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Sample records for barley root growth

  1. Responses of growth and primary metabolism of water-stressed barley roots to rehydration

    Science.gov (United States)

    Barley seedlings [Hordeum vulgare L. Brant] were grown in pots in controlled environment chambers and drought treatments were imposed 11 days after sowing. Soil water content decreased from 92% to 10% after an additional 14 days of water stress. Shoot and root growth ceased after 4 and 9 days of wat...

  2. Interactive effects of soil acidity and fluoride on soil solution aluminium chemistry and barley (Hordeum vulgare L.) root growth.

    Science.gov (United States)

    Manoharan, V; Loganathan, P; Tillman, R W; Parfitt, R L

    2007-02-01

    A greenhouse study was conducted to determine if concentrations of fluoride (F), which would be added to acid soils via P fertilisers, were detrimental to barley root growth. Increasing rates of F additions to soil significantly increased the soil solution concentrations of aluminium (Al) and F irrespective of the initial adjusted soil pH, which ranged from 4.25 to 5.48. High rates of F addition severely restricted root growth; the effect was more pronounced in the strongly acidic soil. Speciation calculations demonstrated that increasing rates of F additions substantially increased the concentrations of Al-F complexes in the soil. Stepwise regression analysis showed that it was the combination of the activities of AlF2(1+) and AlF(2+) complexes that primarily controlled barley root growth. The results suggested that continuous input of F to soils, and increased soil acidification, may become an F risk issue in the future.

  3. Interactive effects of soil acidity and fluoride on soil solution aluminium chemistry and barley (Hordeum vulgare L.) root growth

    International Nuclear Information System (INIS)

    Manoharan, V.; Loganathan, P.; Tillman, R.W.; Parfitt, R.L.

    2007-01-01

    A greenhouse study was conducted to determine if concentrations of fluoride (F), which would be added to acid soils via P fertilisers, were detrimental to barley root growth. Increasing rates of F additions to soil significantly increased the soil solution concentrations of aluminium (Al) and F irrespective of the initial adjusted soil pH, which ranged from 4.25 to 5.48. High rates of F addition severely restricted root growth; the effect was more pronounced in the strongly acidic soil. Speciation calculations demonstrated that increasing rates of F additions substantially increased the concentrations of Al-F complexes in the soil. Stepwise regression analysis showed that it was the combination of the activities of AlF 2 1+ and AlF 2+ complexes that primarily controlled barley root growth. The results suggested that continuous input of F to soils, and increased soil acidification, may become an F risk issue in the future. - Addition of high rates of fluoride to strongly acidic soils can reduce barley root growth due to the toxicity of aluminium-fluoride complexes formed in soil solution

  4. Root hair mutants of barley

    International Nuclear Information System (INIS)

    Engvild, K.C.; Rasmussen, K.

    2005-01-01

    Barley mutants without root hairs or with short or reduced root hairs were isolated among M 2 seeds of 'Lux' barley (Hordeum vulgare L.) after acidified sodium azide mutagenesis. Root hair mutants are investigated intensively in Arabidopsis where about 40 genes are known. A few root hair mutants are known in maize, rice, barley and tomato. Many plants without root hairs grow quite well with good plant nutrition, and mutants have been used for investigations of uptake of strongly bound nutrients like phosphorus, iron, zinc and silicon. Seed of 'Lux' barley (Sejet Plant Breeding, Denmark) were soaked overnight, and then treated with 1.5-millimolarsodium azide in 0.1 molar sodium phosphate buffer, pH 3, for 2.5 hours according to the IAEA Manual on Mutation Breeding (2nd Ed.). After rinsing in tap water and air-drying, the M 2 seeds were sown in the field the same day. Spikes, 4-6 per M 1 plant, were harvested. The mutation frequency was similar to that obtained with other barley cultivars from which low-phytate mutants were isolated [5]. Seeds were germinated on black filter paper in tap water for 3 or 4 days before scoring for root hair mutants

  5. The influence of flooding on soil proportion and plant growth. 1. The influence on root development and growth of barley

    International Nuclear Information System (INIS)

    Sisworo, E.L.

