.g. anticipated, accelerated or delayed senescence are important. The factors mentioned above are relevant for the overall performance of crops under drought and heat and must be considered for genotype selection and breeding programs.

  5. Physiological effects of climate warming on flowering plants and insect pollinators and potential consequences for their interactions

    Institute of Scientific and Technical Information of China (English)

    Victoria L.SCAVEN; Nicole E.RAFFERTY

    2013-01-01

    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 summabrize 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.

  6. Plant physiological models of heat, water and photoinhibition stress for climate change modelling and agricultural prediction

    Science.gov (United States)

    Nicolas, B.; Gilbert, M. E.; Paw U, K. T.

    2015-12-01

    Soil-Vegetation-Atmosphere Transfer (SVAT) models are based upon well understood steady state photosynthetic physiology - the Farquhar-von Caemmerer-Berry model (FvCB). However, representations of physiological stress and damage have not been successfully integrated into SVAT models. Generally, it has been assumed that plants will strive to conserve water at higher temperatures by reducing stomatal conductance or adjusting osmotic balance, until potentially damaging temperatures and the need for evaporative cooling become more important than water conservation. A key point is that damage is the result of combined stresses: drought leads to stomatal closure, less evaporative cooling, high leaf temperature, less photosynthetic dissipation of absorbed energy, all coupled with high light (photosynthetic photon flux density; PPFD). This leads to excess absorbed energy by Photosystem II (PSII) and results in photoinhibition and damage, neither are included in SVAT models. Current representations of photoinhibition are treated as a function of PPFD, not as a function of constrained photosynthesis under heat or water. Thus, it seems unlikely that current models can predict responses of vegetation to climate variability and change. We propose a dynamic model of damage to Rubisco and RuBP-regeneration that accounts, mechanistically, for the interactions between high temperature, light, and constrained photosynthesis under drought. Further, these predictions are illustrated by key experiments allowing model validation. We also integrated this new framework within the Advanced Canopy-Atmosphere-Soil Algorithm (ACASA). Preliminary results show that our approach can be used to predict reasonable photosynthetic dynamics. For instances, a leaf undergoing one day of drought stress will quickly decrease its maximum quantum yield of PSII (Fv/Fm), but it won't recover to unstressed levels for several days. Consequently, cumulative effect of photoinhibition on photosynthesis can cause

  7. Evaluation of structural and physiological plant characteristics in relation to the distribution of cadmium in maize inbred lines.

    NARCIS (Netherlands)

    Florijn, P.J.; Nelemans, J.A.; Beusichem, van M.L.

    1993-01-01

    To establish the structural and physiological characteristics related to the genotypic variation in Cd distribution between maize inbred lines (shoot Cd excluders and non-shoot Cd excluders), shoot and root morphological parameters were studied on plants grown in nutrient solution. Furthermore, the

  8. The Use of Light-Emitting Diodes (LEDs) as Green and Red/Far-Red Light Sources in Plant Physiology.

    Science.gov (United States)

    Jackson, David L.; And Others

    1985-01-01

    The use of green, red, and far-red light-emitting diodes (LEDs) as light sources for plant physiological studies is outlined and evaluated. Indicates that LED lamps have the advantage over conventional light sources in that they are lightweight, low-cost, portable, easily constructed, and do not require color filters. (Author/DH)

  9. Effect of Humic Acid and Organic Manure Tea on Plant Physiology and Fruit Characteristics of Pepino

    Directory of Open Access Journals (Sweden)

    Jamal Javanmardi

    2017-02-01

    Full Text Available Introduction Pepino (SolanummuricatumAit., a Solanaceous vegetable fruit has been recently introduced to Iran markets. Organic farming is currently the fastest growing agricultural sector worldwide. Although several investigations are available on chemical fertilization of pepino, the knowledge of organic fertilization ismostly lacking. Therefore, at the beginning of introducing pepino plant to Iranian farmers it worth to evaluate the impact of organic fertilization on the productivity, profitability, acceptability and sustainability of farming systemsto this plant. High chemical fertilization of pepinoincreases the vegetative growth over the generative and fruit production. The aim of this investigation was to introduce the possibility of organic production of pepino. Materials and Methods.A two-year experiment was carried out to assess the possibility of organic production of pepino using organic fertilizers. Humistar® organic fertilizer (containing 8.6% humic acid at 50 L/ha and sheep or cow manure teas at 1:10 and 1:5 ratios were used for production of pepino cv. Kanseola to evaluate their effects on the physiology of reproductive stage and some fruit quality characteristics. The experiments were arranged as factorial in a randomized complete block design comprised of 3 replications, each of which 10 plants. Mother plants were obtained from Mashhad Ferdowsi University and incubated in a greenhouse (mean temperature of 25 °C and 60-70% relative humidity for 1 month to proliferate. Cuttings with 2-3 leaves at the top, 3-5 healthy buds and 20 cm length were rooted for 14 days in a rooting media, ( 1:1:2 of field soil, composted leaf and perlite, respectively. Plants were transplanted into the field in 100 × 75 cm spacing after the danger of frost was over. Treatments consisted of two levels of 1:5 and 1:10 (w:w cow or sheep manure teas in combination with two levels of Humistar® organic fertilizer as 0 and 50L/ha levels. Control plants

  10. Reversible, partial inactivation of plant betaine aldehyde dehydrogenase by betaine aldehyde: mechanism and possible physiological implications.

    Science.gov (United States)

    Zárate-Romero, Andrés; Murillo-Melo, Darío S; Mújica-Jiménez, Carlos; Montiel, Carmina; Muñoz-Clares, Rosario A

    2016-04-01

    In plants, the last step in the biosynthesis of the osmoprotectant glycine betaine (GB) is the NAD(+)-dependent oxidation of betaine aldehyde (BAL) catalysed by some aldehyde dehydrogenase (ALDH) 10 enzymes that exhibit betaine aldehyde dehydrogenase (BADH) activity. Given the irreversibility of the reaction, the short-term regulation of these enzymes is of great physiological relevance to avoid adverse decreases in the NAD(+):NADH ratio. In the present study, we report that the Spinacia oleracea BADH (SoBADH) is reversibly and partially inactivated by BAL in the absence of NAD(+)in a time- and concentration-dependent mode. Crystallographic evidence indicates that the non-essential Cys(450)(SoBADH numbering) forms a thiohemiacetal with BAL, totally blocking the productive binding of the aldehyde. It is of interest that, in contrast to Cys(450), the catalytic cysteine (Cys(291)) did not react with BAL in the absence of NAD(+) The trimethylammonium group of BAL binds in the same position in the inactivating or productive modes. Accordingly, BAL does not inactivate the C(450)SSoBADH mutant and the degree of inactivation of the A(441)I and A(441)C mutants corresponds to their very different abilities to bind the trimethylammonium group. Cys(450)and the neighbouring residues that participate in stabilizing the thiohemiacetal are strictly conserved in plant ALDH10 enzymes with proven or predicted BADH activity, suggesting that inactivation by BAL is their common feature. Under osmotic stress conditions, this novel partial and reversible covalent regulatory mechanism may contribute to preventing NAD(+)exhaustion, while still permitting the synthesis of high amounts of GB and avoiding the accumulation of the toxic BAL.

  11. 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

  12. 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.

  13. Phenolic metabolites in carnivorous plants: Inter-specific comparison and physiological studies.

    Science.gov (United States)

    Kováčik, Jozef; Klejdus, Bořivoj; Repčáková, Klára

    2012-03-01

    Despite intensive phytochemical research, data related to the accumulation of phenols in carnivorous plants include mainly qualitative reports. We have quantified phenolic metabolites in three species: Drosera capensis, Dionaea muscipula and Nepenthes anamensis in the "leaf" (assimilatory part) and the "trap" (digestive part). For comparison, commercial green tea was analysed. Phenylalanine ammonia-lyase (PAL) activities in Dionaea and Nepenthes were higher in the trap than in the leaf while the opposite was found in Drosera. Soluble phenols and majority of phenolic acids were mainly accumulated in the trap among species. Flavonoids were abundant in Drosera and Dionaea traps but not in Nepenthes. Phenolic acids were preferentially accumulated in a glycosidically-bound form and gallic acid was the main metabolite. Green tea contained more soluble phenols and phenolic acids but less quercetin. In vitro experiments with Drosera spathulata revealed that nitrogen deficiency enhances PAL activity, accumulation of phenols and sugars while PAL inhibitor (2-aminoindane-2-phosphonic acid) depleted phenols and some amino acids (but free phenylalanine and sugars were elevated). Possible explanations in physiological, biochemical and ecological context are discussed. Copyright © 2011 Elsevier Masson SAS. All rights reserved.

  14. A novel ammonia-oxidizing archaeon from wastewater treatment plant: Its enrichment, physiological and genomic characteristics

    Science.gov (United States)

    Li, Yuyang; Ding, Kun; Wen, Xianghua; Zhang, Bing; Shen, Bo; Yang, Yunfeng

    2016-03-01

    Ammonia-oxidizing archaea (AOA) are recently found to participate in the ammonia removal processes in wastewater treatment plants (WWTPs), similar to their bacterial counterparts. However, due to lack of cultivated AOA strains from WWTPs, their functions and contributions in these systems remain unclear. Here we report a novel AOA strain SAT1 enriched from activated sludge, with its physiological and genomic characteristics investigated. The maximal 16S rRNA gene similarity between SAT1 and other reported AOA strain is 96% (with “Ca. Nitrosotenuis chungbukensis”), and it is affiliated with Wastewater Cluster B (WWC-B) based on amoA gene phylogeny, a cluster within group I.1a and specific for activated sludge. Our strain is autotrophic, mesophilic (25 °C–33 °C) and neutrophilic (pH 5.0–7.0). Its genome size is 1.62 Mb, with a large fragment inversion (accounted for 68% genomic size) inside. The strain could not utilize urea due to truncation of the urea transporter gene. The lack of the pathways to synthesize usual compatible solutes makes it intolerant to high salinity (>0.03%), but could adapt to low salinity (0.005%) environments. This adaptation, together with possibly enhanced cell-biofilm attachment ability, makes it suitable for WWTPs environment. We propose the name “Candidatus Nitrosotenuis cloacae” for the strain SAT1.

  15. Ripening Physiology of Fruit from Transgenic Tomato (Lycopersicon esculentum) Plants with Reduced Ethylene Synthesis.

    Science.gov (United States)

    Klee, H. J.

    1993-07-01

    The physiological effects of reduced ethylene synthesis in a transgenic tomato (Lycopersicon esculentum) line expressing 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase enzyme have been examined. Fruit from the transgenic line 5673 ripen significantly slower than control fruit when removed from the vine early in ripening. In contrast, fruit that remain attached to the plants ripen much more rapidly, exhibiting little delay relative to the control. Ethylene determinations on attached fruit revealed that there was significantly more internal ethylene in attached than detached fruit. The higher ethylene content can fully account for the observed faster on-the-vine ripening. All of the data are consistent with a catalytic role for ethylene in promoting many, although not all, aspects of fruit ripening. Biochemical analyses of transgenic fruit indicated no significant differences from controls in the levels of ACC oxidase or polygalacturonase. Because transgenic fruit are significantly firmer than controls, this last result indicates that other enzymes may have a significant role in fruit softening.

  16. 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.

  17. 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.

  18. FPGA-Based Smart Sensor for Drought Stress Detection in Tomato Plants Using Novel Physiological Variables and Discrete Wavelet Transform

    Directory of Open Access Journals (Sweden)

    Carlos Duarte-Galvan

    2014-10-01

    Full Text Available Soil drought represents one of the most dangerous stresses for plants. It impacts the yield and quality of crops, and if it remains undetected for a long time, the entire crop could be lost. However, for some plants a certain amount of drought stress improves specific characteristics. In such cases, a device capable of detecting and quantifying the impact of drought stress in plants is desirable. This article focuses on testing if the monitoring of physiological process through a gas exchange methodology provides enough information to detect drought stress conditions in plants. The experiment consists of using a set of smart sensors based on Field Programmable Gate Arrays (FPGAs to monitor a group of plants under controlled drought conditions. The main objective was to use different digital signal processing techniques such as the Discrete Wavelet Transform (DWT to explore the response of plant physiological processes to drought. Also, an index-based methodology was utilized to compensate the spatial variation inside the greenhouse. As a result, differences between treatments were determined to be independent of climate variations inside the greenhouse. Finally, after using the DWT as digital filter, results demonstrated that the proposed system is capable to reject high frequency noise and to detect drought conditions.

  19. FPGA-based smart sensor for drought stress detection in tomato plants using novel physiological variables and discrete wavelet transform.

    Science.gov (United States)

    Duarte-Galvan, Carlos; Romero-Troncoso, Rene de J; Torres-Pacheco, Irineo; Guevara-Gonzalez, Ramon G; Fernandez-Jaramillo, Arturo A; Contreras-Medina, Luis M; Carrillo-Serrano, Roberto V; Millan-Almaraz, Jesus R

    2014-10-09

    Soil drought represents one of the most dangerous stresses for plants. It impacts the yield and quality of crops, and if it remains undetected for a long time, the entire crop could be lost. However, for some plants a certain amount of drought stress improves specific characteristics. In such cases, a device capable of detecting and quantifying the impact of drought stress in plants is desirable. This article focuses on testing if the monitoring of physiological process through a gas exchange methodology provides enough information to detect drought stress conditions in plants. The experiment consists of using a set of smart sensors based on Field Programmable Gate Arrays (FPGAs) to monitor a group of plants under controlled drought conditions. The main objective was to use different digital signal processing techniques such as the Discrete Wavelet Transform (DWT) to explore the response of plant physiological processes to drought. Also, an index-based methodology was utilized to compensate the spatial variation inside the greenhouse. As a result, differences between treatments were determined to be independent of climate variations inside the greenhouse. Finally, after using the DWT as digital filter, results demonstrated that the proposed system is capable to reject high frequency noise and to detect drought conditions.

  20. Is There a Positive Synergistic Effect of Biochar and Compost Soil Amendments on Plant Growth and Physiological Performance?

    Directory of Open Access Journals (Sweden)

    M. Lukas Seehausen

    2017-02-01

    Full Text Available The combination of biochar (BC with compost has been suggested to be a promising strategy to promote plant growth and performance, but although “synergistic” effects have been stated to occur, full-factorial experiments are few, and explicit tests for synergism are lacking. We tested the hypothesis that a combination of BC and spent mushroom substrate (SMS has a positive synergistic effect on plant growth and physiological performance in a nutrient-limited growing media. A greenhouse experiment with a full factorial design was conducted using mixed-wood BC (3.0 kg·m−2 and SMS (1.5 kg·m−2 (the combination was not co-composted as organic soil amendments for the annual Abutilon theophrasti and the perennial Salix purpurea. Several measurements related to plant growth and physiological performance were taken throughout the experiment. Contrary to the hypothesis, we found that the combination of BC + SMS had neutral or antagonistic interactive effects on many plant growth traits. Antagonistic effects were found on maximum leaf area, above- and belowground biomass, reproductive allocation, maximum plant height, chlorophyll fluorescence, and stomatal conductance of A. theophrasti. The effect on S. purpurea was mostly neutral. We conclude that the generalization that BC and compost have synergistic effects on plant performance is not supported.

  1. Relating nutritional and physiological characteristics to growth of Pinus radiata clones planted on a range of sites in New Zealand.

    Science.gov (United States)

    Hawkins, Barbara J; Xue, Jianming; Bown, Horacio E; Clinton, Peter W

    2010-09-01

    Six clones of radiata pine with known differences in growth rate were examined for clonal nutritional characteristics and for physiological determinants of clonal growth rate. We compared growth, foliar characteristics and nutrient, ¹³C and ¹⁵N concentration data for the six clones in 4- to 6-year-old field trials planted over a range of nutritionally contrasting sites. These data were also compared with growth, nutrient uptake and remobilization, foliar characteristic and gas exchange data from intensive physiological glasshouse experiments using 1- and 2-year-old plants of the same clones. Significant genotype x environment interactions in our field experiments conducted over strong nutritional gradients allowed us to identify radiata pine clones with consistent, superior growth and nutritional characteristics and clones that may be suited to particular site conditions. Our results suggest that the opportunity exists to exploit clone x site variation for site-specific clonal deployment and planting of fast-growing clones could be accompanied by planting of clones able to take relative advantage of site nutritional characteristics. Faster tree growth was not strongly related to any physiological characteristic, and the factors influencing growth rate differed among clones. The fastest-growing clone had consistent, high uptake of all nutrients, high fascicle weights and high water-use efficiency.

  2. 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

    2017-01-01

    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. PMID:28272515

  3. 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.

  4. Model development and calibration for investigating climate, soil, and plant physiological controls on desert ecosystems

    Science.gov (United States)

    Ng, G. C.; Bedford, D.; Miller, D. M.

    2011-12-01

    Arid ecosystems have adapted to cope with extreme temperatures and unreliable moisture inputs. Understanding desert vegetation dynamics through seasonal to inter-annual meteorological variability is important for assessing how further intensification of the hydrological system under climate change may impact desert ecosystems. Furthermore, due to world-wide problems with desertification, proper ecological characterization of deserts, which already cover a fifth of the world's land surface, is increasingly critical for monitoring global-scale ecology. We present a model-based study that examines spatio-temporal dynamics of desert vegetation in a research watershed located in the Mojave Desert. Moving from the basin floor to higher elevations, the study area covers a range of meteorological and soil conditions, allowing us to explore how various climate, soil, and plant physiological factors interact to affect desert ecosystems. The first stage of this work entails developing a model appropriate for simulating desert ecological systems. NCAR's CLM-CN model fully couples dynamics within the soil-vegetation-atmosphere continuum. It includes parameterizations for diverse vegetation types, making it a flexible and accessible tool for ecohydrological studies. The dominant plant-type in our study area is Larrea tridentata, a shrub abundantly found in deserts of North and South America. We find that the current CLM-CN sub-model for (semi-)arid region shrubs may not be suitable for the extreme conditions found in parts of the study area. Model modifications representing various adaptations of drought-resistant Larrea are crucial for properly simulating vegetation growth. Changes to CLM's soil hydraulic property functions are also needed to represent gravelly soils typical of the region. After developing a suitable parameterization for desert shrubs and soils, we calibrate the model to soil moisture and vegetation measurements in the study area. This includes soil moisture

  5. Interactive physiological response of potato (Solanum tuberosum L. plants to fungal colonization and Potato virus Y (PVY infection

    Directory of Open Access Journals (Sweden)

    Dominika Thiem

    2014-11-01

    Full Text Available Potato plants can be colonized by various viruses and by symbiotic, saprophytic and pathogenic fungi. However, the significance of interactions of viral infection and fungal colonization is hardly known. This work presents a model experiment in which the influence of three different types of fungal associations on the growth and physiology of the potato variety Pirol was tested individually or in combination with infection by PVY. It was hypothesized that simultaneous viral and fungal infections increase the biotic stress of the host plant, but mutualistic plant-fungal associations can mask the impact of viral infection. In the present study, a symbiotic arbsucular mycorrhizal fungus, Glomus intraradices, significantly stimulated the growth of plants infected with PVY. In contrast, two saprophytic Trichoderma spp. strains either did not influence or even inhibited the growth of PVY-infected plants. Also, inoculation of PVY-infected potato plants with a pathogenic strain of Colletotrichum coccodes did not inhibit the plant growth. Growth of the PVY-free potato plants was not promoted by the symbiotic fungus, whereas T. viride, T. harzianum and C. coccodes had an evident inhibitory effect. The strongest growth inhibition and highest concentration of H2O2, as an indicator of biotic stress, was observed in PVY-free potato plants inoculated with T. harzianum and C. coccodes strains. Surprisingly, ultrastructural analysis of PVY-infected plant roots colonized by G. intraradices showed virus-like structures in the arbuscules. This pointed to the possibility of mycorrhizal-mediated transmission of virus particles and has to be further examined by testing with immunoassays and real transmission to uninfected plants. In conclusion, although mycorrhiza formation might decrease the impact of PVY infection on plants, a possible role of mycorrhizal fungi as virus vectors is discussed.

  6. A developmental biologist’s journey to rediscover the Zen of plant physiology [v1; ref status: indexed, http://f1000r.es/53n

    OpenAIRE

    José R Dinneny

    2015-01-01

    Physiology, which is often viewed as a field of study distinct from development, is technically defined as the branch of biology that explores the normal function of living organisms and their parts. Because plants normally develop continuously throughout their life, plant physiology actually encompasses all developmental processes. Viewing plant biology from a physiologist’s perspective is an attempt to understand the interconnectedness of development, form, and function in the context of mu...

  7. Evaluating the physiological state of maize (Zea mays L.) plants by direct-injection electrospray mass spectrometry (DIESI-MS).

    Science.gov (United States)

    García-Flores, Martín; Juárez-Colunga, Sheila; Montero-Vargas, Josaphat Miguel; López-Arciniega, Janet Ana Isabel; Chagolla, Alicia; Tiessen, Axel; Winkler, Robert

    2012-06-01

    Climatic change is an increasing challenge for agriculture that is driving the development of suitable crops in order to ensure supply for both human nutrition and animal feed. In this context, it is increasingly important to understand the biochemical responses of cells to environmental cues at the whole system level, an aim that is being brought closer by advances in high throughput, cost-efficient plant metabolomics. To support molecular breeding activities, we have assessed the economic, technical and statistical feasibility of using direct mass spectrometry methods to evaluate the physiological state of maize (Zea mays L.) plants grown under different stress conditions.

  8. Effect of Various Doses Application of Metribuzin Herbicide and Plant Density on Yield and Physiological Indices of Wheat (Triticum aestivum

    Directory of Open Access Journals (Sweden)

    M Naghshbandi

    2012-10-01

    Full Text Available In order to survey the influence of metribuzin herbicide on physiological indices and yield of wheat, an experiment was conducted at experimental field of Plant Pest and Disease Research Institute, Karaj, Iran during 2007. Treatments were in factorial arrangement laid out in four randomized complete blocks. The factors investigated were three plant densities: 400, 500 and 600 plant.m-2 and metribuzin doses: 0, 0.2, 0.4, 0.6 and 0.8 kg.ha-1. The result showed that the highest physiological indices and grain yield were obsevered in densities of 500 plant.m-2 and in applications of 0.6 and 0.8 kg. ha-1. Higher rates could be provided an acceptable level of weed control. Plant density could provide good control on weed and could be decrease using herbicide too by decreasing of available light for weed. This strategy can reduce the peresure of selection in resistant weeds population.

  9. 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.

  10. 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 (GA4, GA8, GA9, GA19, and GA20) 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 GA4 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.

  11. Physiological studies on cultivar-specific resistance of tomato plants to Cladosporium fulvum

    NARCIS (Netherlands)

    Wit, de P.J.G.M.

    1981-01-01

    Ultrastructural and physiological aspects of cultivar-specific resistance of tomato against Cladosporium fulvum (syn. Fulvia fulva) are subject of this thesis.The ultrastructural study described in the first paper was meant as an introduction to a physiological study of cultivar-specific resistance.

  12. A monitoring system of radioactive tracers in hydroponic solution for research on plant physiology

    Energy Technology Data Exchange (ETDEWEB)

    Suzui, N.; Kawachi, N.; Ishioka, N.; Fujimaki, S. [Quantum Beam Science Directorate, Japan Atomic Energy Agency, Takasaki, Gunma 370-1292 (Japan); Yamaguchi, M. [Takasaki Advanced Radiation Research Institute, Atomic Energy Agency, Takasaki, Gunma 370-1292 (Japan)

    2009-07-01

    The mechanism of nutrient uptake in plants has received considerable attention in the field of plant science. Here we describe the development of a new monitoring system of radioactive tracers in hydroponic solution, which enables the noninvasive measurement of radioactive tracer uptake by an intact plant. In addition, we incorporated a weighing instrument into this system in order to simultaneously monitor water uptake by the same plant. For an evaluation of this monitoring system, we conducted a tracer experiment with a rice plant and a positron-emitting radioactive tracer, and successfully obtained continuous data for the amounts of radioactive tracer and water taken up by the intact plant over 36 h. (authors)

  13. Plant physiological, morphological and yield-related responses to night temperature changes across different species and plant functional types

    OpenAIRE

    Panpan Jing; Dan Wang; Chunwu Zhu; Jiquan Chen

    2016-01-01

    Land surface temperature over the past decades has shown a faster warming trend during the night than during the day. Extremely low night temperatures have occurred frequently due to the influence of land-sea thermal difference, topography and climate change. This asymmetric night temperature change is expected to affect plant ecophysiology and growth, as the plant carbon consumption processes could be affected more than the assimilation processes because photosynthesis in most plants occurs ...

  14. Effects of Organic and Chemical Fertilizations and Microbe Inoculation on Physiology and Growth ofSweet Corn Plants

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    A pot culture experiment was carried out in a glasshouse to compare the physiology and growth of sweet corn plants (Zea mays L. cv. Honey Bantam) grown under organic and chemical fertilizations with or without microbial inoculation (MI). The organic fertilizer used was fermented mainly using rice bran and oil mill sludge, and the MI was a liquid product containing many beneficial microbes such as lactic acid bacteria, yeast, photosynthetic bacteria and actinomycetes. The application amounts of the organic fertilizer and chemical fertilizers were based on the same rate of nitrogen, phosphorus and potassium. Sweet corn plants fertilized with organic materials inoculated with beneficial microbes grew better than those without inoculation. There were no significant differences in physiology and growth of the sweet corn plants between treatments of chemical fertilizers with and without MI. Among the organic fertilization treatments, only the sweet corn plants with organic fertilizer and MI applied 4 weeks before sowing had similar photosynthetic capacity, total dry matter yield and ear yield to those with chemical fertilizers. Sweet corn plants in other organic fertilization treatments were weaker in physiology and growth than those in chemical fertilization treatments. There was no significant variance among chemical fertilization treatments at different time. It is concluded from this research that this organic fertilizer would be more effective if it was inoculated with the beneficial microbes. Early application of the organic fertilizer with beneficial microbes before sowing was recommended to make the nutrients available before the rapid growth at the early stage and obtain a yield similar to or higher than that with chemical fertilizations.

  15. Efficacy of Physiologically Active Anti-Transpirants on Excised Leaves of Potted Plants

    NARCIS (Netherlands)

    Besufkad Degif, A.; Woltering, E.J.

    2015-01-01

    Pot plant production in the greenhouse is most of the time under high relative humidity and frequent irrigation. While, during shipping and retailing plants may be exposed to high temperature and infrequent irrigation. These unfavorable conditions often cause water loss, desiccation of plants and sh

  16. Plant performance: a physiological and genetic analysis using Arabidopsis thaliana natural variation

    NARCIS (Netherlands)

    El-Lithy, M.E.M.

    2005-01-01

    Plant performance implies complex traits, controlled by a large set of genes and affected by the environment. In this thesis we have tried to take the first steps in unravelling the genes controlling plant performance using naturally occurring accessions (ecotypes) of the model plant Arabidopsis

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

    NARCIS (Netherlands)

    Holmgren, M.; Gomez-Aparicio, L.; Quero, J.L.; Valladares, F.

    2012-01-01

    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 model

  18. The effect of dehydration on plant regeneration and some physiology characters in rice calli

    Institute of Scientific and Technical Information of China (English)

    ZHAOChengzhang; WULianbin; YANGChangdeng; QIXiufang

    1997-01-01

    The plant regeneration frequencies of calli from plant tissue and cell culture, especially that of the calli from rice tissue culture and rice anther culture, and that of the foreign-DNA-transfor-matlon-derived rice calli is very low (usually 10-15%). It is therefor very important to improve the plant regeneration frequency of rice calli.

  19. Soil organic matter influences cerium translocation and physiological processes in kidney bean plants exposed to cerium oxide nanoparticles.

    Science.gov (United States)

    Majumdar, Sanghamitra; Peralta-Videa, Jose R; Trujillo-Reyes, Jesica; Sun, Youping; Barrios, Ana C; Niu, Genhua; Margez, Juan P Flores-; Gardea-Torresdey, Jorge L

    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 0-500mg/kg cerium oxide nanoparticles (nano-CeO2) under greenhouse condition. After 52days 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-CeO2 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-CeO2 concentration in LOMS, the effect on the physiological processes were inconsequential. In OMES leaves, exposure to 62.5-250mg/kg nano-CeO2 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 250mg/kg nano-CeO2. In addition, catalase activity increased in LOMS stems, and ascorbate peroxidase increased in OMES leaves of nano-CeO2 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. Copyright © 2016 Elsevier B.V. All rights reserved.

  20. Modifications of Morphometrical and Physiological Parameters of Pepper Plants Grown on Artificial Nutrient Medium for Experiments in Spaceflight

    Science.gov (United States)

    Nechitailo, Galina S.

    2016-07-01

    MODIFICATIONS OF MORPHOMETRICAL AND PHYSIOLOGICAL PARAMETERS OF PEPPER PLANTS GROWN ON ARTIFICIAL NUTRIENT MEDIUM FOR EXPERIMENTS IN SPACEFLIGHT Lui Min*, Zhao Hui*, Chen Yu*, Lu Jinying*, Li Huasheng*, Sun Qiao*, Nechitajlo G.S.**, Glushchenko N.N.*** *Shenzhou Space Biotechnology Group, China Academy of Space Technology (CAST), **Emanuel Institute of Biochemical Physics of Russian Academy of Sciences (IBCP RAS) mail: spacemal@mail.ru ***V.L. Talrose Institute for Energy Problems of Chemical Physics of Russian Academy of Science (INEPCP RAS) mail: nnglu@ mail.ru In circumstances of space flights, long residence of the staff at space stations and space settlements an optimal engineering system of the life-support allowing to solve a number of technical and psychological problems for successful work and a life of cosmonauts, researchers, etc. is important and prime. In this respect it is necessary to consider growing plants on board of spacecraft as one of the units in a life-support system. It is feasible due to modern development of biotechnologies in growing plants allowing us to receive materials with new improved properties. Thus, a composition and ratio of components of nutrient medium can considerably influence on plants properties. We have developed the nutrient medium in which essential metals such as iron, zinc, copper were added in an electroneutral state in the form of nanoparticles instead of sulfates or other salts of the same metals. Such replacement is appropriate through unique nanoparticles properties: metal nanoparticles are less toxic than their corresponding ionic forms; nanoparticles produce a prolonged effect, serving as a depot for elements in an organism; nanoparticles introduced in biotic doses stimulate the metabolic processes of the organism; nanoparticles effect is multifunctional. Pepper strain LJ-king was used for growing on a nutrient medium with ferrous, zinc, copper nanoparticles in different concentrations. Pepper plants grown on

  1. Optimal plant water use across temporal scales: bridging eco-hydrological theories and plant eco-physiological responses

    Science.gov (United States)

    Manzoni, S.; Vico, G.; Palmroth, S.; Katul, G. G.; Porporato, A. M.

    2013-12-01

    In terrestrial ecosystems, plant photosynthesis occurs at the expense of water losses through stomata, thus creating an inherent hydrologic constrain to carbon (C) gains and productivity. While such a constraint cannot be overcome, evolution has led to a number of adaptations that allow plants to thrive under highly variable and often limiting water availability. It may be hypothesized that these adaptations are optimal and allow maximum C gain for a given water availability. A corollary hypothesis is that these adaptations manifest themselves as coordination between the leaf photosynthetic machinery and the plant hydraulic system. This coordination leads to functional relations between the mean hydrologic state, plant hydraulic traits, and photosynthetic parameters that can be used as bridge across temporal scales. Here, optimality theories describing the behavior of stomata and plant morphological features in a fluctuating soil moisture environment are proposed. The overarching goal is to explain observed global patterns of plant water use and their ecological and biogeochemical consequences. The problem is initially framed as an optimal control problem of stomatal closure during drought of a given duration, where maximizing the total photosynthesis under limited and diminishing water availability is the objective function. Analytical solutions show that commonly used transpiration models (in which stomatal conductance is assumed to depend on soil moisture) are particular solutions emerging from the optimal control problem. Relations between stomatal conductance, vapor pressure deficit, and atmospheric CO2 are also obtained without any a priori assumptions under this framework. Second, the temporal scales of the model are expanded by explicitly considering the stochasticity of rainfall. In this context, the optimal control problem becomes a maximization problem for the mean photosynthetic rate. Results show that to achieve maximum C gains under these

  2. Plant biostimulants: physiological responses induced by protein hydrolyzed-based products and humic substances in plant metabolism

    Directory of Open Access Journals (Sweden)

    Serenella Nardi

    2016-02-01

    Full Text Available ABSTRACT In recent years, the use of biostimulants in sustainable agriculture has been growing. Biostimulants can be obtained from different organic materials and include humic substances (HS, complex organic materials, beneficial chemical elements, peptides and amino acids, inorganic salts, seaweed extracts, chitin and chitosan derivatives, antitranspirants, amino acids and other N-containing substances. The application of biostimulants to plants leads to higher content of nutrients in their tissue and positive metabolic changes. For these reasons, the development of new biostimulants has become a focus of scientific interest. Among their different functions, biostimulants influence plant growth and nitrogen metabolism, especially because of their content in hormones and other signalling molecules. A significant increase in root hair length and density is often observed in plants treated with biostimulants, suggesting that these substances induce a “nutrient acquisition response” that favors nutrient uptake in plants via an increase in the absorptive surface area. Furthermore, biostimulants positively influence the activity and gene expression of enzymes functioning in the primary and secondary plant metabolism. This article reviews the current literature on two main classes of biostimulants: humic substances and protein-based biostimulants. The characteristic of these biostimulants and their effects on plants are thoroughly described.

  3. Biochemical and physiological characterisation of the purine degradation pathway in plants

    OpenAIRE

    Werner, Andrea

    2013-01-01

    Plant growth is often limited by nitrogen availability in the soil. Not only do plants depend on efficient nitrogen uptake, they also require effective means to internally redistribute nitrogen during every stage of development. The purine degradation pathway contributes to this nitrogen recycling in plants. In tropical legumes it is also of central importance to the plants’ nitrogen supply under nitrogen-fixing conditions. This is the first time that the complete ureide degradation pathway h...

  4. Physiological and molecular implications of plant polyamine metabolism during biotic interactions

    Directory of Open Access Journals (Sweden)

    Juan Francisco Jiménez Bremont

    2014-03-01

    Full Text Available During ontogeny, plants interact with a wide variety of microorganisms. The association with mutualistic microbes results in benefits for the plant. By contrast, pathogens may cause a remarkable impairment of plant growth and development. Both types of plant-microbe interactions provoke notable changes in the polyamine (PA metabolism of the host and/or the microbe, being each interaction a complex and dynamic process. It has been well documented that the levels of free and conjugated PAs undergo profound changes in plant tissues during the interaction with microorganisms. In general, this is correlated with a precise and coordinated regulation of PA biosynthetic and catabolic enzymes. Interestingly, some evidence suggests that the relative importance of these metabolic pathways may depend on the nature of the microorganism, a concept that stems from the fact that these amines mediate the activation of plant defense mechanisms. This effect is mediated mostly through PA oxidation, even though part of the response is activated by non-oxidized PAs. In the last years, a great deal of effort has been devoted to profile plant gene expression following microorganism recognition. In addition, the phenotypes of transgenic and mutant plants in PA metabolism genes have been assessed. In this review, we integrated the current knowledge on this field and analyze the possible roles of these amines during the interaction of plants with microbes.

  5. Effects of narrow plant spacing on root distribution and physiological nitrogen use efficiency in summer maize

    Directory of Open Access Journals (Sweden)

    Wenshun Jiang

    2013-10-01

    Full Text Available The objective of this study was to understand the effects of plant spacing on grain yield and root competition in summer maize (Zea mays L.. Maize cultivar Denghai 661 was planted in rectangular tanks (0.54 m × 0.27 m × 1.00 m under 27 cm (normal and 6 cm (narrow plant spacing and treated with zero and 7.5 g nitrogen (N per plant. Compared to normal plant spacing, narrow plant spacing generated less root biomass in the 0–20 cm zone under both N rates, slight reductions of dry root weight in the 20–40 cm and 40–70 cm zones at the mid-grain filling stage, and slight variation of dry root weights in the 70–100 cm zone during the whole growth period. Narrow plant spacing decreased root reductive activity in all root zones, especially at the grain-filling stage. Grain yield and above-ground biomass were 5.0% and 8.4% lower in the narrow plant spacing than with normal plant spacing, although narrow plant spacing significantly increased N harvest index and N use efficiency in both grain yield and biomass, and higher N translocation rates from vegetative organs. These results indicate that the reductive activity of maize roots in all soil layers and dry weights of shallow roots were significantly decreased under narrow plant spacing conditions, resulting in lower root biomass and yield reduction at maturity. Therefore, a moderately dense sowing is a basis for high yield in summer maize.

  6. Effects of narrow plant spacing on root distribution and physiological nitrogen use efficiency in summer maize

    Institute of Scientific and Technical Information of China (English)

    Wenshun; Jiang; Kongjun; Wang; Qiuping; Wu; Shuting; Dong; Peng; Liu; Jiwang; Zhang

    2013-01-01

    The objective of this study was to understand the effects of plant spacing on grain yield and root competition in summer maize(Zea mays L.). Maize cultivar Denghai 661 was planted in rectangular tanks(0.54 m × 0.27 m × 1.00 m) under 27 cm(normal) and 6 cm(narrow) plant spacing and treated with zero and 7.5 g nitrogen(N) per plant. Compared to normal plant spacing, narrow plant spacing generated less root biomass in the 0–20 cm zone under both N rates, slight reductions of dry root weight in the 20–40 cm and 40–70 cm zones at the mid-grain filling stage, and slight variation of dry root weights in the 70–100 cm zone during the whole growth period. Narrow plant spacing decreased root reductive activity in all root zones, especially at the grain-filling stage. Grain yield and above-ground biomass were 5.0% and 8.4% lower in the narrow plant spacing than with normal plant spacing, although narrow plant spacing significantly increased N harvest index and N use efficiency in both grain yield and biomass, and higher N translocation rates from vegetative organs. These results indicate that the reductive activity of maize roots in all soil layers and dry weights of shallow roots were significantly decreased under narrow plant spacing conditions, resulting in lower root biomass and yield reduction at maturity. Therefore, a moderately dense sowing is a basis for high yield in summer maize.

  7. Physiological response and sulfur metabolism of the V. dahliae-infected tomato plants in tomato/potato onion companion cropping

    Science.gov (United States)

    Fu, Xuepeng; Li, Chunxia; Zhou, Xingang; Liu, Shouwei; Wu, Fengzhi

    2016-01-01

    Companion cropping with potato onions (Allium cepa var. agrogatum Don.) can enhance the disease resistance of tomato plants (Solanum lycopersicum) to Verticillium dahliae infection by increasing the expressions of genes related to disease resistance. However, it is not clear how tomato plants physiologically respond to V. dahliae infection and what roles sulfur plays in the disease-resistance. Pot experiments were performed to examine changes in the physiology and sulfur metabolism of tomato roots infected by V. dahliae under the companion cropping (tomato/potato onion). The results showed that the companion cropping increased the content of total phenol, lignin and glutathione and increased the activities of peroxidase, polyphenol oxidase and phenylalanine ammonia lyase in the roots of tomato plants. RNA-seq analysis showed that the expressions of genes involved in sulfur uptake and assimilation, and the formation of sulfur-containing defense compounds (SDCs) were up-regulated in the V. dahlia-infected tomatoes in the companion cropping. In addition, the interactions among tomato, potato onion and V. dahliae induced the expression of the high- affinity sulfate transporter gene in the tomato roots. These results suggest that sulfur may play important roles in tomato disease resistance against V. dahliae. PMID:27808257

  8. Ascending migration of endophytic rhizobia, from roots to leaves, inside rice plants and assessment of benefits to rice growth physiology.

    Science.gov (United States)

    Chi, Feng; Shen, Shi-Hua; Cheng, Hai-Ping; Jing, Yu-Xiang; Yanni, Youssef G; Dazzo, Frank B

    2005-11-01

    Rhizobia, the root-nodule endosymbionts of leguminous plants, also form natural endophytic associations with roots of important cereal plants. Despite its widespread occurrence, much remains unknown about colonization of cereals by rhizobia. We examined the infection, dissemination, and colonization of healthy rice plant tissues by four species of gfp-tagged rhizobia and their influence on the growth physiology of rice. The results indicated a dynamic infection process beginning with surface colonization of the rhizoplane (especially at lateral root emergence), followed by endophytic colonization within roots, and then ascending endophytic migration into the stem base, leaf sheath, and leaves where they developed high populations. In situ CMEIAS image analysis indicated local endophytic population densities reaching as high as 9 x 10(10) rhizobia per cm3 of infected host tissues, whereas plating experiments indicated rapid, transient or persistent growth depending on the rhizobial strain and rice tissue examined. Rice plants inoculated with certain test strains of gfp-tagged rhizobia produced significantly higher root and shoot biomass; increased their photosynthetic rate, stomatal conductance, transpiration velocity, water utilization efficiency, and flag leaf area (considered to possess the highest photosynthetic activity); and accumulated higher levels of indoleacetic acid and gibberellin growth-regulating phytohormones. Considered collectively, the results indicate that this endophytic plant-bacterium association is far more inclusive, invasive, and dynamic than previously thought, including dissemination in both below-ground and above-ground tissues and enhancement of growth physiology by several rhizobial species, therefore heightening its interest and potential value as a biofertilizer strategy for sustainable agriculture to produce the world's most important cereal crops.

  9. Modelling grass digestibility on the basis of morphological and physiological plant characteristics

    NARCIS (Netherlands)

    Groot, J.C.J.

    1999-01-01

    Grass digestibility is determined by the rate of plant development, mass of plant organs (leaf blades, leaf sheaths and stem internodes) and composition of organs. The development of an integrating model for grass digestibility necessitates the quantification of developmental

  10. Physiology and toxicology of hormone-disrupting chemicals in higher plants.

    Science.gov (United States)

    Couée, Ivan; Serra, Anne-Antonella; Ramel, Fanny; Gouesbet, Gwenola; Sulmon, Cécile

    2013-06-01

    Higher plants are exposed to natural environmental organic chemicals, associated with plant-environment interactions, and xenobiotic environmental organic chemicals, associated with anthropogenic activities. The effects of these chemicals result not only from interaction with metabolic targets, but also from interaction with the complex regulatory networks of hormone signaling. Purpose-designed plant hormone analogues thus show extensive signaling effects on gene regulation and are as such important for understanding plant hormone mechanisms and for manipulating plant growth and development. Some natural environmental chemicals also act on plants through interference with the perception and transduction of endogenous hormone signals. In a number of cases, bioactive xenobiotics, including herbicides that have been designed to affect specific metabolic targets, show extensive gene regulation effects, which are more in accordance with signaling effects than with consequences of metabolic effects. Some of these effects could be due to structural analogies with plant hormones or to interference with hormone metabolism, thus resulting in situations of hormone disruption similar to animal cell endocrine disruption by xenobiotics. These hormone-disrupting effects can be superimposed on parallel metabolic effects, thus indicating that toxicological characterisation of xenobiotics must take into consideration the whole range of signaling and metabolic effects. Hormone-disruptive signaling effects probably predominate when xenobiotic concentrations are low, as occurs in situations of residual low-level pollutions. These hormone-disruptive effects in plants may thus be of importance for understanding cryptic effects of low-dosage xenobiotics, as well as the interactive effects of mixtures of xenobiotic pollutants.

  11. Morphological and Physiological Plant Responses to Drought Stress in Thymus citriodorus

    Directory of Open Access Journals (Sweden)

    Zdzislaw Attila Tátrai

    2016-01-01

    Full Text Available Water availability is considered as a determinant factor that affects plant growth. The commercial medicinal values of an aromatic plant rely on the presence of secondary metabolites that are affected under water shortage. Two-year-old Thymus citriodorus plants were subjected to different polyethylene glycol (PEG-6000 levels (0, 2%, and 4% under greenhouse condition. PEG treatment lasted for 15 days. Thyme plant showed a morphological drought avoidance mechanism by maintaining the root system development through shoot fresh weight reduction resulting in promoted root absorption capacity and sustained plant growth. Moreover, stressed plants were able to maintain water use efficiency and root : shoot ratio suggesting a strong relation between root water uptake and water use saving strategies. Furthermore, thyme plants reduced tissue dehydration through stomatal closure and improved root water uptake. Content of volatile oil constituents of geraniol and diisobutyl phthalate increased upon drought stress while pseudophytol was reduced. Unexpectedly, thymol was not reported as a main oil element under either control or mild stress condition, while it was increased upon high drought stress in measure of 4.4%. Finally, carvacrol significantly accumulated under high drought stress (+31.7% as compared to control plants.

  12. Substantial roles of hexokinase and fructokinase in the effects of sugars on plant physiology and development.

    Science.gov (United States)

    Granot, David; Kelly, Gilor; Stein, Ofer; David-Schwartz, Rakefet

    2014-03-01

    The basic requirements for plant growth are light, CO2, water, and minerals. However, the absorption and utilization of each of these requires investment on the part of the plant. The primary products of plants are sugars, and the hexose sugars glucose and fructose are the raw material for most of the metabolic pathways and organic matter in plants. To be metabolized, hexose sugars must first be phosphorylated. Only two families of enzymes capable of catalysing the essential irreversible phosphorylation of glucose and fructose have been identified in plants, hexokinases (HXKs) and fructokinases (FRKs). These hexose-phosphorylating enzymes appear to coordinate sugar production with the abilities to absorb light, CO2, water, and minerals. This review describes the long- and short-term effects mediated by HXK and FRK in various tissues, as well as the role of these enzymes in the coordination of sugar production with the absorption of light, CO2, water, and minerals.

  13. Casuarina root exudates alter the physiology, surface properties, and plant infectivity of Frankia sp. strain CcI3.

    Science.gov (United States)

    Beauchemin, Nicholas J; Furnholm, Teal; Lavenus, Julien; Svistoonoff, Sergio; Doumas, Patrick; Bogusz, Didier; Laplaze, Laurent; Tisa, Louis S

    2012-01-01

    The actinomycete genus Frankia forms nitrogen-fixing symbioses with 8 different families of actinorhizal plants, representing more than 200 different species. Very little is known about the initial molecular interactions between Frankia and host plants in the rhizosphere. Root exudates are important in Rhizobium-legume symbiosis, especially for initiating Nod factor synthesis. We measured differences in Frankia physiology after exposure to host aqueous root exudates to assess their effects on actinorhizal symbioses. Casuarina cunninghamiana root exudates were collected from plants under nitrogen-sufficient and -deficient conditions and tested on Frankia sp. strain CcI3. Root exudates increased the growth yield of Frankia in the presence of a carbon source, but Frankia was unable to use the root exudates as a sole carbon or energy source. Exposure to root exudates caused hyphal "curling" in Frankia cells, suggesting a chemotrophic response or surface property change. Exposure to root exudates altered Congo red dye binding, which indicated changes in the bacterial surface properties at the fatty acid level. Fourier transform infrared spectroscopy (FTIR) confirmed fatty acid changes and revealed further carbohydrate changes. Frankia cells preexposed to C. cunninghamiana root exudates for 6 days formed nodules on the host plant significantly earlier than control cells. These data support the hypothesis of early chemical signaling between actinorhizal host plants and Frankia in the rhizosphere.

  14. Physiological effects of magnetite (Fe3O4) nanoparticles on perennial ryegrass (Lolium perenne L.) and pumpkin (Cucurbita mixta) plants.

    Science.gov (United States)

    Wang, Huanhua; Kou, Xiaoming; Pei, Zhiguo; Xiao, John Q; Shan, Xiaoquan; Xing, Baoshan

    2011-03-01

    To date, knowledge gaps and associated uncertainties remain unaddressed on the effects of nanoparticles (NPs) on plants. This study was focused on revealing some of the physiological effects of magnetite (Fe(3)O(4)) NPs on perennial ryegrass (Lolium perenne L.) and pumpkin (Cucurbita mixta cv. white cushaw) plants under hydroponic conditions. This study for the first time reports that Fe(3)O(4) NPs often induced more oxidative stress than Fe(3)O(4) bulk particles in the ryegrass and pumpkin roots and shoots as indicated by significantly increased: (i) superoxide dismutase and catalase enzyme activities, and (ii) lipid peroxidation. However, tested Fe(3)O(4) NPs appear unable to be translocated in the ryegrass and pumpkin plants. This was supported by the following data: (i) No magnetization was detected in the shoots of either plant treated with 30, 100 and 500 mg l(-1) Fe(3)O(4) NPs; (ii) Fe K-edge X-ray absorption spectroscopic study confirmed that the coordination environment of Fe in these plant shoots was similar to that of Fe-citrate complexes, but not to that of Fe(3)O(4) NPs; and (iii) total Fe content in the ryegrass and pumpkin shoots treated with Fe(3)O(4) NPs was not significantly increased compared to that in the control shoots.