    1975-01-01

    An experiment has been carried out to study the extent of root and shoot of barley exposed to flooding at various time of flooding. Several parameters were used in the experiment, namely the percentage of 86 Rb in the root system, dry weight of root as well as shoot, increase of leaf size, number of leaves and tillers and nitrogen content in leaf tissue. Radioactive 86 Rb-Cl was used in the experiment and injected into the plant 24 hours before harvest. The plants were harvested 2, 6, and 20 days after flooding. From the result obtained, it turned out that flooding conditions apparently reduced root development in the lower part of soil layer, while in the top layer a proper development of root was concentrated. Injury symptoms were mainly observed in the shoot; where leaf yellowing occured and started with the first leaf five days after flooding and subsequently reduced the number of leaves and tillers. (author)

  6. Barley root hair growth and morphology in soil, sand, and water solution media and relationship with nickel toxicity.

    Science.gov (United States)

    Lin, Yanqing; Allen, Herbert E; Di Toro, Dominic M

    2016-08-01

    Barley, Hordeum vulgare (Doyce), was grown in the 3 media of soil, hydroponic sand solution (sand), and hydroponic water solution (water) culture at the same environmental conditions for 4 d. Barley roots were scanned, and root morphology was analyzed. Plants grown in the 3 media had different root morphology and nickel (Ni) toxicity response. Root elongations and total root lengths followed the sequence soil > sand > water. Plants grown in water culture were more sensitive to Ni toxicity and had greater root hair length than those from soil and sand cultures, which increased root surface area. The unit root surface area as root surface area per centimeter of length of root followed the sequence water > sand > soil and was found to be related with root elongation. Including the unit root surface area, the difference in root elongation and 50% effective concentration were diminished, and percentage of root elongations can be improved with a root mean square error approximately 10% for plants grown in different media. Because the unit root surface area of plants in sand culture is closer to that in soil culture, the sand culture method, not water culture, is recommended for toxicity parameter estimation. Environ Toxicol Chem 2016;35:2125-2133. © 2016 SETAC. © 2016 SETAC.

  7. Unique and Conserved Features of the Barley Root Meristem

    Directory of Open Access Journals (Sweden)

    Gwendolyn K. Kirschner

    2017-07-01

    Full Text Available Plant root growth is enabled by root meristems that harbor the stem cell niches as a source of progenitors for the different root tissues. Understanding the root development of diverse plant species is important to be able to control root growth in order to gain better performances of crop plants. In this study, we analyzed the root meristem of the fourth most abundant crop plant, barley (Hordeum vulgare. Cell division studies revealed that the barley stem cell niche comprises a Quiescent Center (QC of around 30 cells with low mitotic activity. The surrounding stem cells contribute to root growth through the production of new cells that are displaced from the meristem, elongate and differentiate into specialized root tissues. The distal stem cells produce the root cap and lateral root cap cells, while cells lateral to the QC generate the epidermis, as it is typical for monocots. Endodermis and inner cortex are derived from one common initial lateral to the QC, while the outer cortex cell layers are derived from a distinct stem cell. In rice and Arabidopsis, meristem homeostasis is achieved through feedback signaling from differentiated cells involving peptides of the CLE family. Application of synthetic CLE40 orthologous peptide from barley promotes meristem cell differentiation, similar to rice and Arabidopsis. However, in contrast to Arabidopsis, the columella stem cells do not respond to the CLE40 peptide, indicating that distinct mechanisms control columella cell fate in monocot and dicot plants.

  8. Use of Co speciation and soil properties to explain variation in Co toxicity to root growth of barley (Hordeum vulgare L.) in different soils

    International Nuclear Information System (INIS)

    Mico, C.; Li, H.F.; Zhao, F.J.; McGrath, S.P.

    2008-01-01

    The influence of soil properties on the bioavailability and toxicity of Co to barley (Hordeum vulgare L.) root elongation was investigated. Ten soils varying widely in soil properties were amended with seven doses of CoCl 2 . Soil properties greatly influenced the expression of Co toxicity. The effective concentration of added Co causing 50% inhibition (EC 50 ) ranged from 45 to 863 mg kg -1 , representing almost 20-fold variation among soils. Furthermore, we investigated Co toxicity in relation to Co concentrations and free Co 2+ activity in soil solution. The EC 50 values showed variation among soils of 17- and 29-fold, based on the Co concentration in soil solution and free Co 2+ activity, respectively. Single regressions were carried out between Co toxicity threshold values and selected soil properties. Models obtained showed that soil effective cation exchange capacity (eCEC) and exchangeable calcium were the most consistent single predictors of the EC 50 values based on soil added Co. - Soil eCEC and exchangeable Ca were found to be the best predictors of the toxicity threshold values of Co to barley root growth on different soils

  9. Development and validation of a terrestrial biotic ligand model predicting the effect of cobalt on root growth of barley (Hordeum vulgare)

    International Nuclear Information System (INIS)

    Lock, K.; De Schamphelaere, K.A.C.; Becaus, S.; Criel, P.; Van Eeckhout, H.; Janssen, C.R.