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

    DEFF Research Database (Denmark)

    Stranne, Maria

    wall acetylation (Chapter 2), identification of a candidate gene required for acetylation of pectin (Chapter 3), screening of pectin mutants for susceptibility to the nectrotrophic fungal pathogen Botrytis cinerea (Chapter 4), and identification and functional characterization of an arabinan......-degrading enzyme secreted by B. cinerea during infection of plants (Chapter 5). The results described resulted in valuable new knowledge regarding the role of pectin acetylation and arabinosylation in the model plant Arabidopsis thaliana documented in three published research papers, one manuscript and one...

  16. Plant physiological response of strawberry fruit to chlorine dioxide gas treatment during postharvest storage

    Science.gov (United States)

    Chlorine dioxide, a strong oxidizing and sanitizing agent, is used as a postharvest sanitizer for fruits and vegetables and generally applied on a packing line using a chlorine dioxide generator. The objective of this research was to study the physiological responses of strawberries to ClO2 when app...

  17. Linking Leaf Chlorophyll Fluorescence Properties to Physiological Responses for Stress Detection in Coastal Plant Species

    Science.gov (United States)

    2007-01-01

    temperature and light. Stress may be apparent in morphological and physiological character- istics, which represent integrated responses to multiple...australis (Cav.) Trin. ex Steud. (common reed), Poaceae , is an invasive perennial grass that has formed numerous large colonies, fringing freshwater and...EP, Guntenspergen GR, Brown JJ, Nelson SG (2006) Salt tolerance and osmotic adjustment of Spartina alterniflora ( Poaceae ) and the invasive M

  18. Influence of Environmental Changes on Physiology and Development of Polar Vascular Plants

    Science.gov (United States)

    Giełwanowska, Irena; Pastorczyk, Marta; Kellmann-Sopyła, Wioleta

    2011-01-01

    Polar vascular plants native to the Arctic and the Antarctic geobotanical zone have been growing and reproducing effectively under difficult environmental conditions, colonizing frozen ground areas formerly covered by ice. Our macroscopic observations and microscopic studies conducted by means of a light microscope (LM) and transmission electron microscope (TEM) concerning the anatomical and ultrastructural observations of vegetative and generative tissue in Cerastium arcticum, Colobanthus quitensis, Silene involucrata, plants from Caryophyllaceae and Deschampsia antarctica, Poa annua and Poa arctica, from Poaceae family. In the studies, special attention was paid to plants coming from diversity habitats where stress factors operated with clearly different intensity. In all examinations plants, differences in anatomy were considerable. In Deschampsia antarctica the adaxial epidermis of hairgrass leaves from a humid microhabitat, bulliform cells differentiated. Mesophyll was composed of cells of irregular shapes and resembled aerenchyma. The ultrastructural observations of mesophyll in all plants showed tight adherence of chloroplasts, mitochondria and peroxisomes, surface deformations of these organelles and formation of characteristic outgrowths and pocket concavities filled with cytoplasm with vesicles and organelles by chloroplasts. In reproduction biology of examined Caryophyllaceae and Poaceae plants growing in natural conditions, in the Arctic and in the Antarctic, and in a greenhouse in Olsztyn showed that this plant develops two types of bisexual flowers. Almost all ovules developed and formed seeds with a completely differentiated embryo both under natural conditions in the Arctic and the Antarctic and in a greenhouse in Olsztyn.

  19. Calcium signaling in plant endosymbiotic organelles: mechanism and role in physiology.

    Science.gov (United States)

    Nomura, Hironari; Shiina, Takashi

    2014-07-01

    Recent studies have demonstrated that chloroplasts and mitochondria evoke specific Ca(2+) signals in response to biotic and abiotic stresses in a stress-dependent manner. The identification of Ca(2+) transporters and Ca(2+) signaling molecules in chloroplasts and mitochondria implies that they play roles in controlling not only intra-organellar functions, but also extra-organellar processes such as plant immunity and stress responses. It appears that organellar Ca(2+) signaling might be more important to plant cell functions than previously thought. This review briefly summarizes what is known about the molecular basis of Ca(2+) signaling in plant mitochondria and chloroplasts.

  20. Relationships between xylem embolism and eco-physiological indices in eight woody plants in sltu(Ⅱ):The relationship with photosynthetic eco-physiological indices

    Institute of Scientific and Technical Information of China (English)

    AN Feng; CAI Jing; JIANG Zaimin; ZHANG Yuanying; ZHAO Pingjuan; ZHANG Shuoxin

    2007-01-01

    The relationship between xylem embolism and eco-physiology indices (I.e.photosynthetic available radiation,temperature,relative humidity,photosynthetic rate,transpiration rate,stomatal conductance and water use efficiency) in eight tree species was investigated in situ.The species studied,Robinia pseudoacacia L.,Acer truncatum Bge.,Hippophae rhamnoides L.,Ulmus pumila L.,Pinus tabulaeformis Carr., Pinus bungeana Zucc.ex Endl.,Ligustrum lucidum Ait.,and Salix matsudana Koidz.f.pendula Schneid,grow well on the Xilin campus of Northwest A&F University.Results indicated that photosynthetic available radiation,air temperature and relative humidity can affect xylem embolism by daily adjustment of stomatal conductance,transpiration rate and water relations of a tree.Embolism was a common case in the daily growth of the plants,and there was some correlation between xylem embolism and photosynthetic rate,transpiration rate,stornatal conductance,and water use efficiency.Embolism may thus be an adaptive mechanism by some tree species to water stress.

  1. Recent Advances in the Role of the Elongator Complex in Plant Physiology and tRNA Modiifcation:A Review

    Institute of Scientific and Technical Information of China (English)

    YAN Xu; JIN Xiao-huan; WANG You-mei; ZHENG Bo; CHEN Peng

    2014-01-01

    The Elongator complex is a multifunction protein complex which has been shown to be involved in transcriptional elongation, DNA replication and repair, tubulin and histone acetylation, gene silencing and tranfer RNA uridine modiifcation. The composition of the Elongator complex is found to be highly conserved in eukaryotes, protein homologs of various subunits have been identiifed in fungi, plant, animal, and human. Remarkably, mutation in genes encoding the Elongator complex structural components all results in defects of transfer RNA wobble uridine modiifcation, and this function of the Elongator complex is also conserved in eukaryotes. The Elongator complex mutants in higher plants have pleiotropic phenotypes including defects in vegetative growth, abiscisic acid hypersensitivity, elevated tolerance to drought and oxidative stress. What is the relationship between the Elongator complex’s function in nucleoside modiifcation and its activity in other cellular pathways? This review summarizes the recent advances in study of function of the Elongator complex, in the aspects of cell physiology and molecular biology.

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

    National Research Council Canada - National Science Library

    Sasan Mohsenzadeh; Nadereh Naderi; Mahdi Nazari

    2016-01-01

    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...

  3. Diverse Functional Roles of Monosaccharide Transporters and their Homologs in Vascular Plants: A Physiological Perspective

    Institute of Scientific and Technical Information of China (English)

    Thomas L. Slewinski

    2011-01-01

    Vascular plants contain two gene families that encode monosaccharide transporter proteins. The classical monosaccharide transporter(-like)gene superfamily is large and functionally diverse, while the recently identified SWEET transporter family is smaller and, thus far, only found to transport glucose. These transporters play essential roles at many levels, ranging from organelles to the whole plant. Many family members are essential for cellular homeostasis and re-productive success. Although most transporters do not directly participate in long-distance transport, their indirect roles greatly impact carbon allocation and transport flux to the heterotrophic tissues of the plant. Functional characterization of some members from both gene families has revealed their diverse roles in carbohydrate partitioning, phloem function,resource allocation, plant defense, and sugar signaling. This review highlights the broad impacts and implications of monosaccharide transport by describing some of the functional roles of the monosaccharide transporter(-like)superfamily and the SWEET transporter family.

  4. Physiological and Genetic Bases of the Circadian Clock in Plants and Their Relationship with Herbicides Efficacy

    OpenAIRE

    DALAZEN,G.; Merotto Jr.,A.

    2016-01-01

    In order to adapt to daily environmental changes, especially in relation to light availability, many organisms, such as plants, developed a vital mechanism that controls time-dependent biological events: the circadian clock. The circadian clock is responsible for predicting the changes that occur in the period of approximately 24 hours, preparing the plants for the following phases of the cycle. Some of these adaptations can influence the response of weeds to the herbicide application. Thus, ...

  5. Ways of signal transmission and physiological role of electrical potentials in plants

    Directory of Open Access Journals (Sweden)

    Halina Dziubińska

    2011-01-01

    Full Text Available Plants are subject to stimuli from the environment on which they strongly depend and in contrast to animals, they are unable to escape harmful influences. Therefore, being able to receive stimuli they have developed adequate responses to them. Such a reaction can occur in the area of a stimulus action or cover the whole plant or its parts. In the latter case, it is a systemic reaction. The plant reaction is expressed by various intensity, rate and kind of response. It is interesting to know the character of the signal informing about a stimulus, the routes of its propagation and the transmission mechanism. Three conceptions of excitation are distinguished: 1 propagation of chemical agents formed at the site of a stimulus action with the flow of the phloem sap or through the atmosphere (in the case of volatile substances to other plant parts, 2 a very fast transmission by the xylem in the wave of hydraulic pressure formed after a plant damage. From combining the "hydraulic" and "chemical" hypothesis a conception of hydraulic dispersion has been formulated which assumes that chemical substances synthetized after an injury can be transferred very fast with the wave of hydraulic pressure changes in the whole plant, 3 a stimulus evokes the action potential (AP, and its transmission along the whole plant, plant organ or specialized tissue, by local circuits from cell to cell. Strong, damaging stimuli can evoke variation potentials (VPs, the character of which differs from APs. It is postulated that transmission of VP occurs by a hydraulic dispersion and electrical changes seem to be secondary phenomena.

  6. INTERACTIVE EFFECTS OF SALINITY STRESS AND NICOTINAMIDE ON PHYSIOLOGICAL AND BIOCHEMICAL PARAMETERS ON FABA BEAN PLANT

    Directory of Open Access Journals (Sweden)

    Magdi T. Abdelhamid

    2013-09-01

    Full Text Available A possible survival strategy of plants under saline conditions is to use some compounds that could alleviate salt stress effect. One of these compounds is nicotinamide. The effect of exogenously application of nicotinamide with different concentrations (0, 200 and 400 mg/l on Vicia faba L. plant against different NaCl treatments (0, 50 and 100 mM NaCl was investigated at the wire house of the National Research Centre, Cairo, Egypt. Salinity stress reduced significantly plant height, dry weight of shoot, photosynthetic pigments, polysaccharides, total carbohydrates, total-N contents of shoot, seed yield, total carbohydrates & total crude protein of the yielded seeds compared with those of the control plants. In contrast, salinity induced marked increases in sucrose, total soluble sugars, total free amino acids, proline, lipid peroxidation product (MDA and some oxidative enzymes (polyphenol oxidase and peroxidase enzymes. Also, salinity stress increased Na+ contents with the decreases of other macro and micro elements contents (P, K+, Mg+, Ca2+, Fe2+, Mn2+, Zn2+ and Cu2+ of shoots and the yielded seeds of faba bean. Foliar spraying of nicotinamide alleviated the adverse effects of salinity stress through increased plant height, dry weight of shoot, photosynthetic pigments, polysaccharides, total carbohydrates, total-N contents of shoot and seed yield as well as, sucrose, total soluble sugars, total free amino acids and proline, compared with those of the corresponding salinity levels, while decreased lipid peroxidation product as MDA and the oxidative enzymes (polyphenol oxidase and peroxidase enzymes. Nicotinamide inhibited the uptake of Na+ and accelerated the accumulation of P, K+ , Mg+, Ca2+, Fe2+, Mn2+, Zn2+ and Cu2+ contents in the shoots of salt stressed plants and enhanced total carbohydrate and total crude protein percentage and solutes concentrations in seeds of salinity treated plants

  7. Physiological response of natural plants to the change of groundwater level in the lower reaches of Tarim River,Xinjiang

    Institute of Scientific and Technical Information of China (English)

    CHEN Yaning; LI Weihong; CHEN Yapeng; ZHANG Hongfeng; ZHUANG Li

    2004-01-01

    Based on the analysis of the three-year (2000-2002) monitoring data of the four times intermittent stream water conveyance to the lower reaches of Tarim River where the stream flow was dried up for more than 30 years and the measurement of PRO, SOD and POD in plants collected from 24 vegetation plots, it is concluded that the stream water conveyance plays an important role in lifting groundwater level. The groundwater nearby the watercourse was raised from 5~8 m in depth before the stream water conveyance to 2.5~5 m after stream water conveyance. The physiological response of Phragmites communis, Tamarix spp. And Populus euphratica to the change of groundwater is sensitive and represents a grads change obviously. The growth of the plants in the lower reaches of Tarim River is stressed by drought to various degrees. Lengthways, the drought stress exposed to the plants increases with groundwater depth from the upper sections to the lower sections; and breadthwise, the drought stress exposed to the plants is increased with the increase of distance away from the river channel of stream intermittent water releases and of the groundwater depth. Combining the field investigation and the analysis of the plots, it is considered that the stress groundwater depths for the Phragmites communis, Tamarix spp. And Populus euphratica are 3.5 m, 5 m and 4.5 m respectively.

  8. 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

  9. 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

  10. Effect of various soil salinity level on the antioxidant and physiological properties of corn plant (Zea mays

    Directory of Open Access Journals (Sweden)

    Ramin Ezzati

    2015-10-01

    Full Text Available To study the effect of various soil salinity levels on the antioxidant enzymes and physiological characteristics of corn as an indicator of salt stress resistance, present study was conducted in 2013 at Research lab of environmental, Faculty of Biological Sciences, University of Kharazmi, Iran. Furthermore, desert soils of Libya, India, Iraq and Karaj were used for testing the effect of soil salinity on the quantity of oxidant enzymes and various properties of maize plant. For providing favorable atmospheric conditions 33000 lux light and spray of perlite medium was used. Corn crop is highly sensitive to soil salinity so all the cultivation was carried out under conditions of soil EC lower than 20 ds/m and 8.5 pH. Results of the study revealed that the salt stress significantly affect the amount of antioxidant enzymes such as guaiacol peroxidase and malondialdehyde. Furthermore, it was reported that saline soil did not have any negative effect on the physiological characteristics and growth of corn plant growth.

  11. Physiological responses of macaúba young plants to cyclical drought conditions

    Directory of Open Access Journals (Sweden)

    Clenilso Sehnen Mota

    2016-09-01

    Full Text Available The objective of this study was to evaluate the impact of three cycles of drought/irrigation on the quantum yields of chlorophyll a fluorescence, proline accumulation and osmotic adjustment. Ten plants were submitted to three consecutive cycles of drought/irrigation (D/I and the other ten were maintained at field capacity.Cycles D/I did not promote osmotic adjustment in plants with suspension of irrigation (WSI, despite the proline accumulation. The minimum fluorescence adapted to dark increased and the maximum quantum efficiency of PSII was reduced in WSI plants. Quantum yield of photochemical energy conversion of photosystem II (PSII and the apparent rate of electron transport decreased, while quantum yield dissipation regulated non-photochemical energy in PSII showed an increase in WSI plants over those without suspension of irrigation (WOSI. Quantum yield of no regulated dissipation of PSII non-photochemical energy and chlorophyll and carotenoid content showed no change between WSI and WOSI plants over D/I cycles. Thus it was observed that macaubeira presents an efficient mechanism of non-photochemical energy dissipation.

  12. Plant eco-physiological responses to multiple environmental and climate changes

    DEFF Research Database (Denmark)

    Albert, Kristian Rost

    2009-01-01

    The current global changes of temperature, precipitation, atmospheric CO2 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...... interacted. Current UV-B levels decreases productivity in high arctic heath plants, and advanced spring in response to warming may lead to further decrease while other climatic changes as elevated CO2 may negate this. Stimulated productivity of temperate heath plants is likely under the climatic conditions...... 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 CO2, experimental summer drought, and passive nighttime warming...

  13. EFFECT OF FOLIAR APPLICATION OF AMINOACIDS ON PLANT YIELD AND PHYSIOLOGICAL PARAMETERS IN FABA BEAN PLANTS IRRIGATED WITH SEAWATER

    Directory of Open Access Journals (Sweden)

    Magdi T. ABDELHAMID

    2014-05-01

    Full Text Available Salinity decreases yield in arid and semi-arid areas. With increasing demand for irrigation water, alternative sources are being sought. Seawater salinity was previously considered unusable for irrigation. However, this water can be used successfully to grow crops under certain conditions. Amino acids is well known biostimulant which has positive effects on plant growth and yield, and significantly mitigates the injuries caused by abiotic stresses Therefore, in the present study, the effect of exogenously treatment amino acid on faba bean plant growing under sea water salt stress was investigated. Reduction of salinity damage in faba bean by using a mixture of amino acids to improve morphological and biochemical parameters, and thus raising the level of plant yield was tested. A pot experiment was conducted to alleviate the harmful effects of seawater salinity on faba bean cv. Giza 843 by foliar spraying of an amino acid mixture with different concentrations (0.0, 500, 1000 or 1500 mg L-1. Irrigation of faba bean plants with seawater levels of 3.13 and 6.25 dS m-1 led to significant reductions in plant height, number of leaves plant, fresh and dry weight of shoots, photosynthetic pigments, total carbohydrates, polysaccharides, nucleic acid DNA and RNA contents of faba bean leaves. Seawater salinity induced higher contents of Na+ and Cl- and decreased contents of K+, K+:Na+, Ca2+, Mg2+ and P3+. Irrigation of faba bean plant with different levels of seawater decreased seed yield and total dry weight per plant compared with those irrigated with tap water. Also, total carbohydrates and total protein contents in seeds were reduced by increased seawater salinity levels. Amino acid application as foliar spray significantly improved all the reduced parameters due to seawater stress. However, the highest level of amino acid of 1500 mg L-1 exerted the strongest effect in alleviating the harmful effect of seawater salinity stress. Efecto de la aplicaci

  14. Models for the physiological effects of short O3 exposures on plants

    NARCIS (Netherlands)

    Schut, H.E.

    1985-01-01

    Some published effects of ozone on plant photosynthesis and evaporation are detailed, and attempts were made to develop explanatory models of increasing complexity. Stomatal regulation, which keeps the CO2 concentration inside the lead constant, is assumed. The O3 concentration inside the leaf is as

  15. Biochemical and physiological changes in plants as a result of different sonic exposures.

    Science.gov (United States)

    Qin, Yu-Chuan; Lee, Won-Chu; Choi, Young-Cheol; Kim, Tae-Wan

    2003-07-01

    The effects of two different sonic exposures on two vegetables, namely Chinese cabbage and cucumber at two growth stages, including seedlings and mature plants were investigated. The 3 h exposures included either 20 kHz sound waves or "green music" that comprised classic music and natural sounds such as those of birds, insects, water, etc. Analysis of variance between groups (ANOVA) was used to determine the appropriate statistics parameters for the different treatments. Both exposures caused significant elevations in the level of polyamines (PAs) and increased uptake of oxygen O(2) in comparison with the controls. For Chinese cabbage the highest PAs' levels were determined for both seedlings and mature plants that were exposed to "green music". The oxygen uptake in Chinese cabbage also increased as a result of sonic exposures, and the highest oxygen uptake was also observed after "green music" treatment. For cucumber, the highest content of PAs for both seedlings and mature cucumber plants was determined as a result of 20 kHz ultrasound exposure. 20 kHz exposure of mature plants also resulted in the highest level of oxygen uptake. No statistically significant differences in the vitamin C level were determined between the different sonic treatments and sham exposed vegetables.

  16. Physiological and transcriptomic aspects of urea uptake and assimilation in Arabidopsis plants.

    Science.gov (United States)

    Mérigout, Patricia; Lelandais, Maud; Bitton, Frédérique; Renou, Jean-Pierre; Briand, Xavier; Meyer, Christian; Daniel-Vedele, Françoise

    2008-07-01

    Urea is the major nitrogen (N) form supplied as fertilizer in agriculture, but it is also an important N metabolite in plants. Urea transport and assimilation were investigated in Arabidopsis (Arabidopsis thaliana). Uptake studies using (15)N-labeled urea demonstrated the capacity of Arabidopsis to absorb urea and that the urea uptake was regulated by the initial N status of the plants. Urea uptake was stimulated by urea but was reduced by the presence of ammonium nitrate in the growth medium. N deficiency in plants did not affect urea uptake. Urea exerted a repressive effect on nitrate influx, whereas urea enhanced ammonium uptake. The use of [(15)N]urea and [(15)N]ammonium tracers allowed us to show that urea and ammonium assimilation pathways were similar. Finally, urea uptake was less efficient than nitrate uptake, and urea grown-plants presented signs of N starvation. We also report the first analysis, to our knowledge, of Arabidopsis gene expression profiling in response to urea. Our transcriptomic approach revealed that nitrate and ammonium transporters were transcriptionally regulated by urea as well as key enzymes of the glutamine synthetase-glutamate synthase pathway. AtDUR3, a high-affinity urea transporter in Arabidopsis, was strongly up-regulated by urea. Moreover, our transcriptomic data suggest that other genes are also involved in urea influx.

  17. MPS/CAS Partner Group on Plant Molecular Physiology and Signal Transduction

    Institute of Scientific and Technical Information of China (English)

    Xue Hongwei; Lothar Willmitzer

    2004-01-01

    @@ Rice is mankind's most important food crop - the staple diet for half of the world's population - and is also tremendously important for Chinese food production.Hence, understanding how rice grows and interacts with its environment, which often adversely affects plant development and crop yield, is of prime importance.

  18. Physiological and biochemical response of plants to engineered NMs: Implications on future design.

    Science.gov (United States)

    de la Rosa, Guadalupe; García-Castañeda, Concepción; Vázquez-Núñez, Edgar; Alonso-Castro, Ángel Josabad; Basurto-Islas, Gustavo; Mendoza, Ángeles; Cruz-Jiménez, Gustavo; Molina, Carlos

    2017-01-01

    Engineered nanomaterials (ENMs) form the basis of a great number of commodities that are used in several areas including energy, coatings, electronics, medicine, chemicals and catalysts, among others. In addition, these materials are being explored for agricultural purposes. For this reason, the amount of ENMs present as nanowaste has significantly increased in the last few years, and it is expected that ENMs levels in the environment will increase even more in the future. Because plants form the basis of the food chain, they may also function as a point-of-entry of ENMs for other living systems. Understanding the interactions of ENMs with the plant system and their role in their potential accumulation in the food chain will provide knowledge that may serve as a decision-making framework for the future design of ENMs. The purpose of this paper was to provide an overview of the current knowledge on the transport and uptake of selected ENMs, including Carbon Based Nanomaterials (CBNMs) in plants, and the implication on plant exposure in terms of the effects at the macro, micro, and molecular level. We also discuss the interaction of ENMs with soil microorganisms. With this information, we suggest some directions on future design and areas where research needs to be strengthened. We also discuss the need for finding models that can predict the behavior of ENMs based on their chemical and thermodynamic nature, in that few efforts have been made within this context. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  19. Incorporation of {sup 137}Cs by tropical tree species and its correlation with plant physiology

    Energy Technology Data Exchange (ETDEWEB)

    Cid, Alberto Silva; Anjos, Roberto Meigikos dos; Macario, K.D.; Veiga, R.; Ayubi, J. Juri; Lacerda, T. [Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil). Instituto de Fisica; Zamboni, C.B.; Medeiros, I.M.A. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN- SP), Sao Paulo, SP (Brazil); Velasco, H.; Rizzotto, M. [Universidad Nacional de San Luis (UNSL) (Argentina). Instituto de Matematica Aplicada San Luis; Audicio, P. [Facultad de Ciencias (UDELAR), Montevideo (Uruguay). Centro de Investigaciones Nucleares

    2011-07-01

    Environmental phenomena associated with potential releases of radionuclides to terrestrial ecosystems have attracted the interest of several researches around the world. However, such interest has not been focused exclusively in its effects on human health. Several radionuclides have also been used as tracers of physicochemical or biological phenomena. These studies depend on both the development of auxiliary analysis techniques, which help to improve the results of traditional methods, and the production of additional data, so that a wide variety of natural processes can be understood. In this sense, the same radiometric results can be analyzed or interpreted from different viewpoints, allowing the interdisciplinary understanding of the overall structure of terrestrial ecosystems. {sup 137}Cs, for example, is one of the main fission products of nuclear reactors and atmospheric nuclear testing that is persistent in the biosphere because of its half-life of 30.2 years and biological mobility. This radionuclide remains in the top soil due to fixation and adsorption to clay minerals and organic matter, persisting in the root zone of plant for a long period of time. As its chemical behavior is similar to other monovalent inorganic cations (such as NH{sup +}{sub 4} , Na{sup +} and K{sup +}), Cs{sup +} can be readily absorbed by roots and translocated to the aboveground parts of plant. In this work, concentrations of {sup 137}Cs{sup +}, K{sup +} and Na{sup +} in fruits of lemon (Citrus limon B.) and coconut (Cocos nucifera L.) were measured by both gamma spectrometry and neutron activation analysis, with the aim to understand the behavior of monovalent inorganic cations in tropical plants as well as the plant ability to store these elements. In contrast to K{sup +} and Na{sup +}, Cs{sup +} is not an essential element to plants. However, our results have shown that {sup 137}Cs{sup +} incorporation to vegetal tissues is positively correlated to K{sup +} distribution inside

  20. 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.

  1. Physiological effects of the air pollutant hydrogen fluoride on phloem transport in soybean plants

    Energy Technology Data Exchange (ETDEWEB)

    Madkour, S.A.A.S.

    1984-01-01

    The effect of continuous exposure to HF at ca. 0, 1, and 5 ugF m/sup -3/ for 8-10 days on the transport and relative distribution of /sup 14/C-labelled photosynthetic assimilates in Hodgson soybean plants at three stages of development (vegetative, flowering and early fruit set, and pod filling) were investigated. Fumigated and non-fumigated plants were supplied with /sup 14/CO/sub 2/ by enclosing the second fully-expanded trifoliolate leaf in a cuvette designed for the purpose. Results from these experiments indicate that transport from the source leaves of /sup 14/C-labelled assimilates to sink tissues was partially inhibited by exposure to both concentrations of HF and at each stage of development. However, the greatest degree of inhibition in the transport occurred in plants that were exposed during the flowering stage. Results indicated that there was a greater retention of sugars and a greater incorporation of the /sup 14/C into non-transport compounds in the source leaves accompanied by a reduced transport to sink tissue as the HF concentration increases. This suggested that F-induced inhibition of phloem loading of sugars. The effect of HF fumigation on phloem loading was investigated by monitoring the uptake of /sup 14/C-sucrose supplied to source leaf discs, collected from fumigated and non-fumigated plants. HF was shown to inhibit the loading of /sup 14/C-sucrose. The effect of F on the activity of plasma membrane ATPase was investigated both in vivo, by isolating plasma membranes from fumigated and non-fumigated plants, and in vitro by exposure of plasma membranes to NaF. F was shown to inhibit ATPase activity both in vivo and in vitro. It is concluded that plasma membrane ATPases is the target site for F inhibition of phloem transport, and that the inhibition occurs through the formation of Mg/sup +2/-fluorophosphate complexes.

  2. Physiological and behavioral responses in Drosophila melanogaster to odorants present at different plant maturation stages.

    Science.gov (United States)

    Versace, Elisabetta; Eriksson, Anna; Rocchi, Federico; Castellan, Irene; Sgadò, Paola; Haase, Albrecht

    2016-09-01

    The fruit fly Drosophila melanogaster feeds and oviposits on fermented fruit, hence its physiological and behavioral responses are expected to be tuned to odorants abundant during later stages of fruit maturation. We used a population of about two-hundred isogenic lines of D. melanogaster to assay physiological responses (electroantennograms (EAG)) and behavioral correlates (preferences and choice ratio) to odorants found at different stages of fruit maturation. We quantified electrophysiological and behavioral responses of D. melanogaster for the leaf compound β-cyclocitral, as well as responses to odorants mainly associated with later fruit maturation stages. Electrophysiological and behavioral responses were modulated by the odorant dose. For the leaf compound we observed a steep dose-response curve in both EAG and behavioral data and shallower curves for odorants associated with later stages of maturation. Our data show the connection between sensory and behavioral responses and are consistent with the specialization of D. melanogaster on fermented fruit and avoidance of high doses of compounds associated with earlier stages of maturation. Odor preferences were modulated in a non-additive way when flies were presented with two alternative odorants, and combinations of odorants elicited higher responses than single compounds. Copyright © 2016 Elsevier Inc. All rights reserved.

  3. Alkane distribution and carbon isotope composition in fossil leaves: An interpretation of plant physiology in the geologic past

    Science.gov (United States)

    Graham, H. V.; Freeman, K. H.

    2014-12-01

    The relative chain-length distribution and carbon-isotope composition of n-alkanes extracted from sedimentary rocks are important geochemical tools for investigating past terrestrial ecosystems. Alkanes preserved in ancient sediments are assumed to be contemporaneous, derived from the same ecosystem, and integrated from the biomass present on the landscape at the time of deposition. Further, there is an underlying assumption that ancient plants exhibited the same metabolic and physiological responses to climate conditions that are observed for modern plants. Interpretations of alkane abundances and isotopic signatures are complicated by the strong influence of phylogenetic affiliation and ecological factors, such as canopy structure. A better understanding of how ecosystem and taxa influence alkane properties, including homologue abundance patterns and leaf-lipid carbon isotope fractionation would help strengthen paleoecological interpretations based on these widely employed plant biomarkers. In this study, we analyze the alkane chain-length distribution and carbon-isotope composition of phytoleim and alkanes (d13Cleaf and d13Clipid) extracted from a selection of Cretaceous and Paleocene fossil leaves from the Guaduas and Cerrejon Formations of Colombia. These data were compared with data for the same families in a modern analogue biome. Photosynthetic and biosynthetic fractionation (∆leaf and elipid) values determined from the fossil material indicate carbon metabolism patterns were similar to modern plants. Fossil data were incorporated in a biomass-weighted mixing model to represent the expected lipid complement of sediment arising from this ecosystem and compared with alkane measurements from the rock matrix. Modeled and observed isotopic and abundance patterns match well for alkane homologs most abundant in plants (i.e., n-C27 to n-C33). The model illustrates the importance of understanding biases in litter flux and taphonomic pressures inherent in the

  4. 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

  5. Effect of Seed Position on Parental Plant on Proportion of Seeds Produced with Nondeep and Intermediate Physiological Dormancy.

    Science.gov (United States)

    Lu, Juan J; Tan, Dun Y; Baskin, Carol C; Baskin, Jerry M

    2017-01-01

    The position in which seeds develop on the parental plant can have an effect on dormancy-break and germination. We tested the hypothesis that the proportion of seeds with intermediate physiological dormancy (PD) produced in the proximal position on a raceme of Isatis violascens plants is higher than that produced in the distal position, and further that this difference is related to temperature during seed development. Plants were watered at 3-day intervals, and silicles and seeds from the proximal (early) and distal (late) positions of racemes on the same plants were collected separately and tested for germination. After 0 and 6 months dry storage at room temperature (afterripening), silicles and seeds were cold stratified for 0-16 weeks and tested for germination. Mean daily maximum and minimum temperatures during development/maturation of the two groups of seeds did not differ. A higher proportion of seeds with the intermediate level than with the nondeep level of PD was produced by silicles in the proximal position than by those in the distal position, while the proportion of seeds with nondeep PD was higher in the distal than in the proximal position of the raceme. The differences were not due only to seed mass. Since temperature and soil moisture conditions were the same during development of the seeds in the raceme, differences in proportion of seeds with intermediate and nondeep PD are attributed to position on parental plant. The ecological consequence of this phenomenon is that it ensures diversity in dormancy-breaking and germination characteristics within a seed cohort, a probable bet-hedging strategy. This is the first demonstration of position effects on level of PD in the offspring.

  6. Effects of Riyadh cement industry pollutions on some physiological and morphological factors of Datura innoxia Mill. plant.

    Science.gov (United States)

    Salama, Hediat M H; Al-Rumaih, M M; Al-Dosary, M A

    2011-07-01

    Cement factory emissions into air cause serious air pollution and affect the plant and animal life in the environment. Herein, we report the effects of cement industry emissions (O3, SO2 and NO2) in air, as pollutants, at Riyadh City on Datura innoxia Mill. plant. Morphological characters including plant height, leaves area and number, fresh and dry weight of shoot and root systems of D. innoxia showed a significant reduction from their normal control plants as a response to exposure to pollutant emissions. Chlorophyll and carotenoid contents recorded reductions in values compared to control plant, and the lowest values of chlorophyll A, B, total chlorophyll, carotenoids and total pigments were 0.431, 0.169, 0.60, 0.343 and 0.943 mg/g respectively at a distance of 1-5 m from the cement factory in fruiting stage. These changes in values may be attributed to a probable deceleration of the biosynthetic process rather than degradation of pigments. Further D. innoxia showed a significant (P plant. The root system recorded the lowest values of reducing sugars (0.350 mg/g f. wt.), non-reducing sugars (0.116 mg/g f. wt.), total sugars (0.466 mg/g f. wt.), protein content (0.931 mg/g f. wt.) and total lipids content (0.669 mg/g f. wt.) in fruiting stage at a distance of 1-5 m from the cement factory. The peroxidase activity of shoot and root systems of the studied plant was also significantly higher than those of control plant. Thus a highest value of (29.616 units/g f. wt.) peroxidase activity was recorded in vegetative stage of shoot system at a distance 1-5 m from the cement factory. Results of the study indicated that cement industry emission strongly influence the physiology and morphology of date palm D. innoxia which contribute date fruits, a staple food in the Arab world.

  7. Physiological and genetic characterization of plant growth and gravitropism in LED light sources

    Science.gov (United States)

    Deitzer, Gerald F.

    1994-01-01

    Among the many problems of growing plants in completely controlled environments, such as those anticipated for the space station and the CELSS program, is the need to provide light that is both adequate for photosynthesis and of proper quality for normal growth and development. NASA scientists and engineers have recently become interested in the possibility of utilizing densely packed, solid state, light emitting diodes (LED's) as a source for this light. Unlike more conventional incandescent or electrical discharge lamps, these sources are highly monochromatic and lack energy in spectral regions thought to be important for normal plant development. In addition, a recent observation by NASA scientist has suggested that infra-red LED's, that are routinely used as photographic safelights for plants grown in darkness, may interact with the ability of plants to detect gravity. In order to establish how plants respond to light from these LED light sources we carried out a series of experiments with known pigment mutants of the model mustard plant, Arabidopsis thaliana, growing in either a gravity field or on a clinostat to simulate a micro-gravity environment. Results indicate that only red light from the 665 nm LED's disrupts the ability of normal wildtype seedlings to detect a gravity stimulus. There was no consistent effect found for the far-red (735 nm) LED's or either of the infrared (880 nm or 935 nm) LED sources but both showed some effect in one or more of the genotypes tested. Of these five members of the phytochrome multigene family in Arabidopsis, only the phytochrome B pigment mutant (hy3) lacked the ability to detect gravity under all conditions. There was no effect of either micro-gravity (clinostat) or the infra-red LED's on the light induced inhibition of hypocotyl elongation. Measurements of the pigment phytochrome in oats also showed no photoconversion by 15 min irradiations with the infra-red LED's. We conclude that phytochrome B is required for the

  8. [Effect of plant growth regulators on physiological activity of Bradyrhizobium japonicum ].

    Science.gov (United States)

    Leonova, N O; Tytova, L V; Tantsiurenko, O V; Antypchuk, A F

    2005-01-01

    Influence of plant growth regulators Ivin, Emistim C, Eney and Agrostimulin on the biomass production and exopolymers synthesis of soybean nodule bacteria, which have contrasting symbiotic properties, and glutamine synthetase activity of their cell-free extracts were studied. It was shown that the processes of the biomass and exopolymers accumulation had an opposite direction. Of all preparations only Ivin and Agrostimulin intensificol growth activity of the microorganisms under study. The level of glutamine synthetase activity and this enzymatic reaction specificity to the bivalent metal ions were determined by the special features of Bradyrhizobium strains and nature of the plant growth regulators. Only in the presence of Eney the increase of glutamine synthetase activity of both cultures of Bradyrhizobium japonicum was established.

  9. 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

  10. Effect of cadmium on physiological parameters of cereal and millet plants-A comparative study.

    Science.gov (United States)

    Asopa, Prem Prakash; Bhatt, Ritika; Sihag, Santosh; Kothari, S L; Kachhwaha, Sumita

    2017-03-04

    Metal load is an abiotic stress that becomes stronger by continual industrial production, wastage, and long-range transport of contaminants. It deteriorates the conditions of agricultural soil that leads to lower growth of cereals as well as decreasing nutritional value of harvested grains. Cadmium (Cd) entry by food chain also affects the health of population. The present study is focused on finding out the superior cereal variety under increasing Cd regime. The plants were grown in increasing Cd levels (0-1000 µM) in the medium and were investigated on 15th day of the exposure. Various parameters like antioxidative enzymes and osmoprotectant levels were studied in both roots and shoots. Cd accumulation in plant organs was determined by atomic absorption spectrophotometry (AAS). Analysis of stress tolerance mechanisms through reactive oxygen species (ROS) scavenging and better partitioning of Cd in roots indicated kodo millet to be more stress tolerant than wheat.

  11. Evolution and challenges of dynamic global vegetation models for some aspects of plant physiology and elevated atmospheric CO2

    Science.gov (United States)

    Rezende, L. F. C.; Arenque, B. C.; Aidar, S. T.; Moura, M. S. B.; Von Randow, C.; Tourigny, E.; Menezes, R. S. C.; Ometto, J. P. H. B.

    2016-07-01

    Dynamic global vegetation models (DGVMs) simulate surface processes such as the transfer of energy, water, CO2, and momentum between the terrestrial surface and the atmosphere, biogeochemical cycles, carbon assimilation by vegetation, phenology, and land use change in scenarios of varying atmospheric CO2 concentrations. DGVMs increase the complexity and the Earth system representation when they are coupled with atmospheric global circulation models (AGCMs) or climate models. However, plant physiological processes are still a major source of uncertainty in DGVMs. The maximum velocity of carboxylation (Vcmax), for example, has a direct impact over productivity in the models. This parameter is often underestimated or imprecisely defined for the various plant functional types (PFTs) and ecosystems. Vcmax is directly related to photosynthesis acclimation (loss of response to elevated CO2), a widely known phenomenon that usually occurs when plants are subjected to elevated atmospheric CO2 and might affect productivity estimation in DGVMs. Despite this, current models have improved substantially, compared to earlier models which had a rudimentary and very simple representation of vegetation-atmosphere interactions. In this paper, we describe this evolution through generations of models and the main events that contributed to their improvements until the current state-of-the-art class of models. Also, we describe some main challenges for further improvements to DGVMs.

  12. Evolution and challenges of dynamic global vegetation models for some aspects of plant physiology and elevated atmospheric CO2.

    Science.gov (United States)

    Rezende, L F C; Arenque, B C; Aidar, S T; Moura, M S B; Von Randow, C; Tourigny, E; Menezes, R S C; Ometto, J P H B

    2016-07-01

    Dynamic global vegetation models (DGVMs) simulate surface processes such as the transfer of energy, water, CO2, and momentum between the terrestrial surface and the atmosphere, biogeochemical cycles, carbon assimilation by vegetation, phenology, and land use change in scenarios of varying atmospheric CO2 concentrations. DGVMs increase the complexity and the Earth system representation when they are coupled with atmospheric global circulation models (AGCMs) or climate models. However, plant physiological processes are still a major source of uncertainty in DGVMs. The maximum velocity of carboxylation (Vcmax), for example, has a direct impact over productivity in the models. This parameter is often underestimated or imprecisely defined for the various plant functional types (PFTs) and ecosystems. Vcmax is directly related to photosynthesis acclimation (loss of response to elevated CO2), a widely known phenomenon that usually occurs when plants are subjected to elevated atmospheric CO2 and might affect productivity estimation in DGVMs. Despite this, current models have improved substantially, compared to earlier models which had a rudimentary and very simple representation of vegetation-atmosphere interactions. In this paper, we describe this evolution through generations of models and the main events that contributed to their improvements until the current state-of-the-art class of models. Also, we describe some main challenges for further improvements to DGVMs.

  13. Plant physiological and soil characteristics associated with methane and nitrous oxide emission from rice paddy

    OpenAIRE

    Baruah, K.K.; Gogoi, Boby; Gogoi, P.

    2010-01-01

    Methane (CH4) and nitrous oxide (N2O) are important greenhouse gases causing global warming and climate change. Efforts were made to analyze the CH4 and N2O flux in relation to plant and soil factors from rice (Oryza sativa L.) paddy. Ten popularly grown rice varieties namely Rashmisali, Bogajoha, Basmuthi, Lalkalamdani, Choimora (traditional varieties); Mahsuri, Moniram, Kushal, Gitesh and Profulla (high yielding varieties = HYV) were grown during monsoon season of July 2006. The CH4 and N2O...

  14. Engineering Triterpene and Methylated Triterpene Production in Plants Provides Biochemical and Physiological Insights into Terpene Metabolism.

    Science.gov (United States)

    Jiang, Zuodong; Kempinski, Chase; Bush, Caroline J; Nybo, S Eric; Chappell, Joe

    2016-02-01

    Linear, branch-chained triterpenes, including squalene (C30), botryococcene (C30), and their methylated derivatives (C31-C37), generated by the green alga Botryococcus braunii race B have received significant attention because of their utility as chemical and biofuel feedstocks. However, the slow growth habit of B. braunii makes it impractical as a production system. In this study, we evaluated the potential of generating high levels of botryococcene in tobacco (Nicotiana tabacum) plants by diverting carbon flux from the cytosolic mevalonate pathway or the plastidic methylerythritol phosphate pathway by the targeted overexpression of an avian farnesyl diphosphate synthase along with two versions of botryococcene synthases. Up to 544 µg g(-1) fresh weight of botryococcene was achieved when this metabolism was directed to the chloroplasts, which is approximately 90 times greater than that accumulating in plants engineered for cytosolic production. To test if methylated triterpenes could be produced in tobacco, we also engineered triterpene methyltransferases (TMTs) from B. braunii into wild-type plants and transgenic lines selected for high-level triterpene accumulation. Up to 91% of the total triterpene contents could be converted to methylated forms (C31 and C32) by cotargeting the TMTs and triterpene biosynthesis to the chloroplasts, whereas only 4% to 14% of total triterpenes were methylated when this metabolism was directed to the cytoplasm. When the TMTs were overexpressed in the cytoplasm of wild-type plants, up to 72% of the total squalene was methylated, and total triterpene (C30+C31+C32) content was elevated 7-fold. Altogether, these results point to innate mechanisms controlling metabolite fluxes, including a homeostatic role for squalene.

  15. Physiological and Anatomical Response of Plant Leaf Tissue to Designated Air Pollutants.

    Science.gov (United States)

    1982-01-07

    of the spongy mesophyll . Alternatively, cells associated with intercellular air chambers immediately beneath stomata may collapse or be disrupted. This...crenalate and plasmolyzed. Cells of the spongy mesophyll 75 were also plasmolyzed. Membrane damage was prevalent in both cell types and the plasmalemma was...and more extensively than palisade or spongy parenchyma cells. Because there are no detailed cytological ultrastructural studies of HCl-fumigated plant

  16. Interaction of plant phenols with food macronutrients: characterisation and nutritional-physiological consequences.

    Science.gov (United States)

    Zhang, Hao; Yu, Dandan; Sun, Jing; Liu, Xianting; Jiang, Lu; Guo, Huiyuan; Ren, Fazheng

    2014-06-01

    Polyphenols are dietary constituents of plants associated with health-promoting effects. In the human diet, polyphenols are generally consumed in foods along with macronutrients. Because the health benefits of polyphenols are critically determined by their bioavailability, the effect of interactions between plant phenols and food macronutrients is a very important topic. In the present review, we summarise current knowledge, with a special focus on the in vitro and in vivo effects of food macronutrients on the bioavailability and bioactivity of polyphenols. The mechanisms of interactions between polyphenols and food macronutrients are also discussed. The evidence collected in the present review suggests that when plant phenols are consumed along with food macronutrients, the bioavailability and bioactivity of polyphenols can be significantly affected. The protein-polyphenol complexes can significantly change the plasma kinetics profile but do not affect the absorption of polyphenols. Carbohydrates can enhance the absorption and extend the time needed to reach a maximal plasma concentration of polyphenols, and fats can enhance the absorption and change the absorption kinetics of polyphenols. Moreover, as highlighted in the present review, not only a nutrient alone but also certain synergisms between food macronutrients have a significant effect on the bioavailability and biological activity of polyphenols. The review emphasises the need for formulations that optimise the bioavailability and in vivo activities of polyphenols.

  17. The Relationship between Human Operators' Psycho-physiological Condition and Human Errors in Nuclear Power Plants

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Arryum; Jang, Inseok; Kang, Hyungook; Seong, Poonghyun [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of)

    2013-05-15

    The safe operation of nuclear power plants (NPPs) is substantially dependent on the performance of the human operators who operate the systems. In this environment, human errors caused by inappropriate performance of operator have been considered to be critical since it may lead serious problems in the safety-critical plants. In order to provide meaningful insights to prevent human errors and enhance the human performance, operators' physiological conditions such as stress and workload have been investigated. Physiological measurements were considered as reliable tools to assess the stress and workload. T. Q. Tran et al. and J. B. Brooking et al pointed out that operators' workload can be assessed using eye tracking, galvanic skin response, electroencephalograms (EEGs), heart rate, respiration and other measurements. The purpose of this study is to investigate the effect of the human operators' tense level and knowledge level to the number of human errors. For this study, the experiments were conducted in the mimic of the main control rooms (MCR) in NPP. It utilized the compact nuclear simulator (CNS) which is modeled based on the three loop Pressurized Water Reactor, 993MWe, Kori unit 3 and 4 in Korea and the subjects were asked to follow the tasks described in the emergency operating procedures (EOP). During the simulation, three kinds of physiological measurement were utilized; Electrocardiogram (ECG), EEG and nose temperature. Also, subjects were divided into three groups based on their knowledge of the plant operation. The result shows that subjects who are tense make fewer errors. In addition, subjects who are in higher knowledge level tend to be tense and make fewer errors. For the ECG data, subjects who make fewer human errors tend to be located in higher tense level area of high SNS activity and low PSNS activity. The results of EEG data are also similar to ECG result. Beta power ratio of subjects who make fewer errors was higher. Since beta

  18. A developmental biologist’s journey to rediscover the Zen of plant physiology [v1; ref status: indexed, http://f1000r.es/53n

    Directory of Open Access Journals (Sweden)

    José R. Dinneny

    2015-07-01

    Full Text Available Physiology, which is often viewed as a field of study distinct from development, is technically defined as the branch of biology that explores the normal function of living organisms and their parts. Because plants normally develop continuously throughout their life, plant physiology actually encompasses all developmental processes. Viewing plant biology from a physiologist’s perspective is an attempt to understand the interconnectedness of development, form, and function in the context of multidimensional complexity in the environment. To meet the needs of an expanding human population and a degrading environment, we must understand the adaptive mechanisms that plants use to acclimate to environmental change, and this will require a more holistic approach than is used by current molecular studies. Grand challenges for studies on plant physiology require a more sophisticated understanding of the environment that plants grow in, which is likely to be at least as complex as the plant itself. Moving the lab to the field and using the field for inspiration in the lab need to be expressly promoted by the community as we work to apply the basic concepts learned through reductionist approaches toward a more integrated and realistic understanding of the plant.

  19. Predicting invasive species impacts on hydrological processes: the consequences of plant physiology for landscape processes

    CSIR Research Space (South Africa)

    Le Maitre, David C

    2004-01-01

    Full Text Available stream_source_info Le maitre _2004.pdf.txt stream_content_type text/plain stream_size 13237 Content-Encoding ISO-8859-1 stream_name Le maitre _2004.pdf.txt Content-Type text/plain; charset=ISO-8859-1 1408 Weed Technology... that reduce evaporation in practice to ??actual Et?? (Jarvis and McNaughton 1986). Most of these ap- WEED TECHNOLOGY Volume 18, Invasive Weed Symposium 2004 1409 Figure 1. Root depth distributions for plants with different growth forms based on data compiled...

  20. Plant physiology at the institute for philosophy in Brno in Mendel’s teacher F. Diebl textbook from 1835

    Directory of Open Access Journals (Sweden)

    Jiří Šebánek

    2012-01-01

    Full Text Available Gregor Mendel attended lectures of F. Diebl, professor of natural history and agricultural science at the Institute of Philosophy in Brno. Diebl published his lectures in a textbook “Abhandlungen über die allgemeine und besondere Naturgeschichte, Brünn 1835.” From the textbook the level of scientific knowledge in plant biology is obvious, with which the later founder of a new field of biology – genetics got acquainted. Diebl considered germination to be a specific method of fermentation transforming seed starch into a sugary matter which nourishes the germinating plant. In the physiology of nutrition he distinguished nutrition from the soil via roots from nutrition from the air via leaves. The former is based primarily on the humus theory of A. Thaer (1809 because not until 5 years after the publication of Diebl’s textbook J. Liebig initiated the mineral theory. Diebl’s presentation of photosynthesis was based on information available at that time about the release of oxygen by green plants under conditions of light and the uptake of CO2, but he had no knowledge about the passage of CO2 into the leaves through stomata. Remarkable is Diebl’s discovery that respiration increases during flowering. Electricity is considered to be a force significantly supporting the life processes of plants. Diebl also noticed the difference between diurnal and night evaporation of water from the leaves. In his textbook growth is connected with nutrition only, as it was the entire 19th century. Stem thickening from the cambium is described very simply. Bud and root regeneration is given the term reproduction which today is commonly used in relation to sexual reproduction. Diebl considered nyctinastic movements (bending or unbending of the leaves and closing of the flowers at night to be “sleep”. He described fertilisation in a primitive way, because it was not until 1848 that the first exact description came out.

  1. Physiological and genetic control mechanisms for plant adaptation to high temperature and elevated CO2

    Energy Technology Data Exchange (ETDEWEB)

    Zeiger, Eduardo

    2001-02-01

    Acclimations of the stomatal response to CO2 were characterized. Stomata from the model plant used, Vicia faba, are very sensitive to ambient CO2 when grown in growth chambers as compared to stomata from green house grown leaves. The different CO2 sensitivities of growth chamber and green house grown guard cells was confirmed by reciprocal transfer experiments. Stomata acclimated to their new environment and acquired the CO2 sensitivity typical of that environment. A mechanism for CO2 sensing was also characterized. Results show that CO2 concentration alters the concentration of zeaxanthin in the guard cell chloroplast, thus modifying the light response of the guard cells. This mechanism accounts for the well characterized interactions of light and CO2 in the stomatal responses. The xanthophyll cycle in the stomata of the facultative CAM plant, Mesembryanthemum crystallinum, was characterized. In the C3 mode, zeaxanthin is formed in the light and stomata open. Upon induction of the CAM mode, zeaxanthin synthesis is blocked and stomata no longer respond to light. These results implicate the regulation of the xanthophyll cycle of guard cells in the CAM adaptation.

  2. PHYSIOLOGICAL RESPONSE AND YIELD OF PEPPER PLANTS (CAPSICUM ANNUM L. TO ORGANIC FERTILIZATION

    Directory of Open Access Journals (Sweden)

    Małgorzata BEROVA

    2009-06-01

    Full Text Available The experience was brought out to the experimental fi eld of the Agroecological Centre at the Agricultural University of Plovdiv which owns a Certifi cate of ecological farm work. The research was carried out on two pepper cultivars: Gorogled 6 and Buketen 50 – intended for production of red pepper for grinding. For the purpose of the experiment a bio-fertilizer, produced by the Californian earthworm Lumbricus rubellus was used. Two levels of the bio-fertilizer were applied - 50 and 100 ml/per plant. It was determined that the bio-fertilizer speeds up plant growth. It infl uences the growth rate of the roots and stems and affects the formation of the foliage. The bio-fertilizer has a positive effect upon the functional activity of the photosynthetic apparatus /increased content of photosynthetic pigments, improved leaf gas exchange/. The biofertilizer also infl uences the yield (raw material for drying. The highest effect has been achieved at application of 100 ml fertilizer to the Gorogled 6 cultivar.

  3. Effect of aluminium uptake on physiology, phenols and amino acids in Matricaria chamomilla plants.

    Science.gov (United States)

    Kovácik, Jozef; Klejdus, Borivoj; Hedbavny, Josef

    2010-06-15

    Chamomile is a widely used medicinal plant and, as observed in our previous studies, also accumulates some metals in its above-ground biomass. We therefore tested selected metabolic responses after treatments with 60 and 120 microM Al for 7 days. Shoot Al content was not elevated in comparison with control (12.3-14.1 microg g(-1) DW) while total root Al increased strongly, reaching 2680 and 4400 microg g(-1) DW in 60 and 120 microM treatments, respectively. "Intra-root" Al represented 83.6 (60 microM treatment) and 75.8% (120 microM treatment) of total root Al. Soluble proteins were not significantly affected. Free amino acids were almost unaffected in shoots while in roots the highest content was found in 60 microM Al. Ascorbate- and guaiacol-peroxidase activities were the highest in 60 microM Al-exposed roots. On the other hand, phenylalanine ammonia-lyase activity, total soluble phenols, flavonoids, a sum of 13 phenolic acids and partially two flavonols (quercetin and kaempferol) increased in the shoots. Present study has shown lower Al toxicity and unaltered shoot Al content seems to be the most positive outcome in comparison with previously tested metals (Cd, Ni and Cu). Our results indicate that phenols in shoots and free amino acids in roots are influenced by Al excess in chamomile plants. Possible mechanisms in the context of available literature are suggested and discussed.

  4. A LOV protein modulates the physiological attributes of Xanthomonas axonopodis pv. citri relevant for host plant colonization.

    Directory of Open Access Journals (Sweden)

    Ivana Kraiselburd

    Full Text Available Recent studies have demonstrated that an appropriate light environment is required for the establishment of efficient vegetal resistance responses in several plant-pathogen interactions. The photoreceptors implicated in such responses are mainly those belonging to the phytochrome family. Data obtained from bacterial genome sequences revealed the presence of photosensory proteins of the BLUF (Blue Light sensing Using FAD, LOV (Light, Oxygen, Voltage and phytochrome families with no known functions. Xanthomonas axonopodis pv. citri is a Gram-negative bacterium responsible for citrus canker. The in silico analysis of the X. axonopodis pv. citri genome sequence revealed the presence of a gene encoding a putative LOV photoreceptor, in addition to two genes encoding BLUF proteins. This suggests that blue light sensing could play a role in X. axonopodis pv. citri physiology. We obtained the recombinant Xac-LOV protein by expression in Escherichia coli and performed a spectroscopic analysis of the purified protein, which demonstrated that it has a canonical LOV photochemistry. We also constructed a mutant strain of X. axonopodis pv. citri lacking the LOV protein and found that the loss of this protein altered bacterial motility, exopolysaccharide production and biofilm formation. Moreover, we observed that the adhesion of the mutant strain to abiotic and biotic surfaces was significantly diminished compared to the wild-type. Finally, inoculation of orange (Citrus sinensis leaves with the mutant strain of X. axonopodis pv. citri resulted in marked differences in the development of symptoms in plant tissues relative to the wild-type, suggesting a role for the Xac-LOV protein in the pathogenic process. Altogether, these results suggest the novel involvement of a photosensory system in the regulation of physiological attributes of a phytopathogenic bacterium. A functional blue light receptor in Xanthomonas spp. has been described for the first time, showing

  5. The assessment of physiology parameters of willow plants as a criterion for selection of prospective clones

    Directory of Open Access Journals (Sweden)

    Rodzkin Aleh I.

    2015-01-01

    Full Text Available Bioenergy production based on short rotation coppice willow plantations (SRC is an effective direction both for economic and environment profit. The yield of willow wood can amount to 10-15 tons per hectare of dry biomass per year and the cost of thus obtained energy is lower in comparison with other energy crops. In order to achieve high yield and profitability, the use of special willow clones is necessary. Species most often used in selection for biomass production are shrub type willows: Salix viminalis, Salix dasyclados and Salix schwerini, while the clones tested in this paper were also of tree species Salix alba. The productivity and some physiology characteristics of Serbian selection clones of Salix alba (Bačka, Volmianka and Drina and Swedish selection clone Jorr (Salix viminalis were investigated in greenhouses and in field conditions. As the result of testing three clones of Salix alba - Bačka, Volmianka and Drina, having special preferences and adaptability to different environmental conditions, these were included in State register of Republic of Belarus in 2013. In our experiment it was also satisfactory that specific properties of willows (intensity of transpiration and photosynthesis, water use efficiency and others, were conserved both in greenhouses and in field conditions. This factor gives opportunity to select prospective clones of willows at an early stage of ontogenesis for further testing.

  6. Effects of salinity on anatomical features and physiology of a semi-mangrove plant Myoporum bontioides.

    Science.gov (United States)

    Xu, H M; Tam, N F Y; Zan, Q J; Bai, M; Shin, P K S; Vrijmoed, L L P; Cheung, S G; Liao, W B

    2014-08-30

    The effect of different concentrations of NaCl, 0, 100, 200, 300 and 400 mM, on the anatomical features and physiology of Myoporum bontioides was investigated. The photosynthetic rates (Pn) were significantly reduced by salt stress, with the lowest values at 400 mM NaCl. The content of malondialdehyde (MDA), proline and soluble sugar, as well as the activities of peroxidase (POD) and catalase (CAT) increased at the beginning, but became similar to the control as the experiment proceeded. The NaCl effect on superoxide dismutase (SOD) was different from the other parameters, with a significant reduction at 400 mM NaCl at Day 7. Salt glands were found in both upper and lower epidermis, and the ratios of the thickness of palisade to spongy mesophyll tissues increased with NaCl concentrations. The medullary ray was clearly damaged by NaCl at levels of 200 and 300 mM. These results demonstrated that M. bontioides could adapt to a relatively low salinity, and was not a halophilous species.

  7. Physiological responses of root-less epiphytic plants to acid rain.

    Science.gov (United States)

    Kováčik, Jozef; Klejdus, Bořivoj; Bačkor, Martin; Stork, František; Hedbavny, Josef

    2011-03-01

    Selected physiological responses of Tillandsia albida (Bromeliaceae) and two lichens (Hypogymnia physodes and Xanthoria parietina) exposed to simulated acid rain (AR) over 3 months were studied. Pigments were depressed in all species being affected the most in Tillandsia. Amounts of hydrogen peroxide and superoxide were elevated and soluble proteins decreased only in AR-exposed Hypogymnia. Free amino acids were slightly affected among species and only glutamate sharply decreased in AR-exposed Xanthoria. Slight increase in soluble phenols but decrease in flavonoids in almost all species suggests that the latter are not essential for tolerance to AR. Almost all phenolic acids in Tillandsia leaves decreased in response to AR and activities of selected enzymes (phenylalanine ammonia-lyase, polyphenol oxidase, ascorbate- and guaiacol-peroxidase) were enhanced by AR. In lichens, considerable increase in metabolites (physodalic acid, atranorin and parietin) in response to AR was found but amount of ergosterol was unchanged. Macronutrients (K, Ca, Mg) decreased more pronouncedly in comparison with micronutrients in all species. Xanthoria showed higher tolerance in comparison with Hypogymnia, suggesting that could be useful for long-term biomonitoring.

  8. Quantitative aerobic physiology of the yeast Dekkera bruxellensis, a major contaminant in bioethanol production plants.

    Science.gov (United States)

    Leite, Fernanda Cristina Bezerra; Basso, Thiago Olitta; Pita, Will de Barros; Gombert, Andreas Karoly; Simões, Diogo Ardaillon; de Morais, Marcos Antonio

    2013-02-01

    Dekkera bruxellensis has been described as the major contaminant yeast of industrial ethanol production, although little is known about its physiology. The aim of this study was to investigate the growth of this yeast in diverse carbon sources and involved conducting shake-flask and glucose- or sucrose-limited chemostats experiments, and from the chemostat data, the stoichiometry of biomass formation during aerobic growth was established. As a result of the shake-flask experiments with hexoses or disaccharides, the specific growth rates were calculated, and a different behavior in rich and mineral medium was observed concerning to profile of acetate and ethanol production. In C-limited chemostats conditions, the metabolism of this yeast was completely respiratory, and the biomass yields reached values of 0.62 gDW gS(-1) . In addition, glucose pulses were applied to the glucose- or sucrose-limited chemostats. These results showed that D. bruxellensis has a short-term Crabtree effect. While the glucose pulse was at the sucrose-limited chemostat, sucrose accumulated at the reactor, indicating the presence of a glucose repression mechanism in D. bruxellensis. © 2012 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

  9. Protection of palak (Beta vulgaris L. var Allgreen) plants from ozone injury by ethylenediurea (EDU): roles of biochemical and physiological variations in alleviating the adverse impacts.

    Science.gov (United States)

    Tiwari, Supriya; Agrawal, Madhoolika

    2009-06-01

    Ameliorative effects of ethylenediurea (N-[2-(2-oxo-1-imidazolinidyl) ethyl]-N' phenylurea, abbreviated as EDU) against ozone stress were studied on selected growth, biochemical, physiological and yield characteristics of palak (Beta vulgaris L. var Allgreen) plants grown in field at a suburban site of Varanasi, India. Mean eight hourly ozone concentration varied from 52 to 73 ppb which was found to produce adverse impacts on plant functioning and growth characteristics. The palak plants were treated with 300 ppm EDU at 10 days after germination at 10 days interval up to the plant maturity. Lipid peroxidation in EDU treated plants declined significantly as compared to non-EDU treated ones. Significant increment in F(v)/F(m) ratio in EDU treated plants as compared to non-EDU treated ones was recorded. EDU treated plants showed significant increment in ascorbic acid contents and reduction in peroxidase activity as compared to non-EDU treated ones. As a result of the protection provided by EDU against ozone induced stress on biochemical and physiological characteristics of palak, the morphological parameters also responded positively. Significant increments were recorded in shoot length, number of leaves plant(-1), leaf area and root and shoot biomass of EDU treated plants as compared to non-EDU treated ones. Contents of Na, K, Ca, Mg and Fe were higher in EDU treated plants as compared to non-EDU treated ones. The present investigation proves the usefulness of EDU in partially ameliorating ozone injury in ambient conditions.

  10. Temperate heath plant response to dry conditions depends on growth strategy and less on physiology

    DEFF Research Database (Denmark)

    Albert, Kristian Rost; Kongstad, J.; Schmidt, I. K.

    2012-01-01

    The evidence that is currently available demonstrates that future changes in precipitation patterns will affect plant carbon uptake. However, the outcome in terms of success, productivity and fecundity depends upon individual species and different responses of various growth forms. Examination...... of these differences in response in dry versus rewetting conditions can be used to highlight the limitations coherent in different strategies adopted by, for example, evergreen shrubs and grasses. We investigated the leaf-level photosynthetic performance, leaf C, N and d13C along with vegetation cover and biomass...... rewetting increased leaf nitrogen and photosynthesis in the grass much more than for the dwarf shrub. These different strategies may have a considerable impact on carbon uptake and on the ability of a species to compete, as future climatic changes are likely to extend the summer drought period together...

  11. Physiological Functions of Cyclic Electron Transport Around Photosystem I in Sustaining Photosynthesis and Plant Growth.

    Science.gov (United States)

    Yamori, Wataru; Shikanai, Toshiharu

    2016-04-29

    The light reactions in photosynthesis drive both linear and cyclic electron transport around photosystem I (PSI). Linear electron transport generates both ATP and NADPH, whereas PSI cyclic electron transport produces ATP without producing NADPH. PSI cyclic electron transport is thought to be essential for balancing the ATP/NADPH production ratio and for protecting both photosystems from damage caused by stromal overreduction. Two distinct pathways of cyclic electron transport have been proposed in angiosperms: a major pathway that depends on the PROTON GRADIENT REGULATION 5 (PGR5) and PGR5-LIKE PHOTOSYNTHETIC PHENOTYPE 1 (PGRL1) proteins, which are the target site of antimycin A, and a minor pathway mediated by the chloroplast NADH dehydrogenase-like (NDH) complex. Recently, the regulation of PSI cyclic electron transport has been recognized as essential for photosynthesis and plant growth. In this review, we summarize the possible functions and importance of the two pathways of PSI cyclic electron transport.

  12. Determinants of parasitoid communities of willow-galling sawflies: habitat overrides physiology, host plant and space.

    Science.gov (United States)

    Nyman, Tommi; Leppänen, Sanna A; Várkonyi, Gergely; Shaw, Mark R; Koivisto, Reijo; Barstad, Trond Elling; Vikberg, Veli; Roininen, Heikki

    2015-10-01

    Studies on the determinants of plant-herbivore and herbivore-parasitoid associations provide important insights into the origin and maintenance of global and local species richness. If parasitoids are specialists on herbivore niches rather than on herbivore taxa, then alternating escape of herbivores into novel niches and delayed resource tracking by parasitoids could fuel diversification at both trophic levels. We used DNA barcoding to identify parasitoids that attack larvae of seven Pontania sawfly species that induce leaf galls on eight willow species growing in subarctic and arctic-alpine habitats in three geographic locations in northern Fennoscandia, and then applied distance- and model-based multivariate analyses and phylogenetic regression methods to evaluate the hierarchical importance of location, phylogeny and different galler niche dimensions on parasitoid host use. We found statistically significant variation in parasitoid communities across geographic locations and willow host species, but the differences were mainly quantitative due to extensive sharing of enemies among gallers within habitat types. By contrast, the divide between habitats defined two qualitatively different network compartments, because many common parasitoids exhibited strong habitat preference. Galler and parasitoid phylogenies did not explain associations, because distantly related arctic-alpine gallers were attacked by a species-poor enemy community dominated by two parasitoid species that most likely have independently tracked the gallers' evolutionary shifts into the novel habitat. Our results indicate that barcode- and phylogeny-based analyses of food webs that span forested vs. tundra or grassland environments could improve our understanding of vertical diversification effects in complex plant-herbivore-parasitoid networks. © 2015 John Wiley & Sons Ltd.

  13. Morphological, physiological and biochemical responses of biofuel plant Euphorbia lathyris to salt stress

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Jie; Cao, Yan; Yang, Ziyi; Lu, Changmei [Jiangsu Key Laboratory for Biodiversity and Biotechnology, College of Life Science, Nanjing Normal Univ., Nanjing (China)], E-mail: 08134@njnu.edu.cn); Zhang, Weiming; Sun, Lijun [Nanjing Inst. for the Comprehensive Utilization of Wild plants, Nanjing (China)

    2013-05-15

    Saline lands are characterized by salinity and nutrient deficiency and there is an ever increasing need for economical, adaptable plant species to rejuvenate these lands. In this study, we determined the suitability and tolerance of Euphorbia lathyris L. (Caper spurge), a well-known biofuel plant, as a sustainable candidate to colonize saline lands. We investigated the germination rate, seedling growth, solute change and anti-oxidative enzyme activities etc. under salt stress conditions. Our results showed that Caper spurge seeds prefer to germinate under nonsaline environments and high salt stress induced temporary dormancy during germination, but did not completely hamper the viability of the seeds. The seedling biomass increased without any visible distress symptoms in the presence of NaCl not over 171 mM. Further increase in NaCl concentration had a negative impact on the seedling growth. These demonstrate that Caper spurge seedlings have the potential to grow in saline lands. The salinity tolerance of Caper spurge seedlings was closely associated with the regional distribution of Na{sup + }in roots, stable absorption of Ca{sup 2{sup +,}} K{sup + }and Mg{sup 2{sup +,}} accumulation of organic solutes, and increased activity of superoxide dismutase (SOD) and catalase (CAT) enzymes. However, excessive accumulation of Na{sup +,} sharp increase of superoxide (O{sub 2}), H{sub 2}O{sub 2}, malonaldehyde (MDA) and cell membrane leakage, reduction of osmoprotectants, and decreased activities of CAT and ascorbate peroxidase (APX) etc. under high salinity might be the reasons for the restrained seedling growth.

  14. Physiological and biochemical effect of neem and other Meliaceae plants secondary metabolites against Lepidopteran insects

    Directory of Open Access Journals (Sweden)

    Senthil-Nathan eSengottayan

    2013-12-01

    Full Text Available This review described the physiological and biochemical effects of various secondary metabolites from Meliaceae against major Lepidopteran insect pest including, Noctuidae and Pyralidae. The biochemical effect of major Meliaceae secondary metabolites were discussed more in this review. Several enzymes based on food materials have critical roles in nutritional indices (food utilization of the insect pest population. Several research work has been referred and the effect of Meliaceae secondary metabolites on feeding parameters of insects by demonstrating food consumption, approximate digestibility of consumed food, efficiency of converting the ingested food to body substance, efficiency of converting digested food to body substance and consumption index was reviewed in detail. Further how the digestive enzymes including a-Amylases, α and β- glucosidases (EC 3.2.1.1, lipases (EC 3.1.1 Proteases, serine, cysteine, and aspartic proteinases affected by the Meliaceae secondary metabolites was reviewed. Further effect of Meliaceae secondary metabolites on detoxifying enzymes have been found to react against botanical insecticides including general esterases (EST, glutathione S-transferase (GST and phosphatases was reviewed. Alkaline phosphatase (ALP, E.C.3.1.3.1 and acid phosphatase (ACP, E.C.3.1.3.2 are hydrolytic enzymes, which hydrolyze phosphomonoesters under alkaline or acid conditions, respectively. These enzymes were affected by the secondary metabolites treatment. The detailed mechanism of action was further explained in this review. Acethylcholine esterase (AChE is a key enzyme that terminates nerve impulses by catalyzing the hydrolysis of neurotransmitter, acetylcholine, in the nervous system of various organisms. How the AChE activity was altered by the Meliaceae secondary metabolites reviewed in detail.

  15. Phylogeny, physiology and distribution of 'Candidatus Microthrix calida', a new Microthrix species isolated from industrial activated sludge wastewater treatment plants.

    Science.gov (United States)

    Levantesi, Caterina; Rossetti, Simona; Thelen, Karin; Kragelund, Caroline; Krooneman, Janneke; Eikelboom, Dick; Nielsen, Per Halkjaer; Tandoi, Valter

    2006-09-01

    Twelve strains of filamentous bacteria morphologically identified as 'Microthrix parvicella' were isolated from industrial activated sludge wastewater treatment plants. 16S rRNA gene sequences analysis showed that these strains were all closely related to 'Candidatus Microthrix parvicella'. Six of them, however, had a 16S rRNA gene similarity of only 95.7% and 96.7% to 'Candidatus Microthrix parvicella' suggesting the presence of a new species. The name 'Candidatus Microthrix calida' is proposed for this new microorganism. The physiological properties of these six isolates supported the description of a new taxon. The 'Candidatus Microthrix calida' strains produced thin filaments (0.3-0.7 microm diameter), they did not grow on the media supporting the growth of 'Candidatus Microthrix parvicella' and could be cultivated at higher temperature (up to 36.5 degrees C). Preliminary data on substrate uptake were obtained by microautoradiography on pure culture. Two new fluorescence in situ hybridization (FISH) probes, Mpa-T1-1260 specific for 'Candidatus Microthrix calida' and Mpa-all-1410 targeting both Microthrix species, were designed. The presence of Microthrix spp. was investigated in 114 activated sludge plants. 'Microthrix parvicella' morphotype was detected in 23% of the analysed samples and FISH analysis revealed that 'Candidatus Microthrix calida' was present in 5% of them. The remaining 'M. parvicella' filaments were positive with probe Mpa-all-1410 but could not all be identified as 'Candidatus Microthrix parvicella' suggesting the presence of more hitherto undescribed biodiversity within this morphotype.

  16. Potential of the Sentinel-2 Red Edge Spectral Bands for Estimation of Eco-Physiological Plant Parameters

    Science.gov (United States)

    Malenovsky, Zbynek; Homolova, Lucie; Janoutova, Ruzena; Landier, Lucas; Gastellu-Etchegorry, Jean-Philippe; Berthelot, Beatrice; Huck, Alexis

    2016-08-01

    In this study we investigated importance of the space- borne instrument Sentinel-2 red edge spectral bands and reconstructed red edge position (REP) for retrieval of the three eco-physiological plant parameters, leaf and canopy chlorophyll content and leaf area index (LAI), in case of maize agricultural fields and beech and spruce forest stands. Sentinel-2 spectral bands and REP of the investigated vegetation canopies were simulated in the Discrete Anisotropic Radiative Transfer (DART) model. Their potential for estimation of the plant parameters was assessed through training support vector regressions (SVR) and examining their P-vector matrices indicating significance of each input. The trained SVR were then applied on Sentinel-2 simulated images and the acquired estimates were cross-compared with results from high spatial resolution airborne retrievals. Results showed that contribution of REP was significant for canopy chlorophyll content, but less significant for leaf chlorophyll content and insignificant for leaf area index estimations. However, the red edge spectral bands contributed strongly to the retrievals of all parameters, especially canopy and leaf chlorophyll content. Application of SVR on Sentinel-2 simulated images demonstrated, in general, an overestimation of leaf chlorophyll content and an underestimation of LAI when compared to the reciprocal airborne estimates. In the follow-up investigation, we will apply the trained SVR algorithms on real Sentinel-2 multispectral images acquired during vegetation seasons 2015 and 2016.

  17. A new cadmium reduction device for the microplate determination of nitrate in water, soil, plant tissue, and physiological fluids.

    Science.gov (United States)

    Crutchfield, James D; Grove, John H

    2011-01-01

    A reusable catalytic reductor consisting of 96 copperized-cadmium pins attached to a microplate lid was developed to simultaneously reduce nitrate (NO3-) to nitrite (NO2-) in all wells of a standard microplate. The resulting NO2- is analyzed colorimetrically by the Griess reaction using a microplate reader. Nitrate data from groundwater samples analyzed using the new device correlated well with data obtained by ion chromatography (r2 = 0.9959). Soil and plant tissue samples previously analyzed for NO3- in an interlaboratory validation study sponsored by the Soil Science Society of America were also analyzed using the new technique. For the soil sample set, the data are shown to correlate well with the other methods used (r2 = 0.9976). Plant data correlated less well, especially for samples containing low concentrations of NO3-. Reasons for these discrepancies are discussed, and new techniques to increase the accuracy of the analysis are explored. In addition, a method is presented for analyzing NO3- in physiological fluids (blood serum and urine) after matrix modification with Somogyi's reagent. A protocol for statistical validation of data when analyzing samples with complex matrixes is also established. The simplicity, adaptability, and low cost of the device indicate its potential for widespread application.

  18. [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.

  19. Effects of cerium on growth and physiological mechanism in plants under enhanced ultraviolet-B radiation

    Institute of Scientific and Technical Information of China (English)

    LIANG Chan-juan; HUANG Xiao-hua; TAO Wen-yi; ZHOU Qing

    2006-01-01

    Effect of cerium (Ce3+) on the growth, photosynthesis and antioxidant enzyme system in rape seedlings (Brassica juncea L.)exposed to two levels of UV-B radiation (T1: 0.15 W/m2 and T2:0.35 W/m2) was studied by hydroponics under laboratory conditions.After 5 d of UV-B treatment, the aboveground growth indices were obviously decreased by 13.2%-44.1%(T1) and 21.4%-49.3%(T2), compared to CK, and except active absorption area of roots, the belowground indices by 14.1%-35.6%(T1) and 20.3%-42.6%(T2). For Ce+UV-B treatments, the aboveground and belowground growth indices were decreased respectively by 4.1%-23.6%, 5.2%-23.3%(Ce+T1) and 10.8%-28.4%, 7.0%-27.8%(Ce+T2), lower than those of UV-B treatments. The decrease of growth indices appeared to be the result of changes of physiological processes. Two levels of UV-B radiation induced the decrease in chlorophyll content, net photosynthesis rate, transpiration rate, stomatal conductance and water use efficiency by 11.2%-25.9%(T1) and 20.9%-56.9%(T2), whereas increase in membrane permeability and activities of antioxidant enzymes including superoxide dismutase(SOD),catalase (CAT) and peroxidase (POD) by 6.9%, 22.8%, 21.5%, 9.5%(T1) and 36.6%, 122.3%, 103.5%, 208.9%(T2), respectively. The reduction of the photosynthetic parameters in Ce+UV-B treatments was lessened to 3.2%-13.8%(Ce+T1) and 4.9%-27.6%(Ce+T2),and the increase of membrane permeability and activities of antioxidant enzymes except POD in the same treatments were lessened to 2.4%, 8.4%, 6.6%(Ce+T1) and 30.1%, 116.7%, 75.4%(Ce+T2). These results indicate that the regulative effect of Ce on photosynthesis and antioxidant enzymatic function is the ecophysiological basis of alleviating the suppression of UV-B radiation on growth of seedlings. Furthermore, the protective effect of Ce on seedlings exposed to T1 level of UV-B radiation is superior to T2 level.

  20. Effect of soil salinity on physiological characteristics of functional leaves of cotton plants.

    Science.gov (United States)

    Zhang, Lei; Zhang, Guowei; Wang, Youhua; Zhou, Zhiguo; Meng, Yali; Chen, Binglin

    2013-03-01

    This study analyzes the effects of soil salinity on fatty acid composition, antioxidative enzyme activity, lipid peroxidation, and photosynthesis in functional leaves during the flowering and boll-forming stages of two cotton cultivars, namely, CCRI-44 (salt-tolerant) and Sumian 12 (salt-sensitive), grown under different soil salinity conditions. Saturated (C16:0 and C18:0) and unsaturated fatty acid (FA) contents (C18:1), as well as superoxide dismutase activity increased, whereas high-unsaturated FA (C18:2 and C18:3) decreased, with the increase in soil salinity. The production of malondialdehyde increased with increasing lipoxygenase (LOX) activity, indicating that LOX catalyzed FA peroxidation under salt stress. Soil salinity had no significant effect on catalase (CAT) and peroxidases (POD) activity in the salt-sensitive cultivar Sumian 12, but significantly increased CAT and POD activities in the salt-tolerant cultivar CCRI-44. Net photosynthesis and stomatal conductance of the cotton cultivars decreased in response to salt stress; however, CCRI-44 showed a smaller reduction in photosynthesis than Sumian 12. The results indicated that stomatal apparatus limited leaf photosynthetic capacity in the salinity-treated plants of both cultivars. The net photosynthetic rate, maximum photochemical efficiency, and photochemical quantum yield of the cotton functional leaves showed positive correlation with double-bond index (DBI). These results suggested that salt stress caused DBI reduction and decreased the photochemical conversion efficiency of solar radiation and, thereby resulting in lower net photosynthetic rates.

  1. The signature of seeds in resurrection plants: a molecular and physiological comparison of desiccation tolerance in seeds and vegetative tissues.

    Science.gov (United States)

    Illing, Nicola; Denby, Katherine J; Collett, Helen; Shen, Arthur; Farrant, Jill M

    2005-11-01

    Desiccation-tolerance in vegetative tissues of angiosperms has a polyphyletic origin and could be due to 1) appropriation of the seed-specific program of gene expression that protects orthodox seeds against desiccation, and/or 2) a sustainable version of the abiotic stress response. We tested these hypotheses by comparing molecular and physiological data from the development of orthodox seeds, the response of desiccation-sensitive plants to abiotic stress, and the response of desiccation-tolerant plants to extreme water loss. Analysis of publicly-available gene expression data of 35 LEA proteins and 68 anti-oxidant enzymes in the desiccation-sensitive Arabidopsis thaliana identified 13 LEAs and 4 anti-oxidants exclusively expressed in seeds. Two (a LEA6 and 1-cys-peroxiredoxin) are not expressed in vegetative tissues in A. thaliana, but have orthologues that are specifically activated in desiccating leaves of Xerophyta humilis. A comparison of antioxidant enzyme activity in two desiccation-sensitive species of Eragrostis with the desiccation-tolerant E. nindensis showed equivalent responses upon initial dehydration, but activity was retained at low water content in E. nindensis only. We propose that these antioxidants are housekeeping enzymes and that they are protected from damage in the desiccation-tolerant species. Sucrose is considered an important protectant against desiccation in orthodox seeds, and we show that sucrose accumulates in drying leaves of E. nindensis, but not in the desiccation-sensitive Eragrostis species. The activation of "seed-specific" desiccation protection mechanisms (sucrose accumulation and expression of LEA6 and 1-cys-peroxiredoxin genes) in the vegetative tissues of desiccation-tolerant plants points towards acquisition of desiccation tolerance from seeds.

  2. An update: improvements in imaging perfluorocarbon-mounted plant leaves with implications for studies of plant pathology, physiology, development and cell biology.

    Directory of Open Access Journals (Sweden)

    George R Littlejohn

    2014-04-01

    Full Text Available Plant leaves are optically complex, which makes them difficult to image by light microscopy. Careful sample preparation is therefore required to enable researchers to maximise the information gained from advances in fluorescent protein labelling, cell dyes and innovations in microscope technologies and techniques. We have previously shown that mounting leaves in the non-toxic, non-fluorescent perfluorocarbon (PFC, perfluorodecalin (PFD enhances the optical properties of the leaf with minimal impact on physiology. Here, we assess the use of the perfluorocarbons PFD, and perfluoroperhydrophenanthrene (PP11 for in vivo plant leaf imaging using 4 advanced modes of microscopy: laser scanning confocal microscopy (LSCM, Two-photon fluorescence (TPF microscopy, second harmonic generation (SHG microscopy and stimulated Raman scattering (SRS microscopy. For every mode of imaging tested, we observed an improved signal when leaves were mounted in PFD or in PP11, compared to mounting the samples in water. Using an image analysis technique based on autocorrelation to quantitatively assess LSCM image deterioration with depth, we show that PP11 outperformed PFD as a mounting medium by enabling the acquisition of clearer images deeper into the tissue. In addition, we show that SRS microscopy can be used to image perfluorocarbons directly in the mesophyll and thereby easily delimit the negative space within a leaf, which may have important implications for studies of leaf development. Direct comparison of on and off resonance SRS micrographs show that PFCs do not to form intracellular aggregates in live plants. We conclude that the application of PFCs as mounting media substantially increases advanced microscopy image quality of living mesophyll and leaf vascular bundle cells.

  3. Martin Gibbs (1922-2006): Pioneer of (14)C research, sugar metabolism & photosynthesis; vigilant Editor-in-Chief of Plant Physiology; sage Educator; and humanistic Mentor.

    Science.gov (United States)

    Black, Clanton C

    2008-01-01

    The very personal touch of Professor Martin Gibbs as a worldwide advocate for photosynthesis and plant physiology was lost with his death in July 2006. Widely known for his engaging humorous personality and his humanitarian lifestyle, Martin Gibbs excelled as a strong international science diplomat; like a personal science family patriarch encouraging science and plant scientists around the world. Immediately after World War II he was a pioneer at the Brookhaven National Laboratory in the use of (14)C to elucidate carbon flow in metabolism and particularly carbon pathways in photosynthesis. His leadership on carbon metabolism and photosynthesis extended for four decades of working in collaboration with a host of students and colleagues. In 1962, he was selected as the Editor-in-Chief of Plant Physiology. That appointment initiated 3 decades of strong directional influences by Gibbs on plant research and photosynthesis. Plant Physiology became and remains a premier source of new knowledge about the vital and primary roles of plants in earth's environmental history and the energetics of our green-blue planet. His leadership and charismatic humanitarian character became the quintessence of excellence worldwide. Martin Gibbs was in every sense the personification of a model mentor not only for scientists but also shown in devotion to family. Here we pay tribute and honor to an exemplary humanistic mentor, Martin Gibbs.

  4. Exogenously Applied Plant Growth Regulators Enhance the Morpho-Physiological Growth and Yield of Rice under High Temperature.

    Science.gov (United States)

    Fahad, Shah; Hussain, Saddam; Saud, Shah; Hassan, Shah; Ihsan, Zahid; Shah, Adnan N; Wu, Chao; Yousaf, Muhammad; Nasim, Wajid; Alharby, Hesham; Alghabari, Fahad; Huang, Jianliang

    2016-01-01

    A 2-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.

  5. 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.

  6. A self-referencing biosensor for real-time monitoring of physiological ATP transport in plant systems.

    Science.gov (United States)

    Vanegas, Diana C; Clark, Greg; Cannon, Ashley E; Roux, Stanley; Chaturvedi, Prachee; McLamore, Eric S

    2015-12-15

    The objective of this study was to develop a self-referencing electrochemical biosensor for the direct measurement of ATP flux into the extracellular matrix by living cells/organisms. The working mechanism of the developed biosensor is based on the activity of glycerol kinase and glycerol-3-phosphate oxidase. A stratified bi-enzyme nanocomposite was created using a protein-templated silica sol gel encapsulation technique on top of graphene-modified platinum electrodes. The biosensor exhibited excellent electrochemical performance with a sensitivity of 2.4±1.8 nA/µM, a response time of 20±13 s and a lower detection limit of 1.3±0.7 nM. The self-referencing biosensor was used to measure exogenous ATP efflux by (i) germinating Ceratopteris spores and (ii) growing Zea mays L. roots. This manuscript demonstrates the first development of a non-invasive ATP micro-biosensor for the direct measurement of eATP transport in living tissues. Before this work, assays of eATP have not been able to record the temporally transient movement of ATP at physiological levels (nM and sub-nM). The method demonstrated here accurately measured [eATP] flux in the immediate vicinity of plant cells. Although these proof of concept experiments focus on plant tissues, the technique developed herein is applicable to any living tissue, where nanomolar concentrations of ATP play a critical role in signaling and development. This tool will be invaluable for conducting hypothesis-driven life science research aimed at understanding the role of ATP in the extracellular environment.

  7. The disadvantages of being a hybrid during drought: A combined analysis of plant morphology, physiology and leaf proteome in maize.

    Science.gov (United States)

    Holá, Dana; Benešová, Monika; Fischer, Lukáš; Haisel, Daniel; Hnilička, František; Hniličková, Helena; Jedelský, Petr L; Kočová, Marie; Procházková, Dagmar; Rothová, Olga; Tůmová, Lenka; Wilhelmová, Naďa

    2017-01-01

    A comparative analysis of various parameters that characterize plant morphology, growth, water status, photosynthesis, cell damage, and antioxidative and osmoprotective systems together with an iTRAQ analysis of the leaf proteome was performed in two inbred lines of maize (Zea mays L.) differing in drought susceptibility and their reciprocal F1 hybrids. The aim of this study was to dissect the parent-hybrid relationships to better understand the mechanisms of the heterotic effect and its potential association with the stress response. The results clearly showed that the four examined genotypes have completely different strategies for coping with limited water availability and that the inherent properties of the F1 hybrids, i.e. positive heterosis in morphological parameters (or, more generally, a larger plant body) becomes a distinct disadvantage when the water supply is limited. However, although a greater loss of photosynthetic efficiency was an inherent disadvantage, the precise causes and consequences of the original predisposition towards faster growth and biomass accumulation differed even between reciprocal hybrids. Both maternal and paternal parents could be imitated by their progeny in some aspects of the drought response (e.g., the absence of general protein down-regulation, changes in the levels of some carbon fixation or other photosynthetic proteins). Nevertheless, other features (e.g., dehydrin or light-harvesting protein contents, reduced chloroplast proteosynthesis) were quite unique to a particular hybrid. Our study also confirmed that the strategy for leaving stomata open even when the water supply is limited (coupled to a smaller body size and some other physiological properties), observed in one of our inbred lines, is associated with drought-resistance not only during mild drought (as we showed previously) but also during more severe drought conditions.

  8. Research with radiation and radioisotopes to better understand plant physiology and agricultural consequences of radioactive contamination from the Fukushima Daiichi nuclear accident.

    Science.gov (United States)

    Nakanishi, Tomoko M

    2017-01-01

    Research carried out by me and my group over the last almost four decades are summarized here. The main emphasis of my work was and continues to be on plant physiology using radiation and radioisotopes. Plants live on water and inorganic elements. In the case of water, we developed neutron imaging methods and produced (15)O-labeled water (half-life 2 min) and applied them to understand water circulation pattern in the plant. In the case of elements, we developed neutron activation analysis methods to analyze a large number of plant tissues to follow element specific distribution. Then, we developed real-time imaging system using conventional radioisotopes for the macroscopic and microscopic observation of element movement. After the accident in Fukushima Daiichi nuclear power plant, we, the academic staff of Graduate School, have been studying agricultural effects of radioactive fallout; the main results are summarized in two books published by Springer.

  9. Observed and simulated effect of plant physiology and structure on land surface energy fluxes and soil conditions

    Science.gov (United States)

    Lu, Yen-Sen; Rihani, Jehan; Langensiepen, Matthias; Simmer, Clemens

    2016-04-01

    The parameterization of stomatal conductance and leaf area index (LAI) in land surface models largely influence simulated terrestrial system states. While stomatal conductance mainly controls transpiration, latent heat flux, and root-water-uptake, LAI impacts additionally the radiative energy exchange. Thus both affect canopy evaporation and transpiration and land surface energy and water fluxes as a whole. Common parameterizations of stomatal conductance follow either semi-mechanistic forms based on photosynthesis (Ball-Berry Type (BB)) or forms which consider environmental factors such as impact of light, temperature, humidity and soil moisture (Jarvis-Stewart Type (JS)). Both approaches differ also in the interpretation of humidity effects and light-use efficiency. While soil moisture plays an important role for root-water-uptake there is no clear conclusion yet about how soil moisture interacts with stomata activity. Values for LAI can be obtained from field measurements, satellite estimates or modelling and are used as an essential model input. While field measurements are very time consuming and only represent single points, satellite estimates may have biases caused by variable albedo and sensor limitations. Representing LAI within land surface models requires complex schemes in order to represent all processes contributing to plant growth. We use the Terrestrial System Modelling Platform (TerrSysMP) over the Rur watershed in Germany for studying the influence of plant physiology and structure on the state of the terrestrial system. The Transregional Collaborative Research Center 32 (TR32) extensively monitors this catchment for almost a decade. The land surface (CLM3.5) and the subsurface (ParFlow) modules of TerrSysMP are conditioned based on satellite-retrieved land cover and the soil map from FAO and forced with a high-resolution reanalysis by DWD. For studying the effect of plant physiology, the Ball-Berry-Leuning, and Jarvis-Stewart stomatal

  10. Arbuscular mycorrhizal symbiosis regulates physiology and performance of Digitaria eriantha plants subjected to abiotic stresses by modulating antioxidant and jasmonate levels.

    Science.gov (United States)

    Pedranzani, H; Rodríguez-Rivera, M; Gutiérrez, M; Porcel, R; Hause, B; Ruiz-Lozano, J M

    2016-02-01

    This study evaluates antioxidant responses and jasmonate regulation in Digitaria eriantha cv. Sudafricana plants inoculated (AM) and non-inoculated (non-AM) with Rhizophagus irregularis and subjected to drought, cold, or salinity. Stomatal conductance, photosynthetic efficiency, biomass production, hydrogen peroxide accumulation, lipid peroxidation, antioxidants enzymes activities, and jasmonate levels were determined. Stomatal conductance and photosynthetic efficiency decreased in AM and non-AM plants under all stress conditions. However, AM plants subjected to drought, salinity, or non-stress conditions showed significantly higher stomatal conductance values. AM plants subjected to drought or non-stress conditions increased their shoot/root biomass ratios, whereas salinity and cold caused a decrease in these ratios. Hydrogen peroxide accumulation, which was high in non-AM plant roots under all treatments, increased significantly in non-AM plant shoots under cold stress and in AM plants under non-stress and drought conditions. Lipid peroxidation increased in the roots of all plants under drought conditions. In shoots, although lipid peroxidation decreased in AM plants under non-stress and cold conditions, it increased under drought and salinity. AM plants consistently showed high catalase (CAT) and ascorbate peroxidase (APX) activity under all treatments. By contrast, the glutathione reductase (GR) and superoxide dismutase (SOD) activity of AM roots was lower than that of non-AM plants and increased in shoots. The endogenous levels of cis-12-oxophytodienoc acid (OPDA), jasmonic acid (JA), and 12-OH-JA showed a significant increase in AM plants as compared to non-AM plants. 11-OH-JA content only increased in AM plants subjected to drought. Results show that D. eriantha is sensitive to drought, salinity, and cold stresses and that inoculation with AM fungi regulates its physiology and performance under such conditions, with antioxidants and jasmonates being involved

  11. Differences in Copper Absorption and Accumulation between Copper-Exclusion and Copper-Enrichment Plants: A Comparison of Structure and Physiological Responses.

    Science.gov (United States)

    Fu, Lei; Chen, Chen; Wang, Bin; Zhou, Xishi; Li, Shuhuan; Guo, Pan; Shen, Zhenguo; Wang, Guiping; Chen, Yahua

    2015-01-01

    Differences in copper (Cu) absorption and transport, physiological responses and structural characteristics between two types of Cu-resistant plants, Oenothera glazioviana (Cu-exclusion type) and Elsholtzia haichowensis (Cu-enrichment type), were investigated in the present study. The results indicated the following: (1) After 50 μM Cu treatment, the Cu ratio in the xylem vessels of E. haichowensis increased by 60%. A Cu adsorption experiment indicated that O. glazioviana exhibited greater resistance to Cu, and Cu absorption and the shoot/root ratio of Cu were significantly lower in O. glazioviana than in E. haichowensis. (2) An analysis of the endogenous abscisic acid (ABA) variance and exogenous ABA treatment demonstrated that the ABA levels of both plants did not differ; exogenous ABA treatment clearly reduced Cu accumulation in both plants. (3) The leaf stomatal density of O. glazioviana was significantly less than that of E. haichowensis. Guard cells in E. haichowensis plants were covered with a thick cuticle layer, the epidermal hair was more numerous and longer, and the number of xylem conduits in the root was small. (4) The transpiration rate and the stomatal conductance of O. glazioviana were both significantly lower than those of E. haichowensis, regardless of whether the plants were treated with Cu. Taken together, these results indicate that the differences in the structural characteristics between these two plant species, particularly in the characteristics related to plant transpiration, are important factors that govern whether plants acquire or exclude Cu.

  12. Differences in Copper Absorption and Accumulation between Copper-Exclusion and Copper-Enrichment Plants: A Comparison of Structure and Physiological Responses.

    Directory of Open Access Journals (Sweden)

    Lei Fu

    Full Text Available Differences in copper (Cu absorption and transport, physiological responses and structural characteristics between two types of Cu-resistant plants, Oenothera glazioviana (Cu-exclusion type and Elsholtzia haichowensis (Cu-enrichment type, were investigated in the present study. The results indicated the following: (1 After 50 μM Cu treatment, the Cu ratio in the xylem vessels of E. haichowensis increased by 60%. A Cu adsorption experiment indicated that O. glazioviana exhibited greater resistance to Cu, and Cu absorption and the shoot/root ratio of Cu were significantly lower in O. glazioviana than in E. haichowensis. (2 An analysis of the endogenous abscisic acid (ABA variance and exogenous ABA treatment demonstrated that the ABA levels of both plants did not differ; exogenous ABA treatment clearly reduced Cu accumulation in both plants. (3 The leaf stomatal density of O. glazioviana was significantly less than that of E. haichowensis. Guard cells in E. haichowensis plants were covered with a thick cuticle layer, the epidermal hair was more numerous and longer, and the number of xylem conduits in the root was small. (4 The transpiration rate and the stomatal conductance of O. glazioviana were both significantly lower than those of E. haichowensis, regardless of whether the plants were treated with Cu. Taken together, these results indicate that the differences in the structural characteristics between these two plant species, particularly in the characteristics related to plant transpiration, are important factors that govern whether plants acquire or exclude Cu.

  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. The decrease in the population of Gluconacetobacter diazotrophicus in sugarcane after nitrogen fertilization is related to plant physiology in split root experiments.

    Science.gov (United States)

    Rodríguez-Andrade, Osvaldo; Fuentes-Ramírez, Luis E; Morales-García, Yolanda E; Molina-Romero, Dalia; Bustillos-Cristales, María R; Martínez-Contreras, Rebeca D; Muñoz-Rojas, Jesús

    2015-01-01

    It has been established that a decrease in the population of Gluconacetobacter diazotrophicus associated with sugarcane occurs after nitrogen fertilization. This fact could be due to a direct influence of NH(4)NO(3) on bacterial cells or to changes in plant physiology after fertilizer addition, affecting bacterial establishment. In this work, we observed that survival of G. diazotrophicus was directly influenced when 44.8mM of NH(4)NO(3) (640mgN/plant) was used for in vitro experiments. Furthermore, micropropagated sugarcane plantlets were inoculated with G. diazotrophicus and used for split root experiments, in which both ends of the system were fertilized with a basal level of NH(4)NO(3) (0.35mM; 10mgN/plant). Twenty days post inoculation (dpi) one half of the plants were fertilized with a high dose of NH(4)NO(3) (6.3mM; 180 mgN/plant) on one end of the system. This nitrogen level was lower than that directly affecting G. diazotrophicus cells; however, it caused a decrease in the bacterial population in comparison with control plants fertilized with basal nitrogen levels. The decrease in the population of G. diazotrophicus was higher in pots fertilized with a basal nitrogen level when compared with the corresponding end supplied with high levels of NH4NO3 (100dpi; 80 days post fertilization) of the same plant system. These observations suggest that the high nitrogen level added to the plants induce systemic physiological changes that affect the establishment of G. diazotrophicus.

  15. Wetland Plant Physiology Exhibits Controls on Carbon Sequestration Processes in a Restored Temperate Peatland of California, USA

    Science.gov (United States)

    Windham-Myers, L.; Byrd, K. B.; Khanna, S.; Miller, R.; Anderson, F.