    2007-01-01

    A Biotic Ligand Model was developed predicting the effect of cobalt on root growth of barley (Hordeum vulgare) in nutrient solutions. The extent to which Ca 2+ , Mg 2+ , Na + , K + ions and pH independently affect cobalt toxicity to barley was studied. With increasing activities of Mg 2+ , and to a lesser extent also K + , the 4-d EC50 Co2+ increased linearly, while Ca 2+ , Na + and H + activities did not affect Co 2+ toxicity. Stability constants for the binding of Co 2+ , Mg 2+ and K + to the biotic ligand were obtained: log K CoBL = 5.14, log K MgBL = 3.86 and log K KBL = 2.50. Limited validation of the model with one standard artificial soil and one standard field soil showed that the 4-d EC50 Co2+ could only be predicted within a factor of four from the observed values, indicating further refinement of the BLM is needed. - Biotic Ligand Models are not only a useful tool to assess metal toxicity in aquatic systems but can also be used for terrestrial plants

  10. Genomic Regions Influencing Seminal Root Traits in Barley.

    Science.gov (United States)

    Robinson, Hannah; Hickey, Lee; Richard, Cecile; Mace, Emma; Kelly, Alison; Borrell, Andrew; Franckowiak, Jerome; Fox, Glen

    2016-03-01

    Water availability is a major limiting factor for crop production, making drought adaptation and its many component traits a desirable attribute of plant cultivars. Previous studies in cereal crops indicate that root traits expressed at early plant developmental stages, such as seminal root angle and root number, are associated with water extraction at different depths. Here, we conducted the first study to map seminal root traits in barley ( L.). Using a recently developed high-throughput phenotyping method, a panel of 30 barley genotypes and a doubled-haploid (DH) population (ND24260 × 'Flagship') comprising 330 lines genotyped with diversity array technology (DArT) markers were evaluated for seminal root angle (deviation from vertical) and root number under controlled environmental conditions. A high degree of phenotypic variation was observed in the panel of 30 genotypes: 13.5 to 82.2 and 3.6 to 6.9° for root angle and root number, respectively. A similar range was observed in the DH population: 16.4 to 70.5 and 3.6 to 6.5° for root angle and number, respectively. Seven quantitative trait loci (QTL) for seminal root traits (root angle, two QTL; root number, five QTL) were detected in the DH population. A major QTL influencing both root angle and root number (/) was positioned on chromosome 5HL. Across-species analysis identified 10 common genes underlying root trait QTL in barley, wheat ( L.), and sorghum [ (L.) Moench]. Here, we provide insight into seminal root phenotypes and provide a first look at the genetics controlling these traits in barley. Copyright © 2016 Crop Science Society of America.

  11. Genomic Regions Influencing Seminal Root Traits in Barley

    Directory of Open Access Journals (Sweden)

    Hannah Robinson

    2016-03-01

    Full Text Available Water availability is a major limiting factor for crop production, making drought adaptation and its many component traits a desirable attribute of plant cultivars. Previous studies in cereal crops indicate that root traits expressed at early plant developmental stages, such as seminal root angle and root number, are associated with water extraction at different depths. Here, we conducted the first study to map seminal root traits in barley ( L.. Using a recently developed high-throughput phenotyping method, a panel of 30 barley genotypes and a doubled-haploid (DH population (ND24260 × ‘Flagship’ comprising 330 lines genotyped with diversity array technology (DArT markers were evaluated for seminal root angle (deviation from vertical and root number under controlled environmental conditions. A high degree of phenotypic variation was observed in the panel of 30 genotypes: 13.5 to 82.2 and 3.6 to 6.9° for root angle and root number, respectively. A similar range was observed in the DH population: 16.4 to 70.5 and 3.6 to 6.5° for root angle and number, respectively. Seven quantitative trait loci (QTL for seminal root traits (root angle, two QTL; root number, five QTL were detected in the DH population. A major QTL influencing both root angle and root number (/ was positioned on chromosome 5HL. Across-species analysis identified 10 common genes underlying root trait QTL in barley, wheat ( L., and sorghum [ (L. Moench]. Here, we provide insight into seminal root phenotypes and provide a first look at the genetics controlling these traits in barley.