    2011-12-01

    Wetland soils, especially peatlands, serve as the leading long-term sink of carbon (C) in the terrestrial biosphere, representing ~5% of global terrestrial ecosystem acreage but ~25% of total stored terrestrial organic C. While inhibition of microbial respiration rates is a necessary component of peat formation, plant processes regulate gross and net organic matter production (GPP and NPP) and microbial respiration in the rhizosphere. Recent work in a 14-year-old, 6-ha experimental wetland complex in the California's Sacramento-San Joaquin Delta has documented that continuous flooding at 25 cm depth can generate peat growth averaging 1 kg C m-2 y-1, and elevation gains approaching 4 cm y-1, 40-fold greater than historic rates tied to mean sea level rise (1mm y-1). To determine macrophyte controls on organic matter production and respiration in emergent marsh habitats, plant physiological processes were examined for 3 dominant species: hardstem bulrush (Schoenoplectus acutus), narrowleaf and broadleaf cattail (Typha angustifolia and T. latifolia). Leaf-level photosynthetic rates (GPP) were collected monthly with a LiCor 6400XT in May-September of 2010 and 2011 across a gradient of water residence time. GPP, stomatal conductance, photosynthetically active radiation (PAR), relative humidity and leaf temperatures were assessed from pre-dawn to solar-noon to assess light-use (LUE) and water-use efficiency (WUE) for carbon assimilation (A). CO2 levels (Ci) were regulated to generate A-Ci curves, indicating leaf capacity to assimilate recycled CO2. Porewater acetate concentrations and live root concentrations of ethanol and acetaldehyde were assayed seasonally in 2011 as relative indices of fermentative respiration. Plant species distribution, NPP and leaf-area indices (LAI) were calculated using allometric relationships, and used to scale-up leaf-level GPP estimates, as well as to ground-truth high-resolution CIR imagery, to compare NDVIs with recent hyperspectral data

  16. Carbonic Anhydrase and Zinc in Plant Physiology Anhidrasa Carbónica y Zinc en Fisiología Vegetal

    Directory of Open Access Journals (Sweden)

    Dalila Jacqueline Escudero-Almanza

    2012-03-01

    Full Text Available Carbonic anhydrase (CA (EC: 2.4.1.1 catalyzes the rapid conversion of carbon dioxide plus water into a proton and the bicarbonate ion (HCO3- that can be found in prokaryotes and higher organisms; it is represented by four different families. Carbonic anhydrase is a metalloenzyme that requires Zn as a cofactor and is involved in diverse biological processes including pH regulation, CO2 transfer, ionic exchange, respiration, CO2 photosynthetic fixation, and stomatal closure. Therefore, the review includes relevant aspects about CA morphology, oligomerization, and structural differences in the active site. On the other hand, we consider the general characteristics of Zn, its geometry, reactions, and physiology. We then consider the CA catalysis mechanism that is carried out by the metal ion and where Zn acts as a cofactor. Zinc deficiency can inhibit growth and protein synthesis, and there is evidence that it reduces the CA content in some plants, which is a relationship addressed in this review. In leaves, CA represents 20.1% of total soluble protein, while it is the second most abundant in the chloroplast after ribulose 1,5-disphosphate carboxylase/oxygenase (RuBisCO. This facilitates the supply of CO2 to the phosphoenolpyruvate carboxylase in C4 and CAM plants and RuBisCO in C3 plants.La anhidrasa carbónica (CA (EC: 4.2.1.1 cataliza la conversión rápida de dióxido de carbono más agua en un protón y el ion bicarbonato (HCO3-; la cual puede encontrarse en procariotas y en organismos superiores y está representada por cuatro familias distintas. La CA es una metaloenzima que requiere Zn como cofactor y está implicada en diversos procesos biológicos, incluyendo la regulación del pH, la transferencia de CO2, intercambio iónico, la respiración, la fijación fotosintética de CO2, y el cierre estomático. Por lo cual, la revisión incluye aspectos relevantes sobre la morfología de laAC, su oligomerización y diferencias estructurales en el

  17. Morphological, physiological and anatomical traits of plant functional types in temperate grasslands along a large-scale aridity gradient in northeastern China.

    Science.gov (United States)

    Guo, Chengyuan; Ma, Linna; Yuan, Shan; Wang, Renzhong

    2017-01-20

    At the species level, plants can respond to climate changes by changing their leaf traits; however, there is scant information regarding the responses of morphological, physiological and anatomical traits of plant functional types (PFTs) to aridity. Herein, the leaf traits of five PFTs representing 17 plant species in temperate grasslands were examined along a large-scale aridity gradient in northeastern China. The results show that leaf thickness in shrubs, perennial grasses and forbs increased with heightened aridity. Trees increased soluble sugar content, but shrubs, perennials and annual grasses enhanced proline accumulation due to increasing aridity. Moreover, vessel diameter and stomatal index in shrubs and perennial grasses decreased with increasing aridity, but stomatal density and vascular diameter of five PFTs were not correlated with water availability. In conclusion, divergences in adaptive strategies to aridity among these PFTs in temperate grasslands were likely caused by differences in their utilization of water resources, which have different temporal and spatial distribution patterns. Leaf traits of shrubs and perennial grasses had the largest responses to variability of aridity through regulation of morphological, physiological and anatomical traits, which was followed by perennial forbs. Trees and annual grasses endured aridity only by adjusting leaf physiological processes.

  18. Morphological, physiological and anatomical traits of plant functional types in temperate grasslands along a large-scale aridity gradient in northeastern China

    Science.gov (United States)

    Guo, Chengyuan; Ma, Linna; Yuan, Shan; Wang, Renzhong

    2017-01-01

    At the species level, plants can respond to climate changes by changing their leaf traits; however, there is scant information regarding the responses of morphological, physiological and anatomical traits of plant functional types (PFTs) to aridity. Herein, the leaf traits of five PFTs representing 17 plant species in temperate grasslands were examined along a large-scale aridity gradient in northeastern China. The results show that leaf thickness in shrubs, perennial grasses and forbs increased with heightened aridity. Trees increased soluble sugar content, but shrubs, perennials and annual grasses enhanced proline accumulation due to increasing aridity. Moreover, vessel diameter and stomatal index in shrubs and perennial grasses decreased with increasing aridity, but stomatal density and vascular diameter of five PFTs were not correlated with water availability. In conclusion, divergences in adaptive strategies to aridity among these PFTs in temperate grasslands were likely caused by differences in their utilization of water resources, which have different temporal and spatial distribution patterns. Leaf traits of shrubs and perennial grasses had the largest responses to variability of aridity through regulation of morphological, physiological and anatomical traits, which was followed by perennial forbs. Trees and annual grasses endured aridity only by adjusting leaf physiological processes. PMID:28106080

  19. Physiological response of riparian plants to watering in hyper-arid areas of Tarim River,China

    Institute of Scientific and Technical Information of China (English)

    RUAN Xiao; WANG Qiang; CHEN Yaning; LI Weihong

    2007-01-01

    The physiological responses and adaptive strategies of Populus euphratica Oliv.(arbor species),Tamarix ramosissima Ldb.(bush species),and Apocynum venetum L.(herb species)to variations in water and salinity stress were studied in the hyper-arid environment of the Tarim River in China.The groundwater table,the saline content of the groundwater,as well as the content of free proline,soluble sugars,plant endogenous hormones (abscisic acid (ABA),and cytokinins (CTK))of the leaves of the three species were monitored and analyzed at the lower reaches of the Tarim River in the study area where five transects were fixed at 100 m intervals along a vertical sampling line before and after water release.Saline stress dramatically increased soluble sugar concentration of the three species.Differences in sugar accumulation were determined among the species at different transects.The free proline concentration of the leaves of T.ramosissima and P.euphratica showed a proportional decrease with various degrees of elevation of the groundwater table after water release.There was a least correlation between the soluble sugars and proline stimulation in T.ramosissima.It was strongly suggested that T.ramosissima developed a different strategy to accumulate organic solutes to adapt to the stress environment.The soluble sugars and proline accumulation responded to the changes of groundwater table independently:the former occurred under salt stress,whereas the latter was more significant under drought stress.The concentration and the increase in concentration of ABA and CTK involved in stress resistance of the three species were also determined.This increase in the hormone concentration in P.euphratica was different from that of the other two species.Expressed as a function of increase of ABA concentration in leaves,A.venetum and T.ramosissima showed a different solute accumulation in response to groundwater table.There was a significant correlation between ABA accumulation and A [proline

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

    Science.gov (United States)

    Yang, Yongqing; Yao, Yinan; He, Hai

    2008-07-01

    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 UV-B-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 CO(2) 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.

  1. Leaf d15N as a physiological indicator of the responsiveness of N2-fixing alfalfa plants to elevated [CO2], temperature and low water availability

    Directory of Open Access Journals (Sweden)

    Idoia eAriz

    2015-08-01

    Full Text Available The natural 15N/14N isotope composition (δ15N of a tissue is a consequence of its N source and N physiological mechanisms in response to the environment. It could potentially be used as a tracer of N metabolism in plants under changing environmental conditions, where primary N metabolism may be complex, and losses and gains of N fluctuate over time. In order to test the utility of δ15N as an indicator of plant N status in N2-fixing plants grown under various environmental conditions, alfalfa (Medicago sativa L. plants were subjected to distinct conditions of [CO2] (400 versus 700 mol mol-1, temperature (ambient versus ambient + 4ºC and water availability (fully watered versus water deficiency - WD. As expected, increased [CO2] and temperature stimulated photosynthetic rates and plant growth, whereas these parameters were negatively affected by WD. The determination of δ15N in leaves, stems, roots and nodules showed that leaves were the most representative organs of the plant response to increased [CO2] and WD. Depletion of heavier N isotopes in plants grown under higher [CO2] and WD conditions reflected decreased transpiration rates, but could also be related to a higher N demand in leaves, as suggested by the decreased leaf N and total soluble protein (TSP contents detected at 700 mol mol-1 [CO2] and WD conditions. In summary, leaf δ15N provides relevant information integrating parameters which condition plant responsiveness (e.g. photosynthesis, TSP, N demand and water transpiration to environmental conditions.

  2. 丛枝菌根对植物生理代谢的影响%Effects of VA Mycorrhiza on Physiology and Metabolism of Plant

    Institute of Scientific and Technical Information of China (English)

    范继红; 韩振芹; 陈秀新

    2012-01-01

    Based on extensive literatures both at home and abroad,the research progress in the nutritional physiology and resistant physiology of VA mycorrhiza was analyzed,especially its functions in promoting the nutrients uptake,and improving the stress resistance and disease resistance of host plants.%参阅国内外大量文献,分析了丛枝菌根在营养生理及抗性生理方面的研究进展.同时,重点就丛枝菌根在促进宿主植物对氯、磷等营养元素的吸收、提高宿主植物抗逆性及抗病性研究进展进行了阐述.

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

    Science.gov (United States)

    Jammer, Alexandra; Gasperl, Anna; Luschin-Ebengreuth, Nora; Heyneke, Elmien; Chu, Hyosub; Cantero-Navarro, Elena; Großkinsky, Dominik K; Albacete, Alfonso A; Stabentheiner, Edith; Franzaring, Jürgen; Fangmeier, Andreas; van der Graaff, Eric; Roitsch, Thomas

    2015-09-01

    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 assays. The comparison of extraction buffers and requirement for dialysis of crude protein extracts resulted in a universal protein extraction protocol, suitable for the preparation of protein extracts from different organs of various species. Individual published kinetic activity assays were optimized and adapted for a semi-high-throughput 96-well assay format. These assays proved to be robust and are thus suitable for physiological phenotyping, enabling the characterization and diagnosis of the physiological state. The potential of the determination of distinct enzyme activity signatures as part of a physiological fingerprint was shown for various organs and tissues from three monocot and five dicot model and crop species, including two case studies with external stimuli. Differential and specific enzyme activity signatures are apparent during inflorescence development and upon in vitro cold treatment of young inflorescences in the monocot ryegrass, related to conditions for doubled haploid formation. Likewise, treatment of dicot spring oilseed rape with elevated CO2 concentration resulted in distinct patterns of enzyme activity responses in leaves.

  4. Autochthonous arbuscular mycorrhizal fungi and Bacillus thuringiensis from a degraded Mediterranean area can be used to improve physiological traits and performance of a plant of agronomic interest under drought conditions.

    Science.gov (United States)

    Armada, Elisabeth; Azcón, Rosario; López-Castillo, Olga M; Calvo-Polanco, Mónica; Ruiz-Lozano, Juan Manuel

    2015-05-01

    Studies have shown that some microorganisms autochthonous from stressful environments are beneficial when used with autochthonous plants, but these microorganisms rarely have been tested with allochthonous plants of agronomic interest. This study investigates the effectiveness of drought-adapted autochthonous microorganisms [Bacillus thuringiensis (Bt) and a consortium of arbuscular mycorrhizal (AM) fungi] from a degraded Mediterranean area to improve plant growth and physiology in Zea mays under drought stress. Maize plants were inoculated or not with B. thuringiensis, a consortium of AM fungi or a combination of both microorganisms. Plants were cultivated under well-watered conditions or subjected to drought stress. Several physiological parameters were measured, including among others, plant growth, photosynthetic efficiency, nutrients content, oxidative damage to lipids, accumulation of proline and antioxidant compounds, root hydraulic conductivity and the expression of plant aquaporin genes. Under drought conditions, the inoculation of Bt increased significantly the accumulation of nutrients. The combined inoculation of both microorganisms decreased the oxidative damage to lipids and accumulation of proline induced by drought. Several maize aquaporins able to transport water, CO2 and other compounds were regulated by the microbial inoculants. The impact of these microorganisms on plant drought tolerance was complementary, since Bt increased mainly plant nutrition and AM fungi were more active improving stress tolerance/homeostatic mechanisms, including regulation of plant aquaporins with several putative physiological functions. Thus, the use of autochthonous beneficial microorganisms from a degraded Mediterranean area is useful to protect not only native plants against drought, but also an agronomically important plant such as maize.

  5. Morphological and physiological characteristics of rapeseed plants regenerated in vitro from thin cell layers in the presence of zinc.

    Science.gov (United States)

    Ben Ghnaya, Asma; Charles, Gilbert; Hourmant, Annick; Ben Hamida, Jeannette; Branchard, Michel

    2007-10-01

    Phytoremediation offers owners and managers of metal-contaminated sites an innovative and cost-effective option to address recalcitrant environmental contamination. The use of plants to restore or stabilize contaminated sites, known as phytoremediation, takes advantage of the natural abilities of plants to take up, accumulate or store metals. This includes the use of plants that tolerate and accumulate metals at high levels for phytoextraction and the use of plants growing under conditions that are toxic to other plants, for preventing, for example, soil erosion (phytostabilisation). Rapeseed (Brassica napus L.) was shown to be able to accumulate substantial amounts of metals combined with high biomass. Brassica napus was therefore selected for heavy metal (HM) tolerance and accumulation through in vitro selection. A selective pressure applied during the neoformation process from transversal thin cell layers (tTCLs) allowed us to select tolerant cells and tissues. Toxic metals (such as Zn) were added to the culture media in order to select zinc-tolerant plants. Exerting a selective pressure during tTCLs regeneration aimed at selecting plants with exceptional zinc tolerance and/or accumulating capacity. The morphological and physicochemical characteristics of regenerated plants cultivated in greenhouse appeared to depend very significantly on the concentration of ZnSO(4) applied during the neoformation process. Plants regenerated in the presence of ZnSO(4) at 100 microM exhibited a greater size and a higher biomass together with flowering precocity. The contents of zinc, chlorophyll, and proline were modified in the regenerated plants. Pre-treatment with an excess of ZnSO(4) (>500 microM) was responsible for a percentage of tTCLs intolerance above 96%. With lower Zn concentrations (100-250 microM), the survival rates (33-15%) were higher.

  6. Science and Measurement Requirements for a Plant Physiology and Functional Types Mission: Measuring the Composition, Function and Health of Global Land and Coastal Ocean Ecosystems

    Science.gov (United States)

    Green, Robert O.; Rogez, Francois; Green, Rob; Ungar, Steve; Knox, Robert; Asner, Greg; Muller-Karger, Frank; Bissett, Paul; Chekalyuk, Alex; Dierssen, Heidi; Gamon, John; Hook, Simon; Meister, Gerhard; Middleton, Betsy; Ollinger, Scott; Roberts, Dar; Siegel, Dave; Townsend, Phil; Saatchi, Sassan; Unstin, Susan; Turner, Woody; Wickland, Diane; Bontempi, Paula; Emanuel, Bill

    2007-01-01

    This slide presentation reviews the proposed Plant Physiology and Functional Types (PPFT) Mission. The National Academy of Sciences Decadal Survey, placed a critical priority on a Mission to observe distribution and changes in ecosystem functions. The PPFT satellite mission provides the essential measurements needed to assess drivers of change in biodiversity and ecosystem services that affect human welfare. The presentation reviews the science questions that the mission will be designed to answer, the science rationale, the science measurements, the mission concept, the planned instrumentation, the calibration method, and key signal to noise ratios and uniformity requirements.

  7. Research Progress on Plant Physiological Processes in Response to Climate Change%植物对气候变化生理响应研究进展

    Institute of Scientific and Technical Information of China (English)

    冯彩云; 许新桥; 马月萍; 孙振元; 冯世强

    2012-01-01

    Since the industrial revolution, human activities, especially in the developed countries, have consumed a great amount of resources and energy in the process of industrialization, which have resulted in the increased concentration of greenhouse gases in the air and triggered the global climate change. The change has not only brought severe challenges to human survival and development, but also imposed impacts on the physiological processes of plants. The influences on plant physiological processes by enriching CO2, changing climate factors and environmental stress factors have attracted wide concerns of scientists. This paper attempted to classify and analyze the national and international research on the influence of climate change on plant physiological processes carried out in recent years, and described the research progress of plant physiological response to CO2, temperature and moisture. Finally, the future research directions were prospected.%自工业革命以来,人类活动尤其是发达国家在工业化过程中消耗大量资源、能源,造成大气中温室气体浓度增加,引起全球范围内的气候变化,给人类的生存和发展带来严峻挑战,也对植物的生理过程产生了影响。关于CO2浓度升高及其与气候因子和环境胁迫因子对植物生理过程的影响已引起各国科学家广泛关注。文中就近年来气候变化对植物生理过程的影响国内外研究进行归类和分析,介绍了植物对CO2、温度、水分等因素变化的响应过程研究进展,并提出对进一步研究的展望。

  8. The combined effect of salinity and heat reveals a specific physiological, biochemical and molecular response in tomato plants.

    Science.gov (United States)

    Rivero, Rosa M; Mestre, Teresa C; Mittler, Ron; Rubio, Francisco; Garcia-Sanchez, Francisco; Martinez, Vicente

    2014-05-01

    Many studies have described the response mechanisms of plants to salinity and heat applied individually; however, under field conditions some abiotic stresses often occur simultaneously. Recent studies revealed that the response of plants to a combination of two different stresses is specific and cannot be deduced from the stresses applied individually. Here, we report on the response of tomato plants to a combination of heat and salt stress. Interestingly, and in contrast to the expected negative effect of the stress combination on plant growth, our results show that the combination of heat and salinity provides a significant level of protection to tomato plants from the effects of salinity. We observed a specific response of plants to the stress combination that included accumulation of glycine betaine and trehalose. The accumulation of these compounds under the stress combination was linked to the maintenance of a high K(+) concentration and thus a lower Na(+) /K(+) ratio, with a better performance of the cell water status and photosynthesis as compared with salinity alone. Our findings unravel new and unexpected aspects of the response of plants to stress combination and provide a proposed list of enzymatic targets for improving crop tolerance to the abiotic field environment.

  9. Evidence of translocation and physiological impacts of foliar applied CeO2 nanoparticles on cucumber (Cucumis sativus) plants.

    Science.gov (United States)

    Hong, Jie; Peralta-Videa, Jose R; Rico, Cyren; Sahi, Shivendra; Viveros, Marian N; Bartonjo, Jane; Zhao, Lijuan; Gardea-Torresdey, Jorge L

    2014-04-15

    Currently, most of the nanotoxicity studies in plants involve exposure to the nanoparticles (NPs) through the roots. However, plants interact with atmospheric NPs through the leaves, and our knowledge on their response to this contact is limited. In this study, hydroponically grown cucumber (Cucumis sativus) plants were aerially treated either with nano ceria powder (nCeO2) at 0.98 and 2.94 g/m(3) or suspensions at 20, 40, 80, 160, and 320 mg/L. Fifteen days after treatment, plants were analyzed for Ce uptake by using ICP-OES and TEM. In addition, the activity of three stress enzymes was measured. The ICP-OES results showed Ce in all tissues of the CeO2 NP treated plants, suggesting uptake through the leaves and translocation to the other plant parts. The TEM results showed the presence of Ce in roots, which corroborates the ICP-OES results. The biochemical assays showed that catalase activity increased in roots and ascorbate peroxidase activity decreased in leaves. Our findings show that atmospheric NPs can be taken up and distributed within plant tissues, which could represent a threat for environmental and human health.

  10. Application of continuous light in a plant factory system 4. Physiological changes and concept of injury induction in plant leaves under continuous light

    OpenAIRE

    畑, 直樹; 桝田, 正治; 村上,賢治; 小林, 昭雄

    2012-01-01

    Physiological changes and concept of injury induction occurring under continuous light are comprehensively reviewed. Continuous light usually reduces photosynthetic rate, which may relate to changes in transpiration and leaf necrosis caused by reactive oxygen species. Other factors apart from photosynthesis may also affect leaf injuries occurring under continuous light. Continuous light sometimes increases carbohydrate and some secondary metabolite contents.

  11. BIOMETRIC AND PHYSIOLOGICAL CHARACTERISTICS OF CHRYSANTHEMUM (CHRYSANTHEMUM INDICUM L. PLANTS GROWN AT DIFFERENT RATES OF NITROGEN FERTILIZATION

    Directory of Open Access Journals (Sweden)

    V IVANOVA

    2003-07-01

    Full Text Available A trial with large the flowered chrysanthemum cultivar Dark Westland was carried out in an unheated greenhouse. Three rates of nitrogen fertilization were studied: 0, 100 and 140 kgN/ha, as well as two modes of plant formation – single- and two-stemmed plants. Parameters of the biometric characteristics, leaf gasexchange and leaf pigment content were determined. The best results about growth and decorative behaviour were achieved at nitrogen fertilization level of 100 kgN/ha. It was established that nitrogen fertilization in rates of 100 and 140 kgN/ha enhances photosynthetic rate in both modes of plant formation.

  12. Nitrogen level and physiological basis of yield of mungbean at varying plant population in High Ganges River Flood Plain soil of Bangladesh.

    Science.gov (United States)

    Mian, M A K; Hossain, J

    2014-07-01

    A field experiment was conducted at the Regional Agricultural Research Station of Bangladesh Agricultural Research Institute, Jessore during early kharif season of 2009 and 2010 to observe the effect of nitrogen on the physiological basis of yield of mungbean at varying plant population. In the experiment, four nitrogen levels (N0, N40, N60 and N80 kg ha(-1)) were assigned in the main plots and three plant population (P30, P35 and P40 m(-2)) in the sub plots. The results revealed that mungbean showed better growth in N60 and N80 kg ha(-1) representing higher values of CGR, TDM, LAI and plant height while N40 exhibited intermediate growth. Again, growth of mungbean was better in higher plant population (35-40 m(-2)) representing higher values of growth parameters. Seed yield of mungbean was obtained the highest (1908 kg ha(-1)) associated with the highest No. of pods plant(-1) (29.98), seeds pod(-1) (10.41) and 1000-seed weight (37.70 g) in N40 kg ha(-1). Further, seed yield of mungbean was the highest (1919 kg ha(-1)) in plant population of 40 m(-2). In interaction, seed yield was the highest (1963 kg ha(-1)) in N40 kg ha(-1) with plant population of 40 m(-2). The effect of applied nitrogen on the seed yield of mungbean can be explained 78% (R2 = 0.78) by this function (Y = 1540.70+16.069x-0.173x2). The optimum nitrogen level was 46 kg ha(-1) by using the developed functional model and then the predicted seed yield of mungbean would be 1944 kg ha(-1).

  13. Analytical traceability of melon (Cucumis melo var reticulatus): proximate composition, bioactive compounds, and antioxidant capacity in relation to cultivar, plant physiology state, and seasonal variability.

    Science.gov (United States)

    Maietti, Annalisa; Tedeschi, Paola; Stagno, Caterina; Bordiga, Matteo; Travaglia, Fabiano; Locatelli, Monica; Arlorio, Marco; Brandolini, Vincenzo

    2012-06-01

    Two morphologically different cultivars of Italian melons (Baggio and Giusto) were characterized considering samples harvested in different times, at the beginning (BPP) and at the end of the physiological plant production period (EPP). Proximate composition, protein, minerals, pH, phenolic content, antioxidant capacity, ascorbic acid, carotenoids, condensed tannins, and flavonoids were measured, showing a significant decrease in EPP samples (phenolics, antioxidant capacity, condensed tannins, and flavonoids); ascorbic acid decreased in Giusto cv, carotenoids in Baggio cv. Mineral content increased in either the cultivars (EPP samples). Year-to-year difference was significantly highlighted; the plant growing cycle significantly affected the chemotype. Despite these effects, the Principal Component Analysis (PCA) permitted the discrimination of Baggio from Giusto cv, and the discrimination of BPP from EPP samples as well.

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

    OpenAIRE

    Fang eCheng; Zhihui eCheng

    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 ...

  15. 草甘膦对植物生理影响的研究进展%Research Progress in the Effects of Glyphosate on Plant Physiology

    Institute of Scientific and Technical Information of China (English)

    张冬; 张宇; 王萌; 郑服丛; 杨叶

    2016-01-01

    草甘膦影响非靶标植物的正常生长和发育。为进一步探究草甘膦在植物中的致毒机理,减轻草甘膦对非靶标植物的药害,介绍了草甘膦除草和代谢机制,概述草甘膦对植物光合作用、碳氮代谢等生理过程的影响,并对草甘膦的研究方向做出展望。%Glyphosate has an influence on the regular growth of non-target plants. To figure out the toxicity mechanism of glyphosate in plants and reduce the injury of glyphosate to non-target plants, this review sheds light on the weeds controlling and metabolism mechanisms of glyphosate, expounds the effects of glyphosate on several physiological processes in the plants, such as photosynthesis, carbon metabolism and nitrogen metabolism, and put forwards some prospectives on further research of glyphosate.

  16. Reproduction, physiology and biochemistry

    Science.gov (United States)

    This chapter summarizes fundamental knowledge and recent discoveries about the reproduction, physiology and biochemistry of plant-parasitic nematodes. Various types of reproduction are reviewed, including sexual reproduction and mitotic and meiotic parthenogenesis. Although much is known about the p...

  17. Research on the Plant Physiological Sensor in China%我国植物生理传感器的研究现状

    Institute of Scientific and Technical Information of China (English)

    邱兆美; 张昆; 毛鹏军

    2013-01-01

      利用传感器测量植物生长状况,用以指导灌溉、施肥以及病虫害防治,可以使植物始终处于最佳生长状态。为此,从植物外部形态特征和内部生理特征两个方面,论述了我国植物生理传感器的研究现状。主要介绍了叶片厚度、叶片面积、果实尺寸、茎秆直径、茎秆液流和植物激素等传感器的工作原理以及应用领域,分析了这些传感器在测量中的优缺点,指出植物生理传感器的高精化和无线化、无损动态监测、新型传感器的开发是今后研究的重点问题。%Using the sensor measuring plant growth , guiding irrigation , fertilization and insect control , it can make plants always growing in the best state .This paper introduces the research status of the plant physiological sensor in China , based on the two aspects of the plant external morphological characteristics and internal features .It mainly narrates the operating principles and application fields of the sensor that measure blade thickness , leaf area , fruit size , stem diame-ter , stem SAP flow and plant hormone ,and analyzes the advantages and disadvantages in the measurement of the sensor . Then it points out that plant growth sensor of high precision and wireless , nondestructively dynamic monitoring and the development of new type sensors are the development trend in the future .

  18. Capacity of the aquatic fern (Salvinia minima Baker) to accumulate high concentrations of nickel in its tissues, and its effect on plant physiological processes.

    Science.gov (United States)

    Fuentes, Ignacio I; Espadas-Gil, Francisco; Talavera-May, Carlos; Fuentes, Gabriela; Santamaría, Jorge M

    2014-10-01

    An experiment was designed to assess the capacity of Salvinia minima Baker to uptake and accumulate nickel in its tissues and to evaluate whether or not this uptake can affect its physiology. Our results suggest that S. minima plants are able to take up high amounts of nickel in its tissues, particularly in roots. In fact, our results support the idea that S. minima might be considered a hyper-accumulator of nickel, as it is able to accumulate 16.3 mg g(-1) (whole plant DW basis). Our results also showed a two-steps uptake pattern of nickel, with a fast uptake of nickel at the first 6 to 12h of being expose to the metal, followed by a slow take up phase until the end of the experiment at 144 h. S. minima thus, may be considered as a fern useful in the phytoremediation of residual water bodies contaminated with this metal. Also from our results, S. minima can tolerate fair concentrations of the metal; however, at concentrations higher than 80 μM Ni (1.5 mg g(-1) internal nickel concentration), its physiological performance can be affected. For instance, the integrity of cell membranes was affected as the metal concentration and exposure time increased. The accumulation of high concentrations of internal nickel did also affect photosynthesis, the efficiency of PSII, and the concentration of photosynthetic pigments, although at a lower extent. Copyright © 2014 Elsevier B.V. All rights reserved.

  19. Physiological impacts of soil pollution and arsenic uptake in three plant species: Agrostis capillaris, Solanum nigrum and Vicia faba.

    Science.gov (United States)

    Austruy, A; Wanat, N; Moussard, C; Vernay, P; Joussein, E; Ledoigt, G; Hitmi, A

    2013-04-01

    In order to revegetate an industrial soil polluted by trace metals and metalloids (As, Pb, Cu, Cd, Sb), the impact of pollution on three plant species, Solanum nigrum and Agrostis capillaris, both native species in an industrial site, and Vicia faba, a plant model species, is studied. Following the study of soil pollution from the industrial wasteland of Auzon, it appears that the As is the principal pollutant. Particular attention is given to this metalloid, both in its content and its speciation in the soil that the level of its accumulation in plants. In V. faba and A. capillaris, the trace metals and metalloids inhibit the biomass production and involve a lipid peroxidation in the leaves. Furthermore, these pollutants cause a photosynthesis perturbation by stomatal limitations and a dysfunction of photosystem II. Whatever the plant, the As content is less than 0.1 percent of dry matter, the majority of As absorbed is stored in the roots which play the role of trap organ. In parallel, the culture of S. nigrum decreases significantly the exchangeable and weakly adsorbed fraction of As in rhizospheric soil. This study has highlighted the ability of tolerance to trace metals of S. nigrum and to a lesser extent A. capillaris. Our data indicate that V. faba is not tolerant to soil pollution and is not a metallophyte species. Copyright © 2012 Elsevier Inc. All rights reserved.

  20. Low level of selenium increases the efficacy of 24-epibrassinolide through altered physiological and biochemical traits of Brassica juncea plants.

    Science.gov (United States)

    Naz, Fatima Salva; Yusuf, Mohammad; Khan, Tanveer A; Fariduddin, Qazi; Ahmad, Aqil

    2015-10-15

    This study was conducted to provide an insight into the effect of Se (through soil) induced changes in Brassica juncea plants in the presence and absence of 24-epibrassinolide (EBL; foliar). The Se treatments showed dual response, 10 μM of Se significantly increased growth, water relations, photosynthetic attributes along with carbonic anhydrase activity whereas its higher concentrations proved inhibitory in concentration dependent manner. The follow-up application of EBL to the Se stressed plants improved growth, water relations, photosynthesis and simultaneously enhanced the various antioxidant enzymes viz. catalase, peroxidase and superoxide dismutase with the excess accumulation of proline. In addition to this, 10 μM Se increases the efficacy of 10(-8) M of EBL and both in combination showed maximum increase for the growth and photosynthetic traits of plants. On the other hand, the elevated level of antioxidant enzymes as well as proline could have conferred tolerance to the Se-stressed plants resulting in improved growth, water relations and photosynthesis.

  1. Capacity of the aquatic fern (Salvinia minima Baker) to accumulate high concentrations of nickel in its tissues, and its effect on plant physiological processes

    Energy Technology Data Exchange (ETDEWEB)

    Fuentes, Ignacio I.; Espadas-Gil, Francisco; Talavera-May, Carlos; Fuentes, Gabriela; Santamaría, Jorge M., E-mail: jorgesm@cicy.mx

    2014-10-15

    Highlights: • We document the capacity of an aquatic fern to hyper-accumulate Ni. • Effects of high Ni concentrations uptake on plant performance is documented. • High concentration of Ni in tissues damage photosynthesis. • Damage is related to carboxylation mechanisms than to electron transfer efficiency. • S. minima is a good candidate for remediation of water bodies contaminated with Ni. - Abstract: An experiment was designed to assess the capacity of Salvinia minima Baker to uptake and accumulate nickel in its tissues and to evaluate whether or not this uptake can affect its physiology. Our results suggest that S. minima plants are able to take up high amounts of nickel in its tissues, particularly in roots. In fact, our results support the idea that S. minima might be considered a hyper-accumulator of nickel, as it is able to accumulate 16.3 mg g{sup −1} (whole plant DW basis). Our results also showed a two-steps uptake pattern of nickel, with a fast uptake of nickel at the first 6 to 12 h of being expose to the metal, followed by a slow take up phase until the end of the experiment at 144 h. S. minima thus, may be considered as a fern useful in the phytoremediation of residual water bodies contaminated with this metal. Also from our results, S. minima can tolerate fair concentrations of the metal; however, at concentrations higher than 80 μM Ni (1.5 mg g{sup −1} internal nickel concentration), its physiological performance can be affected. For instance, the integrity of cell membranes was affected as the metal concentration and exposure time increased. The accumulation of high concentrations of internal nickel did also affect photosynthesis, the efficiency of PSII, and the concentration of photosynthetic pigments, although at a lower extent.

  2. Impact of Cinnamic Acid on Physiological and Anatomical Changes in Maize Plants (Zea mays L. Grown under Salinity Stress

    Directory of Open Access Journals (Sweden)

    Pramod Kumar Singh

    2014-05-01

    Full Text Available The environmental contamination with high salt is the elementary intimidation to the agriculture. Maize plants were deeply affected due to salinity worldwide and a severe problem to scientists. A probable survival strategy of the plants under unpleasant environmental circumstances is to use of endogenous metabolites that could ameliorate the harsh effect of salinity. Current study was under taken to observe the effect of cinnamic acid (CA, a central molecule of phenylpropanoid pathway (Secondary metabolism on the growth and development of maize plants under NaCl stress conditions. CA is rapidly produced by plants in response to stressful condition. Response to maize seed to the presoaking treatment 0.05mM CA was deliberated under different concentration of NaCl stress such as 50, 100, 150, 200, mM NaCl for 14 days. The injurious effects of salinity on growth and development were manifested by decreased fresh weight, dry weight, and relative water content (RWC and chlorophyll pigment contents. Degree of lipid peroxidation turned down through the significant decrease in MDA content in maize seedlings. CA induced the anatomical properties under salinity .In present exploration. The cortical cells were induced in root in response to CA than stress. Here, the present study was undertaken with the aim of determining salt induced anatomical and morphological alteration in the presence of exogenous CA. The major reduction in dimension of cortical cells was observed which indicate that salt stress reduced the tolerance of cortical cell more than treatment in maize root. We conclude that CA is a potential phenylpyranoid for protecting crop plant under saline environment.

  3. Comparison of individual and combined effects of salinity and deficit irrigation on physiological, nutritional and ornamental aspects of tolerance in Callistemon laevis plants.

    Science.gov (United States)

    Álvarez, Sara; Sánchez-Blanco, M Jesús

    2015-08-01

    The effect of water deficit, salinity and both applied simultaneously on several physiological and morphological parameters in the ornamental plant Callistemon laevis was studied to identify the tolerance mechanisms developed by this species to these sources of stress and to evaluate their adaptability to such conditions. C. laevis plants were grown in pots outdoors and subjected to four irrigation treatments lasting ten months: control (0.8 dS m(-1), 100% water holding capacity), water deficit (0.8 dS m(-1), 50% of the amount of water supplied in control), saline (4.0 dS m(-1), same amount of water supplied as control) and saline water deficit (4.0 dS m(-1), 50% of the water supplied in the control). Water and saline stress, when applied individually, led to a reduction of 12% and 39% of total biomass, respectively, while overall plant quality (leaf color and flowering) was unaffected. However, saline water deficit affected leaf color and flowering and induced an excessive decrease of growth (68%) due to leaf tissue dehydration and a high leaf Cl and Na concentration. Biomass partitioning depended not only on the amount of water applied, but also on the electrical conductivity of the water. Water stress induced active osmotic adjustment and decreased leaf tissue elasticity. Although both Na and Cl concentrations in the plant tissues increased with salinity, Cl entry through the roots was more restricted. In plants submitted to salinity individually, Na tended to remain in the roots and stems, and little reached the leaves. However, plants simultaneously submitted to water and saline stress were not able to retain this ion in the woody parts. The decrease in stomatal conductance and photosynthesis was more marked in the plants submitted to both stresses, the effect of which decreased photosynthesis, and this together with membrane damage delayed plant recovery. The results show that the combination of deficit irrigation and salinity in C. laevis is not recommended

  4. Genome-Guided Insights into the Plant Growth Promotion Capabilities of the Physiologically Versatile Bacillus aryabhattai Strain AB211

    Science.gov (United States)

    Bhattacharyya, Chandrima; Bakshi, Utpal; Mallick, Ivy; Mukherji, Shayantan; Bera, Biswajit; Ghosh, Abhrajyoti

    2017-01-01

    Bacillus aryabhattai AB211 is a plant growth promoting, Gram-positive firmicute, isolated from the rhizosphere of tea (Camellia sinensis), one of the oldest perennial crops and a major non-alcoholic beverage widely consumed all over the world. The whole genome of B. aryabhattai AB211 was sequenced, annotated and evaluated with special focus on genomic elements related to plant microbe interaction. It’s genome sequence reveals the presence of a 5,403,026 bp chromosome. A total of 5226 putative protein-coding sequences, 16 rRNA, 120 tRNA, 8 ncRNAs, 58 non-protein coding genes, and 11 prophage regions were identified. Genome sequence comparisons between strain AB211 and other related environmental strains of B. aryabhattai, identified about 3558 genes conserved among all B. aryabhattai genomes analyzed. Most of the common genes involved in plant growth promotion activities were found to be present within core genes of all the genomes used for comparison, illustrating possible common plant growth promoting traits shared among all the strains of B. aryabhattai. Besides the core genes, some genes were exclusively identified in the genome of strain AB211. Functional annotation of the genes predicted in the strain AB211 revealed the presence of genes responsible for mineral phosphate solubilization, siderophores, acetoin, butanediol, exopolysaccharides, flagella biosynthesis, surface attachment/biofilm formation, and indole acetic acid production, most of which were experimentally verified in the present study. Genome analysis and experimental evidence suggested that AB211 has robust central carbohydrate metabolism implying that this bacterium can efficiently utilize the root exudates and other organic materials as an energy source. Genes for the production of peroxidases, catalases, and superoxide dismutases, that confer resistance to oxidative stresses in plants were identified in AB211 genome. Besides these, genes for heat shock tolerance, cold shock tolerance

  5. Qualidade fisiológica de sementes e desempenho de plantas de rúcula no campo Seed physiological quality and field performance of rocket plants

    Directory of Open Access Journals (Sweden)

    Rogério Gomes Pêgo

    2011-08-01

    Full Text Available O estudo teve como objetivo avaliar a influência da qualidade fisiológica de diferentes lotes de sementes de rúcula (Eruca sativa L. no desenvolvimento inicial e na produção comercial. Avaliou-se a qualidade fisiológica das sementes mediante testes de germinação, primeira contagem de germinação, índice de velocidade de germinação, comprimento da raiz primária e da parte aérea, massa fresca e seca de plântulas. Aos 10 dias após a semeadura em campo, avaliou-se a percentagem de emergência, comprimento de raiz e da parte aérea, massa fresca e seca das plântulas. Aos 35 dias após a semeadura, foram avaliados o número de folhas, número de folhas maiores que dez centímetros, massa fresca e seca das plantas. O delineamento experimental foi inteiramente casualizado utilizando-se quatro tratamentos (lotes e quatro repetições. Quanto à qualidade fisiológica das sementes de rúcula, houve estratificação dos lotes, sendo que os mais vigorosos possibilitaram o maior desenvolvimento de raiz e da parte aérea aos 10 dias após a semeadura, entretanto a qualidade fisiológica das sementes não influenciou na produção comercial da cultura.The study had as objective evaluates the influence of different physiologic quality seeds of Eruca sativa L. in the initial development and in the commercial production. It was evaluated the physiological quality of seeds by tests of germination, first count, speed of germination-index, root length and shoot, fresh and dry weight of seedlings. At 10 days after sowing in the field, the percentage of emergence, root length and shoot, fresh and dry plants was estimated. After 35 days of sowing, the number of leaves, number of leaves greater than 10 cm, fresh and dry plants was evaluated. A randomized complete block design was used with four treatments (lots and four replications. There was stratification of lots on the physiological quality of rocket seeds. The seeds vigorous possible the further

  6. Assessment of operators’ mental workload using physiological and subjective measures in cement, city traffic and power plant controlcenters

    Directory of Open Access Journals (Sweden)

    Majid Fallahi

    2016-06-01

    Conclusion: The results suggested that when operators’ mental demands especially in traffic control and power plant tasks increased, their mental fatigue and stress level increased and their mental health deteriorated. Therefore, it may be necessary to implement an ergonomic program or administrative control to manage mental probably health in these control centers.Furthermore, by evaluating MW, the control center director can organize the human resources for each MW condition to sustain the appropriate performance as well as improve system functions.

  7. Engineering Triterpene and Methylated Triterpene Production in Plants Provides Biochemical and Physiological Insights into Terpene Metabolism1[OPEN

    Science.gov (United States)

    Jiang, Zuodong; Kempinski, Chase; Bush, Caroline J.; Nybo, S. Eric; Chappell, Joe

    2016-01-01

    Linear, branch-chained triterpenes, including squalene (C30), botryococcene (C30), and their methylated derivatives (C31–C37), generated by the green alga Botryococcus braunii race B have received significant attention because of their utility as chemical and biofuel feedstocks. However, the slow growth habit of B. braunii makes it impractical as a production system. In this study, we evaluated the potential of generating high levels of botryococcene in tobacco (Nicotiana tabacum) plants by diverting carbon flux from the cytosolic mevalonate pathway or the plastidic methylerythritol phosphate pathway by the targeted overexpression of an avian farnesyl diphosphate synthase along with two versions of botryococcene synthases. Up to 544 µg g−1 fresh weight of botryococcene was achieved when this metabolism was directed to the chloroplasts, which is approximately 90 times greater than that accumulating in plants engineered for cytosolic production. To test if methylated triterpenes could be produced in tobacco, we also engineered triterpene methyltransferases (TMTs) from B. braunii into wild-type plants and transgenic lines selected for high-level triterpene accumulation. Up to 91% of the total triterpene contents could be converted to methylated forms (C31 and C32) by cotargeting the TMTs and triterpene biosynthesis to the chloroplasts, whereas only 4% to 14% of total triterpenes were methylated when this metabolism was directed to the cytoplasm. When the TMTs were overexpressed in the cytoplasm of wild-type plants, up to 72% of the total squalene was methylated, and total triterpene (C30+C31+C32) content was elevated 7-fold. Altogether, these results point to innate mechanisms controlling metabolite fluxes, including a homeostatic role for squalene. PMID:26603654

  8. Measuring sap flow, and other plant physiological conditions across a soil salinity gradient in the lower Colorado River at Cibola National Wildlife Refuge: Vegetation and soil physiology linkages with microwave dielectric constant

    Science.gov (United States)

    McDonald, K. C.; Lasne, Y.; Schroeder, R.; Morino, K.; Hultine, K. R.; Nagler, P. L.

    2009-12-01

    We used ground measurements to examine stand structure and evapotranspiration of Tamarix in the Cibola National Wildlife Refuge (CNWR) on the Lower Colorado River. Three Tamarix study sites were established at different distances from the Colorado River on a river terrace in the CNWR. The sites were chosen from aerial photographs to represent typical dense stands of Tamarix within the CNWR. The sites were representative of differing saline environments, with each having ground water with distinct salt concentration levels. Wells were established at the site to establish depth to water and the salinity concentration within the ground water. We monitored xylem sap flow within each of the three stands. In addition we measured leaf area index to characterize canopy structure. We compared ET, foliage density, depth to water, and salinity among the Tamarix sites to examine stand-level variability driven by the variations in salinity. We supplemented these collections with measurements to characterize soil and vegetation microwave dielectric properties and their relationship to physiologic parameters. The dielectric properties of a material describe the interaction of an electric field with the material. Previous field experiments have demonstrated that varying degrees of correlation exist between vegetation dielectric properties and tree canopy water status. Temporal variation of the dielectric constant of woody plant tissue may result from changes in water status (e.g., water content) and chemical composition, albeit to varying degrees of sensitivity. The varying amount of ground water salinity at CNWR offers a unique opportunity to examine the relationship between vegetation and soil dielectric constant as related to vegetation ecophysiology. A field portable vector network analyzer is used to measure the microwave dielectric spectrum of the soil and vegetation Combined with measurements of vegetation xylem sap flux and soil chemistry, these measurements allow

  9. Nasal Physiology

    Science.gov (United States)

    ... Caregivers Contact ARS HOME ANATOMY Nasal Anatomy Sinus Anatomy Nasal Physiology Nasal Endoscopy Skull Base Anatomy Virtual Anatomy Disclosure ... Patient Education About this Website Font Size + - Home > ANATOMY > Nasal Physiology Nasal Anatomy Sinus Anatomy Nasal Physiology Nasal Endoscopy ...

  10. Discoloured seeds of amaranth plant infected by Alternaria alternata: physiological, histopathological alterations and fungal secondary metabolites associated or registered

    Directory of Open Access Journals (Sweden)

    Noelting María Cristina

    2016-07-01

    Full Text Available In the present study the aspects of discolouration that could influence both the production and consumption of amaranth were analyzed with the objectives to identify the presence of Alternaria alternata on seeds, to analyze possible changes in the anatomy of seed tissues and to detect the presence of fungal secondary metabolites. Component plating, histopathological and mycological analyses on discoloured seeds allowed i location of propagules of A. alternata in all seminal components; ii observation of hypertrophies in perisperm and embryo and iii determination of several fungal secondary metabolites, mainly high concentrations of tenuazonic acid. To our knowledge, the information presented in this paper, related to physiological, histopathological changes and fungal secondary metabolites on discoloured seeds of (Amaranthus mantegazzianus syn. A. caudatus subsp. mantegazzianus (Pass Hanelt affected by A. alternata, is the first worldwide record.

  11. Cistus creticus subsp. eriocephalus as a Model for Studying Plant Physiological and Metabolic Responses to Environmental Stress Factors.

    Science.gov (United States)

    Paolessi, Paola; Nicoletti, Marcello; Catoni, Rosangela; Puglielli, Giacomo; Toniolo, Chiara; Gratani, Loretta

    2015-12-01

    Variations in physiology and metabolic products of Cistus creticus subsp. eriocephalus along an altitudinal gradient (350-750 m.a.s.l.) within the Monti Lucretili Regional Natural Park (central Italy) were studied. The results showed that the phenol production was in relationship with the net photosynthetic rates and the chlorophyll content. In particular, the increasing caffeic acid (CA) content with altitude suggested its role in providing an additional photo-protection mechanism, by its ability to consume photochemical reducing power and acting as an alternative C-atom sink under high light conditions. The metabolic production was tested by high performance thin layer chromatography (HPTLC) fingerprint analysis, highlighting the potential of this technique in biologic studies. Copyright © 2015 Verlag Helvetica Chimica Acta AG, Zürich.

  12. Aftereffect conditions of prolonged space flight on physiological and biochemical processes and plant resistance Lycopersicon esculentum Mill. to pathogens

    Science.gov (United States)

    Mishchenko, Lidiya

    2016-07-01

    Tomatoes (Lycopersicon esculentum Mill.) - one of the most popular vegetables in Ukraine, they are a valuable product of therapeutic and dietetic foods because they contain a significant amount of nutrients and essential to the human body minerals and vitamins, but by the content of carotenoids - lycopene and β-carotene - is a powerful antioxidant. Therefore, tomato plants can be used successfully to astronauts on long space flights. We aftereffect was studied factors of space flight on the variety of tomato seeds Mir-1, which lasted (6 years) were on an orbital space station "Mir". Then, also after long-term storage in 2011, seeds were sown in the laboratory and received seedlings grown in field conditions Kiev region. The resulting seeds of the tomato crop in 2011 ("Space" and still) we used in our subsequent field studies in Kyiv and Poltava regions. We have previously shown that the "space" seeds had shown in 2011-2012 increased resistance to viruses PVY and PVM natural infectious background. Therefore, it is necessary continue the investigation and started to observe in future years, including 2015 and to analyze the results obtained. Because plants grown constantly in the field natural infectious background, there was a high probability of their defeat pathogens of different nature, including viruses. The works of many authors proved reduce the concentration of carotene and lycopene in tomatoes with the defeat of viruses (Raithak, 2012). In addition, the control plants were observed symptoms of such that is a viral infection, namely in 2011 - leaves curl in 2012 - except leaves curl and even mosaics. The research results were confirmed in 2013, namely on the plants of "space" seed no symptoms of, and in control - detection of potato virus Y (method RT-PCR) and symptoms of leaf curl and mosaic. During the bearing samples were taken leaves of the options and experiment conducted determination of photosynthetic pigments. It should be emphasized that in plant

  13. Can physiological endpoints improve the sensitivity of assays with plants in the risk assessment of contaminated soils?

    Directory of Open Access Journals (Sweden)

    Ana Gavina

    Full Text Available Site-specific risk assessment of contaminated areas indicates prior areas for intervention, and provides helpful information for risk managers. This study was conducted in the Ervedosa mine area (Bragança, Portugal, where both underground and open pit exploration of tin and arsenic minerals were performed for about one century (1857-1969. We aimed at obtaining ecotoxicological information with terrestrial and aquatic plant species to integrate in the risk assessment of this mine area. Further we also intended to evaluate if the assessment of other parameters, in standard assays with terrestrial plants, can improve the identification of phytotoxic soils. For this purpose, soil samples were collected on 16 sampling sites distributed along four transects, defined within the mine area, and in one reference site. General soil physical and chemical parameters, total and extractable metal contents were analyzed. Assays were performed for soil elutriates and for the whole soil matrix following standard guidelines for growth inhibition assay with Lemna minor and emergence and seedling growth assay with Zea mays. At the end of the Z. mays assay, relative water content, membrane permeability, leaf area, content of photosynthetic pigments (chlorophylls and carotenoids, malondialdehyde levels, proline content, and chlorophyll fluorescence (Fv/Fm and ΦPSII parameters were evaluated. In general, the soils near the exploration area revealed high levels of Al, Mn, Fe and Cu. Almost all the soils from transepts C, D and F presented total concentrations of arsenic well above soils screening benchmark values available. Elutriates of several soils from sampling sites near the exploration and ore treatment areas were toxic to L. minor, suggesting that the retention function of these soils was seriously compromised. In Z. mays assay, plant performance parameters (other than those recommended by standard protocols, allowed the identification of more phytotoxic soils

  14. Transcriptomic and physiological responses to fishmeal substitution with plant proteins in formulated feed in farmed Atlantic salmon (Salmo salar

    Directory of Open Access Journals (Sweden)

    Tacchi Luca

    2012-08-01

    Full Text Available Abstract Background Aquaculture of piscivorous fish is in continual expansion resulting in a global requirement to reduce the dependence on wild caught fish for generation of fishmeal and fish oil. Plant proteins represent a suitable protein alternative to fish meal and are increasingly being used in fish feed. In this study, we examined the transcriptional response of Atlantic salmon (Salmo salar to a high marine protein (MP or low fishmeal, higher plant protein replacement diet (PP, formulated to the same nutritional specification within previously determined acceptable maximum levels of individual plant feed materials. Results After 77 days of feeding the fish in both groups doubled in weight, however neither growth performance, feed efficiency, condition factor nor organ indices were significantly different. Assessment of histopathological changes in the heart, intestine or liver did not reveal any negative effects of the PP diet. Transcriptomic analysis was performed in mid intestine, liver and skeletal muscle, using an Atlantic salmon oligonucleotide microarray (Salar_2, Agilent 4x44K. The dietary comparison revealed large alteration in gene expression in all the tissues studied between fish on the two diets. Gene ontology analysis showed, in the mid intestine of fish fed PP, higher expression of genes involved in enteritis, protein and energy metabolism, mitochondrial activity/kinases and transport, and a lower expression of genes involved in cell proliferation and apoptosis compared to fish fed MP. The liver of fish fed PP showed a lower expression of immune response genes but a higher expression of cell proliferation and apoptosis processes that may lead to cell reorganization in this tissue. The skeletal muscle of fish fed PP vs MP was characterized by a suppression of processes including immune response, energy and protein metabolism, cell proliferation and apoptosis which may reflect a more energy efficient tissue. Conclusions The PP

  15. Interaction indole-3-acetic acid IAA with lectin Canavalia maritima seeds reveal new function of lectins in plant physiology

    Energy Technology Data Exchange (ETDEWEB)

    Silva Filho, J.C.; Santi-Gadelha, T.; Gadelha, C.A.A.; Delatorre, P. [Universidade Federal da Paraiba (UFPB), Joao Pessoa, PB (Brazil); Teixeira, C.S.; Rocha, B.A.M.; Nobrega, R.B.; Alencar, K.L.L.; Cavada, B.S. [Universidade Federal do Ceara (UFC), Fortaleza, CE (Brazil)

    2012-07-01

    Full text: Lectins are a class of proteins of non-immune origin characterized by its capability in interacts specifically and reversibly to mono and oligosaccharides. In plant several possible roles have been suggested including their function in seed maturation, cell wall assembly, defense mechanisms, or rhizobial nodulation of legume roots. Nearly all application and proposed of the plant lectins are based on their specific carbohydrate binding. However, it has been reported that lectins from legumes, might interact with other molecules, such as non proteic amino acids and hydrophobic compounds. This study show the first the crystal structure based on molecular replacement of the Canavalia maritima (CML) complexed with IAA correlated with possible role in plant development. Purified CML was dissolved in 20 mMTrisHCl pH 7.6 containing 5 mM IAA, the suitable co-crystals from CML-IAA complex grew in condition 4 of screen I (0.1 M TrisHCl pH 8.5 and 2.0 M ammonium sulfate). This crystal belong to the orthorhombic space group I222 with unit-cell parameters a = 67.1 ; b = 70.7 , c = 97.7 , The structure was refined at 2.1 of resolution to a final R factor of 20.63 % and an R free of 22.54 %. To check the relative position of the IAA molecule in relation to the biological assemble of the CML, the tetrameric structure was generate by crystallographic symmetry. IAA molecules are positioned in the central cavity. The IAA is stabilized by interacting through hydrogen bounds and Van der Waals forces with the amino acids residues Ser 108 and Asn131, and two water molecules. The hydrophilic interactions occur between IAA and side chains of Ser 108, Asn131 and water molecules 26 and 31 by H-bonds. The OG oxygen from Ser108 display H-bonds with O2 and O3 oxygen atoms from IAA, 3.1 and 2.8 respectively. The tetrameric structure of CML complexed with IAA revels which this protein can act during the seedling in plant development. (author)

  16. Physiological Functions of Trigonelline in Plants%葫芦巴碱在植物体内的生理功能

    Institute of Scientific and Technical Information of China (English)

    武菲; 付玉杰

    2012-01-01

    介绍了葫芦巴碱在植物体内的代谢和生理功能,包括葫芦巴碱在细胞周期的调节、信号分子、氧化和紫外胁迫、盐和干旱胁迫、感夜运动和DNA甲基化等方面的最新研究进展.%This paper introduced the metabolism and physiological functions of trigonelline in plants, and showed the recent studies on trigo-nelline, including on its regulation of cell cycle, signal molecular, oxidative and ultraviolet stress, drought and salt stress, nyctinastic movement and DNA methylation.

  17. Spatial variation of eco-physiological parameters in the lichen Pseudevernia furfuracea transplanted in an area surrounding a cement plant (S Italy).

    Science.gov (United States)

    Lucadamo, Lucio; Corapi, Anna; Loppi, Stefano; Paoli, Luca; Gallo, Luana

    2015-08-01

    Thalli of the lichen Pseudevernia furfuracea were transplanted for 3 months (November 2010-January 2011) at 61 monitoring sites around a cement plant near Castrovillari (Calabria, southern Italy). NH3, NO x and SO2 concentrations were monitored monthly in a subarea of 10 sites (SA10) where the cement plant was located. At the end of the exposure period, the integrity of cell membranes; membrane lipid peroxidation (thiobarbituric acid reactive substances, TBARS level); vitality (cell respiration); chlorophyll a; chlorophyll b; carotenoids; phaeophytization quotient; photosynthetic efficiency and thalli concentrations of Al, Ca, Mg, V and Fe were measured. NO x concentrations correlated with the site distance from the cement plant while NH3 concentrations correlated with lichen vitality within SA10. For the monitoring area as a whole, only Fe and Mg concentrations correlated with membrane lipid peroxidation, while TBARS levels showed a significant increase and chlorophyll a, chlorophyll b and carotenoids a significant decrease with respect to the lichen origin area. Multivariate analysis (detrended correspondence analysis, cluster analysis and multi-response permutation procedure) of the eco-physiological parameters × monitoring sites data set resulted in four clusters termed C1, C2, C3 and C4. The eco-physiological parameters were compared among the four clusters and lichen origin area by one-way ANOVA. An index of environmental favourableness (IEF) to lichens was calculated to evaluate the spatial recovery of impaired values of TBARS, chlorophyll a, chlorophyll b, xanthophylls + carotenoids and phaeophytization quotient. The results indicate that there is no clear spatial trend in mycobiont impairment even though the IEF values suggest a higher number of sites with low levels of membrane lipid peroxidation in the 2--3-km distance band from the cement plant (the outermost) than in the two other distance bands (0-1 and 1-2 km). The photobiont seems to be

  18. Effects of silicon application on diurnal variations of physiological properties of rice leaves of plants at the heading stage under elevated UV-B radiation.

    Science.gov (United States)

    Lou, Yun-sheng; Wu, Lei; Lixuan, Ren; Meng, Yan; Shidi, Zhao; Huaiwei, Zhu; Yiwei, Zhang

    2016-02-01

    We investigated the effects of silicon (Si) application on diurnal variations of photosynthetic and transpiration physiological parameters in potted rice (Oryza sativa L. cv Nanjing 45) at the heading stage. The plants were subjected to two UV-B radiation levels, i.e., reference UV-B (A, ambient, 12.0 kJ m(-2) day(-1)) and elevated UV-B radiation (E, a 20% higher dose of UV-B than the reference, 14.4 kJ m(-2) day(-1)), and four Si application levels, i.e., Si0 (no silicon supplementation, 0 kg SiO2 ha(-1)), Si1 (sodium silicate, 100 kg SiO2 ha(-1)), Si2 (sodium silicate, 200 kg SiO2 ha(-1)), and Si3 (slag silicon fertilizer, 200 kg SiO2 ha(-1)). Compared with the reference, elevated UV-B radiation decreased the diurnal mean values of the net photosynthetic rate (Pn), intercellular carbon dioxide (CO2) concentration (Ci), transpiration rate (Tr), stomatal conductivity (Gs), and water use efficiency (WUE) by 11.3, 5.5, 10.4, 20.3, and 6.3%, respectively, in plants not supplemented with silicon (Si0), and decreased the above parameters by 3.8-5.5, 0.7-4.8, 4.0-8.7, 7.4-20.2, and 0.7-5.9%, respectively, in plants treated with silicon (Si1, Si2, and Si3), indicating that silicon application mitigates the negative effects of elevated UV-B radiation. Under elevated UV-B radiation, silicon application (Si1, Si2, and Si3) increased the diurnal mean values of Pn, Ci, Gs, and WUE by 16.9-28.0, 3.5-14.3, 16.8-38.7, and 29.0-51.2%, respectively, but decreased Tr by 1.9-10.8%, compared with plants not treated with silicon (E+Si0), indicating that silicon application mitigates the negative effects of elevated UV-B radiation by significantly increasing the P n, C i, G s, and WUE and decreasing the T r of rice. Evident differences existed in mitigating the depressive effects of elevated UV-B radiation on diurnal variations of physiological parameters among different silicon application treatments, exhibiting as Si3>Si2>Si1>Si0. In addition to recycling steel industrial wastes, the

  19. Effects of silicon application on diurnal variations of physiological properties of rice leaves of plants at the heading stage under elevated UV-B radiation

    Science.gov (United States)

    Lou, Yun-sheng; Wu, Lei; Lixuan, Ren; Meng, Yan; Shidi, Zhao; Huaiwei, Zhu; Yiwei, Zhang

    2016-02-01

    We investigated the effects of silicon (Si) application on diurnal variations of photosynthetic and transpiration physiological parameters in potted rice ( Oryza sativa L. cv Nanjing 45) at the heading stage. The plants were subjected to two UV-B radiation levels, i.e., reference UV-B (A, ambient, 12.0 kJ m-2 day-1) and elevated UV-B radiation (E, a 20 % higher dose of UV-B than the reference, 14.4 kJ m-2 day-1), and four Si application levels, i.e., Si0 (no silicon supplementation, 0 kg SiO2 ha-1), Si1 (sodium silicate, 100 kg SiO2 ha-1), Si2 (sodium silicate, 200 kg SiO2 ha-1), and Si3 (slag silicon fertilizer, 200 kg SiO2 ha-1). Compared with the reference, elevated UV-B radiation decreased the diurnal mean values of the net photosynthetic rate ( Pn), intercellular carbon dioxide (CO2) concentration ( Ci), transpiration rate ( Tr), stomatal conductivity ( Gs), and water use efficiency (WUE) by 11.3, 5.5, 10.4, 20.3, and 6.3 %, respectively, in plants not supplemented with silicon (Si0), and decreased the above parameters by 3.8-5.5, 0.7-4.8, 4.0-8.7, 7.4-20.2, and 0.7-5.9 %, respectively, in plants treated with silicon (Si1, Si2, and Si3), indicating that silicon application mitigates the negative effects of elevated UV-B radiation. Under elevated UV-B radiation, silicon application (Si1, Si2, and Si3) increased the diurnal mean values of Pn, Ci, Gs, and WUE by 16.9-28.0, 3.5-14.3, 16.8-38.7, and 29.0-51.2 %, respectively, but decreased Tr by 1.9-10.8 %, compared with plants not treated with silicon (E+Si0), indicating that silicon application mitigates the negative effects of elevated UV-B radiation by significantly increasing the P n, C i, G s, and WUE and decreasing the T r of rice. Evident differences existed in mitigating the depressive effects of elevated UV-B radiation on diurnal variations of physiological parameters among different silicon application treatments, exhibiting as Si3>Si2>Si1>Si0. In addition to recycling steel industrial wastes, the

  20. Application of Spectral Reflectance on Research of Plant Eco-Physiology%光谱分析在植物生理生态研究中的应用

    Institute of Scientific and Technical Information of China (English)

    薛忠财; 高辉远; 彭涛; 姚广

    2011-01-01

    本文介绍了光谱分析技术在植物生理生态研究中的应用.通过分析植物叶片和冠层的反射光谱特征,可以快速、无损伤地研究不同环境条件下植物的各种色素含量,叶黄素循环组分、营养状况、水分状况、光能利用效率、植被盖度以及冠层结构等生理生态特征,此外光谱分析还能用来监测湖泊、河流中水华的发生和分布,研究生态系统中CO2和H2O的通量以及各种逆境胁迫和放牧等对植物生长的影响.%The application of spectral reflectance on research of plant eco-physiology was reviewed. By analysis of spectral reflectance of plant on leaf or canopy levels, concentration of different kinds of pigments,components of xanthophyll cycle, nutrition status, water status, light use efficiency, vegetation coverage and canopy structure of plant under different environments can be fast and non-destructively investigated. In addition, the spectral reflectance can be used to detect algae-bloom in lakes and rivers, carbon and water vapor fluxes in ecosystem atmosphere, and effect of different kinds of stress and graze on plant growth.

  1. Biogeochemistry and plant physiological traits interact to reinforce patterns of post-fire dominance in boreal forests

    Science.gov (United States)

    Shenoy, A.; Kielland, K.; Johnstone, J. F.

    2011-12-01

    Increases in the frequency, extent, and severity of fire in the North American boreal region are projected to continue under a warming climate and are likely to be associated with changes in future vegetation composition. In interior Alaska, fire severity is linked to the relative dominance of deciduous versus coniferous canopy species. Severely burned areas have high levels of deciduous recruitment and subsequent stand dominance, while lightly burned areas exhibit black spruce self-replacement. To elucidate potential mechanisms by which differential fire severity results in differential post-fire vegetation development, we examined changes in soil nitrogen (N) supply (NO3- and NH4+) and in situ 15N uptake by young aspen (Populus tremuloides) and black spruce (Picea mariana) trees growing in lightly and severely burned areas. We hypothesized that (a) soil nitrate supply would be higher in severely burned sites and (b) since conifers have been shown to have a reduced physiological capacity for NO3- uptake, aspen would display greater rates of NO3- uptake than spruce in severely burned sites. Our results suggested that the composition and magnitude of inorganic N supply 14 years after the fire was nearly identical in high-severity and low-severity sites, and nitrate represented nearly 50% of the supply. However, both aspen and spruce took up substantially more NH4+-N than NO3- -N regardless of fire severity. Surprisingly, spruce exhibited only a moderately lower rate of NO3- uptake (μg N/g root-1h-1) than aspen. At the stand level, aspen took up nearly an order-of-magnitude more N per hectare in severely burned sites compared to lightly burned sites, while spruce exhibited the opposite pattern of N uptake with respect to fire severity. Whereas ammonium appeared to be preferred by both species, nitrate represented a larger component of N uptake (based on the NO3-:NH4+ uptake ratio) in aspen (0.7) than in spruce (0.4). We suggest that these species

  2. Potential use of the PRI and active fluorescence for the diagnosis of the physiological state of plants under ozone exposure and high atmospheric vapor pressure deficit.

    Science.gov (United States)

    Merlier, Elodie; Hmimina, Gabriel; Bagard, Matthieu; Dufrêne, Eric; Soudani, Kamel

    2017-08-09

    Assessing photosynthesis rates with remote sensing is important for tracking the physiological state of plants. The photochemical reflectance index (PRI) is a good estimator of short-term light-use efficiency (LUE) at the leaf scale but its responses to environmental factors are poorly understood. In this study, we assessed changes in the responses of the PRI to ozone exposure and to an increase in atmospheric drought (separately and combined) in oak (Quercus robur) and holm oak (Quercus ilex) that were planted in climatic cells under controlled conditions. The aim was to evaluate the ability of the PRI as a relevant indicator to assess the impact of abiotic factors on photosynthesis. Leaf-scale measurements of biochemical, physiological and spectral properties, including the PRI in dim light on dark-adapted leaves (PRI0), kinetics of PRI responses to PAR variations (photosynthetically active radiation), and leaf chlorophyll fluorescence parameters were performed. The results show that PRI0 is a good proxy of the leaf chlorophyll content, and is correlated to chlorophyll fluorescence parameters on dark adapted leaves (Fo, Fm). The correction of the PRI from the leaf chlorophyll content variations (PRIc) significantly improves correlations between the PRI and NPQ (non-photochemical quenching). The variability of PARsat (estimated PAR value at PRI saturation using PRI vs. PAR relationships) depends on ozone exposure and on the increase in atmospheric vapor pressure deficit. For Quercus robur, results highlight that PARsat is linked to abiotic stress indicating that the PRI may be used as a relevant indicator of abiotic factors limiting the photosynthesis. Quercus ilex did not show significant variability in PRI0 and PARsat, which suggest that it is a more drought resistant species than Q. robur.

  3. Physiological Strategies to Improve the Performance of Spring Maize (Zea mays L. Planted under Early and Optimum Sowing Conditions.

    Directory of Open Access Journals (Sweden)

    Muhammad Amir Bakhtavar

    Full Text Available Low temperature at stand establishment and high temperature at reproductive stage are involved in reduction of grain yield of spring maize. A field study was therefore conducted to evaluate different physiological strategies for improving performance of spring maize under temperature extremes. Seed priming and foliar spray with 3% moringa leaf extract (MLE and 100 mg L-1 kinetin solution alone or in all possible combinations with each other at three growth stages (knee height, tasseling and grain filling stage and hydropriming was compared with control. Seed priming plus foliar spray of MLE and kinetin significantly improved stand establishment especially under early sown crop as indicated by reduced mean emergence time (MET, improved emergence index (EI and final emergence percentage (FEP. Similarly increased chlorophyll contents, crop growth rate, leaf area index, photosynthetic rate, transpiration rate, relative water content and decreased membrane permeability were recorded in both early and optimum sowing conditions in MLE priming plus foliar spray treatment. All these improvements were harvested in the form of increased yield and harvest index compared with control treatment. Overall crop sown at optimum time performed best but exogenous application of MLE through seed priming and foliar spray maximally improved the performance of early sown maize crop which is attributed more likely due to improved stand establishment, chlorophyll and phenolic contents, increased leaf area duration and grain filling period. It can be concluded that seed priming with MLE along with its foliar spray could increase production of maize under temperature extremes.

  4. Physiological Strategies to Improve the Performance of Spring Maize (Zea mays L.) Planted under Early and Optimum Sowing Conditions.

    Science.gov (United States)

    Bakhtavar, Muhammad Amir; Afzal, Irfan; Basra, Shahzad Maqsood Ahmed; Ahmad, Azraf-Ul-Haq; Noor, Mehmood Ali

    2015-01-01

    Low temperature at stand establishment and high temperature at reproductive stage are involved in reduction of grain yield of spring maize. A field study was therefore conducted to evaluate different physiological strategies for improving performance of spring maize under temperature extremes. Seed priming and foliar spray with 3% moringa leaf extract (MLE) and 100 mg L-1 kinetin solution alone or in all possible combinations with each other at three growth stages (knee height, tasseling and grain filling stage) and hydropriming was compared with control. Seed priming plus foliar spray of MLE and kinetin significantly improved stand establishment especially under early sown crop as indicated by reduced mean emergence time (MET), improved emergence index (EI) and final emergence percentage (FEP). Similarly increased chlorophyll contents, crop growth rate, leaf area index, photosynthetic rate, transpiration rate, relative water content and decreased membrane permeability were recorded in both early and optimum sowing conditions in MLE priming plus foliar spray treatment. All these improvements were harvested in the form of increased yield and harvest index compared with control treatment. Overall crop sown at optimum time performed best but exogenous application of MLE through seed priming and foliar spray maximally improved the performance of early sown maize crop which is attributed more likely due to improved stand establishment, chlorophyll and phenolic contents, increased leaf area duration and grain filling period. It can be concluded that seed priming with MLE along with its foliar spray could increase production of maize under temperature extremes.

  5. Unity in diversity, a systems approach to regulating plant cell physiology by 2-oxoglutarate-dependent dioxygenases.

    Science.gov (United States)

    Kundu, Siddhartha

    2015-01-01

    Could a disjoint group of enzymes synchronize their activities and execute a complex multi-step, measurable, and reproducible response? Here, I surmise that the alpha-ketoglutarate dependent superfamily of non-haem iron (II) dioxygenases could influence cell physiology as a cohesive unit, and that the broad spectra of substrates transformed is an absolute necessity to this portrayal. This eclectic group comprises members from all major taxa, and participates in pesticide breakdown, hypoxia signaling, and osmotic stress neutralization. The oxidative decarboxylation of 2-oxoglutarate to succinate is coupled with a concomitant substrate hydroxylation and, in most cases, is followed by an additional specialized conversion. The domain profile of a protein sequence was used as an index of miscellaneous reaction chemistry and interpreted alongside existent kinetic data in a linear model of integrated function. Statistical parameters were inferred by the creation of a novel, empirically motivated flat-file database of over 3800 sequences (DB2OG) with putative 2-oxoglutarate dependent activity. The collated information was categorized on the basis of existing annotation schema. The data suggests that 2OG-dependent enzymes incorporate several desirable features of a systems level player. DB2OG, is free, accessible without a login to all users, and available at the following URL (http://comp-biol.theacms.in/DB2OG.html).

  6. EFFECT OF PROTECTIVE FUNCTION OF VERMICULTURE PRODUCTS ON MORPHOLOGICAL AND PHYSIOLOGICAL CHARACTERISTICS OF GROWTH AND DEVELOPMENT OF PLANTS IN THE CONDITION OF ABIOTIC FACTORS

    Directory of Open Access Journals (Sweden)

    O.M. Vasilyuk

    2016-04-01

    Full Text Available The effect of MgSO4 on morphometric specifics of the Salix alba L., which characterized by high rates of growth and development is investigated. Mg2+ was added in the form of MgSO4*3H2O at a concentration of 2.5 g/l considering of salt water content in the research solutions with S. alba L. and  combined with plant growth regulator (GR of natural origin Humisol. These studies have shown toxicity ofMgSO4 at a concentration of 2.5 g/l during all the period of growth and development. So, MgSO4 had toxic effect on plant growth and development within whole period of observation. We registered negative correlation (R = - 0.99 between toxic properties of salt and the age of the studied plants (for example, the growth rate of shoots and leaf blades by S. alba L. and positive correlation (R = 0.99 while studied the root growth rate, which was caused by the direct contact of rhizosphere and negative stressors. The GR Humisol accelerated the rate of physiological processes of growth and development of shoots and roots in 2-3 times, but the growth of leaf blade was not activated regards the control. The combined effect of magnesium salts and GR levelled toxic concentrations of magnesium sulphate were accelerated plant growth or stimulated growth up to control values, promoted adaptation mechanisms of plants and provided a protective role against excessive salinity. We suggested using the Humisol as a natural product, vermiculture, adaptogene, protector, and fertilizer agent of natural origin, which provides for biota to consume the environmental services without damage to the environment under conditions of excessive pressure of salt stress on plant organism.

  7. Surface coating changes the physiological and biochemical impacts of nano-TiO2 in basil (Ocimum basilicum) plants.

    Science.gov (United States)

    Tan, Wenjuan; Du, Wenchao; Barrios, Ana C; Armendariz, Raul; Zuverza-Mena, Nubia; Ji, Zhaoxia; Chang, Chong Hyun; Zink, Jeffrey I; Hernandez-Viezcas, Jose A; Peralta-Videa, Jose R; Gardea-Torresdey, Jorge L

    2017-03-01

    Little is known about the effects of surface coating on the interaction of engineered nanoparticles (ENPs) with plants. In this study, basil (Ocimum basilicum) was cultivated for 65 days in soil amended with unmodified, hydrophobic (coated with aluminum oxide and dimethicone), and hydrophilic (coated with aluminum oxide and glycerol) titanium dioxide nanoparticles (nano-TiO2) at 125, 250, 500, and 750 mg nano-TiO2 kg(-1) soil. ICP-OES/MS, SPAD meter, and UV/Vis spectrometry were used to determine Ti and essential elements in tissues, relative chlorophyll content, carbohydrates, and antioxidant response, respectively. Compared with control, hydrophobic and hydrophilic nano-TiO2 significantly reduced seed germination by 41% and 59%, respectively, while unmodified and hydrophobic nano-TiO2 significantly decreased shoot biomass by 31% and 37%, respectively (p ≤ 0.05). Roots exposed to hydrophobic particles at 750 mg kg(-1) had 87% and 40% more Ti than the pristine and hydrophilic nano-TiO2; however, no differences were found in shoots. The three types of particles affected the homeostasis of essential elements: at 500 mg kg(-)(1), unmodified particles increased Cu (104%) and Fe (90%); hydrophilic increased Fe (90%); while hydrophobic increased Mn (339%) but reduced Ca (71%), Cu (58%), and P (40%). However, only hydrophobic particles significantly reduced root elongation by 53%. Unmodified, hydrophobic, and hydrophilic particles significantly reduced total sugar by 39%, 38%, and 66%, respectively, compared with control. Moreover, unmodified particles significantly decreased reducing sugar (34%), while hydrophobic particles significantly reduced starch (35%). Although the three particles affected basil plants, coated particles impacted the most its nutritional quality, since they altered more essential elements, starch, and reducing sugars.

  8. Dwarifng apple rootstock responses to elevated temperatures:A study on plant physiological features and transcription level of related genes

    Institute of Scientific and Technical Information of China (English)

    ZHOU Bei-bei; SUN Jian; LIU Song-zhong; JIN Wan-mei; ZHANG Qiang; WEI Qin-ping

    2016-01-01

    The aim of this study was to investigate the impact of heat stress on physiological features, together with endogenous hormones and the transcription level of related genes, to estimate the heat resistance ability and stress injury mechanism of different dwarifng apple rootstocks. Among the six rootstocks, the rootstocks of native Shao series (SH series) showed better heat stress resistance than those of Budagovski 9 (B9), Cornel-Geneva 24 (CG24), and Maling 26 (M26) from abroad. Among SH series rootstocks, SH1 and SH6 showed higher heat stress resistance than SH40. M26 demonstrated the lowest adaption ability to heat stress, showing higher leaf conductivity and lower liquid water content (LWC) with the increase in temperature. Heat stress also resulted in the suppression of photosynthesis, which showed no signiifcant res-toration after 7-day recovery. It should be noted that although a higher temperature led to a lower LWC and photosynthetic efifciency (Pn) of CG24, there was no signiifcant increase in leaf conductivity, and 7 days after the treatment, thePn of CG24 recovered. The extremely high temperature tolerance of SH series rootstocks could be related to the greater osmotic ad-justment (OA), which was relfected by smaler reductions in leaf relative water content (RWC) and higher turgor potentials and leaf gas exchange compared with the other rootstocks. Determination of hormones indicated multivariate regulation, and it is presumed that a relatively stable expression levels of functional genes under high-temperature stress is necessary for heat stress resistance of rootstocks.

  9. Trends in Plant Physiology at the Turn of Century%试析世纪之交植物生理学研究的动向

    Institute of Scientific and Technical Information of China (English)

    汤章城

    2001-01-01

    This paper is an attempt to reviewbriefly the following fourresearch trends in plant physiology at the turn of century: from research on biological macromolecules to clarification of complex life activities-genomics,construction and function of gene; a key link in achieving integrated life activity-signal transduction; the energy and material basis of life activity metabolism and its control; the interrelationship between plant and environment (both biological and abiological )-biological coevolution and adaptability.%简要介绍了当今植物生理学研究中值得注意的四个动向,它们是:从研究生物大分子到阐明复杂生命活动——基因组学、基因结构与功能的研究;实现生命整体性的重要环节——信号传递的研究;生命活动的能量和物质基础——代谢及其调节的研究;植物与环境(非生物和生物环境)的相互关系——生物的协同进化和适应的研究。

  10. Morphological and physiological features of the species Asimina triloba (L. dunal, introduced as an ornamental plant in Baia Mare (Maramureş county, Romania

    Directory of Open Access Journals (Sweden)

    Beatrice SZILAGYI

    2011-11-01

    Full Text Available Tree species Asimina triloba (L. Dunal, is native to North America. In the area of origin is cultivated, both as food species because the edible fruit, and as ornamental species. Ornamental value derives both from decorative flowers, that open in early spring, and because habitus species. The species is demanding from slightly acidic soils (pH 5.5 to 7.0 and well drained. Seedlings are susceptible to heatstroke and need areas of the sun, but since the second year, vegetate well in bright light conditions [27]. Optimum climate is temperate to subtropical one. The species exhibits unique quality traits for a temperate fruit that are similar to other fruit in the Annonaceae family, including cherimoya (Annona cherimola Mill., sugar apple or sweetsop, (A. squamosa L., soursop (A. muricata L., custard apple (A. reticulata L., and atemoya (A. squamosa X A. cherimola, all of which are tropical [2].This study follows the behavior of the species, in particular conditions of the Baia Mare and its surroundings. In this area a fewindividuals were introduced, in order to diversigy the range of species of ornamental plants. In Baia Mare, topoclimate is specifically depression, sheltered by mountains, more atenuated as temperature and winds, than in surrounding areas. As a result ofclimatic conditions, chestnut Castanea sativa, grows in good conditions in Baia Mare. Instead, the area is heavily polluted,especially at ground level. Pollution by heavy metals is a historical being generated by the mining industry.The introduction and use of a new plant species into a new area involves: 1. easy to obtain seed; 2.- maintaining the crown shape habitus and and leaf shape and size, respectively; 3 – determination of optimal physiological parameters. Therefore have been performed, the following experimental determinations: 1. - germination of seed obtained in the particular conditions of the Baia Mare; 2. - some morphomtric characteristics of leaves, in the juveniles

  11. 茶树接种VA菌根的生理特性研究%Study on Physiological Characteristic of Tea Plant Inoculated by VA Mycorrhiza

    Institute of Scientific and Technical Information of China (English)

    李远华; 郑芳; 倪德江; 杨江帆; 石玉涛

    2011-01-01

    The physiological characteristic of tea plant inoculated by VA mycorrhiza was studied. Results showed that 50 d after inoculation, the chlorophyll content in tea leaves inoculated by VA mycorrhiza was higher than that uninoculated by VA mycorrhiza. Results also indicated when the photosynthetical available radiation was in the range of 0-1200 umol/m2S, the net photosynthesis rate, the stomata conductance and the transpiration rate of the tea plant inoculated by VA mycorrhiza were all higher than those of the control, the water use efficiency (WUE) increased rapidly in earlier stage, then decreased gradually after reaching the peak, the degrees of saturation of leaves decreased gradually. After the tea plant inoculated by VA mycorrhiza, MDA content of tea leaves decreased while the hydroxyproline content decreased first and increased later with the increase of infection rate. The inoculation of VA mycorrhiza can improve the activities of protective enzymes of tea plant. During the rested of 90 d after inoculation, the activity of POD reached the peak, the activity of SOD increased slightly first and then decreased smoothly. CAT activity of tea plant treated by VA mycorrhiza was always higher than that of the control.%茶树接种VA菌根(丛枝菌根)的生理特性研究表明,茶树叶片接种VA菌根50d后,其叶绿素含量都高于未接种的.在光合有效辐射0~1200μmol/m2s,接种VA菌根的茶树,其净光合速率、气孔导度、蒸腾速率等均有提高;而水分利用率前期快速增加,达到高峰然后下降;茶树叶片相对含水量先上升后下降,叶片的自然饱和亏逐渐降低.接种VA菌根后,随着侵染率的增加,茶树叶片的丙二醛含量越少,脯氨酸的含量先降低后升高.VA菌根能够提高茶树保护酶的活性,在生长到90d时,过氧化物酶(POD)活性达到最高值,超氧化物歧化酶(SOD)活性先升高再降低,但增加幅度均比较小;对过氧化氢酶(CAT)活性的影响一直高于未接种的.

  12. Effect of dietary phytase transgenic corn on physiological characteristics and the fate of recombinant plant DNA in laying hens.

    Science.gov (United States)

    Gao, Chunqi; Ma, Qiugang; Zhao, Lihong; Zhang, Jianyun; Ji, Cheng

    2014-01-01

    The study aimed to evaluate the potential effects of feeding with phytase transgenic corn (PTC) on organ weight, serum biochemical parameters and nutrient digestibility, and to determine the fate of the transgenic DNA in laying hens. A total of 144 50-week-old laying hens were grouped randomly into 2 treatments, with 8 replicates per treatment and 9 hens per replicate. Each treatment group of hens was fed with diets containing 62.4% non-transgenic conventional corn (CC) or PTC for 16 weeks. The phytase activity for CC was 37 FTU/kg of DM, whereas the phytase activity for PTC was 8,980 FTU/kg of DM. We observed that feeding PTC to laying hens had no adverse effect on organ weight or serum biochemical parameters (p>0.05). A fragment of a poultry-specific ovalbumin gene (ov) was amplified from all tissues of hens showing that the DNA preparations were amenable to PCR amplification. Neither the corn-specific invertase gene (ivr) nor the transgenic phyA2 gene was detected in the breast muscle, leg muscle, ovary, oviduct and eggs. The digestibility data revealed no significant differences between the hens that received the CC- and PTC-based diets in the digestibility of DM, energy, nitrogen and calcium (p>0.05). Phosphorus digestibility of hens fed the PTC-based diet was greater than that of hens fed the CC-based diet (58.03% vs 47.42%, phens. No recombinant phyA2 gene was detected in muscle tissues and reproductive organs of laying hens. The novel plant phytase was efficacious in improving the phosphorus digestibility of laying hens.

  13. More than just a vulnerable pipeline: xylem physiology in the light of ion-mediated regulation of plant water transport.

    Science.gov (United States)

    Nardini, Andrea; Salleo, Sebastiano; Jansen, Steven

    2011-10-01

    Major restrictions to the hydraulic conductance of xylem (K(XYL)) in vascular plants have traditionally been attributed to anatomical constraints. More recently, changes in the cationic concentration of xylem sap have been suggested to be responsible for short-term changes in K(XYL) based on data for 35 dicot species, and very few gymnosperms and ferns, indicating that xylem water transport may no longer be considered as an entirely passive process. Recent studies have revealed that this so-called ionic effect: (i) varies from little or no increase to >30%, (ii) is species specific, (iii) changes on a seasonal basis, (iv) depends on the cationic concentration, (v) is enhanced in embolized stems, and (vi) is positively correlated with vessel grouping. Furthermore, the ionic effect has been suggested to play functional roles in planta with respect to: (i) phloem-mediated control of xylem hydraulic properties, (ii) compensation of cavitation-induced loss of hydraulic conductance, with the result of optimizing light and water utilization, and (iii) differential regulation of water delivery to branches exposed to different levels of light. Pits are likely to play a key role in the ionic effect, which has largely been explained as a consequence of the poly-electrolytic nature and hydrogel properties of the pectic matrix of interconduit pit membranes, despite little evidence that pit membrane pectins remain present after cell hydrolysis. More research is needed to address the ionic effect in more species, physico-chemical properties of pit membranes, and how the ionic effect may increase xylem hydraulic conductance 'on demand'.

  14. Improved representation of plant functional types and physiology in the Joint UK Land Environment Simulator (JULES v4.2) using plant trait information

    Science.gov (United States)

    Harper, Anna B.; Cox, Peter M.; Friedlingstein, Pierre; Wiltshire, Andy J.; Jones, Chris D.; Sitch, Stephen; Mercado, Lina M.; Groenendijk, Margriet; Robertson, Eddy; Kattge, Jens; Bönisch, Gerhard; Atkin, Owen K.; Bahn, Michael; Cornelissen, Johannes; Niinemets, Ülo; Onipchenko, Vladimir; Peñuelas, Josep; Poorter, Lourens; Reich, Peter B.; Soudzilovskaia, Nadjeda A.; van Bodegom, Peter

    2016-07-01

    Dynamic global vegetation models are used to predict the response of vegetation to climate change. They are essential for planning ecosystem management, understanding carbon cycle-climate feedbacks, and evaluating the potential impacts of climate change on global ecosystems. JULES (the Joint UK Land Environment Simulator) represents terrestrial processes in the UK Hadley Centre family of models and in the first generation UK Earth System Model. Previously, JULES represented five plant functional types (PFTs): broadleaf trees, needle-leaf trees, C3 and C4 grasses, and shrubs. This study addresses three developments in JULES. First, trees and shrubs were split into deciduous and evergreen PFTs to better represent the range of leaf life spans and metabolic capacities that exists in nature. Second, we distinguished between temperate and tropical broadleaf evergreen trees. These first two changes result in a new set of nine PFTs: tropical and temperate broadleaf evergreen trees, broadleaf deciduous trees, needle-leaf evergreen and deciduous trees, C3 and C4 grasses, and evergreen and deciduous shrubs. Third, using data from the TRY database, we updated the relationship between leaf nitrogen and the maximum rate of carboxylation of Rubisco (Vcmax), and updated the leaf turnover and growth rates to include a trade-off between leaf life span and leaf mass per unit area.Overall, the simulation of gross and net primary productivity (GPP and NPP, respectively) is improved with the nine PFTs when compared to FLUXNET sites, a global GPP data set based on FLUXNET, and MODIS NPP. Compared to the standard five PFTs, the new nine PFTs simulate a higher GPP and NPP, with the exception of C3 grasses in cold environments and C4 grasses that were previously over-productive. On a biome scale, GPP is improved for all eight biomes evaluated and NPP is improved for most biomes - the exceptions being the tropical forests, savannahs, and extratropical mixed forests where simulated NPP is too

  15. Biosynthesis, Metabolism and Physiological Roles of Phytic Acid in Higher Plants%高等植物体中植酸合成、代谢及其生理作用

    Institute of Scientific and Technical Information of China (English)

    靳晓琳; 王新坤; 杨润强; 仲磊; 顾振新

    2014-01-01

    本文对植酸及其存在形式、代谢、调控及在高等植物内的生理作用作了介绍。%This article described the existing form, metabolism, regulation and the possible physiological roles of phytic acid in higher plant.

  16. The physiological and biochemical responses of a medicinal plant (Salvia miltiorrhiza L.) to stress caused by various concentrations of NaCl.

    Science.gov (United States)

    Gengmao, Zhao; Quanmei, Shi; Yu, Han; Shihui, Li; Changhai, Wang

    2014-01-01

    Salvia miltiorrhiza, which is commonly known as Danshen, is a traditional Chinese herbal medicine. To illustrate its physiological and biochemical responses to salt stress and to evaluate the feasibility of cultivating this plant in saline coastal soils, a factorial experiment under hydroponic conditions was arranged on the basis of a completely randomised design with three replications. Five salinity treatments (0, 25, 50, 75 and 100 mM NaCl) were employed in this experiment. The results showed that salinity treatments of <100 mM NaCl did not affect the growth of Salvia miltiorrhiza in a morphological sense, but significantly inhibit the accumulation of dry matter. Salinity treatments significantly decreased the Chl-b content but caused a negligible change in the Chl-a content, leading to a conspicuous overall decrease in the T-Chl content. The Na(+) content significantly increased with increasing hydroponic salinity but the K(+) and Ca(2+) contents were reversed, indicating that a high level of external Na(+) resulted in a decrease in both K(+) and Ca(2+) concentrations in the organs of Salvia miltiorrhiza. Salt stress significantly decreased the superoxide dismutase (SOD) activity of Salvia miltiorrhiza leaves in comparison with that of the control. On the contrary, the catalase (CAT) activity in the leaves markedly increased with the increasing salinity of the hydroponic solution. Moreover, the soluble sugar and protein contents in Salvia miltiorrhiza leaves dramatically increased with the increasing salinity of the hydroponic solution. These results suggested that antioxidant enzymes and osmolytes are partially involved in the adaptive response to salt stress in Salvia miltiorrhiza, thereby maintaining better plant growth under saline conditions.

  17. The physiological and biochemical responses of a medicinal plant (Salvia miltiorrhiza L. to stress caused by various concentrations of NaCl.

    Directory of Open Access Journals (Sweden)

    Zhao Gengmao

    Full Text Available Salvia miltiorrhiza, which is commonly known as Danshen, is a traditional Chinese herbal medicine. To illustrate its physiological and biochemical responses to salt stress and to evaluate the feasibility of cultivating this plant in saline coastal soils, a factorial experiment under hydroponic conditions was arranged on the basis of a completely randomised design with three replications. Five salinity treatments (0, 25, 50, 75 and 100 mM NaCl were employed in this experiment. The results showed that salinity treatments of <100 mM NaCl did not affect the growth of Salvia miltiorrhiza in a morphological sense, but significantly inhibit the accumulation of dry matter. Salinity treatments significantly decreased the Chl-b content but caused a negligible change in the Chl-a content, leading to a conspicuous overall decrease in the T-Chl content. The Na(+ content significantly increased with increasing hydroponic salinity but the K(+ and Ca(2+ contents were reversed, indicating that a high level of external Na(+ resulted in a decrease in both K(+ and Ca(2+ concentrations in the organs of Salvia miltiorrhiza. Salt stress significantly decreased the superoxide dismutase (SOD activity of Salvia miltiorrhiza leaves in comparison with that of the control. On the contrary, the catalase (CAT activity in the leaves markedly increased with the increasing salinity of the hydroponic solution. Moreover, the soluble sugar and protein contents in Salvia miltiorrhiza leaves dramatically increased with the increasing salinity of the hydroponic solution. These results suggested that antioxidant enzymes and osmolytes are partially involved in the adaptive response to salt stress in Salvia miltiorrhiza, thereby maintaining better plant growth under saline conditions.

  18. Representation of pheromones, interspecific signals, and plant odors in higher olfactory centers; mapping physiologically identified antennal-lobe projection neurons in the male heliothine moth

    Directory of Open Access Journals (Sweden)

    Xin-Cheng eZhao

    2014-10-01

    Full Text Available In the primary olfactory centre of the moth brain, for example, a few enlarged glomeruli situated dorsally, at the entrance of the antennal nerve, are devoted to information about female-produced substances whereas a set of more numerous ordinary glomeruli receives input about general odorants. Heliothine moths are particularly suitable for studying central chemosensory mechanisms not only because of their anatomically separated systems for plant odours and pheromones but also due to their use of female-produced substances in communication across the species. Thus, the male-specific system of heliothine moths includes two sub arrangements, one ensuring attraction and mating behavior by carrying information about pheromones released by conspecifics, and the other reproductive isolation via signal information emitted from heterospecifics. Based on previous tracing experiments, a general chemotopic organization of the male-specific glomeruli has been demonstrated in a number of heliothine species. As compared to the well explored organization of the moth antennal lobe, demonstrating a non-overlapping representation of the biologically relevant stimuli, less is known about the neural arrangement residing at the following synaptic level, i.e. the mushroom body calyces and the lateral horn. In the study presented here, we have labelled physiologically characterized antennal-lobe projection neurons in males of the two heliothine species, Heliothis virescens and Helicoverpa assulta, for the purpose of mapping their target regions in the protocerebrum. In order to compare the representation of plant odours, pheromones, and interspecific signals in the higher brain regions of each species, we have created standard brain atlases and registered three-dimensional models of distinct uniglomerular projection neuron types into the relevant atlas.

  19. Taxonomy and Physiology of un-wanted bacterial flora in activated sludge process. Study in a pilot plant; Taxonomia y fisiologia de la flora bacteriana indeseable en el proceso de fangos activados. Estudio de una plant piloto

    Energy Technology Data Exchange (ETDEWEB)

    Berrocal Escobar, M.; Lopez Fernandez, C. L.; Arias Fernandez, M. E.; Perez Leblic, M. I.; Zapatero Martin, I.; Leton Garcia, P.; Garcia Calvo, E. [Universidad de Alcala de Henares. Madrid (Spain); Aznar Munoz, R.; Rodriguez Medina, P. [Departamento Tecnico y de Calidad de Seragua, S.A. Madrid (Spain)

    1998-12-31

    The activated sludge used in the wastewater depuration in treatment plants could be considered as an artificial microbial ecosystem in balance. In this community which is constituted by free and flocculated bacteria, protozoa, rotifers, nematodes and a few other invertebrates, the stability of the system is maintained by the continuous food competition. The breakdown of this stability due to a high proliferation of filametous bacteria drive to the phenomenon called bulking. Nowadays, to avoid bulking is one of the main objectives in research because is the main cause of the malfunction of wastewater depuration interfering with compaction, settling, thickening and, concentration of activated sludge. In the present work, a taxonomical and physiological study of the microbial community which carries out the cleaning of wastewater in an activated sludge system has been performed by using an airlift bioreactor working in continuous. Activated sludge coming from a conventional wastewater plant was used as inoculum (starter culture). The nutritional conditions and bioreactor system parameters in which the filamentous bacteria grow in excess have been established. Several of filamentous bacteria responsible for bulking have been identified: Sphaerotilus natans, type 021N, Nocardia spp., Microthrix parvicella, Thiotrix I, Thiotrix II, type 0803, type 0581, Nostocoida limicola I and III and, type 1863. In addition, protozoa of groups involved in the depuration process (free-swimming ciliates, attached ciliates, crawling ciliates, carnivorous ciliates, flagellates and amoebae) were observed as well as rotifer and nematode populations. (Author) 13 refs.

  20. Physiological indexese macro- and micronutrients in plant tissue and essential oil of Mentha piperita L. grown in nutrient solution with variation in N, P, K and Mg levels

    Directory of Open Access Journals (Sweden)

    E.F.S. David

    2014-03-01

    Full Text Available Mentha piperita L. is an aromatic and medicinal species of the family Lamiaceae, known as mint or peppermint, and its leaves and branches produce essential oil rich in menthol. This study aimed to evaluate physiological indexes, macro- and micronutrients inthe shootsand essential oil of Mentha piperita L. grown in nutrient solution number 2 of Hoagland and Arnon (1950 with different N, P, K and Mg levels. Shoot length, dry mass of the different organs, total dry mass, leaf area, essential oil yield and composition, and macronutrient (N, P, K, Mg, Ca, S and micronutrient (Mn, Cu, Fe, Zn contents in the shoot were evaluated. Plants treated with 65%N/50%P/25%K/100%Mg had a tendency towards longer shoot, greaterroot and leaf blade dry masses, higher essential oil yield, higher menthol levels and lower menthone levels. The results showed that Mentha can be grown in nutrient solution by reducing 65% N, 50% P, 25% K and 100% Mg. This solution had better development compared to the other tested treatments. Therefore,we recommendMentha piperita L. to be grown with such nutrient levels.

  1. A 7500-year record of plant physiology as palaeoenvironmental proxy from tree-ring δ13C and growth rates - the CARATE project

    Science.gov (United States)

    Arppe, L.; Helama, S.; Mielikäinen, K.; Oinonen, M.; Timonen, M.

    2012-12-01

    This contribution presents a recently launched 4-year research project, "CARATE", aiming to produce new climatic and plant physiological records at high temporal resolution by the synthesis of annually/decadally resolved tree-ring archives of growth-rates and cellulose δ13C values from high-latitude continental Europe. The project mainly relies on a supra-long pinewood chronology from Finnish Lapland covering the mid and late Holocene times continuously through the millennia since 5634 B.C. until the present-day (Eronen et al. 2002, Helama et al. 2008). The chronology provides a highly sensitive, absolutely dated proxy record of past environment and climate variability at highest possible resolution that can be calibrated directly with instrumental records of environmental variables. While growth rate records are invaluable tools for paleoclimate research at high frequencies, tree-ring δ13C compositions have the potential to portray the high-to-low-frequency climate signals per se, without complications from time-series analysis. By combining isotope and growth rate information, we aim to reconstruct regional high- and low-frequency climate variability over the past 7500 years with increased reliability, and explore the climate forcings behind the observed variations. The project was started by studying the strength of the common climatic signal both within- and between-sites, and possible associations to tree-physiological parameters. For this purpose, a set of 70 living pine trees (Pinus sylvestris) , growing in proximity of the subfossil pinewood collection sites in western and eastern Lapland, were cored for analysis of growth rates and δ13C values. α-cellulose was extracted from decadal samples corresponding to the time period 1970-2010 including both early- and latewood. The δ13C time series show a consistent response to regional environmental forcing over the entire study area, with no discernable differences between western and eastern Lapland. Within

  2. Physiological Networks: towards systems physiology

    Science.gov (United States)

    Bartsch, Ronny P.; Bashan, Amir; Kantelhardt, Jan W.; Havlin, Shlomo; Ivanov, Plamen Ch.

    2012-02-01

    The human organism is an integrated network where complex physiologic systems, each with its own regulatory mechanisms, continuously interact, and where failure of one system can trigger a breakdown of the entire network. Identifying and quantifying dynamical networks of diverse systems with different types of interactions is a challenge. Here, we develop a framework to probe interactions among diverse systems, and we identify a physiologic network. We find that each physiologic state is characterized by a specific network structure, demonstrating a robust interplay between network topology and function. Across physiologic states the network undergoes topological transitions associated with fast reorganization of physiologic interactions on time scales of a few minutes, indicating high network flexibility in response to perturbations. The proposed system-wide integrative approach may facilitate new dimensions to the field of systems physiology.

  3. Relationship Between Remotely-sensed Vegetation Indices, Canopy Attributes and Plant Physiological Processes: What Vegetation Indices Can and Cannot Tell Us About the Landscape

    Directory of Open Access Journals (Sweden)

    Stephen G. Nelson

    2008-03-01

    Full Text Available Vegetation indices (VIs are among the oldest tools in remote sensing studies. Although many variations exist, most of them ratio the reflection of light in the red and NIR sections of the spectrum to separate the landscape into water, soil, and vegetation. Theoretical analyses and field studies have shown that VIs are near-linearly related to photosynthetically active radiation absorbed by a plant canopy, and therefore to light-dependent physiological processes, such as photosynthesis, occurring in the upper canopy. Practical studies have used time-series VIs to measure primary production and evapotranspiration, but these are limited in accuracy to that of the data used in ground truthing or calibrating the models used. VIs are also used to estimate a wide variety of other canopy attributes that are used in Soil-Vegetation-Atmosphere Transfer (SVAT, Surface Energy Balance (SEB, and Global Climate Models (GCM. These attributes include fractional vegetation cover, leaf area index, roughness lengths for turbulent transfer, emissivity and albedo. However, VIs often exhibit only moderate, non-linear relationships to these canopy attributes, compromising the accuracy of the models. We use case studies to illustrate the use and misuse of VIs, and argue for using VIs most simply as a measurement of canopy light absorption rather than as a surrogate for detailed features of canopy architecture. Used this way, VIs are compatible with "Big Leaf" SVAT and GCMs that assume that canopy carbon and moisture fluxes have the same relative response to the environment as any single leaf, simplifying the task of modeling complex landscapes.

  4. Effects of Hydrargyrum Stress on Physiological Indexes of Grape Plants%Hg污染胁迫对葡萄果树生理特性的影响

    Institute of Scientific and Technical Information of China (English)

    马堃; 冯圣东; 杨志新

    2012-01-01

    [目的]研究Hg污染胁迫对葡萄果树生理特性的影响.[方法]通过盆栽试验,研究不同浓度汞胁迫下葡萄果树细胞膜透性、游离脯氨酸含量、MDA含量及SOD、POD、CAT保护酶活性在不同生长发育期的变化规律.[结果]随着土壤汞浓度的增加,葡萄叶片相对电导率、MDA含量、游离脯氨酸含量以及SOD活性均逐渐升高.POD活性则呈现出随Hg浓度增加先升高后降低的变化趋势.CAT活性却随汞浓度增加而下降.在葡萄不同的生育时期,相对电导率和MDA含量随葡萄果树生长而减少,其顺序为成熟期>转色期>幼果生长期>开花期,游离脯氨酸含量和SOD活性则呈现出相反的顺序,即开花期>幼果生长期>转色期>成熟期,POD活性随时间的变化顺序为转色期>幼果生长期>开花期>成熟期,CAT活性随时间的变化顺序则是幼果生长期>转色期>开花期>成熟期.[结论]葡萄植株在较短生长期内对低浓度Hg有较强的抵御能力,而在较长生长期内对高浓度Hg的抵抗力下降,并受到Hg污染的严重伤害.%[Objective]The research aimed to study the effects of hydrargyrum stress on physiological indexes of grape plants. [Method]Grapes was planted in pot and different content of hydrargyrum was added to soil. The chang of cell membrane permeability, proline contents,MDA content and SOD,POD,CAT activities in grape leaf in different cultivation times were analyzed. [Result] With the inerease of Hg content in soil,relative electric conductivity,MDA content,proline content and SOD activity in leaves of grape increased. POD ativity increased first and then decreased. Hg obviously inhibited CAT activity. In different cultivation times, relative electric conductivity and MDA content decreased with the growth of grape trees. It showed in an order of flowering period young fruit growth period > turn color period > mature period. POD activity showed mature period turn color

  5. Exposure studies of core-shell Fe/Fe(3)O(4) and Cu/CuO NPs to lettuce (Lactuca sativa) plants: Are they a potential physiological and nutritional hazard?

    Science.gov (United States)

    Trujillo-Reyes, J; Majumdar, S; Botez, C E; Peralta-Videa, J R; Gardea-Torresdey, J L

    2014-02-28

    Iron and copper nanomaterials are widely used in environmental remediation and agriculture. However, their effects on physiological parameters and nutritional quality of terrestrial plants such as lettuce (Lactuca sativa) are still unknown. In this research, 18-day-old hydroponically grown lettuce seedlings were treated for 15 days with core-shell nanoscale materials (Fe/Fe(3)O(4), Cu/CuO) at 10 and 20mg/L, and FeSO(4)·7H(2)O and CuSO(4)·5H(2)O at 10mg/L. At harvest, Fe, Cu, micro and macronutrients were determined by ICP-OES. Also, we evaluated chlorophyll content, plant growth, and catalase (CAT) and ascorbate peroxidase (APX) activities. Our results showed that iron ions/NPs did not affect the physiological parameters with respect to water control. Conversely, Cu ions/NPs reduced water content, root length, and dry biomass of the lettuce plants. ICP-OES results showed that nano-Cu/CuO treatments produced significant accumulation of Cu in roots compared to the CuSO(4)·5H(2)O treatment. In roots, all Cu treatments increased CAT activity but decreased APX activity. In addition, relative to the control, nano-Cu/CuO altered the nutritional quality of lettuce, since the treated plants had significantly more Cu, Al and S but less Mn, P, Ca, and Mg. Copyright © 2013 Elsevier B.V. All rights reserved.

  6. A Brief Analysis of Subcellular Distribution and Physiological Functions of Plant Aquaporins%植物水孔蛋白的亚细胞分布与生理功能研究浅析

    Institute of Scientific and Technical Information of China (English)

    庞永奇; 王高奇; 王旭初; 陈珈; 王学臣

    2012-01-01

    水孔蛋白(aquaporin,AQP)因具有水转运活性而得名,然而随着研究的深入,水孔蛋白转运活性的多样性与生理功能的多样性不断被报道.本文综合分析了植物水孔蛋白亚细胞定位与功能多样性的研究进展,重点综述了植物水孔蛋白广泛的亚细胞分布特点,以及亚细胞上的再分布现象与植物水孔蛋白生理功能多样性间的关系,并对植物水孔蛋白研究中存在的问题及研究方向进行了分析,认为水孔蛋白多样化的生理功能的作用机制需要结合其组织定位与亚细胞定位进行分析才能揭示.%Aquaporins (AQPs) got their name from the water transport ability, and recently, their multi-transport activities and multiple physiological functions were also frequently reported. This review focused on the analysis of recent progress on physiological functions and subcellular localizations of plant aquaporins. The relationship between the multi-physiological functionality and the multiple intracellular localizations and redistribution of plant aquaporins were also thoroughly discussed, thus raising questions about the current research and research direction for plant aquaporins. To reveal the possible mechanism on the multiple physiological functions, it is necessary and essential to analyze the connections between functions and tissue and subcellular localizations in future.

  7. Mathematical physiology

    CERN Document Server

    Sneyd, James

    2009-01-01

    There has been a long history of interaction between mathematics and physiology. This book looks in detail at a wide selection of mathematical models in physiology, showing how physiological problems can be formulated and studied mathematically, and how such models give rise to interesting and challenging mathematical questions. With its coverage of many recent models it gives an overview of the field, while many older models are also discussed, to put the modern work in context. In this second edition the coverage of basic principles has been expanded to include such topics as stochastic differential equations, Markov models and Gibbs free energy, and the selection of models has also been expanded to include some of the basic models of fluid transport, respiration/perfusion, blood diseases, molecular motors, smooth muscle, neuroendrocine cells, the baroreceptor loop, turboglomerular oscillations, blood clotting and the retina. Owing to this extensive coverage, the second edition is published in two volumes. ...

  8. The Influence of Ornamental Plants Color on Human's Physiology and Psychology%园林植物色彩对人的生理和心理的影响

    Institute of Scientific and Technical Information of China (English)

    果媛媛; 姜瑶; 王松

    2015-01-01

    文章介绍了园林植物色彩,探讨了园林植物色彩对人的作用,提出园林植物色彩在配置中的建议。%This paper introduces the landscape plant color, discusses the role of the garden plant color, and puts forward the suggestion of the garden plant color in the configuration.

  9. Seed isotopic analysis as a tool to understand ecological processes influencing plant development and physiology: the case study of Quercus rotundifolia Lam. in a desertification gradient in Mediterranean areas

    Science.gov (United States)

    Oliveira, Tatiana; Silva, Anabela; Rodrigues, Carla; Antunes Antunes, Cristina; Pinho, Pedro; Ramos, Alzira; João Pereira, Maria; Branquinho, Cristina; Máguas, Cristina

    2014-05-01

    Plant responses to climate change highly depend on the temporal variability in precipitation events and on plant specific strategies, such as drought tolerance and resilience. Within the different plant organs, seeds have become an important research tool in the past years to study plant development and nutrients allocation. Key features of seeds such as the tendency to accumulate and store nutrient compounds open many possibilities to explore isotope analysis (13C, 15N and 18O), with many outcomes in fields from ecology to food traceability. The application of light stable isotopes to plant materials have been used to study both physiological (i.e. photosynthesis and stomatal conductance), nutrients uptake and metabolism (origin of nitrogen and symbiotic associations) as well as many ecological processes, which will produce a distinctive isotope fingerprint on the plant tissues. Thus, the isotopic composition of certain bio and geo-elements of seeds, yielding relevant information on plant ecophysiology, are able to relate the plant functioning with local climatic conditions (e.g., temperature and precipitation). The application of isotope analysis in this way can be used as a proxy to understand complex environmental degradation processes such as land degradation in drylands resulting from various factors including climatic variations and human activities. In this study acorns of Quercus ilex plants were sampled during 2012-2013 in a region of southern Portugal, according to (i) soil land-use; (ii) aridity and desertification indexes. The approach developed combined plant seed analysis (seed morphology and compounds quantification) with isotope ratio mass spectrometry (δ13C, δ15N and δ18O) as a "tool" to study changes in plant ecophysiology over time and space. Seeds allow studies at specific temporal scale (development period) which varies according to its biology and depends on the climatic conditions where the plant is grown (i.e, seed's biomass integrate

  10. Physiological and Ecological Studies in Environmental Adaptation of Plants. : III. Altitudinal Variation in Some Characters of Cytochrome Oxidase Isozymes in Polygonum cuspidatum Sieb. et Zucc.

    OpenAIRE

    1987-01-01

    The number and the activity of cytochrome oxidase isozymes in Polygonum cuspidatum Sieb. et Zucc. were investigated on the mature plants growing in a few different altitudes and on these seedlings grown under various levels of a constant temperature. The number of the isozymes in the mature plants was 3 at low altitude and 2 at high altitude, but that in the plants transplanted from high to low altitude was 4. The number and the activity of the isozymes in the seedlings derived from the plant...

  11. The Physiological and Biochemical Mechanisms Providing the Increased Constitutive Cold Resistance in the Potato Plants, Expressing the Yeast SUC2 Gene Encoding Apoplastic Invertase

    Directory of Open Access Journals (Sweden)

    A.N. Deryabin

    2016-05-01

    Full Text Available The expression of heterologous genes in plants is an effective method to improve our understanding of plant resistance mechanisms. The purpose of this work was to investigate the involvement of cell-wall invertase and apoplastic sugars into constitutive cold resistance of potato (Solanum tuberosum L., cv. Dйsirйe plants, which expressed the yeast SUC2 gene encoding apoplastic invertase. WT-plants of a potato served as the control. The increase in the essential cell-wall invertase activity in the leaves of transformed plants indicates significant changes in the cellular carbohydrate metabolism and regulatory function of this enzyme. The activity of yeast invertase changed the composition of intracellular sugars in the leaves of the transformed potato plant. The total content of sugars (sucrose, glucose, fructose in the leaves and apoplast was higher in the transformants, in comparison by WT-plants. Our data indicate higher constitutive resistance of transformants to severe hypothermia conditions compared to WT-plants. This fact allows us to consider cell-wall invertase as a enzyme of carbohydrate metabolism playing an important regulatory role in the metabolic signaling upon forming increased plant resistance to low temperature. Thus, the potato line with the integrated SUC2 gene is a convenient tool to study the role of the apoplastic invertase and the products of its activity during growth, development and formation constitutive resistance to hypothermia.

  12. Reproductive physiology

    Science.gov (United States)

    Gee, G.F.; Russman, S.E.; Ellis, David H.; Gee, George F.; Mirande, Claire M.

    1996-01-01

    Conclusions: Although the general pattern of avian physiology applies to cranes, we have identified many physiological mechanisms (e.g., effects of disturbance) that need further study. Studies with cranes are expensive compared to those done with domestic fowl because of the crane's larger size, low reproductive rate, and delayed sexual maturity. To summarize, the crane reproductive system is composed of physiological and anatomical elements whose function is controlled by an integrated neural-endocrine system. Males generally produce semen at a younger age than when females lay eggs. Eggs are laid in clutches of two (1 to 3), and females will lay additional clutches if the preceding clutches are removed. Both sexes build nests and incubate the eggs. Molt begins during incubation and body molt may be completed annually in breeding pairs. However, remiges are replaced sequentially over 2 to 3 years, or abruptly every 2 to 3 years in other species. Most immature birds replace their juvenal remiges over a 2 to 3 year period. Stress interferes with reproduction in cranes by reducing egg production or terminating the reproductive effort. In other birds, stress elevates corticosterone levels and decreases LHRH release. We know little about the physiological response of cranes to stress.

  13. Exercise physiology

    DEFF Research Database (Denmark)

    Kiens, Bente; Richter, Erik; Wojtaszewski, Jørgen

    2014-01-01

    The passing of Professor Bengt Saltin on September 12, 2014 truly marks the end of an era. As editor of the Journal of Applied Physiology and one of Bengt’s many collaborators and colleagues, I wanted the Journal to celebrate his many seminal contributions by means of an Editorial. Professor Bent...

  14. Cyclic electron flow around photosystem I via chloroplast NAD(P)H dehydrogenase (NDH) complex performs a significant physiological role during photosynthesis and plant growth at low temperature in rice.

    Science.gov (United States)

    Yamori, Wataru; Sakata, Naoki; Suzuki, Yuji; Shikanai, Toshiharu; Makino, Amane

    2011-12-01

    The role of NAD(P)H dehydrogenase (NDH)-dependent cyclic electron flow around photosystem I in photosynthetic regulation and plant growth at several temperatures was examined in rice (Oryza sativa) that is defective in CHLORORESPIRATORY REDUCTION 6 (CRR6), which is required for accumulation of sub-complex A of the chloroplast NDH complex (crr6). NdhK was not detected by Western blot analysis in crr6 mutants, resulting in lack of a transient post-illumination increase in chlorophyll fluorescence, and confirming that crr6 mutants lack NDH activity. When plants were grown at 28 or 35°C, all examined photosynthetic parameters, including the CO(2) assimilation rate and the electron transport rate around photosystems I and II, at each growth temperature at light intensities above growth light (i.e. 800 μmol photons m(-2) sec(-1)), were similar between crr6 mutants and control plants. However, when plants were grown at 20°C, all the examined photosynthetic parameters were significantly lower in crr6 mutants than control plants, and this effect on photosynthesis caused a corresponding reduction in plant biomass. The F(v)/F(m) ratio was only slightly lower in crr6 mutants than in control plants after short-term strong light treatment at 20°C. However, after long-term acclimation to the low temperature, impairment of cyclic electron flow suppressed non-photochemical quenching and promoted reduction of the plastoquinone pool in crr6 mutants. Taken together, our experiments show that NDH-dependent cyclic electron flow plays a significant physiological role in rice during photosynthesis and plant growth at low temperature.

  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. Application of Module Teaching in the Curriculum Reform of University Plant Physiology Experi-ments%模块式教学在高校植物生理学实验课程改革中的应用

    Institute of Scientific and Technical Information of China (English)

    彭元成; 王云生; 高俊山

    2014-01-01

    Plant physiology is an important basic course among university curriculums of biological sciences. However,there are some shortcomings of the traditional education method,which makes students pay less at-tention to experiments of the plant physiology,resulting a inactive education mode.Here,we provide a new teaching method about the experimental teaching of plant physiology based on my own work experiences, named module teaching.By intensifying the basic experiment skills and carrying out more comprehensive ex-periments,this method focuses on the scientific research qualities of students.Furthermore,module teaching method also lays emphasis on the experimental process and analyses of experimental results,thereby train-ing the rigorous work styles and the scientific attitudes in the future.%植物生理学是高等院校重要的生物学专业基础课,该门课程理论性强,实验要求也较高。该文从分析传统植物生理学实验教学过程中存在的问题出发,着重分析了其在现代植物生理学教学上的不足。并提出了模块式教学方法,通过强化基础实验技能,综合实验和研究性实验来提高学生综合科研素质。此外,还注重实验过程和实验结果分析,从而培养学生严谨的工作作风和端正的科学态度。

  17. Influence of salinity on the in vitro development of Glomus intraradices and on the in vivo physiological and molecular responses of mycorrhizal lettuce plants.

    Science.gov (United States)

    Jahromi, Farzad; Aroca, Ricardo; Porcel, Rosa; Ruiz-Lozano, Juan Manuel

    2008-01-01

    Increased salinization of arable land is expected to have devastating global effects in the coming years. Arbuscular mycorrhizal fungi (AMF) have been shown to improve plant tolerance to abiotic environmental factors such as salinity, but they can be themselves negatively affected by salinity. In this study, the first in vitro experiment analyzed the effects of 0, 50, or 100 mM NaCl on the development and sporulation of Glomus intraradices. In the second experiment, the effects of mycorrhization on the expression of key plant genes expected to be affected by salinity was evaluated. Results showed that the assayed isolate G. intraradices DAOM 197198 can be regarded as a moderately salt-tolerant AMF because it did not significantly decrease hyphal development or formation of branching absorbing structures at 50 mM NaCl. Results also showed that plants colonized by G. intraradices grew more than nonmycorrhizal plants. This effect was concomitant with a higher relative water content in AM plants, lower proline content, and expression of Lsp5cs gene (mainly at 50 mM NaCl), lower expression of the stress marker gene Lslea gene, and lower content of abscisic acid in roots of mycorrhizal plants as compared to nonmycorrhizal plants, which suggest that the AM fungus decreased salt stress injury. In addition, under salinity, AM symbiosis enhanced the expression of LsPIP1. Such enhanced gene expression could contribute to regulating root water permeability to better tolerate the osmotic stress generated by salinity.

  18. Influence of thiourea application on some physiological and molecular criteria of sunflower (Helianthus annuus L.) plants under conditions of heat stress.

    Science.gov (United States)

    Akladious, Samia Ageeb

    2014-05-01

    High temperature is a major factor limiting the growth of plant species during summer. Understanding the mechanisms of plant tolerance to high temperature would help in developing effective management practices and heat-tolerant cultivars through breeding or biotechnology. The present investigation was carried out to study the role of thiourea in enhancing the tolerance of sunflower plants to heat stress. Sunflower plants were subjected to temperature stress by exposing plants to 35 or 45 °C for 12 h. Two levels of thiourea (10 and 20 mM) were applied before sowing (seed treatment). The results indicated that the plants exposed to temperature stress exhibited a significant decline in growth parameters, chlorophylls, relative leaf water content, oil content, leaf nutrient status, and nitrate reductase activity. Treatment with thiourea, especially when applied at 10 mM, improved the above parameters and induced non-enzymatic and enzymatic antioxidants responsible for antioxidation. SDS-PAGE of protein revealed that high-temperature treatments alone or in combination with thiourea were associated with the disappearance of some bands or the appearance of unique ones. The result of RAPD analysis using five primers showed variable qualitative and quantitative changes. These findings confirm the effectiveness of applying thiourea on alleviating heat injuries in sunflower plants.

  19. 水杨酸在植物逆境生理中的作用%Role of Salicylic Acid in Plant Stress Physiology

    Institute of Scientific and Technical Information of China (English)

    张会

    2013-01-01

    Plants live in natural environment, and can be affected by a variety of adversity damage. Salicylic acid (SA) as the plant endogenous signal molecules, in the adverse circumstance will be induced, alleviate adversity injury to the plant. This paper integrated in recent years research results, to salicylic acid in plant under adversity mechanism were reviewed.%植物生存于自然环境中,会受到各种逆境的伤害.水杨酸(salicylic acid,SA)作为植物内源信号分子,在逆境下会诱导产生,缓解逆境对植物的伤害.本文综合近些年来的研究成果,对水杨酸在植物逆境下的作用机理进行了简要综述.

  20. Changes in growth, physiological parameters and the hormonal status of Myrtus communis L. plants irrigated with water with different chemical compositions.

    Science.gov (United States)

    Acosta-Motos, José Ramón; Ortuño, María Fernanda; Álvarez, Sara; López-Climent, María Fernanda; Gómez-Cadenas, Aurelio; Sánchez-Blanco, María Jesús

    2016-02-01

    Myrtus communis, an important Mediterranean ornamental shrub, was used to study the effect of irrigation water with different chemical compositions in the plant response. A treatment with NaCl was used to establish the plant resistance to high salinity at long term. Plants were subjected to four irrigation treatments with drainage for three months: Control (0.8 dS m(-1)); two treatments using reclaimed water (RWs): RW1 (2.0 dS m(-1)) and RW2 (5.0 dS m(-1)); and NaCl (10.0 dS m(-1)). High levels of electric conductivity of RWs not affected plant growth, while NaCl decreased leaf dry weight. Coinciding with the accumulation of Na(+) and Cl(-) in the roots, soil water potential decreased, which hinders the mobilization of water to the leaves, decreasing leaf water potential. The osmotic adjustment in the NaCl treatment was due to Na(+) and Cl(-) ions, although the proline could contribute as an Osmo compatible solute, increasing the turgor plants. Also changes in cell walls rigidity minimize the negative effects on the water balance; however, a higher lipid peroxidation was observed in these plants. Stomatal closure was associated with a decrease in K(+) and an increase in abscisic acid. NaCl produced an increase in salicylic acid and did not affect jasmonic acid contents at the end of the experiment. Similar behavior in soil and leaf water potentials, although less pronounced than in NaCl, was shown in RW2 plants. The abscisic acid increased in the RW2 with respect to the control and a decrease in stomatal conductance was observed at the end of the experiment. Plants irrigated with RW1 behaved similarly to the control.

  1. Effect of different levels of spraying with ascorbic acid (Vitamin c and application of super absorbent polymer on eco-physiological characteristics of plants in soils contaminated by Lead

    Directory of Open Access Journals (Sweden)

    S. Mohsen Naghibi,

    2016-03-01

    Full Text Available In order to study the effects of application super absorbent polymer and sprayingof ascorbic acid in the soils contaminated by Lead on wheat plant, this experimentwas carried out in factorial form with two factors completely randomized design with 9 treatments and 3 replications in crop year 1393 in Varamin. For contaminating the soil, Lead chloride 200 mg per kg of soil applied for all treatments.The first factor is superabsorbent in three levels (0, 4 and 8 g per kg soil and the second factoris ascorbic acidinthree levels (0, 75 and 150 ppm. The results of this experiment showed that increasing concentrations of ascorbic acid and superabsorbent inwheatIncreased the morphological traits such as plant height, spike and seeds, grain weight and total weight of shoot and root dry weight andthe weight of one thousand seedsas well as increased physiological traits such as protein and chlorophyll a, b and total wheat and superabsorbent and ascorbic acid concentration in the plant, such as a reduction in antioxidant enzyme superoxide dismutase, catalase, and the physiological traits such as proline and increasedthe relative water content leaves and reduce the amount of Lead in leaves and roots.So it can be concluded that it seems necessary that given thatIran located in the arid and semiarid and according to Iranian soil pollution with heavy metals such as ascorbic acid and superabsorbent, the use of effective treatments that can enhance the plant's water-holding capacity as well asreduce the toxic effects of these elements. Due to the long life and non-degradable heavy metals in soil, hydrophilic polymers insoluble in water with different percentages of carboxylic groups are used. The surface carboxylic groups of the polymer (SAP due to exposure to environments, Ionize and a solid linkconstitute with the metals contaminating soil ,finally, form a gel and are separated from the soil.

  2. Weaving Together Space Biology and the Human Research Program: Selecting Crops and Manipulating Plant Physiology to Produce High Quality Food for ISS Astronauts

    Science.gov (United States)

    Massa, Gioia; Hummerick, Mary; Douglas, Grace; Wheeler, Raymond

    2015-01-01

    Researchers from the Human Research Program (HRP) have teamed up with plant biologists at KSC to explore the potential for plant growth and food production on the international space station (ISS) and future exploration missions. KSC Space Biology (SB) brings a history of plant and plant-microbial interaction research for station and for future bioregenerative life support systems. JSC HRP brings expertise in Advanced Food Technology (AFT), Advanced Environmental Health (AEH), and Behavioral Health and Performance (BHP). The Veggie plant growth hardware on the ISS is the platform that first drove these interactions. As we prepared for the VEG-01 validation test of Veggie, we engaged with BHP to explore questions that could be asked of the crew that would contribute both to plant and to behavioral health research. AFT, AEH and BHP stakeholders were engaged immediately after the return of the Veggie flight samples of space-grown lettuce, and this team worked with the JSC human medical offices to gain approvals for crew consumption of the lettuce on ISS. As we progressed with Veggie testing we began performing crop selection studies for Veggie that were initiated through AFT. These studies consisted of testing and down selecting leafy greens, dwarf tomatoes, and dwarf pepper crops based on characteristics of plant growth and nutritional levels evaluated at KSC, and organoleptic quality evaluated at JSCs Sensory Analysis lab. This work has led to a successful collaborative proposal to the International Life Sciences Research Announcement for a jointly funded HRP-SB investigation of the impacts of light quality and fertilizer on salad crop productivity, nutrition, and flavor in Veggie on the ISS. With this work, and potentially with other pending joint projects, we will continue the synergistic research that will advance the space biology knowledge base, help close gaps in the human research roadmap, and enable humans to venture out to Mars and beyond.

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

    Directory of Open Access Journals (Sweden)

    Raifa Ahmed Hassanein

    2013-11-01

    Full Text Available 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 irrigation. The magnitude of Cd in soils after irrigation with industrial wastewater exceeds the maximum allowable limit (3 mg Kg-1. Both turnip and lettuce exhibited significant decreases in leaf area, fresh weight and dry weight of shoots and roots as well as all the measured yield components in response to wastewater irrigation. The magnitude of decrease was positively correlated with the amounts of heavy metals detected in the soil and the inhibitory effect on turnip was much more pronounced than in lettuce. Furthermore, heavy metals accumulation in soil resulted in an oxidative damage to turnip and lettuce as indicated by the significant increase in lipid peroxidation and H2O2 levels in both plants comparing to control values. The significant increases in putrescine in lettuce and turnip shoots and roots and spermidine in lettuce roots as well as total phenolics and flavonoids in plants cultivated in soil enriched with heavy metals are believed to be defense mechanisms in turnip and lettuce plants to counteract the oxidative stress resulted from heavy metals contamination generated from irrigation with wastewater.

  4. 硼胁迫下植物生理调控机制的研究进展%The Advances of Physiological Regulatory Mechanism of Plants under Boron Stress

    Institute of Scientific and Technical Information of China (English)

    王瑞东; 姜存仓; 刘桂东; 张祥; 王运华; 彭抒昂

    2011-01-01

    硼是植物的必需营养元素,它对植物的许多生理过程有着重要的作用,特别是在低硼或高硼胁迫情况时会影响植物正常的生理代谢.本文将对最近几年有关硼胁迫下植物生理调节机制的研究成果进行综述,着重阐述低硼胁迫下诱发植物产生硼高效吸收、转运、分配和再利用的机理,以及在高硼胁迫下植物自身可能存在的调控机制.%Boron is an essential nutrient element for plant. It plays an important role in variety of biological processes of plants and may affect the normal physiological metabolism especially in the low B or high boron stress situations. This review is related on recent research about the regulatory mechanisms of plant in boron stress, focusing on the mechanism of B-efficient absorption, transport, distribution and reuse in low B stress and the possible regulatory mechanisms in high B stress in plant.

  5. Occupational physiology

    CERN Document Server

    Toomingas, Allan; Tornqvist, Ewa Wigaeus

    2011-01-01

    In a clear and accessible presentation, Occupational Physiology focuses on important issues in the modern working world. Exploring major public health problems-such as musculoskeletal disorders and stress-this book explains connections between work, well-being, and health based on up-to-date research in the field. It provides useful methods for risk assessment and guidelines on arranging a good working life from the perspective of the working individual, the company, and society as a whole.The book focuses on common, stressful situations in different professions. Reviewing bodily demands and r

  6. 锰对植物的生理作用及锰中毒的研究进展%Research progress in physiological function of manganese and manganese poisoning in plants

    Institute of Scientific and Technical Information of China (English)

    许文博; 邵新庆; 王宇通; 王堃

    2011-01-01

    Manganese is one of the most important biotic elements in plants which plays a significant part of role during the plants growth and development. It has an irreplaceable role in plants photosynthetic oxygen evolution, maintaining the normal structure of cell organelles and enzyme activity. However,excess manganese will lead to manganese toxicity and it can inhibit the absorption and activity of Fe2 + and Mg2 + and other elements, which lead to destruction of chloroplast structure and decrease of chlorophy Ⅱ synthesis and photosynthetic rate. Author illustrates physiological function of manganese in plants and also various mechanisms of plants to o-vercome manganese toxicity. Meanwhile, more prospects on the research between manganese and plants have been introduced.%锰是植物体内重要生命元素之一,在植物的生长发育过程中发挥着重要作用.它对植物的光合放氧、维持细胞器的正常结构、活化酶活性等方面具有不可替代的作用.但是,过量的锰亦会对植物造成毒害.它可抑制Fe2+和Mg2+等元素的吸收及活性,并可破坏叶绿体结构导致叶绿素合成下降及光合速率降低.作者详细阐述了锰在植物体内的生理功能及植物的多种解毒或耐性机制.并对锰与植物关系方面的研究做出了进一步展望.

  7. Biodiversity, bioaccumulation and physiological changes in lichens growing in the vicinity of coal-based thermal power plant of Raebareli district, north India.

    Science.gov (United States)

    Bajpai, Rajesh; Upreti, Dalip K; Nayaka, S; Kumari, B

    2010-02-15

    The lichen diversity assessment carried out around a coal-based thermal power plant indicated the increase in lichen abundance with the increase in distance from power plant in general. The photosynthetic pigments, protein and heavy metals were estimated in Pyxine cocoes (Sw.) Nyl., a common lichen growing around thermal power plant for further inference. Distributions of heavy metals from power plant showed positive correlation with distance for all directions, however western direction has received better dispersion as indicated by the concentration coefficient-R(2). Least significant difference analysis showed that speed of wind and its direction plays a major role in dispersion of heavy metals. Accumulation of Al, Cr, Fe, Pb and Zn in the thallus suppressed the concentrations of pigments like chlorophyll a, chlorophyll b and total chlorophyll, however, enhanced the level of protein. Further, the concentrations of chlorophyll contents in P. cocoes increased with the decreasing the distance from the power plant, while protein, carotenoid and phaeophytisation exhibited significant decrease.

  8. Effects of potentially acidic air pollutants on the intracellular distribution and transport of plant growth regulators in mesophyll cells of leaves. Consequences on stress- and developmental physiology

    Energy Technology Data Exchange (ETDEWEB)

    Kremer, H.; Pfanz, H.; Hartung, W.

    1987-07-11

    The influence of SO/sub 2/ on the intracellular distribution of abscisic acid (ABA) and indole-acetic acid (IAA) in mesophyll cells of Picea abies, Tsuga americana and Hordeum vulgare was investigated. The compartmentation of ABA and IAA depends on intracellular pH-gradients. The hydrophilic anions ABA and IAA are accumulated in the alkaline cell compartments cytosol and chloroplasts, which act as anion traps for weak acids. Uptake of sulfur dioxide into leaves leads to an acidification of alkaline cell compartments, thus decreasing intracellular pH-gradients. Consequently this results in an increased release of plant growth regulators from the cell interior into the apoplast. Therefore the target cells of plant hormones i.e. meristems and stomates are exposed to altered hormone concentrations. Obviously this influences the regulation of cellular metabolism plant development and growth.

  9. Improved phytoaccumulation of cadmium by genetically modified tobacco plants (Nicotiana tabacum L.). Physiological and biochemical response of the transformants to cadmium toxicity

    Energy Technology Data Exchange (ETDEWEB)

    Gorinova, N. [AgroBioInstitute, 8 Dragan Tzankov Blvd., 1164 Sofia (Bulgaria)]. E-mail: noraig60@yahoo.co.uk; Nedkovska, M. [AgroBioInstitute, 8 Dragan Tzankov Blvd., 1164 Sofia (Bulgaria); Todorovska, E. [AgroBioInstitute, 8 Dragan Tzankov Blvd., 1164 Sofia (Bulgaria); Simova-Stoilova, L. [Institute of Plant Physiology, Bulgarian Academy of Sciences, 1113 Sofia (Bulgaria); Stoyanova, Z. [Institute of Plant Physiology, Bulgarian Academy of Sciences, 1113 Sofia (Bulgaria); Georgieva, K. [Institute of Plant Physiology, Bulgarian Academy of Sciences, 1113 Sofia (Bulgaria); Demirevska-Kepova, K. [Institute of Plant Physiology, Bulgarian Academy of Sciences, 1113 Sofia (Bulgaria); Atanassov, A. [AgroBioInstitute, 8 Dragan Tzankov Blvd., 1164 Sofia (Bulgaria); Herzig, R. [Phytotech-Foundation PT-F, Quartiergasse 12, CH 3013 Bern (Switzerland)

    2007-01-15

    The response of tobacco plants (Nicotiana tabacum L.)-non-transformed and transformed with a metallothionein gene MThis from Silene vulgaris L. - to increase cadmium supply in the nutrient solution was compared. The transgenic plants accumulated significantly more Cd both in the roots and the leaves. Visual toxicity symptoms and disturbance in water balance were correlated with Cd tissue content. Treatment with 300 {mu}M CdCl{sub 2} resulted in inhibition of photosynthesis and mobilization of the ascorbate-glutathione cycle. Treatment with 500 {mu}M CdCl{sub 2} led to irreversible damage of photosynthesis and oxidative stress. An appearance of a new peroxidase isoform and changes in the leaf polypeptide pattern were observed at the highest Cd concentration. The level of non-protein thiols gradually increased following the Cd treatment both in transgenic and non-transformed plants. - Genetic transformation of Nicotiana tabacum L. by metallothionein gene improved phytoaccumulation of cadmium.

  10. Growth Limitations and Physiological Advantages in Crop Plants Grown with Organic Fertilization%有机栽培对作物生产的影响--植株生长的局限和生理活性的优势

    Institute of Scientific and Technical Information of China (English)

    徐会连

    2001-01-01

    Organic and chemical fertilizers were applied to sweet com, tomato and other crops to compare the growth, yield, physiological responses and resistance to water stress and diseases. Several mathematical ap proaches to physiological analysis were used in this research. Organic fertilizers promoted root growth and ac tivity and enhanced photosynthesis in most crop plants at the later growth stages although the seedling growth was lower at the early stage. Analysis of declining photosynthetic curve with time in the excised corn leaves showed that leaves of corn plants fertilized with organic materials possessed a higher photosynthetic maintain ing ability, which was consistent with the results of water stress avoidance. It is concluded that organic fertilized crop plants possess higher physiological activities and higher environ mental stresses resistance with higher quality in the edible parts, but lower nutrient availability at the early stage usually limits the seedling growth, compared with the chemical fertilized control plants%本研究就有机栽培和化肥栽培的玉米,西红柿和其它作物,在营养体生长,经济产量以及对水分胁迫和病害的反应方面进行了比较.另外,本文在生理学分析方面采用几种新颖的数学方法.研究结果证明,尽管苗期生长不尽如意,但有机肥料促进根系的营养体生长以及生理活性,从而能使大多数作物的中后期光合活性增强.对切断叶的光合作用降低曲线的分析证实有机栽培的作物在彻底断水的情况下具有较强的光合活性维持能力.这与以前报道的水分胁迫回避性是一致的.因此可以下结论说,与化肥栽培的作物相比,有机栽培的作物其生理活性高,环境胁迫抗性强,可食部位的营养质量高,但是苗期生长往往受可给态养分不足的限制.

  11. 高光和低光下木本植物形态和生理可塑性响应%MORPHOLOGICAL AND PHYSIOLOGICAL PLASTICITY OF WOODY PLANT IN RESPONSE TO HIGH LIGHT AND LOW LIGHT

    Institute of Scientific and Technical Information of China (English)

    段宝利; 吕艳伟; 尹春英; 李春阳

    2005-01-01

    Being sessile, plants have evolved numerous strategies to accommodate contrasting light environment, so as to efficiently capture and use limited light resource and to avoid the damaging effects of excessive irradiance. Plant performance is enhanced through morphological and physiological acclimation to light environment. The plasticity of morphological and physiological traits enables the woody plants to survive at the extremes of light gradients. Shade plants and sun plants have developed distinct morphological and physiological strategies for acclimation to contrasting light environment. These strategies involve changes in growth, alteration in biomass allocation, readjustment in structure of the photosynthetic apparatus, nitrogen allocation to different photosynthetic processes, up - regulation antioxidant defense systems and thermal dissipation, as well as a long -term adjustment that renders a differentiated phenotype. Frequent evidence indicates that sun plants display a larger phenotype plasticity than shade - tolerant ones, though the reverse is sometimes observed. A rational understanding of how plants survive and thrive in adverse light environment is provided in this review. Results from this review lead to useful conclusions for establishing better management practices. Extensive studies on natural light conditions in conjunction with artificial simulation experiments are needed to quantify the effects of natural light conditions on woody plants, so as to facilitate the development of silvicultural regeneration techniques for forest management. Ref 96%光资源的时空异质性普遍存在.为了提高光利用效率或有效避免强光的伤害,植物通常采取多种调节措施.植物适应林下异质、多变的环境过程中,表型的可塑性是非常关键的.植物表型可塑性与其环境异质性密不可分.植物通过生长变化、生物量分配、光合器官结构调整、叶氮分配、抗氧化防御系统、热耗散机制,

  12. Molecular and physiological changes in response to salt stress in Citrus macrophylla W plants overexpressing Arabidopsis CBF3/DREB1A.

    Science.gov (United States)

    Alvarez-Gerding, Ximena; Espinoza, Carmen; Inostroza-Blancheteau, Claudio; Arce-Johnson, Patricio

    2015-07-01

    Plant stress induced by high salinity has leading to an important reduction in crop yields. Due to their tropical origin, citrus fruits are highly sensitive to salts. Rootstocks are the root system of fruit trees, regulating ion uptake and transport to the canopy. Therefore, increasing their salt tolerance could improve the salt tolerance of the fruit tree. For this, we genetically-transformed an important rootstock for lemon, Citrus macrophylla W, to constitutively express the CBF3/DREB1A gene from Arabidopsis, a well-studied salinity tolerance transcription factor. Transgenic lines showed normal size, with no dwarfism. Under salt stress, some transgenic lines showed greater growth, similar accumulation of chloride and sodium in the leaves and better stomatal conductance, in comparison to wild-type plants. Quantitative real-time analyses showed a similar expression of several CBF3/DREB1A target genes, such as COR15A, LEA 4/5, INV, SIP1, P5CS, GOLS, ADC2 and LKR/SDH, in transgenic lines and wild type plants, with the exception of INV that shows increased expression in line 4C15. Under salt stress, all measured transcript increased in both wild type and transgenics lines, with the exception of INV. Altogether, these results suggest a higher salt tolerance of transgenic C. macrophylla plants induced by the overexpression of AtCBF3/DREB1A.

  13. Research on the effects of the ‘Dance of the Spiral’ methodology upon the physiological parameters of plants and the essential oil content

    Directory of Open Access Journals (Sweden)

    Doncho Krastev

    2016-03-01

    Full Text Available “The Dance of the Spiral” is the original methodology consisting of physical exercises that based on ancient health and longevity practices. A research has been done in which this methodology has been applied to plants. Eight plants were chosen including common yarrow, wood violet, dandelion, common chicory, shepherd’s purse, cranesbill, broadleaf plantain and snowdrop, each of them grows the best in one of the eight directions. The planting was performed in eight directions, since each exercise supposedly has an effect on the state of health. Two circles were empirically defined – the Spiral and the Antispiral. Further clinical trials with 20 volunteers suffered from neurological, gastro-intestinal, cardio-vascular, and articular conditions and diseases, who stayed consecutively in the Antispiral and Spiral plant circles for 6 min in each circle were performed based on their subjective assessment of their state of health and their experience after their being stayed in the Antispiral and Spiral circles as a relaxing effect (the Antispiral circle and a stimulating effect (the Spiral circle. The research involves the composition of essential oil extracts by 1H NMR, gas chromatography and gas chromatography-mass spectrometry as well as the spectral analysis by the methods of NES and DNES of water extracts from the common plant (Achillea millefolium from the control group growing in its natural habitat and from the plants grown correspondingly in the Spiral and Antispiral circles. The result in the sample of common yarrow from the Spiral circle is an increase of the average energy of hydrogen bonds between H2O molecules. The result in the sample of common yarrow from the Antispiral circle is a decrease of the average energy of hydrogen bonds between H2O molecules. The essential oil composition of the samples planted in the Spiral and Antispiral circles is not identical in the quantitative and qualitative composition regarding the 83

  14. Physiological Acoustics

    Science.gov (United States)

    Young, Eric D.

    The analysis of physiological sound in the peripheral auditory system solves three important problems. First, sound energy impinging on the head must be captured and presented to the transduction apparatus in the ear as a suitable mechanical signal; second, this mechanical signal needs to be transduced into a neural representation that can be used by the brain; third, the resulting neural representation needs to be analyzed by central neurons to extract information useful to the animal. This chapter provides an overview of some aspects of the first two of these processes. The description is entirely focused on the mammalian auditory system, primarily on human hearing and on the hearing of a few commonly used laboratory animals (mainly rodents and carnivores). Useful summaries of non-mammalian hearing are available [1]. Because of the large size of the literature, review papers are referenced wherever possible.

  15. Physiological Basis and Cultivation Practices of Dense Planting of Multiple Cropping Oil Sunflower%复播油葵密植栽培的生理基础与栽培实践

    Institute of Scientific and Technical Information of China (English)

    刘胜利; 陈寅初; 李万云; 柳延涛; 王鹏; 赵刚

    2015-01-01

    Along with the dwarfing of the newly bred cultivars and innovation of the farming system, the planting density of the multiple cropping oil sunflower has been on a trend of increase in the production. The results of the study of the dense planting cultivation showed that the proper dense planting could increase the values of the related groups' physiological parameters closely related to the yield, was conducive to the synthesis and accumulation of the photosynthetic products and was good for the increase of production. The production investigation and cultivation practices shows that the dense planting cultivation of the multiple cropping sunflower is feasible, and the key points of the dense planting cultivation technology has formed.%随着育成品种的矮化及耕作制度的创新,生产上复播油用向日葵种植密度呈增大的趋势。油葵密植栽培研究结果表明,适当密植可增加与产量密切相关的有关群体生理参数的数值,有利于光合产物的合成与积累,对产量的提高是有利的。生产调查及栽培实践表明,复播向日葵密植栽培是可行的,并形成了密植栽培技术要点。

  16. Effects of zinc addition to a copper-contaminated vineyard soil on sorption of Zn by soil and plant physiological responses.

    Science.gov (United States)

    Tiecher, Tadeu L; Ceretta, Carlos A; Tiecher, Tales; Ferreira, Paulo A A; Nicoloso, Fernando T; Soriani, Hilda H; Rossato, Liana V; Mimmo, Tanja; Cesco, Stefano; Lourenzi, Cledimar R; Giachini, Admir J; Brunetto, Gustavo

    2016-07-01

    The occurrence of high levels of Cu in vineyard soils is often the result of intensive use of fungicides for the preventive control of foliar diseases and can cause toxicity to plants. Nowadays many grape growers in Southern Brazil have replaced Cu-based with Zn-based products. The aim of the study was to evaluate whether the increase in Zn concentration in a soil with high Cu contents can interfere with the dynamics of these elements, and if this increase in Zn may cause toxicity to maize (Zea mays L.). Soil samples were collected in two areas, one in a vineyard with more than 30 years of cultivation and high concentration of Cu and the other on a natural grassland area adjacent to the vineyard. Different doses of Cu and Zn were added to the soil, and the adsorption isotherms were built following the Langmuir's model. In a second experiment, the vineyard soil was spiked with different Zn concentrations (0, 30, 60, 90, 180, and 270mg Zn kg(-1)) in 3kg pots where maize was grown in a greenhouse for 35 days. When Cu and Zn were added together, there was a reduction in the quantities adsorbed, especially for Zn. Zn addition decreased the total plant dry matter and specific leaf mass. Furthermore, with the increase in the activity of catalase, an activation of the antioxidant system was observed. However, the system was not sufficiently effective to reverse the stress levels imposed on soil, especially in plants grown in the highest doses of Zn. At doses higher than 90Znmgkg(-1) in the Cu-contaminated vineyard soil, maize plants were no longer able to activate the protection mechanism and suffered from metal stress, resulting in suppressed dry matter yields due to impaired functioning of the photosynthetic apparatus and changes in the enzymatic activity of plants. Replacement of Cu- by Zn-based fungicides to avoid Cu toxicity has resulted in soil vineyards contaminated with these metals and damaging of plant photosynthetic apparatus and enzyme activity. Copyright

  17. Use Of Absolute Function And Its Associates In Formation And `Redevelopment' Of Mathematical Models In Some Plant-Related Quantitative Physiology: Salinity Effects On Leaf Development Of Schefflera arboricola And Harvest Index In Rice

    Science.gov (United States)

    Selamat, Ahmad; Awang, Yahya; Mohamed, Mahmud T. M.; Wahab, Zakaria; Osman, Mohammad

    2008-01-01

    The roles of quantitative physiology are becoming more apparent and crucial in the era of ICT recently. As based on the rate-related variables, most of the mathematical models are in the form of `non-linear' function in describing the responses or the observed within-plant processes outcomes versus time. Even though if some responses change in a drastic manner at certain response point within a biological unit or space of a plant system, the response curve `should' be dependent on a continuous independent variable range in a specified period of determination where biologically `should not' functioned by independent variable range having `IF' statement(s). Subjected to nutrient concentration of high salinity (6.0 mS cm-1), the leaf turgidity (measured as leaf surface area) of S. arboricola which initially was described by one form of the logistic growth functions [(y = 1/(a+be-cx)] abruptly reduced as explained by a model having terms of Absolute function (ABS) containing tan-1(x) and its parameter of leaf life expectancy as affected by high salinity growing medium at a certain point of days after planting. This yielded an overall function of y = 1/(a+be-cx)-A[tan-1{(x-B)/D}+ABS(tan-1{(x-B)/D})]E, where a, b, c, A, B, D, and E are constants that most of them can be `biologically' interpreted. The constant B is the point similar to `IF statement' as normally used in other mathematical functions. Plants subjected to lower salinity status (planting seasons, the long flattened tails at both sides of a peak in the middle of function of y = R+B(T+ABS(B-x))e-k(T+ABS(B-x)) had indicated that those varieties maturing at 123 to 133 days after transplanting were having high HI values. In our observation, Absolute (ABS) function coupled with some terms could be used in the formation of some mathematical functions having biological meaningful constants in explaining some quantitative physiological and biological responses vs. independent variables studied.

  18. 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

  19. Physiological and ecological studies of the vegetation on ore deposits. I. Zinc flora and indicator plants on the 2nd Yunwha mine. [Sedum sp. ; Dianthus sinensis

    Energy Technology Data Exchange (ETDEWEB)

    Chang, N.K.; Chang, S.M.

    1977-01-01

    During the period of 1975-76, a survey was carried out to find out zinc indicators in the natural vegetation in Korea. The symptoms of chlorosis were observed in flowering plants in the areas of zinc outcrop of Wolgok-A, Seokgok-9, and Sowolgok. Although 28 species were found to be chlorotic, the total quantity of chlorotic foliage observed was small. Reasons for chlorosis in the areas of zinc ore deposits is considered as effects of zinc, lead, copper and calcium ions. Sedum sp. and Dianthus sinensis were confined to soil containing more than exchangeable zinc of 30 ppm and to accumulation in the plants contained at least 1,300-14,000 ppm of zinc. Therefore, Sedum sp. and Dianthus sinensis might be used as zinc indicators in Korea. 12 references, 1 figure, 5 tables.

  20. 营养元素的生理功能及其在植物抗旱性中的作用综述%Review on the Physiological Function of Nutrient Elements and Its Role in Drought Resistance of Plants

    Institute of Scientific and Technical Information of China (English)

    赵明城

    2015-01-01

    引用相关文献综述了营养元素与植物生长及抗旱性的研究进展,重点讨论了必需元素氮、磷、钾、钙及有益元素钠和硅的生理功能及其在植物抗旱性中的作用,并对今后植物抗旱性中存在的问题及发展趋势等进行了简要评述。%The study briefly presented the progress of nutrient elements on promoting growth and enhancing drought resistance of plants by citing relevant references,and emphatically discussed the physiological function of essential elementsnitrogen,phosphorus,potassium,calcium,and beneficial elementssodium and silicon,and its role in the drought resistance of plants. Some important aspects concerning these issues such as existing problems and development tendency in the drought resistance of plants were also discussed briefly.

  1. Review of Plant Protoplast Recalcitrance and Its Physiological and Genetic Bases%植物原生质体顽拗现象及其生理和遗传基础研究进展

    Institute of Scientific and Technical Information of China (English)

    曹文娟; 蔡小东

    2012-01-01

    Regeneration ability of protoplast is the prerequisite for biotechnology breeding using protoplasts as initial materials. However, protoplast culture of some plant genotypes has not been established successfully at present. This review focused on the phenomenon of plant protoplast recalcitrance and relevant physiological and genetic bases from the aspects of the phenomenon of oxidative stress during the process of protoplast isolation and culture as well as the molecular mechanisms of the difference of regeneration ability of plant protoplasts.%利用原生质体进行生物技术育种的先决条件是其能再生完整植株,但目前一些基因型植物原生质体的培养仍然未获得成功.综述了植物原生质体顽拗现象,并从原生质体分离和培养过程中的氧化胁迫、原生质体再生能力差异的分子机制方面对与该现象有关的生理和遗传基础研究进展进行了综述.

  2. Physiological Effects of Plant Polysaccharide on Exercise Body and its Research status%植物多糖对机体运动影响的研究现状及趋势

    Institute of Scientific and Technical Information of China (English)

    朱雪颖; 池爱平; 张海猛

    2012-01-01

    The plant polysaccharide has extensive pharmacological effects, involved in various physiological metabolism of the body. With years of experimental research, this paper describes a variety of biological effects the plant polysaccharide and its relationship with the improvement of the athletic capacity. In addition, the biological mechanisms of the plant polysaccharide to increase athletic ability is explored and the prospect of its as a sports nutritional supplements development prospect.%采用文献资料法,对植物多糖对运动机体的各种生理机能及物质代谢产生的多种生物学效应进行综述:植物多糖对运动机体的免疫系统功能、抗氧化系统功能、神经系统功能、血红蛋白含量以及骨骼肌功能等方面具有一定的改善与提高作用;植物多糖的活性组分可能是其提高机体运动能力及延缓疲劳的主要因素;归纳目前植物多糖在运动领域中的研究现状,推断植物多糖作为运动营养补剂的研究趋势与应用前景。

  3. The first draft genome of the aquatic model plant Lemna minor opens the route for future stress physiology research and biotechnological applications

    OpenAIRE

    Van Hoeck, Arne; Horemans, Nele; Monsieurs, Pieter; Cao, Hieu Xuan; Vandenhove, Hildegarde; Blust, Ronny

    2015-01-01

    Background Freshwater duckweed, comprising the smallest, fastest growing and simplest macrophytes has various applications in agriculture, phytoremediation and energy production. Lemna minor, the so-called common duckweed, is a model system of these aquatic plants for ecotoxicological bioassays, genetic transformation tools and industrial applications. Given the ecotoxic relevance and high potential for biomass production, whole-genome information of this cosmopolitan duckweed is needed. Resu...

  4. Space Physiology within an Exercise Physiology Curriculum

    Science.gov (United States)

    Carter, Jason R.; West, John B.

    2013-01-01

    Compare and contrast strategies remain common pedagogical practices within physiological education. With the support of an American Physiological Society Teaching Career Enhancement Award, we have developed a junior- or senior-level undergraduate curriculum for exercise physiology that compares and contrasts the physiological adaptations of…

  5. Potassium physiology.

    Science.gov (United States)

    Thier, S O

    1986-04-25

    Potassium is the most abundant exchangeable cation in the body. It exists predominantly in the intracellular fluid at concentrations of 140 to 150 meq/liter and in the extracellular fluid at concentrations of 3.5 to 5 meq/liter. The maintenance of the serum potassium concentration is a complex bodily function and results from the balance between intake, excretion, and distribution between intracellular and extracellular space. Ingested potassium is virtually completely absorbed from and minimally excreted through the intestine under nonpathologic circumstances. Renal excretion of potassium, which is the major chronic protective mechanism against abnormalities in potassium balance, depends on filtration, reabsorption, and a highly regulated distal nephron secretory process. Factors regulating potassium secretion include prior potassium intake, intracellular potassium, delivery of sodium chloride and poorly reabsorbable anions to the distal nephron, the urine flow rate, hormones such as aldosterone and beta-catecholamines, and the integrity of the renal tubular cell. The maintenance of distribution between the inside and outside of cells depends on the integrity of the cell membrane and its pumps, osmolality, pH, and the hormones insulin, aldosterone, beta 2-catecholamines, alpha-catecholamines, and prostaglandins. Both distribution across cell membranes and/or renal excretion of potassium may be altered by pharmacologic agents such as diuretics, alpha- and beta-catechol antagonists and agonists, depolarizing agents, and digitalis. Problems with hypokalemia and hyperkalemia can be analyzed on the basis of potassium physiology and pharmacology; proper treatment depends on an accurate analysis.

  6. Aspectos anatômicos e fisiológicos de plantas de guaco submetidas a diferentes fotoperíodos Anatomical and physiological aspects of guaco plants submitted to different photoperiods

    Directory of Open Access Journals (Sweden)

    Evaristo Mauro de Castro

    2005-07-01

    Full Text Available O guaco (Mikania glomerata Sprengel é espécie de uso medicinal conhecida pela atividade broncodilatadora. Muitos estudos têm evidenciado mudanças nas características anatômicas e fisiológicas de plantas medicinais sob influência de condições de radiação. Neste trabalho analisou-se a influência de fotoperíodos (8; 12; 16 e 20 h na anatomia foliar, nos teores de clorofila e condutância estomática em três regiões da planta. Após 90 dias de tratamento, plantas adultas e com diferentes tamanhos influenciados pelos fotoperíodos foram submetidas às avaliações anatômicas e fisiológicas. Os teores de clorofila foram maiores nos fotoperíodos de 8 e 12 h nas regiões superior e mediana da planta e menores no fotoperíodo de 8 h na região basal. A condutância e densidade estomática apresentaram relação inversa ao aumento do fotoperíodo, sendo significativamente decrescente do ápice para a base da planta. Houve aumento da espessura da epiderme adaxial nas regiões mediana e basal da planta até o fotoperíodo de 16 h. Nestas regiões houve aumento progressivo do parênquima esponjoso até o fotoperíodo de 20 h. Verificou-se modificações no tamanho e organização dos feixes vasculares influenciadas pelos fotoperíodos.Guaco (Mikania glomerata Sprengel is a medicinal species known because of its bronchi-dilating activity. Many studies have indicated changes in anatomical and physiological characteristics of medicinal plants when submitted to different conditions of light. The effect of photoperiods (8; 12; 16 and 20 h on leaf anatomy, content of chlorophyll and stomatal conductance in distinct regions of guaco plants were analyzed. Adult plants of different sizes influenced by distinct photoperiods were submitted to anatomical and physiological analyses. 90 days after starting photoperiod treatments the chlorophyll content was higher in plants submitted to photoperiods of 8 and 12 hours in the superior and intermediary

  7. Effect of zinc and lead on the physiological and biochemical properties of aquatic plant Lemna minor: its potential role in phytoremediation

    Science.gov (United States)

    Jayasri, M. A.; Suthindhiran, K.

    2016-01-01

    Plants have gained importance in situ bioremediation of heavy metals. In the present study, different concentrations of zinc (Zn2+) (0.5, 5, 10, 15, 20 mg/l) and lead (Pb2+) (1, 2, 4, 6, 8 mg/l) were used to evaluate metal tolerance level of Lemna minor. L.minor were exposed to metals for 4 days and tested for its dry to fresh weight ratio (DW/FW), photosynthetic pigments production and protein content. The oxidative damage was detected by measuring catalase activity. L.minor showed tolerance against Zn2+ and Pb2+ at a concentration of 10 and 4 mg/l, respectively. Among the metals, Pb2+ showed a significant toxicity at 8 mg/l. High concentration (20 mg/l of Zn2+ and 8 mg/l of Pb2+) of the metals displayed a considerable negative effect on soluble proteins (13 fold decrease with Zn2+ and 4 fold decrease with Pb2+) and photosynthetic pigments (twofold decrease with Zn2+ and onefold decrease with Pb2+) and lead to a consequent reduction in number of fronds. Further, the catalase was greatly increased (twofold decrease with Zn2+ and sixfold decrease with Pb2+) under metal stress. The results indicate that L.minor withstands Zn2+ and Pb2+ toxicity up to the concentration of 10 and 4 mg/l, respectively. Hence, the metal tolerant property of this plant shall be exploited for bioremediation of Zinc and Lead in polluted water. Further, the detailed and wide range of heavy metal toxicity studies should be done to reveal the possible use of this plant on large scale bioremediation purpose.

  8. Effect of zinc and lead on the physiological and biochemical properties of aquatic plant Lemna minor: its potential role in phytoremediation

    Science.gov (United States)

    Jayasri, M. A.; Suthindhiran, K.

    2017-06-01

    Plants have gained importance in situ bioremediation of heavy metals. In the present study, different concentrations of zinc (Zn2+) (0.5, 5, 10, 15, 20 mg/l) and lead (Pb2+) (1, 2, 4, 6, 8 mg/l) were used to evaluate metal tolerance level of Lemna minor. L.minor were exposed to metals for 4 days and tested for its dry to fresh weight ratio (DW/FW), photosynthetic pigments production and protein content. The oxidative damage was detected by measuring catalase activity. L.minor showed tolerance against Zn2+ and Pb2+ at a concentration of 10 and 4 mg/l, respectively. Among the metals, Pb2+ showed a significant toxicity at 8 mg/l. High concentration (20 mg/l of Zn2+ and 8 mg/l of Pb2+) of the metals displayed a considerable negative effect on soluble proteins (13 fold decrease with Zn2+ and 4 fold decrease with Pb2+) and photosynthetic pigments (twofold decrease with Zn2+ and onefold decrease with Pb2+) and lead to a consequent reduction in number of fronds. Further, the catalase was greatly increased (twofold decrease with Zn2+ and sixfold decrease with Pb2+) under metal stress. The results indicate that L.minor withstands Zn2+ and Pb2+ toxicity up to the concentration of 10 and 4 mg/l, respectively. Hence, the metal tolerant property of this plant shall be exploited for bioremediation of Zinc and Lead in polluted water. Further, the detailed and wide range of heavy metal toxicity studies should be done to reveal the possible use of this plant on large scale bioremediation purpose.

  9. Evaluation of the Morpho-physiology characteristics of maize inbred lines introduced from CIMMYT to identify the best candidates for planting in acidic soil in Jasinga, Indonesia

    Science.gov (United States)

    Lubis, K.; Sutjahjo, S. H.; Syukur, M.; Trikoesoemaningtyas

    2016-08-01

    Technological developments and climate change have affected crop planting strategies. For example, maize production has expanded to sub-optimal lands, including acidic soil common in areas like Indonesia. Breeding programs have created inbred lines of maize introduced from CIMMYT; they were tested locally in acidic soils to determine their adaptability and tolerance mechanisms. Breeds CLA 46 and NEI 9008 were found to be excellent candidates for acidic soil due to their ASI, high number of grains per year, and suitable dry seed weight.

  10. The first draft genome of the aquatic model plant Lemna minor opens the route for future stress physiology research and biotechnological applications.

    Science.gov (United States)

    Van Hoeck, Arne; Horemans, Nele; Monsieurs, Pieter; Cao, Hieu Xuan; Vandenhove, Hildegarde; Blust, Ronny

    2015-01-01

    Freshwater duckweed, comprising the smallest, fastest growing and simplest macrophytes has various applications in agriculture, phytoremediation and energy production. Lemna minor, the so-called common duckweed, is a model system of these aquatic plants for ecotoxicological bioassays, genetic transformation tools and industrial applications. Given the ecotoxic relevance and high potential for biomass production, whole-genome information of this cosmopolitan duckweed is needed. The 472 Mbp assembly of the L. minor genome (2n = 40; estimated 481 Mbp; 98.1 %) contains 22,382 protein-coding genes and 61.5 % repetitive sequences. The repeat content explains 94.5 % of the genome size difference in comparison with the greater duckweed, Spirodela polyrhiza (2n = 40; 158 Mbp; 19,623 protein-coding genes; and 15.79 % repetitive sequences). Comparison of proteins from other monocot plants, protein ortholog identification, OrthoMCL, suggests 1356 duckweed-specific groups (3367 proteins, 15.0 % total L. minor proteins) and 795 Lemna-specific groups (2897 proteins, 12.9 % total L. minor proteins). Interestingly, proteins involved in biosynthetic processes in response to various stimuli and hydrolase activities are enriched in the Lemna proteome in comparison with the Spirodela proteome. The genome sequence and annotation of L. minor protein-coding genes provide new insights in biological understanding and biomass production applications of Lemna species.

  11. 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,

  12. Abrupt plant physiological changes in southern New Zealand at the termination of the Mi-1 event reflect shifts in hydroclimate and pCO2

    Science.gov (United States)

    Reichgelt, Tammo; D'Andrea, William J.; Fox, Bethany R. S.

    2016-12-01

    A rise in atmospheric CO2 is believed to be necessary for the termination of large-scale glaciations. Although the Antarctic Ice Sheet is estimated to have melted from ∼125% to ∼50% its modern size, there is thus far no evidence for an increase in atmospheric CO2 associated with the Mi-1 glacial termination in the earliest Miocene. Here, we present evidence from a high-resolution terrestrial record of leaf physiological change in southern New Zealand for an abrupt increase in atmospheric CO2 coincident with the termination of the Mi-1 glaciation and lasting approximately 20 kyr. Quantitative pCO2 estimates, made using a leaf gas exchange model, suggest that atmospheric CO2 levels may have doubled during this period, from 516 ± 111ppm to 1144 ± 410ppm, and subsequently returned back to 425 ± 53ppm. The 20-kyr interval with high pCO2 estimates is also associated with a period of increased moisture supply to southern New Zealand, inferred from carbon and hydrogen isotopes of terrestrial leaf waxes. The results provide the first high-resolution record of terrestrial environmental change at the Oligocene/Miocene boundary, document a ∼20 kyr interval of elevated pCO2 and increased local moisture availability, and provide insight into ecosystem response to a major orbitally driven climatic transition.

  13. Physiological and Growth Responses of C3 and C4 Plants to Reduced Temperature When Grown at Low CO2 of the Last Ice Age

    Institute of Scientific and Technical Information of China (English)

    Joy K. Ward; David A. Myers; Richard B. Thomas

    2008-01-01

    During the last Ice age, CO2 concentration ([CO2]) was 180-200 μmol/mol compared with the modern value of 380 μmol/mol,and global temperatures were ~8 ℃ cooler. Relatively little is known about the responses of C3 and C4 species to longterm exposure to glacial conditions. Here Abutilon theophrasti Medik. (C3) and Amaranthus retroflexus L. (C4) were grown at 200 μmol/mol CO2 with current (30/24 ℃) and glacial (22/16 ℃) temperatures for 22 d. Overall, the C4 species exhibited a large growth advantage over the C3 species at low [CO2]. However, this advantage was reduced at low temperature, where the C4 species produced 5× the total mass of the C3 species versus 14× at the high temperature.This difference was due to a reduction In C4 growth at low temperature, since the C3 species exhibited similar growth between temperatures. Physiological differences between temperatures were not detected for either species, although photorespirationlnet photosynthesis was reduced in the C3 species grown at low temperature, suggesting evidence of improved carbon balance at this treatment. This system suggests that C4 species had a growth advantage over C3 species during low [CO2] of the last ice age, although concurrent reductions in temperatures may have reduced this advantage.

  14. Form and Physiological Property of Plant Adaptation to Potassium Stress%植物适应钾营养胁迫的形态及生理特性

    Institute of Scientific and Technical Information of China (English)

    陈佳广

    2015-01-01

    In the article, it expounds the root system of plants, the secretion proton ability of root, the kinetics of root absorption to potassium, the variation trend and features of crop photosynthesis under potassium stress, provides a theoretical basis for selecting crop tolerance to low potassium and cultivating new germplasm source bearing low potassium.%论述钾营养胁迫下,作物根系形态、根系分泌质子能力、根系钾离子吸收动力学过程、作物光合作用的变化趋势及特点,为进行作物耐低钾筛选及培育耐低钾新种质资源提供理论基础。

  15. UV-B and UV-C pre-treatments induce physiological changes and artemisinin biosynthesis in Artemisia annua L. - an antimalarial plant.

    Science.gov (United States)

    Rai, Rashmi; Meena, Ram Prasad; Smita, Shachi Shuchi; Shukla, Aparna; Rai, Sanjay Kumar; Pandey-Rai, Shashi

    2011-12-02

    Present study was undertaken to investigate if short-term UV-B (4.2 kJ m(-2) day(-1)) and UV-C (5.7 kJ m(-2) day(-1)), pre-treatments can induce artemisinin biosynthesis in Artemisia annua. Twenty-one day old Artemisia seedlings were subjected to short-term (14 days) UV pre-treatment in an environmentally controlled growth chamber and then transplanted to the field under natural conditions. Treatment of A. annua with artificial UV-B and UV-C radiation not only altered the growth responses, biomass, pigment content and antioxidant enzyme activity but enhanced the secondary metabolites (artemisinin and flavonoid) content at all developmental stages as compared to non-irradiated plants. The extent of oxidative damage was measured in terms of the activities of enzymes such as catalase, superoxide dismutase and ascorbate peroxidase. Reinforcement in the antioxidative defense system seems to be a positive response of plants in ameliorating the negative effects of UV-B and UV-C radiations. While the carotenoid content was elevated, the chlorophyll content decreased under UV-B and UV-C pre-treatments. The reverse transcription PCR analysis of the genes associated in artemisinin/isoprenoid biosynthesis like 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGR), cytochrome P450 oxidoreductase (CPR) and amorpha-4,11-diene synthase (ADS) genes at different growth stages revealed UV induced significant over-expression of the above protein genes. UV-B and UV-C pre-treatments, led to an increase in the concentrations of artemisinin at full bloom stage by 10.5% and 15.7% than that of the control respectively. Thus, the result of our study suggests that short term UV-B pre-treatment of seedlings in greenhouse prior to transplantation into the field enhances artemisinin production with lesser yield related damages as compared to UV-C radiation in A. annua.

  16. 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.

  17. Physiological Response to Drought Stress of 13 Excellent Greening Climbing Plants%13种优良绿化攀缘植物对干旱胁迫的生理响应

    Institute of Scientific and Technical Information of China (English)

    席嘉宾; 李寅; 张建国; 黄跃波; 李映仪

    2012-01-01

    为弥补国内在园林绿化攀援植物抗旱能力方面的研究空白,为园林绿化实践提供优良抗旱攀援植物品种,试验以叶片保水力、可溶性糖含量和游离脯氨酸含量等生理生态学指标,对项目组从资源圃中27科共54种攀援植物中筛选出的13种综合性状优良的攀援植物品种,在干旱胁迫下的生理响应进行了研究.研究结果表明,不同供试攀援植物品种在干旱胁迫下表现出来的反应差异比较明显,其中耐旱性最强和耐旱性最弱的材料在许多指标上的差异达到了1倍左右甚至更大,而且具有一定的规律.对13个供试攀援植物品种在抗旱性方面的综合表现进行了模糊评价,初步确定鸡蛋果、红萼龙吐珠、美丽赪桐、金银花、麻雀花、星果藤和清明花等7个品种为比较抗旱的品种,同时也具有较为优良的景观性状,可供将来生产实践中推广应用.%In order to make up the gaps of study in the drought resistance of greening climbing plants and provide climbing plants with excellent drought resistance for landscape greening, physiological response to drought stress of 13 excellent greening climbing plants, which were sieved from 54 species of 27 families in the resource repository, was studied in the test, using the indexes of leaf water retention, soluble sugar content and free proline content. The results showed that the difference of physiological response to drought stress among the 13 plants was significant, of which many indicators between the plant with the best drought resistance and the worst one had difference more than one times. After evaluating the comprehensive performance of 13 test plants using fuzzy function, Passiflora edulia Sims, Clerodendrum, Clerodendrum splendens, Lonicera japonica Thunb., Aristolochia ringens,Tristellateia australasiae A. And Beaumontia grandiflora Wall. Were considered to have relatively better drought resistance while also had excellent

  18. Características fisiológicas e anatômicas de plantas de sibipiruna submetidas à hipoxia Physiological and anatomical characteristics of Sibipiruna plants under hipoxia

    Directory of Open Access Journals (Sweden)

    Paôla de Castro Henrique

    2010-02-01

    Full Text Available Plantas em seu ambiente natural estão sujeitas a condições adversas, passando por períodos de estresse breves ou duradouros. Algumas espécies desenvolvem mecanismos que as fazem suportar as condições adversas, permitindo sua sobrevivência. O objetivo deste estudo foi avaliar as respostas fisiológicas e anatômicas no desenvolvimento inicial de plantas de sibipiruna submetidas à hipoxia. Plantas com três a quatro folhas completamente expandidas foram submetidas a três tratamentos: plantas sem alagamento, alagadas nas raízes e totalmente alagadas. Foram realizadas avaliações dos teores de amido, açúcares solúveis totais e redutores em folhas e raízes coletadas a cada cinco dias, durante 30 dias. Características anatômicas foram avaliadas 15 dias após o início de cada tratamento. A maior redução nos teores de amido nas folhas e raízes foi observada nas plantas totalmente alagadas. Para açúcares solúveis totais e redutores, foi observado comportamento semelhante ao obtido em amido; porém, as plantas alagadas nas raízes apresentaram, em alguns períodos de avaliação, teores, principalmente nas raízes, superiores aos observados nas plantas sem alagamento. Essas plantas também apresentaram maior densidade estomática em relação aos demais tratamentos. Para a espessura do córtex e do cilindro vascular das raízes, foi observada uma redução para os tratamentos alagados, cujas plantas totalmente alagadas apresentaram uma maior barreira apoplástica imposta pelo espessamento em fi caracterizada pela formação de septos nas células próximas à endoderme.Plants in their natural environment are subject to adverse conditions, and the stress periods can be short or long. Some species develop mechanisms that make them bear the adverse conditions, allowing their survival. The aim of this study was to evaluate the anatomic and physiological responses in the initial development of Sibipiruna plants submitted to hypoxia

  19. Co-operative intermolecular kinetics of 2-oxoglutarate dependent dioxygenases may be essential for system-level regulation of plant cell physiology

    Directory of Open Access Journals (Sweden)

    Siddhartha eKundu

    2015-07-01

    Full Text Available Chlorosis, a common manifestation of Fe-deficiency in plants occurs in soils with an alkaline pH and/or a high concentration of calcium carbonate (calcareous, and is an important cause of depressed yield. The core premise of this work is the notion that the response to waning ferrous iron in the cytosol of graminaceous root cells is a well orchestrated pathophysiological event, wherein the principal co-ordinator is not restricted to a single protein, but is an assortment of enzymes. The 2OG-dependent sequences comprise members present in all major kingdoms of life, and catalyze the release of carbon dioxide and succinic acid from 2-oxoglutarate, and the hydroxylation of a substrate molecule. This generic reaction is, in most cases accompanied by a specialized conversion of the product. Here, I present a model of iron deficiency sensing and response actuation in the root cells of graminaceous crops. This hypothesis is centered on the rationale that, iron is an essential co-factor for the catalytic process, and therefore, declining cytosolic levels of this micronutrient could trigger compensatory measures. Regression models of empirically available kinetic data for iron and alpha-ketoglutarate were formulated, analysed, and compared. The results, when viewed in the context of the superfamily responding as a unit to this abiotic stressor, suggest that the 2OG-sequences can indeed, work together to mitigate the effects of this noxious stimulus.

  20. [Human physiology: kidney].

    Science.gov (United States)

    Natochin, Iu V

    2010-01-01

    The content of human physiology as an independent part of current physiology is discussed. Substantiated is the point that subjects of human physiology are not only special sections of physiology where functions are inherent only in human (physiology of intellectual activity, speech, labor, sport), but also in peculiarities of functions, specificity of regulation of each of physiological systems. By the example of physiology of kidney and water-salt balance there are shown borders of norm, peculiarities of regulation in human, new chapters of renal physiology which have appeared in connection with achievements of molecular physiology.

  1. Deficiency and toxicity of nanomolar copper in low irradiance—A physiological and metalloproteomic study in the aquatic plant Ceratophyllum demersum

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, George [University of Konstanz, Department of Biology, D-78457 Konstanz (Germany); Andresen, Elisa [University of Konstanz, Department of Biology, D-78457 Konstanz (Germany); Institute of Plant Molecular Biology, Department Plant Biophysics and Biochemistry, Biology Centre of the ASCR, Branišovská 31/1160, CZ-37005 České Budějovice (Czech Republic); Mattusch, Jürgen [UFZ − Helmholtz Centre for Environmental Research, Department of Analytical Chemistry, Permoserstr. 15, D-04318 Leipzig (Germany); Hubáček, Tomáš [Institute of Hydrobiology, Department of Hydrochemistry and Ecosystem Modelling, Biology Centre of the ASCR, Na Sádkách 7, 37005 České Budějovice (Czech Republic); SoWa National Research Infrastructure, Biology Centre of the ASCR, Na Sádkách 7, 37005 České Budějovice (Czech Republic); and others

    2016-08-15

    Highlights: • Environmentally relevant toxicity and limitation of Cu were investigated. • Copper > 50nM replaces Mg in the LHCII‐trimers. • Deficiency causes decreased electron flow through PSII via lack of plastocyanin. • Of all metabolic pathways, photosynthesis was most affected by Cu toxicity. • Detection of Cu in the Chl peaks of LHCII suggests the generation of [Cu]‐Chl. - Abstract: Essential trace elements (Cu{sup 2+}, Zn{sup 2+}, etc) lead to toxic effects above a certain threshold, which is a major environmental problem in many areas of the world. Here, environmentally relevant sub-micromolar concentrations of Cu{sup 2+} and simulations of natural light and temperature cycles were applied to the aquatic macrophyte Ceratophyllum demersum a s a model for plant shoots. In this low irradiance study resembling non‐summer conditions, growth was optimal in the range 7.5–35 nM Cu, while PSII activity (F{sub v}/F{sub m}) was maximal around 7.5 nM Cu. Damage to the light harvesting complex of photosystem II (LHCII) was the first target of Cu toxicity (>50 nM Cu) where Cu replaced Mg in the LHCII-trimers. This was associated with a subsequent decrease of Chl a as well as heat dissipation (NPQ). The growth rate was decreased from the first week of Cu deficiency. Plastocyanin malfunction due to the lack of Cu that is needed for its active centre was the likely cause of diminished electron flow through PSII (Φ{sub PSII}). The pigment decrease added to the damage in the photosynthetic light reactions. These mechanisms ultimately resulted in decrease of starch and oxygen production.

  2. Plant Biology Science Projects.

    Science.gov (United States)

    Hershey, David R.

    This book contains science projects about seed plants that deal with plant physiology, plant ecology, and plant agriculture. Each of the projects includes a step-by-step experiment followed by suggestions for further investigations. Chapters include: (1) "Bean Seed Imbibition"; (2) "Germination Percentages of Different Types of Seeds"; (3)…

  3. Maintaining a Physiological Blood Glucose Level with ‘Glucolevel’, a Combination of Four Anti-Diabetes Plants Used in the Traditional Arab Herbal Medicine

    Directory of Open Access Journals (Sweden)

    Omar Said

    2008-01-01

    Full Text Available Safety and anti-diabetic effects of Glucolevel, a mixture of dry extract of leaves of the Juglans regia L, Olea europea L, Urtica dioica L and Atriplex halimus L were evaluated using in vivo and in vitro test systems. No sign of toxic effects (using LDH assay were seen in cultured human fibroblasts treated with increasing concentrations of Glucolevel. Similar observations were seen in vivo studies using rats (LD50: 25 g/kg. Anti-diabetic effects were evidenced by the augmentation of glucose uptake by yeast cells (2-folds higher and by inhibition of glucose intestinal absorption (∼49% in a rat gut-segment. Furthermore, treatment with Glucolevel of Streptozotocin-induced diabetic rats for 2–3 weeks showed a significant reduction in glucose levels [above 400 ± 50 mg/dl to 210 ± 22 mg/dl (P < 0.001] and significantly improved sugar uptake during the glucose tolerance test, compared with positive control. In addition, glucose levels were tested in sixteen human volunteers, with the recent onset of type 2 diabetes mellitus, who received Glucolevel tablets 1 × 3 daily for a period of 4 weeks. Within the first week of Glucolevel consumption, baseline glucose levels were significantly reduced from 290 ± 40 to 210 ± 20 mg/dl. At baseline, a subgroup of eleven of these subjects had glucose levels below 300 mg% and the other subgroup had levels ≥ 300 mg%. Clinically acceptable glucose levels were achieved during the 2–3 weeks of therapy in the former subgroup and during the 4th week of therapy in the latter subgroup. No side effect was reported. In addition, a significant reduction in hemoglobin A1C values (8.2 ± 1.03 to 6.9 ± 0.94 was found in six patients treated with Glucolevel. Results demonstrate safety, tolerability and efficacy of herbal combinations of four plants that seem to act differently but synergistically to regulate glucose-homeostasis.

  4. The Effects of Water Deficit Stress on Physiological and Biochemical Changes of Medicinal Plants Ocimum basilicum L. under Climatic Conditions in Ardabil, Iran

    Directory of Open Access Journals (Sweden)

    Ahmad Afkari

    2016-09-01

    Full Text Available Basil (Ocimum basilicum L. is an important medicinal and aromatic plant which is cultivated throughout the world and investigation the effects of important agronomic factors on its quantitative and qualitative yield are necessary.This research was conducted in the years 2013-2014 in agricultural farm of Mr. Abedini in the village Mahmoud Abad of Namin city functions, (Ardabil, Iran, as factorial experiment in a completely randomized block design by 3 replications. The experimental treatments were water deficit stress (D1=70, D2=140 and D3= 210 mm evaporation from pan class A as category factors and three levels of nitrogen fertilizer in the form of urea (N1= 0, N2 = 50, N3 = 100 kg/ha.The results showed that the most ratio of the essential oils of basil obtained in the first and the second harvests (2.37% and 1.81%, respectively in the treatment of without nitrogen fertilizer and the lowest ratio of the essential oils of basil was in the first and second harvests (1.43% and 1.69%, respectively in the treatment of 100 kg/ha nitrogen fertilizer. Interactions of water deficit stress and nitrogen fertilizer on dry matter yield per unit area was significant at total of two harvests (total yield; and the highest dry matter yield was observed in treatments of D1= 70 mm evaporation and 100 kg/ha nitrogen fertilizer (1000.01 kg of dry matter per hectare, and the lowest ratio was achieved in treatments of D3=210 mm evaporation without the use of fertilizer (516.43 kg of dry matter per hectare. On the other hand the results indicated that interactions of water deficit stress and nitrogen fertilizer on essential oil yield per unit area was not significant at the first harvest, the second harvest and total yield. However, the highest essential oil yield was obtained at the first harvest, the second harvest and total yield, (9.08, 7.54 and 15.21 l/ha, respectively in the treatments of D1=70 mm evaporation and nitrogen fertilizer of 100 kg/ ha as well as the

  5. Effects of Planting Period on Vanilla Physiological Indices and Rhizosphere Soil Microbial Community Structure%种植年限对香草兰生理状况及根际土壤微生物区系的影响

    Institute of Scientific and Technical Information of China (English)

    赵青云; 王辉; 王华; 庄辉发; 鱼欢; 谭乐和; 朱自慧; 宋应辉

    2012-01-01

    对不同种植年限香草兰园植株生理指标及根际土壤微生物区系进行测定分析.结果表明:10a以上园龄的香草兰叶片净光合速率、蒸腾速率和叶绿素含量显著降低,而0~5 a园龄香草兰叶片各生理指标并无显著性差异.平板稀释涂布结果显示:5、10和20a园龄香草兰根际可培养细菌和放线菌数量显著低于新植园,根际细菌与新植园相比分别降低了58.4%、91.6%、96.7%;根际真菌及尖孢镰刀菌数量呈相反趋势,与新植园相比,真菌数量分别是新植园的1.6、2.1和3.4倍.综上所述,种植10 a以上的香草兰园植株生长代谢缓慢,土壤微生物由细菌型向真菌型转变,微生物区系失衡.%Series of field and lab tests were carried out to investigate the effects of planting period on Vanilla growth and rhizosphere soil microbial community structure. The main results obtained were listed as follows: (1) with the planting period increasing, net photosynthesis rate, transpiration rate and chlorophyll content of Vanilla leaves were significantly decreased in over ten years plantation, however, these three physiological indices had no significant difference within five years plantation; (2) standard dilution plate count results showed that population of culturable bacteria and actinomycota in Vanilla rhizosphere soil were significantly decreased in 5, 10 and 20 years plantation compared with that of new plantation. Bacteria population was reduced by 58.4%, 91.6% and 96.7%, respectively. An opposite trend was found in fungi and Fusarium oxysporum numbers. The corresponding number of fungi in Vanilla rhizosphere soil was 1.6, 2.1 and 3.4 times higher compared with that of new plantation, respectively. In conclusion, the metabolism of vanilla plants became weak and the soil microbial community structure lost balance in the plantation of planting periods over ten years.

  6. Effects of Three Plant Growth Regulators on the Physiological Indices of Hibiscus Rosa-sinensis%3种植物生长调节剂对七彩朱槿生理指标的影响

    Institute of Scientific and Technical Information of China (English)

    玉舒中; 王美英; 李悦; 杨振德; 雷世满; 吕文玲

    2012-01-01

    [目的]探讨植物生长调节剂对七彩朱槿生长影响的生理机制.[方法]采用L16(43)的正交试验设计,研究多效唑( PP333)、矮壮素(CCC)、比久(B9)3种植物生长调节剂对盆栽七彩朱槿叶绿素含量以及POD、CAT、NR的影响.[结果]叶施与根施生长调节剂对七彩朱槿的生理影响效果不同.叶施生长调节剂对叶绿素含量、POD和CAT的影响大于根施;而根施对NR的促进作用大于叶施,含高浓,度CCC(4000mg/L)的(14)、(15)、(16)处理的NR明显高于对照.3种生长调节剂中,CCC对七彩朱槿NR的影响最显著,其中根施CCC处理的影响达极显著水平.[结论]合理使用植物生长调节剂,不仅能起到化学修剪的作用,同时可以增强七彩朱槿的光合作用能力、抗性以及对氮肥的利用能力.%[Objective] The research aimed to explore the physiological mechanism that plant growth regulators made effects on the growth of Hibiscus Rosa-sinensis. [Method] The experiments were conducted as the orthogonal design of L16 (4 ) to study the effects of three plant growth regulators , namely PP333, CCC, B9, on th e chlorophyll content, POD, CAT and NR of Hibiscus Rosa-sinensis grown in pot. [Result] The effects on the physiological indices of Hibiscus Rosa-sinensis between foliar fertilization and root fertilization of PP333 ,CCC and B9 were different. The effects on the chlorophyll content, POD and CAT made by foliage fertilization were more obvious than by root fertilization, but it was opposite to NR, and the values of NR of Hibiscus Rosa-sinensis treated by the (14), (15) and (16) combinations, which all contained CCC in high concentration (4 000 mg/L) ,were significantly higher than CK. Among the three plant growth regulators, CCC had made the most significant effect on NR of Hibiscus Rosa-sinensis, especially by the way of root fertilization, and the difference could reach extremely significant level compared with the others. [Conclusion] Rational use

  7. Produção e fisiologia de plantas de cajueiro anão precoce sob condições de sequeiro e irrigado Production and physiology of dwarf cashew plants under rainfed and irrigated conditions

    Directory of Open Access Journals (Sweden)

    Aiala V Amorim

    2011-10-01

    Full Text Available A exploração do cajueiro sob condições de irrigação tem-se mostrado bastante promissora, especialmente no estado do Ceará, porém a resposta dessa cultura ao regime hídrico depende do genótipo. Objetivouse, com este trabalho, comparar respostas fisiológicas e bioquímicas (teores de solutos orgânicos e inorgânicos e trocas gasosas, tal como a produtividade de plantas de cajueiro anão precoce (Anacardium occidentale L. sob dois regimes hídricos (sequeiro e irrigado. O experimento foi conduzido no Campo Experimental da Embrapa Agroindústria Tropical, em Pacajus CE, no período de agosto de 2006 a janeiro de 2007. As plantas foram submetidas a dois tratamentos: um sem irrigação e outro com água de poço com condutividade elétrica (CEa de 0,5 dS m-1. As respostas fisiológicas foram avaliadas mensalmente e os dados de produção foram obtidos no período de novembro a janeiro. Os teores foliares de N-aminossolúveis e prolina foram mais elevados nas plantas cultivadas em condições de sequeiro do que naquelas irrigadas, porém não houve diferença significativa entre os tratamentos para as trocas gasosas, teores de carboidratos solúveis, K+, Na+ e Cl-. Entretanto, com exceção da fotossíntese, todas as variáveis estudadas apresentaram alterações com as épocas de coleta. Apesar das alterações em algumas variáveis ao longo do experimento, a produtividade das plantas não foi afetada pelo estresse hídrico.The exploitation of cashew under irrigated conditions has been very promising, especially in the state of Ceará, however, the response of this crop to the water regime depends on the genotype. This work attempts to compare the physiological and biochemical responses (content of organic and inorganic solutes and gas exchange and yield of precocious dwarf cashew (Anacardium occidentale L plants under two water regimes (irrigated and rainfed. The experiment was conducted at the experimental field of Embrapa Agroind

  8. Electronic plants

    Science.gov (United States)

    Stavrinidou, Eleni; Gabrielsson, Roger; Gomez, Eliot; Crispin, Xavier; Nilsson, Ove; Simon, Daniel T.; Berggren, Magnus

    2015-01-01

    The roots, stems, leaves, and vascular circuitry of higher plants are responsible for conveying the chemical signals that regulate growth and functions. From a certain perspective, these features are analogous to the contacts, interconnections, devices, and wires of discrete and integrated electronic circuits. Although many attempts have been made to augment plant function with electroactive materials, plants’ “circuitry” has never been directly merged with electronics. We report analog and digital organic electronic circuits and devices manufactured in living plants. The four key components of a circuit have been achieved using the xylem, leaves, veins, and signals of the plant as the template and integral part of the circuit elements and functions. With integrated and distributed electronics in plants, one can envisage a range of applications including precision recording and regulation of physiology, energy harvesting from photosynthesis, and alternatives to genetic modification for plant optimization. PMID:26702448

  9. 水分胁迫对边坡绿化植物生理特性的影响%Influence of Physiological Characteristics of Slope Greening Plants Under Different Water Stress

    Institute of Scientific and Technical Information of China (English)

    王伟

    2016-01-01

    This paper took Melilotus albus,Medicago sativa,Parthenocissus quinquefolia which are widely used for slope protection in North China as the research object. By setting four kinds of water controlled experiment,various physiological and biochemical parameters of plant were measured. Through analysis the change of multiple physiological indexes,it evaluated physiological characteristics of three difference plant comprehensively. The results show that:a)along with strengthening of water stress,the cell extravasation rates of three plants have different increasing amplitude. Under the same condition of water stress,cell damage degree of Melilotus albus and Medicago sativa is lighter than Parthenocissus quinquefolia;b)the water stress increasing leaf chlorophyll content will gradually reduce,thus affecting the net photosynthetic rate (Pn)of the plant. And the stomatal conductance of plant becomes smaller,thus carbon dioxide cannot get effective supplement. Eventually,the intercellular CO2 concentration (Gi)gradually reduces,and the water use efficiency increases later. But with the reducing of moisture content,the porosity becomes smaller. The carbon dioxide produces by cell cannot get effective releasing and absorption. Then the intercellular carbon dioxide concentrations increases,and the water use efficiency reduces gradually. These effects are different for three plants;c)the POD activity is the highest in Medicago sativa,and is the lowest in Parthenocissus quinquefolia . But along the enhancement of water stress,the POD activity trend first increases and then decreases. The POD activity of Melilotus albus and Medicago sativa is decreased under middle water stress,while the POD activity of Parthenocissus quinquefolia is decreased under slight water stress.%以白花草木樨、五叶地锦、紫花苜蓿3种北方常用护坡植物为研究对象,通过设置4种梯度的控水试验,测定植物多个生理生化参数,并通过多个生

  10. 7种观赏植物对甲醛的净化效果及生理响应%The Capacity on Purifying Indoor Formaldehyde Pollution and Physiology Response of 7 Ornamental Plants

    Institute of Scientific and Technical Information of China (English)

    许桂芳

    2012-01-01

    To select suitable plants for use in purified indoor formaldehyde pollution, seven species of ornamental plants were evaluated for their effectiveness in reducing formaldehyde concentrations in a simulated fumigating box environment, and the absorption capacities were compared and ranked according to the net ratio of absorption and the reduction of formaldehyde in the unit leaf area. Meanwhile, the leaf plasma membrane permeability, MDA content and POD activity were measured to assess those plants' physiological responses to formaldehyde stress. The results indicated that the capacities of different plants in removing formaldehyde were different, and the order of the plants according to the absorption efficiency amount per unit of leaf area was Peperomia tetraphylla> Reineckea carnea> Aspidistra elatior> Crassula portulacea> Stromanthe sanguinea> Nidularium fulgens. The leaf relative conductivity, MDA content and POD activity of all the seven species changed after formaldehyde treatment and the resistances of different species to formaldehyde stress were different. According to formaldehyde removal capacity and the resistance measured in the experiment, 6 ornamental plants (including Peperomia tetraphylla, Reineckea carnea, Aspidistra elatior, Crassula portulacea, Stromanthe sanguine, Nidularium fulgens) had both higher removal capacities and higher resistance that were suitable to be used in indoor decoration.%为净化室内甲醛污染筛选出净化能力强的植物种类,以7种常见室内观赏植物为试材,采用气体密封舱熏气法,进行甲醛熏气处理,以净吸收率及单位叶面积甲醛减少量来比较植物吸收甲醛能力的大小,同时测定了熏气前后植物叶片的相对电导率、丙二醛含量及POD活性等指标.结果显示,被测植物在一定程度上均可以有效吸收甲醛,单位面积吸收量从大到小依次为椒草、吉祥草、一叶兰、燕子掌、紫背竹芋、锦巢凤梨、一品红.不同植物

  11. 植物生理学实验中溶液培养研究性实验的建立研究%The establishment of hydroponics research experiment in plant physiology experiment

    Institute of Scientific and Technical Information of China (English)

    刘阳; 董树刚

    2015-01-01

    Hydroponics experiment is an important content of the teaching in plant physiology .However , the content of this part is mo-notonous in the old syllabus .The author tries to combine the basic experiment with hydroponics experiment in his teaching .Using hy-droponics as a technology and guiding students to carry out research experiment , the author′s teaching innovation has achieved good re-sults, training students′practical ability, observation ability, comprehensive ability and innovation ability .%溶液培养实验是植物生理学实验教学中的重要内容,而旧的教学大纲中该部分内容设置单一,不利于学生的理解掌握。笔者在教学实践中,将基础性实验与溶液培养实验有机结合,以溶液培养为技术手段,引导学生开展研究性实验,锻炼学生的动手能力,培养学生的观察能力、综合能力和创新能力,取得了较好的效果。

  12. Anatomical and physiological modifications of micropropagated 'Caipira' banana plants under natural lighy Modificações anatômicas e fisiológicas de bananeiras 'Caipira' micropropagadas sob luz natural

    Directory of Open Access Journals (Sweden)

    Frederico Henrique da Silva Costa

    2009-06-01

    Full Text Available Research about the use of natural light associated to changes in sucrose levels demonstrated potential in promoting in vitro hardiness of tropical climate species, as well as reducing production costs. However, little is known about physiological and structural changes that happen in the process. This study evaluated the physiological and anatomic performance, and ex vitro survival of micropropagated banana plants in response to cultivation conditions, in the stage of in vitro rooting. Shoots of the 'Caipira' cultivar were cultivated in MS medium, supplemented with 1 mg L-1 NAA and 6 g L-1 agar, in which the following treatments were applied: two sucrose concentrations (15 g L-1 or 30 g L-1 and two cultivation conditions (Natural light - greenhouse and Artificial light - growth chamber. At the end of 45 days, the contents of chlorophyll a, b and total, the relative water content in the tissues, anatomic characteristics and the ex vitro survival were evaluated. Effects of growth environment and sucrose concentration were observed on micropropagated 'Caipira' banana anatomy, physiology and survival. In vitro rooting of the shoots under natural light in the medium containing 15 g L-1 or 30 g L-1 sucrose promoted major alteration in the increase of palisade and spongy parenchyma, as well as reducing leaf water loss and plant death. The results obtained in the present study confirm the potential of the use of natural light as a substitute for artificial light for micropropagation of tropical species.Pesquisas acerca do uso da luz natural associado a alterações nos níveis de sacarose têm apresentado potencial para promover a rustificação in vitro de espécies de clima tropical bem como reduzir os custos de produção. Todavia, pouco se conhece sobre as modificações fisiológicas e estruturais ocasionadas. Avaliaram-se o comportamento fisiológico, anatômico e a sobrevivência ex vitro de bananeiras micropropagadas em resposta às condi

  13. Physiological effects in aromatherapy

    OpenAIRE

    2004-01-01

    The effects of aromas on humans are divided into physiological and psychological effects. The physiological effect acts directly on the physical organism, the psychological effect acts via the sense of smell or olfactory system, which in turn may cause a physiological effect. This paper reviews on the physiological effects which are used for the evaluation of the effects of aromas. Physiological parameters, i.e. heart rate blood pressure, electrodermal activity, electroencephalogram, slow pot...

  14. Physiological cost of induced resistance in cotton plants at different nitrogen levels Custo fisiológico da resistência em algodoeiro sob diferentes níveis de nitrogênio

    Directory of Open Access Journals (Sweden)

    Maria Angélica Guimarães Barbosa

    2008-12-01

    Full Text Available Resistance induction through the use of chemical inducers often results in physiological costs to the plant. In this study, induced resistance in cotton plants was evaluated with regard to physiological costs in a cultivar susceptible to Colletotrichum gossypii var. cephalosporioides (CNPA GO 2002 - 7997. Plants were cultivated in substrates with two levels of nitrogen and received two applications of acibenzolar-S-methyl (ASM, jasmonic acid (JA and Agro-Mos® (AM disease resistance inducers. Plant height (H, internodal length (IL, shoot fresh weight (SFW, root fresh weight (RFW, shoot dry weight (SDW and root dry weight (RDW were evaluated. The activity of the phenylalanine ammonia lyase (PAL and peroxidase (POX was also determined. The plants treated with ASM presented high physiological costs with an accentuated reduction in H, SFW and SDW, whereas those treated with JA exhibited a significant increase in SDW, and did not significantly differ from H and IL. In the potting mix supplemented with nitrogen, all inducers differed from the control treatment regarding to internodal length, whereas only ASM and AM presented a significant difference between one another in the potting mix without the addition of nitrogen. Significant correlations (P=0.05 were found for most of the variables analyzed, with greater correlations observed between SFW and SDW (0.94; IL and H (0.74; SFW and H (0.70; and SDW and H (0.70. ASM induced the least amount of PAL activity, significantly differing from the remaining treatments. Greater POX activity was observed in ASM, which significantly differed from the control. AM and JA, however, presented lower activity than the control with regard to these enzymes, and it was not possible to confirm induction resistance in these two treatments.A indução de resistência pelo uso de indutores químicos tem resultado algumas vezes em custo fisiológico para a planta. A resistência induzida em algodoeiro foi avaliada quanto ao

  15. 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.

  16. Plant Systems Biology (editorial)

    Science.gov (United States)

    In June 2003, Plant Physiology published an Arabidopsis special issue devoted to plant systems biology. The intention of Natasha Raikhel and Gloria Coruzzi, the two editors of this first-of-its-kind issue, was ‘‘to help nucleate this new effort within the plant community’’ as they considered that ‘‘...

  17. Diagnosing plant problems

    Science.gov (United States)

    Cheryl A. Smith

    2008-01-01

    Diagnosing Christmas tree problems can be a challenge, requiring a basic knowledge of plant culture and physiology, the effect of environmental influences on plant health, and the ability to identify the possible causes of plant problems. Developing a solution or remedy to the problem depends on a proper diagnosis, a process that requires recognition of a problem and...

  18. 面向植物生理生化参数反演的光谱信息压缩感知重构%Compressive sensing and reconstruction of vegetation spectra for retrieving plant physiological and biochemical parameters

    Institute of Scientific and Technical Information of China (English)

    徐平; 刘俊峰; 张竞成; 薛凌云

    2016-01-01

    With the development of hyperspectral technology, it is of great significance to establish a specific compression and reconstruction method that can be used for conducting quantitative remote sensing of vegetation. Such a method is expected not only to improve the efficiency of data storage and transmission, but also to maintain the main spectral characteristics in interpreting some physiological and biochemical parameters. In this study, the compressive sensing technique was introduced to the compression and reconstruction of plant spectrum. Three critical physiological and biochemical parameters of plant, i.e. water content, carotenoid content and chlorophyll content, were chosen to test the retrieving efficacy of the proposed method. To facilitate such an analysis, a spectral dataset consisting of 2 500 spectra and corresponding plant physiological and biochemical parameters with multivariate normal distribution was generated by a classic plant leaf radiation model PROSEPCT. Based on the data, the compression and reconstruction method that was specific for vegetation spectral processing was proposed, described and evaluated. To process the spectral dataset using the compressed sensing method, the spectral dataset was firstly sampled by means of constructing random matrix. Then, the sampled data were reconstructed by a classic orthogonal matching pursuit algorithm, and the normalized root mean square error between the reconstructed data and the original data was analyzed. The performance of the method was thoroughly evaluated on 3 different levels: the spectral level, the feature level and the model level. At the spectral level, an error analysis was performed by directly calculating the original spectra and reconstructed spectra of corresponding samples. At the spectral index level, the spectral index was calculated based on both the original spectra and the reconstructed spectra. Then the error of the spectral index was analyzed. At the model level, the

  19. Toxic Effects of Cr3+,Cr6+ on the Physiological and Biochemical Characteristics of Tea Plant%Cr3+和Cr6+胁迫对茶树生理生化特性的影响

    Institute of Scientific and Technical Information of China (English)

    唐茜; 冯德建; 杨华; 吴永胜; 谭和平

    2009-01-01

    The toxic effects of different concentrations of Cr3+ and Cr6+ on the physiological and biochemical characteristics of tea plant were studied in Hoagland solution culture.The results indicated that: with the increasing of Cr3+,Cr6+ concentrations,the symptoms of tea plant became obviously; the contents of chlorophyll and the ratio of chlorophyll a and chlorophyll b reduced obviously,and there were obviously negative effects to net photosynthesis rate,intercellular CO2 concentration,transpiration rate and stoma conductivity.Under the Cr3+ stress,the activities of SOD,POD and CAT increased at first and then decreased,under the Cr6+ stress,the activities of SOD and POD increased at first and then decreased too,but the activity of CAT decreased all the time.At the same time,the contents of MDA and proline (Pro),cytomembrane permeability increased obviously with the increasing of Cr3+,Cr6+ concentrations.Therefore,it highlighted that the Cr3+ and Cr6+ stresses could mangle the cytomembrane system,the structures and functions of the major organelles of tea plant,and the toxic effects of Cr6+ on tea plant was stronger than that of Cr3+.%通过水培试验,研究比较了不同浓度(10~60 mg/L)的Cr3+、Cr6+胁迫对茶树叶片一些生理生化指标的影响.结果表明:随Cr3+、Cr6+胁迫浓度的增加,茶树受害程度加深,中毒症状明显;叶绿素含量以及叶绿素a/b比值极显著降低,并对净光合速率、胞间CO2浓度、蒸腾速率及气孔导度产生显著负面影响.Cr3+胁迫下,SOD、POD、CAT活性随Cr3+浓度增加呈先升高后降低趋势;而Cr6+胁迫下,SOD、POD活性也出现先升后降趋势,但CAT活性则持续下降.丙二醛含量、细胞膜透性和脯氨酸含量也随Cr3+、Cr6+浓度增加显著增加,表明Cr3+、Cr6+胁迫对茶树细胞质膜系统及主要细胞器的结构与功能都具有较强的破坏作用,Cr6+的毒害作用强于Cr3+.

  20. 不同磷水平下植物体内镉的积累、化学形态及生理特性%ACCUMULATION, CHEMICAL FORMS AND PHYSIOLOGICAL CHARACTERIZATION OF CADMIUM IN PLANTS AFFECTED BY PHOSPHORUS

    Institute of Scientific and Technical Information of China (English)

    杨志敏; 郑绍健; 胡霭堂

    2000-01-01

    Corn and wheat cultivated in hydroponic culture solution with supplies of cadmium (c(Cd)0, 4.0 μmol/L) and phosphorus (c(P)0, 0.12, 0.6, 3.0 mmol/L) under controlled growth conditions in relation to the chemical forms of Cd, growth and physiological parameters, and enzyme activities of 21-day-old plants were investigated. The three predominant forms of Cd were NaCl-extractable Cd (related to Cd-binding proteins or polypeptides), acetic acid-extractable Cd (CdHPO4, Cd3(PO4)2, or Cd-polyphosphates), and water-extractable Cd (organic acid complexes). Increasing application of P tended to reduce the percentage of Cd combined with proteins and increase the amount of Cd-phosphates. Decreased cell plasma membrane permeability and K+ leakage of Cd-treated plants were observed with the P supply of 0.6 mmol/L. The moderate supply of P (0.6 mmol/L) also improved the contents of chlorophyll pigments, the activities of root dehydrogenase and leaf nitrate reductase in Cd-treated plants, whereas supply with an excess of P (3.0 mmol/L) showed not to be more effective in the alleviation of Cd toxic to plants. Results showed that wheat was more tolerant to Cd toxicity than corn. Fig 5, Tab 4, Ref17%在控制条件下,将玉米、小麦植株在含有不同浓度磷(c(P)0,0.12,0.6,3.0 mmol/L)和镉(c(Cd)0,4.0 μmol/L)的营养液中培养21d,研究植株体内各种镉的形态、生理特性和酶活性的变化.选择三种主要镉的形态,即氯化钠可提取态(镉与蛋白质或多肽结合态),醋酸可提取态(镉与磷酸盐的结合态)和去离子水可提取态(水溶性、有机酸盐镉的形态)作为优势态镉加以分析和研究.结果表明,提高介质中磷的浓度,降低了与蛋白质结合态镉的含量,而增加了镉-磷酸盐的含量.与缺磷或低磷供应比较,在c(P)0.6~3.0 mmol/L下的两种作物根系脱氢酶的活性明显提高,根系K+的透性减小,玉米叶绿素的含量明显升高,硝酸还原酶活性增大.但高磷(c(P)3

  1. Microarrays for global expression constructed with a low redundancy set of 27,500 sequenced cDNAs representing an array of developmental stages and physiological conditions of the soybean plant

    Directory of Open Access Journals (Sweden)

    Retzel Ernest

    2004-09-01

    stages and physiological conditions of the soybean plant. We also demonstrate that the quality of the data from the soybean cDNA microarrays is sufficiently reliable to examine isogenic lines that differ with respect to a mutant phenotype and thereby to define a small list of candidate genes potentially encoding or modulated by the mutant phenotype.

  2. Physiological Information Database (PID)

    Science.gov (United States)

    EPA has developed a physiological information database (created using Microsoft ACCESS) intended to be used in PBPK modeling. The database contains physiological parameter values for humans from early childhood through senescence as well as similar data for laboratory animal spec...

  3. Chewing Over Physiology Integration

    Science.gov (United States)

    Abdulkader, Fernando; Azevedo-Martins, Anna Karenina; de Arcisio Miranda, Manoel; Brunaldi, Kellen

    2005-01-01

    An important challenge for both students and teachers of physiology is to integrate the differentareas in which physiological knowledge is didactically divided. In developing countries, such an issue is even more demanding, because budget restrictions often affect the physiology program with laboratory classes being the first on the list when it…

  4. Chewing Over Physiology Integration

    Science.gov (United States)

    Abdulkader, Fernando; Azevedo-Martins, Anna Karenina; de Arcisio Miranda, Manoel; Brunaldi, Kellen

    2005-01-01

    An important challenge for both students and teachers of physiology is to integrate the differentareas in which physiological knowledge is didactically divided. In developing countries, such an issue is even more demanding, because budget restrictions often affect the physiology program with laboratory classes being the first on the list when it…

  5. Research Progress on the Physiological and Molecular Mechanisms of Woody Plants Under Low Temperature Stress%木本植物低温胁迫生理及分子机制研究进展

    Institute of Scientific and Technical Information of China (English)

    乌凤章; 王贺新; 徐国辉; 张自川

    2015-01-01

    护细胞;热休克蛋白( HSPs)调节蛋白质的折叠和运输,恢复钝化酶的活性;抗氧化酶系统清除氧自由基和过氧化氢;早期光诱导蛋白参与高光胁迫适应过程,这些蛋白在树木抗冻机制中具有重要作用。在树木抗冷(冻)领域,未来应加强对控制抗冷(冻)生理变化的转录因子及关键功能基因的全面解析,深入探讨光、温度等环境信号诱导抗冻性形成机制,使用蛋白质组学方法与其他技术相结合阐明低温胁迫下重要蛋白质表达机制和功能,完整地揭示木本植物在低温逆境下的生存机制。%Low temperature stress limits the geographical distribution of many wild plant and crops,and reduces their productivity. There are huge differences in survivability of trees to low temperature stress. Chilling sensitive trees from tropics and subtropics are irreversibly damaged at temperature condition higher than freezing point,while those species originated from temperate-zone can withstand extreme freezing conditions. In recent years,the analyses of physiological and biochemical response characteristics, transcriptome, proteome and metabolome of chilling sensitive trees and temperate-zone trees under low temperature stress have been rapidly developed,which from various levels have elucidated the physiological and molecular mechanisms that woody plant regulating low-temperature response and freezing tolerance. These analyses provide important reference for molecular breeding of freezing-tolerant woody plant by using anti-freezing related genes. Under the low temperature stress of 1—10 ℃,chilling sensitive trees would appear disorders physiological processes in water status,mineral nutrition,photosynthesis,respiration and metabolism,and hence lead to chilling damage,and even death. Calcium signal transduction pathway is the important signal transduction pathway during low temperature response process. ABA is involved in the regulation of plant stress response gene by

  6. Physiological effects in aromatherapy

    Directory of Open Access Journals (Sweden)

    Tapanee Hongratanaworakit

    2004-01-01

    Full Text Available The effects of aromas on humans are divided into physiological and psychological effects. The physiological effect acts directly on the physical organism, the psychological effect acts via the sense of smell or olfactory system, which in turn may cause a physiological effect. This paper reviews on the physiological effects which are used for the evaluation of the effects of aromas. Physiological parameters, i.e. heart rate blood pressure, electrodermal activity, electroencephalogram, slow potential brain waves (contingent negativevariation, and eye blink rate or pupil functions, are used as indices for the measurement of the aroma effects

  7. Doppler radar physiological sensing

    CERN Document Server

    Lubecke, Victor M; Droitcour, Amy D; Park, Byung-Kwon; Singh, Aditya

    2016-01-01

    Presents a comprehensive description of the theory and practical implementation of Doppler radar-based physiological monitoring. This book includes an overview of current physiological monitoring techniques and explains the fundamental technology used in remote non-contact monitoring methods. Basic radio wave propagation and radar principles are introduced along with the fundamentals of physiological motion and measurement. Specific design and implementation considerations for physiological monitoring radar systems are then discussed in detail. The authors address current research and commercial development of Doppler radar based physiological monitoring for healthcare and other applications.

  8. Aseptic Plant Culture System (APCS) Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Aseptic plant culture plays a significant role in biotechnology and plant physiology research, and in vegetative propagation of many plant species. The development...

  9. Aseptic Plant Culture System (APCS) Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Aseptic plant culture plays a significant role in biotechnology and plant physiology research and in vegetative propagation of many plant species. The development of...

  10. Production of CarMV-Free Carnation Plants and Its Effects on Some Physiological Indicators%香石竹斑驳病毒(CarMV)脱除对几种生理指标的影响

    Institute of Scientific and Technical Information of China (English)

    王丽花; 吴学尉; 杨秀梅; 瞿素萍; 王继华; 莫锡君

    2012-01-01

    感染病毒的香石竹组培苗于(38.5±1)℃条件下热处理29 d后,切0.1~0.2 mm的茎尖生长点无菌培养成苗后,经DAS-Elisa检测获得脱除香石竹斑驳病毒(Carnation mottle virus,CarMV)的香石竹脱毒苗,取脱毒苗与非脱毒苗的叶片,测量叶绿素a、叶绿素b、类胡萝卜素、丙二醛(MDA)、干物质含量几种生理生化指标.结果表明,脱毒苗与非脱毒苗相比:(1)叶绿素和类胡萝卜素含量增加,具有较强的光合效率;(2)与抗性生理有关的MDA含量下降,衰老减缓;(3)光合物质的形成与积累增多,干物质含量增加.%The common tissue culture seedlings were cultured in heat-treatment conditions (38.5±1) °C for 29 d, then the stem-apexes were cut at 0.1-0.2 mm and cultured in sterile condition. Carnation mottle virus (CarMV)-free carnation plants were obtained which had been detected CarMV by DAS-Elisa. Leaves of CarMV-free seedlings and common seedlings were cut down and measured the contents of chlorophyll a, chlorophyll b, carotenoids, malondialdehyde (MDA) and dry-matter. The results showed that comparative study between CarMV-free seedlings and common seedlings: (1) chlorophyll and carotenoids content of CarMV-free seedlings increased, and the photosynthetic efficiency was high; (2) MDA content which relate to the physiological resistance of CarMV-free seedlings decreased, delaying aging; (3) formation and accumulation of photosynthates increased that could cause more dry-matter content.

  11. To Explore the Experimental Teaching of Plant Physiology Based on "Mini - Project Study"%基于“微课题研究”的植物生理学实验教学探索

    Institute of Scientific and Technical Information of China (English)

    肖望; 涂红艳

    2014-01-01

    让学生参与课题研究、体验科研过程是培养学生创新思维能力最有效、最直接的手段。在实验课程的教学中教师面临的最大挑战是激发学生的学习热情。文章以普通师范院校植物生理学实验课教学为例,将经典的实验设计成微课题形式,通过引导学生参与课题研究,帮助学生理解最基本的原理,提高他们的学习兴趣,培养科学的思维能力。文章设计了适合大班上课的教学程序和能指导学生有目的学习的评价体系,达到在大班教学中引导学生有效开展课题研究的目的。%Students participating in project research and experiencing the process of scientific research is the most effective and direct means to cultivate their creative thinking ability. One of the greatest challenges teachers facing in experimental curriculum is to arouse studentsˊ learning enthusiasm. The paper takes the ex-perimental teaching of plant physiology in general normal universities as example,creates a series of mini -projects from classic experiments,leads students participate in the project research,and then helps students know the basic principle,improves their learning interest and scientific thinking ability. And the teaching pro-gram adapt to large classes and evaluation system for students purposefully learning are designed in the paper, in order to lead students effectively carry out project research in large classes.

  12. Cassava biology and physiology.

    Science.gov (United States)

    El-Sharkawy, Mabrouk A

    2004-11-01

    Cassava or manioc (Manihot esculenta Crantz), a perennial shrub of the New World, currently is the sixth world food crop for more than 500 million people in tropical and sub-tropical Africa, Asia and Latin America. It is cultivated mainly by resource-limited small farmers for its starchy roots, which are used as human food either fresh when low in cyanogens or in many processed forms and products, mostly starch, flour, and for animal feed. Because of its inherent tolerance to stressful environments, where other food crops would fail, it is often considered a food-security source against famine, requiring minimal care. Under optimal environmental conditions, it compares favorably in production of energy with most other major staple food crops due to its high yield potential. Recent research at the Centro Internacional de Agricultura Tropical (CIAT) in Colombia has demonstrated the ability of cassava to assimilate carbon at very high rates under high levels of humidity, temperature and solar radiation,which correlates with productivity across all environments whether dry or humid. When grown on very poor soils under prolonged drought for more than 6 months, the crop reduce both its leaf canopy and transpiration water loss, but its attached leaves remain photosynthetically active, though at greatly reduced rates. The main physiological mechanism underlying such a remarkable tolerance to drought was rapid stomatal closure under both atmospheric and edaphic water stress, protecting the leaf against dehydration while the plant depletes available soil water slowly during long dry periods. This drought tolerance mechanism leads to high crop water use efficiency values. Although the cassava fine root system is sparse, compared to other crops, it can penetrate below 2 m soil,thus enabling the crop to exploit deep water if available. Leaves of cassava and wild Manihot possess elevated activities of the C4 enzyme PEP carboxylase but lack the leaf Kranz anatomy typical of C4

  13. 土壤改良剂对垃圾土生长的五种草坪植物生理特性的影响%Effects of Soil Remediators on the Physiological Characteristics of Lawn Plants in Landfill Soil

    Institute of Scientific and Technical Information of China (English)

    聂磊; 钟秋凤

    2014-01-01

    The effects of the soil remediators composed of bio-char and apatite on the growth and the physiological character-istics of lawn plants grown in landfill soil from a simple dumping-type waste landfill were investigated. The results showed that relative conductivity, the contents of MDA and free proline of Zoysia tenuifolia, Eremochloa ophiuroides and Axonopus affonis were significantly increased under landfill soil treatment. The chlorophyll contents, net photosynthetic rate (Pn), root activity and nitrate reductase acticity were decreased. The biomass accumulation was reduced. Soil remediators alleviated the membrane lipid peroxidation of Zoysia tenuifolia, Eremochloa ophiuroides induced from landfill soil, therefore improved the stress resistance and growth activity of lawn plants. Landfill soil treatment did not caused the stress environment to Arachis duranensis and Wedelia trilobata. Instead, landfill soil environment had the stimulative effects on the growth, similar to the behavior of soil remediators. The results could provide technical basis for land recycling, environment remediation and grass-land construction and planning.%以简易垃圾填埋场的垃圾土为研究对象,通过5种草坪植物盆栽试验,研究了添加生物质焦、磷灰石等改良剂对草坪植物生长及抗逆性的影响。结果表明,垃圾土处理能明显增加细叶结缕草、假俭草和大叶油草叶片的相对电导率和 MDA、脯氨酸的含量,从而加剧植物质膜透性和膜脂过氧化程度,进而明显降低叶绿素含量、净光合速率、根系活力以及硝酸还原酶活性,最终减少植物生物量的积累。由生物质焦和磷灰石组成的土壤改良剂对于缓解垃圾土对细叶结缕草和假俭草叶片质膜伤害、提高植物的抗逆性、改善植物的生长活性有着较明显的作用。垃圾土生长环境并未对蔓花生和三裂叶蟛蜞菊造成逆境胁迫,垃圾土和土壤改良剂处理能

  14. 土壤水分和光照对西葫芦生长和生理特性的影响%Effects of soil moisture content and light intensity on the plant growth and leaf physiological characteristics of squash

    Institute of Scientific and Technical Information of China (English)

    杜社妮; 白岗栓; 梁银丽

    2011-01-01

    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.%以西葫芦"晶莹一号"为试材,采用盆栽和人工遮光的方法研究土壤水分和光照强度对西葫芦生长发育和生理特性的影响.结果表明:遮光30%条件下各处理的植株生长较好,其中遮光30%和土壤相对含水量为70%~80%的处理植株生长最好,产量最高.遮光70%条件下,各处理的植株生长受到严重抑制,只开花,不结果,没有经济产量形成.不同处理西葫芦的耗水趋势一致,日耗水量和总耗水量都随遮光程度

  15. Physiological Disorders of Pear Shoot Cultures

    Science.gov (United States)

    Physiological disorders are some of the most difficult challenges in micropropagation. Little is known of the causes of plant growth disorders which include callus formation, hyperhydricity, shoot tip necrosis, leaf lesions, epinasty, fasciation and hypertrophy. During our study of mineral nutritio...

  16. Advances in physiological computing

    CERN Document Server

    Fairclough, Stephen H

    2014-01-01

    This edited collection will provide an overview of the field of physiological computing, i.e. the use of physiological signals as input for computer control. It will cover a breadth of current research, from brain-computer interfaces to telemedicine.

  17. Phun Week: Understanding Physiology

    Science.gov (United States)

    Limson, Mel; Matyas, Marsha Lakes

    2009-01-01

    Topics such as sports, exercise, health, and nutrition can make the science of physiology relevant and engaging for students. In addition, many lessons on these topics, such as those on the cardiovascular, respiratory, and digestive systems, align with national and state life science education standards. Physiology Understanding Week (PhUn…

  18. Physiology of sport.

    Science.gov (United States)

    Maughan, Ron

    2007-07-01

    The elite athlete represents the extreme of the human gene pool, where genetic endowment is developed by an intensive training programme. Sport encompasses many different activities, calling for different physical and mental attributes. Understanding the physiology of exercise provides insights into normal physiological function.

  19. Physiological changes in pregnancy

    OpenAIRE

    SOMA-PILLAY, Priya; Catherine, Nelson-Piercy; Tolppanen, Heli; Mebazaa, Alexandre

    2016-01-01

    Abstract Physiological changes occur in pregnancy to nurture the developing foetus and prepare the mother for labour and delivery. Some of these changes influence normal biochemical values while others may mimic symptoms of medical disease. It is important to differentiate between normal physiological changes and disease pathology. This review highlights the important changes that take place during normal pregnancy.

  20. 盐胁迫下根际细菌对杨树生长和生理的影响%The effect of plant growth promoting bacteria on growth and physiology of poplars under salt stress

    Institute of Scientific and Technical Information of China (English)

    岳东霞; 张要武

    2011-01-01

    为了明确根际细菌对杨树耐盐能力的影响,采用盆栽方法研究了不同浓度NaCl胁迫下,根际细菌Bacillus sp.和Arthrobacter sp.对杨树生长和生理的影响.结果表明,Bacillus sp.对杨树株高没有明显的影响;在无NaCl或NaCl浓度为85.5 mol/L时,显著降低杨树叶片细胞膜透性;在NaCl浓度为119.7 mmol/L时,显著提高杨树叶片叶绿素含量;在85.5和119.7 mmol/L NaCl胁迫下,均显著提高杨树叶片含糖量,Arthrobacter sp.在119.7 mmol/L NaCl胁迫下,显著增加杨树株高;在无NaCl或NaCl浓度为85.5 mmol/L时显著降低杨树叶片细胞膜透性,不同浓度NaCl处理,对杨树叶片叶绿素含量均没有明显的作用;在85.5和119.7 mmol/L NaCl胁迫下,均显著提高杨树叶片含糖量.不同水平NaCl胁迫下,Bacillus sp.和Arthrobacter sp.对杨树叶片含水量均没有显著影响.%To identify the effect of rhizobacteria on salt tolerance of poplars, the impact of plant growth promoting bacteria(PGPR)-Bacillus sp. and Arthrobacter sp. on growth and physiology of poplars seedlings have been investigated in pot experiment. The inoculation of Arthrobacter sp. significantly increased the height of poplar seedlings grown in the presence of 119.7 mmol/L NaCI salt; Bacillus sp. had no obvious impact on height of poplar seedlings stressed by different NaC1 concentrations. The two bacteria decreased the membrane permeability in the presence of both 0 and 85.5 mmol/L NaC1. At salt stress conditions (85.5 and 119. 7 mmol/L), Bacillus sp. and Arthrobacter sp. significantly enhanced the content of soluble sugar. Bacillus sp. significantly increased the content of chlorophyll at 119.7 mmol/L NaC1 salt; Arthrobacter sp. had no effect on the content of chlorophyll under different NaCl concentrations. Both of the two bacteria had no significant effect on relative water content of poplar seedling leaves.

  1. Plants without arbuscular mycorrhizae

    Science.gov (United States)

    P is second to N as the most limiting element for plant growth. Plants have evolved a number of effective strategies to acquire P and grow in a P-limited environment. Physiological, biochemical, and molecular studies of P-deficiency adaptations that occur in non-mycorrhizal species have provided str...

  2. 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 deficiency

  3. Fetal cardiovascular physiology.

    Science.gov (United States)

    Rychik, J

    2004-01-01

    The cardiovascular system of the fetus is physiologically different than the adult, mature system. Unique characteristics of the myocardium and specific channels of blood flow differentitate the physiology of the fetus from the newborn. Conditions of increased preload and afterload in the fetus, such as sacrococcygeal teratoma and twin-twin transfusion syndrome, result in unique and complex pathophysiological states. Echocardiography has improved our understanding of human fetal cadiovasvular physiology in the normal and diseased states, and has expanded our capability to more effectively treat these disease processes.

  4. Physiological Disorders in Closed, Controlled Environment Crops

    Science.gov (United States)

    Wheeler, Raymond M.; Morrow, Robert C.

    2010-01-01

    This slide presentation reviews some of the physiological disorders that affect crops grown in closed controlled environments. A physiological disorder is understood to be a problem resulting from the influence of environmental and horticultural factors on plan development other than a problem caused by a pathogen or some other abiotic cause. The topics that are addressed are: (1) Calcium-Related Disorders (2) Oedema (Intumescence) (3) Long-Photoperiod Injury (4) Light Spectral Quality Effects (5) Super-Elevated CO2 Injuries (6) Ethylene (7) Other Disorders (8) Considerations for Closed Space Environments. Views of plant with the disorders are shown.

  5. The conservation physiology of seed dispersal.

    Science.gov (United States)

    Ruxton, Graeme D; Schaefer, H Martin

    2012-06-19

    At a time when plant species are experiencing increasing challenges from climate change, land-use change, harvesting and invasive species, dispersal has become a very important aspect of plant conservation. Seed dispersal by animals is particularly important because some animals disperse seeds to suitable sites in a directed fashion. Our review has two aims: (i) to highlight the various ways plant dispersal by animals can be affected by current anthropogenic change and (ii) to show the important role of plant and (particularly) animal physiology in shaping seed-dispersal interactions. We argue that large-bodied seed dispersers may be particularly important for plant conservation because seed dispersal of large-seeded plants is often more specialized and because large-bodied animals are targeted by human exploitation and have smaller population sizes. We further argue that more specialized seed-dispersal systems on island ecosystems might be particularly at risk from climate change both owing to small population sizes involved but also owing to the likely thermal specialization, particularly on tropical islands. More generally, the inherent vulnerability of seed-dispersal mutualisms to disruption driven by environmental change (as well as their ubiquity) demands that we continue to improve our understanding of their conservation physiology.

  6. The conservation physiology of seed dispersal

    Science.gov (United States)

    Ruxton, Graeme D.; Schaefer, H. Martin

    2012-01-01

    At a time when plant species are experiencing increasing challenges from climate change, land-use change, harvesting and invasive species, dispersal has become a very important aspect of plant conservation. Seed dispersal by animals is particularly important because some animals disperse seeds to suitable sites in a directed fashion. Our review has two aims: (i) to highlight the various ways plant dispersal by animals can be affected by current anthropogenic change and (ii) to show the important role of plant and (particularly) animal physiology in shaping seed–dispersal interactions. We argue that large-bodied seed dispersers may be particularly important for plant conservation because seed dispersal of large-seeded plants is often more specialized and because large-bodied animals are targeted by human exploitation and have smaller population sizes. We further argue that more specialized seed-dispersal systems on island ecosystems might be particularly at risk from climate change both owing to small population sizes involved but also owing to the likely thermal specialization, particularly on tropical islands. More generally, the inherent vulnerability of seed-dispersal mutualisms to disruption driven by environmental change (as well as their ubiquity) demands that we continue to improve our understanding of their conservation physiology. PMID:22566677

  7. Physiological mechanisms of prosociality.

    Science.gov (United States)

    Miller, Jonas G

    2017-08-12

    Psychophysiological perspectives can provide unique insights into the nature and motivations of children's prosociality and inform our understanding of individual differences. Here, I review current research on prosociality involving some of the most common physiological measures in developmental psychology, including cortisol, various sympathetic nervous system measures, and high-frequency heart rate variability. The literature has been quite mixed, in part because the link between physiology and prosociality is context-dependent and person-dependent. However, recent advances are refining our understanding of the basic physiological mechanisms of prosociality. Resting physiology that contributes to a balance of regulation and vigilance prepares children to effectively cope with future social challenges, like noticing and attending to the needs of others. Experiencing some arousal is an important aspect of empathy-related responding, but physiological patterns of both heightened and hypoarousal can undermine prosociality. Physiological flexibility in response to others' needs may support emotional and behavioral flexibility important for prosociality. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Neuropeptide physiology in helminths.

    Science.gov (United States)

    Mousley, Angela; Novozhilova, Ekaterina; Kimber, Michael J; Day, Tim A

    2010-01-01

    Parasitic worms come from two distinct, distant phyla, Nematoda (roundworms) and Platyhelminthes (flatworms). The nervous systems of worms from both phyla are replete with neuropeptides and there is ample physiological evidence that these neuropeptides control vital aspects of worm biology. In each phyla, the physiological evidence for critical roles for helminth neuropeptides is derived from both parasitic and free-living members. In the nematodes, the intestinal parasite Ascaris suum and the free-living Caenorhabditis elegans have yielded most of the data; in the platyhelminths, the most physiological data has come from the blood fluke Schistosoma mansoni. FMRFamide-like peptides (FLPs) have many varied effects (excitation, relaxation, or a combination) on somatic musculature, reproductive musculature, the pharynx and motor neurons in nematodes. Insulin-like peptides (INSs) play an essential role in nematode dauer formation and other developmental processes. There is also some evidence for a role in somatic muscle control for the somewhat heterogeneous grouping ofpeptides known as neuropeptide-like proteins (NLPs). In platyhelminths, as in nematodes, FLPs have a central role in somatic muscle function. Reports of FLP physiological action in platyhelminths are limited to a potent excitation of the somatic musculature. Platyhelminths are also abundantly endowed with neuropeptide Fs (NPFs), which appear absent from nematodes. There is not yet any data linking platyhelminth NPF to any particular physiological outcome, but this neuropeptide does potently and specifically inhibit cAMP accumulation in schistosomes. In nematodes and platyhelminths, there is an abundance of physiological evidence demonstrating that neuropeptides play critical roles in the biology of both free-living and parasitic helminths. While it is certainly true that there remains a great deal to learn about the biology of neuropeptides in both phyla, physiological evidence presently available points

  9. Dynamic Plant-Plant-Herbivore Interactions Govern Plant Growth-Defence Integration

    NARCIS (Netherlands)

    Vries, de Jorad; Evers, Jochem B.; Poelman, Erik H.

    2017-01-01

    Plants downregulate their defences against insect herbivores upon impending competition for light. This has long been considered a resource trade-off, but recent advances in plant physiology and ecology suggest this mechanism is more complex. Here we propose that to understand why plants regulate an

  10. Physiological assessment of long pepper seeds

    Directory of Open Access Journals (Sweden)

    Francisco Pacheco Júnior

    2015-12-01

    Full Text Available The environmental and economic potential of long pepper (Piper hispidinervum requires the development of methodology to evaluate seed potential physiological. The work aimed to evaluate the physiological potential of long pepper seeds (Piper hispidinervum C. DC. through different tests and accelerated aging. Seeds were harvested in four different commercial planting and evaluated to water content (%, germination (G%, germination speed index (GSI, seedling emergence (SE%, emergence rate index (ERI and accelerated aging (AA 41 and 45 °C during 24, 48, 72 and 96 hours. The experimental design was completely randomized with a simple scheme for G, GSI, SE and ERI, and 4 x 4 factorial (lots and times at each temperature for AA. Physiological potential of long pepper seeds can be evaluated by germination test, germination speed index, seedling emergence, seedlings emergence speed index and accelerated aging at 41 °C during 24 hours.

  11. Human physiology in space

    Science.gov (United States)

    Vernikos, J.

    1996-01-01

    The universality of gravity (1 g) in our daily lives makes it difficult to appreciate its importance in morphology and physiology. Bone and muscle support systems were created, cellular pumps developed, neurons organised and receptors and transducers of gravitational force to biologically relevant signals evolved under 1g gravity. Spaceflight provides the only microgravity environment where systematic experimentation can expand our basic understanding of gravitational physiology and perhaps provide new insights into normal physiology and disease processes. These include the surprising extent of our body's dependence on perceptual information, and understanding the effect and importance of forces generated within the body's weightbearing structures such as muscle and bones. Beyond this exciting prospect is the importance of this work towards opening the solar system for human exploration. Although both appear promising, we are only just beginning to taste what lies ahead.

  12. Circadian physiology of metabolism.

    Science.gov (United States)

    Panda, Satchidananda

    2016-11-25

    A majority of mammalian genes exhibit daily fluctuations in expression levels, making circadian expression rhythms the largest known regulatory network in normal physiology. Cell-autonomous circadian clocks interact with daily light-dark and feeding-fasting cycles to generate approximately 24-hour oscillations in the function of thousands of genes. Circadian expression of secreted molecules and signaling components transmits timing information between cells and tissues. Such intra- and intercellular daily rhythms optimize physiology both by managing energy use and by temporally segregating incompatible processes. Experimental animal models and epidemiological data indicate that chronic circadian rhythm disruption increases the risk of metabolic diseases. Conversely, time-restricted feeding, which imposes daily cycles of feeding and fasting without caloric reduction, sustains robust diurnal rhythms and can alleviate metabolic diseases. These findings highlight an integrative role of circadian rhythms in physiology and offer a new perspective for treating chronic diseases in which metabolic disruption is a hallmark.

  13. TRY - a global database of plant traits

    NARCIS (Netherlands)

    Kattge, J.; Diaz, S.; Lavorel, S.; Prentice, C.; Leadley, P.; Boenisch, G.; Garnier, E.; Westoby, M.; Reich, P. B.; Wright, I. J.; Cornelissen, J. H. C.; Violle, C.; Harrison, S. P.; van Bodegom, P. M.; Reichstein, M.; Enquist, B. J.; Soudzilovskaia, N. A.; Ackerly, D. D.; Anand, M.; Atkin, O.; Bahn, M.; Baker, T. R.; Baldocchi, D.; Bekker, R.; Blanco, C. C.; Blonder, B.; Bond, W. J.; Bradstock, R.; Bunker, D. E.; Casanoves, F.; Cavender-Bares, J.; Chambers, J. Q.; Chapin, F. S.; Chave, J.; Coomes, D.; Cornwell, W. K.; Craine, J. M.; Dobrin, B. H.; Duarte, L.; Durka, W.; Elser, J.; Esser, G.; Estiarte, M.; Fagan, W. F.; Fang, J.; Fernandez-Mendez, F.; Fidelis, A.; Finegan, B.; Flores, O.; Ford, H.; Frank, D.; Freschet, G. T.; Fyllas, N. M.; Gallagher, R. V.; Green, W. A.; Gutierrez, A. G.; Hickler, T.; Higgins, S. I.; Hodgson, J. G.; Jalili, A.; Jansen, S.; Joly, C. A.; Kerkhoff, A. J.; Kirkup, D.; Kitajima, K.; Kleyer, M.; Klotz, S.; Knops, J. M. H.; Kramer, K.; Kuehn, I.; Kurokawa, H.; Laughlin, D.; Lee, T. D.; Leishman, M.; Lens, F.; Lenz, T.; Lewis, S. L.; Lloyd, J.; Llusia, J.; Louault, F.; Ma, S.; Mahecha, M. D.; Manning, P.; Massad, T.; Medlyn, B. E.; Messier, J.; Moles, A. T.; Mueller, S. C.; Nadrowski, K.; Naeem, S.; Niinemets, Ue.; Noellert, S.; Nueske, A.; Ogaya, R.; Oleksyn, J.; Onipchenko, V. G.; Onoda, Y.; Ordonez, J.; Overbeck, G.; Ozinga, W. A.; Patino, S.; Paula, S.; Pausas, J. G.; Penuelas, J.; Phillips, O. L.; Pillar, V.; Poorter, H.; Poorter, L.; Poschlod, P.; Prinzing, A.; Proulx, R.; Rammig, A.; Reinsch, S.; Reu, B.; Sack, L.; Salgado-Negre, B.; Sardans, J.; Shiodera, S.; Shipley, B.; Siefert, A.; Sosinski, E.; Soussana, J. -F.; Swaine, E.; Swenson, N.; Thompson, K.; Thornton, P.; Waldram, M.; Weiher, E.; White, M.; White, S.; Wright, S. J.; Yguel, B.; Zaehle, S.; Zanne, A. E.; Wirth, C.

    2011-01-01

    Plant traits - the morphological, anatomical, physiological, biochemical and phenological characteristics of plants and their organs - determine how primary producers respond to environmental factors, affect other trophic levels, influence ecosystem processes and services and provide a link from spe

  14. TRY - a global database of plant traits

    NARCIS (Netherlands)

    Kattge, J.; Diaz, S.; Lavorel, S.; Prentices, I.C.; Leadley, P.; Bönisch, G.; Garnier, E.; Westobys, M.; Reich, P.B.; Wrights, I.J.; Cornelissen, C.; Violle, C.; Harisson, S.P.; Bodegom, van P.M.; Reichstein, M.; Enquist, B.J.; Soudzilovskaia, N.A.; Ackerly, D.D.; Anand, M.; Atkin, O.; Bahn, M.; Baker, T.R.; Baldochi, D.; Bekker, R.; Blanco, C.C.; Blonders, B.; Bond, W.J.; Bradstock, R.; Bunker, D.E.; Casanoves, F.; Cavender-Bares, J.; Chambers, J.Q.; Chapin III, F.S.; Chave, J.; Coomes, D.; Cornwell, W.K.; Craine, J.M.; Dobrin, B.H.; Duarte, L.; Durka, W.; Elser, J.; Esser, G.; Estiarte, M.; Fagan, W.F.; Fang, J.; Fernadez-Mendez, F.; Fidelis, A.; Finegan, B.; Flores, O.; Ford, H.; Frank, D.; Freschet, T.; Fyllas, N.M.; Gallagher, R.V.; Green, W.A.; Gutierrez, A.G.; Hickler, T.; Higgins, S.I.; Hodgson, J.G.; Jalili, A.; Jansen, S.; Joly, C.A.; Kerkhoff, A.J.; Kirkup, D.; Kitajima, K.; Kleyer, M.; Klotz, S.; Knops, J.M.H.; Kramer, K.; Kühn, I.; Kurokawa, H.; Laughlin, D.; Lee, T.D.; Leishman, M.; Lens, F.; Lewis, S.L.; Lloyd, J.; Llusia, J.; Louault, F.; Ma, S.; Mahecha, M.D.; Manning, P.; Massad, T.; Medlyn, B.E.; Messier, J.; Moles, A.T.; Müller, S.C.; Nadrowski, K.; Naeem, S.; Niinemets, Ü.; Nöllert, S.; Nüske, A.; Ogaya, R.; Oleksyn, J.; Onipchenko, V.G.; Onoda, Y.; Ordonez Barragan, J.C.; Ozinga, W.A.; Poorter, L.

    2011-01-01

    Plant traits – the morphological, anatomical, physiological, biochemical and phenological characteristics of plants and their organs – determine how primary producers respond to environmental factors, affect other trophic levels, influence ecosystem processes and services and provide a link from spe

  15. TRY - a global database of plant traits

    NARCIS (Netherlands)

    Kattge, J.; Diaz, S.; Lavorel, S.; Prentice, C.; Leadley, P.; Boenisch, G.; Garnier, E.; Westoby, M.; Reich, P. B.; Wright, I. J.; Cornelissen, J. H. C.; Violle, C.; Harrison, S. P.; van Bodegom, P. M.; Reichstein, M.; Enquist, B. J.; Soudzilovskaia, N. A.; Ackerly, D. D.; Anand, M.; Atkin, O.; Bahn, M.; Baker, T. R.; Baldocchi, D.; Bekker, R.; Blanco, C. C.; Blonder, B.; Bond, W. J.; Bradstock, R.; Bunker, D. E.; Casanoves, F.; Cavender-Bares, J.; Chambers, J. Q.; Chapin, F. S.; Chave, J.; Coomes, D.; Cornwell, W. K.; Craine, J. M.; Dobrin, B. H.; Duarte, L.; Durka, W.; Elser, J.; Esser, G.; Estiarte, M.; Fagan, W. F.; Fang, J.; Fernandez-Mendez, F.; Fidelis, A.; Finegan, B.; Flores, O.; Ford, H.; Frank, D.; Freschet, G. T.; Fyllas, N. M.; Gallagher, R. V.; Green, W. A.; Gutierrez, A. G.; Hickler, T.; Higgins, S. I.; Hodgson, J. G.; Jalili, A.; Jansen, S.; Joly, C. A.; Kerkhoff, A. J.; Kirkup, D.; Kitajima, K.; Kleyer, M.; Klotz, S.; Knops, J. M. H.; Kramer, K.; Kuehn, I.; Kurokawa, H.; Laughlin, D.; Lee, T. D.; Leishman, M.; Lens, F.; Lenz, T.; Lewis, S. L.; Lloyd, J.; Llusia, J.; Louault, F.; Ma, S.; Mahecha, M. D.; Manning, P.; Massad, T.; Medlyn, B. E.; Messier, J.; Moles, A. T.; Mueller, S. C.; Nadrowski, K.; Naeem, S.; Niinemets, Ue.; Noellert, S.; Nueske, A.; Ogaya, R.; Oleksyn, J.; Onipchenko, V. G.; Onoda, Y.; Ordonez, J.; Overbeck, G.; Ozinga, W. A.; Patino, S.; Paula, S.; Pausas, J. G.; Penuelas, J.; Phillips, O. L.; Pillar, V.; Poorter, H.; Poorter, L.; Poschlod, P.; Prinzing, A.; Proulx, R.; Rammig, A.; Reinsch, S.; Reu, B.; Sack, L.; Salgado-Negre, B.; Sardans, J.; Shiodera, S.; Shipley, B.; Siefert, A.; Sosinski, E.; Soussana, J. -F.; Swaine, E.; Swenson, N.; Thompson, K.; Thornton, P.; Waldram, M.; Weiher, E.; White, M.; White, S.; Wright, S. J.; Yguel, B.; Zaehle, S.; Zanne, A. E.; Wirth, C.

    2011-01-01

    Plant traits - the morphological, anatomical, physiological, biochemical and phenological characteristics of plants and their organs - determine how primary producers respond to environmental factors, affect other trophic levels, influence ecosystem processes and services and provide a link from spe

  16. The Face of Physiology

    Directory of Open Access Journals (Sweden)

    Paul White

    2008-10-01

    Full Text Available This article explores the relationship between the physiology of the emotions and the display of character in Victorian Britain. Charles Bell and others had begun to link certain physiological functions, such as respiration, with the expression of feelings such as fear, regarding the heart and other internal organs as instruments by which the emotions were made visible. But a purely functional account of the emotions, which emerged through the development of reflex physiology during the second half of the century, would dramatically alter the nature of feelings and the means of observing them. At the same time, instinctual or acquired sympathy, which had long underpinned the accurate reading of expressions, became a problem to be surmounted by new 'objectively'. Graphic recording instruments measuring a variety of physiological functions and used with increasing frequency in clinical diagnostics became of fundamental importance for tracing the movement of feelings during the period prior to the development of cinematography. They remained, in the form of devices such as the polygraph, a crucial and controversial means of measuring affective states, beneath the potentially deceptive surface of the body.

  17. Starting Physiology: Bioelectrogenesis

    Science.gov (United States)

    Baptista, Vander

    2015-01-01

    From a Cartesian perspective of rational analysis, the electric potential difference across the cell membrane is one of the fundamental concepts for the study of physiology. Unfortunately, undergraduate students often struggle to understand the genesis of this energy gradient, which makes the teaching activity a hard task for the instructor. The…

  18. Physiology of Sleep.

    Science.gov (United States)

    Carley, David W; Farabi, Sarah S

    2016-02-01

    IN BRIEF Far from a simple absence of wakefulness, sleep is an active, regulated, and metabolically distinct state, essential for health and well-being. In this article, the authors review the fundamental anatomy and physiology of sleep and its regulation, with an eye toward interactions between sleep and metabolism.

  19. Integrative Physiology of Fasting.

    Science.gov (United States)

    Secor, Stephen M; Carey, Hannah V

    2016-03-15

    Extended bouts of fasting are ingrained in the ecology of many organisms, characterizing aspects of reproduction, development, hibernation, estivation, migration, and infrequent feeding habits. The challenge of long fasting episodes is the need to maintain physiological homeostasis while relying solely on endogenous resources. To meet that challenge, animals utilize an integrated repertoire of behavioral, physiological, and biochemical responses that reduce metabolic rates, maintain tissue structure and function, and thus enhance survival. We have synthesized in this review the integrative physiological, morphological, and biochemical responses, and their stages, that characterize natural fasting bouts. Underlying the capacity to survive extended fasts are behaviors and mechanisms that reduce metabolic expenditure and shift the dependency to lipid utilization. Hormonal regulation and immune capacity are altered by fasting; hormones that trigger digestion, elevate metabolism, and support immune performance become depressed, whereas hormones that enhance the utilization of endogenous substrates are elevated. The negative energy budget that accompanies fasting leads to the loss of body mass as fat stores are depleted and tissues undergo atrophy (i.e., loss of mass). Absolute rates of body mass loss scale allometrically among vertebrates. Tissues and organs vary in the degree of atrophy and downregulation of function, depending on the degree to which they are used during the fast. Fasting affects the population dynamics and activities of the gut microbiota, an interplay that impacts the host's fasting biology. Fasting-induced gene expression programs underlie the broad spectrum of integrated physiological mechanisms responsible for an animal's ability to survive long episodes of natural fasting.

  20. Measurements of VOC fluxes by dynamic plant and soil chambers in wheat and maize crop near Paris with a PTR-Qi-TOF-MS: Quantification and response to environmental and physiological drivers.

    Science.gov (United States)

    Gonzaga-Gomez, Lais; Boissard, Christophe; Ciuraru, Raluca; Lafouge, Florence; Zurfluh, Olivier; Buysse, Pauline; Decuq, Céline; Fanucci, Olivier; Gueudet, Jean-Christophe; Gros, Valérie; Sarda, Roland; Zannoni, Nora; Loubet, Benjamin

    2017-04-01

    Volatile organic compounds (VOC) play an important role in the chemistry of the atmosphere as precursors of secondary pollutants such as ozone and organic aerosols. A large variety of VOC are exchanged between plants (BVOC) and the atmosphere. Their fluxes are strongly dependent on environmental factors (temperature, light, biotic and abiotic stress) and vary greatly among plant species. Only few studies focused on BVOC emissions by agricultural plants and were mostly carried in North America. However, agricultural lands occupy 51% of the total country area in France, with wheat being one of the most important crop. We used a PTR-Qi-TOF-MS (national instrument within the ANAEE-France framework) and dynamic chambers to measure BVOC emissions from plant and soil compartments of a wheat and a maize crop near Paris (FR-GRI ICOS site). More than 700 masses were detected thanks to the resolution and sensitivity of this new instrument. We analyze the emission response to light, temperature and stomatal aperture in order to explain the mechanisms of BVOC exchanges by wheat plants. We investigate the emission differences between soil and plant compartment, and between wheat and maize crops. Acetone (m/z 59.049) was the predominant volatile compound in the emissions from wheat. Both methanol (m/z 33.033) and acetaldehyde (m/z 45.033) were al