  12. Allelopathic effects of barley straw on germination and seedling growth of corn, sugar beet and sunflower

    Directory of Open Access Journals (Sweden)

    mohamad taghi naseri poor yazdi

    2009-06-01

    Full Text Available Allelopathic effects of barley straw and root on germination and growth of maize, sugar beet, and sunflower were investigated under glasshouse and laboratory experiments in Faculty of Agriculture, Ferdowsi University of Mashhad in 2006. The glasshouse experiment was designed based on randomized complete block design with three replications, treatments included: 0, 200, 400, 600 g/m² of grounded barley straw and also 0 and 50 g/m2 barley root. A laboratory experiment was carried out in order to study the effect of different concentrations of barley water extracts on germination and seedling characteristics of corn, sugar beet and sunflower. Treatments in laboratory trial included 0, 33, 50 and 100 percent of barley extracts. Results showed that leaf area of corn was significantly affected by barley straw treatments. Shoot dry matter and seed weight per plant in corn , leaf and tuber weight in sugar beet and leaf , stem weights , plant per plant in corn , leaf and tuber weight in sugar beet and leaf, stem weights, plant height, head diameter, head weight and seed weight in sunflower were significantly higher in treatment of 50g/m² barley roots. Crop seed germination decreased with increasing the amount of barley straw. The best germination response to barley extract was observed in corn. Maize radicle weight was significantly decreased with increasing concentration of barley water extract.

  13. Micro-PIXE evaluation of Fe distribution in barley roots

    International Nuclear Information System (INIS)

    Schneider, T.; Povh, B.; Strasser, O.; Gierth, M.; Przybylowicz, W.; Mesjasz-Przybylowicz, J.; Churms, C.; Schuessler, A.

    1999-01-01

    High Fe concentrations were reported from roots of plants grown in soil. This has been discussed as a possible Fe source for plants, since the concentrations shown in the roots were much higher than in the shoots. There are, however, also some indications that soil contamination at the root surface of soil grown plants could have led to an overestimation of the Fe concentration in roots. Fe distribution in root cross sections of barley (Hordeum vulgare L. cv. Alexis) has been studied to investigate this hypothesis. Micro-PIXE analyses in point and mapping mode were complemented by the STIM technique. Based on the correlation between Fe and soil-related elements (Ti, Al and Si), most of Fe located at the root surface could be attributed to soil contamination. It could also be shown that this soil contamination leads to an overestimation of Fe concentration in roots. (author)

  14. Variation of root system characters in collection of semi-dwarf spring barley mutants

    International Nuclear Information System (INIS)

    Nawrot, M.; Zbieszczyk, J.; Maluszynski, M.

    2000-01-01

    The collection of 371 semi-dwarf mutants, derived from 12 spring barley varieties has been used as material for analysis of root system. The mutants have been obtained after mutagenic treatment with N-methyl-N-nitroso urea (MNH), sodium azide (NaN3), gamma-rays and fast neutrons. The following analysis of root system were performed: seminal root growth of 8-day old seedlings, seminal and adventitious root growth of 6-week old plants and dynamics of root growth during first 6 weeks of plant growth. Seminal root length, root number and the length of the first leaf in barley mutants were investigated with the use of paper rollers. Root system analysis of 6-week old plants was performed on genotypes grown in PVC tubes filled with sand, supplemented with 1 mineral salts of MS medium. The following measurements were made: the length of the longest seminal root and the longest adventitious root, the number of adventitious roots and the number of tillers. Analysis of dynamics of root growth during the first six weeks of vegetation was performed at the end of each 7-day growth period in the PVC tubes filled with sand. Great variability in the seminal root length was found in analysed 8-day old seedling population. Almost half of the analysed mutants showed significant root length reduction, but about ten percent of semi-dwarf mutants developed roots with an increased length in comparison to parents. No significant differences were found between analysed mutants and corresponding parent varieties regarding the number of seminal roots. After six weeks of growth, the selected mutants showed differences in the reduction of root length in comparison to the 8-day old seedlings. The results of root growth dynamics indicated that analysed mutants had different patterns in comparison to the parent variety. Differences in the growth dynamics were also observed among the parent varieties. The observed differences in pattern of root growth between mutants and corresponding parents

  15. Efflux of inorganic substances from young barley roots, (2)

    International Nuclear Information System (INIS)

    Fujimoto, Hiroshi; Kojima, Shigeru

    1977-01-01

    The root system of young barley was almost halved, and the two portions were planted in culture grounds with different composition after severing the capillary connection between both root groups. With one portion in the acid medium solution of various compositions and the other in the 22 Na-absorbing medium solution, the sodium absorbed from one root group moved to and flowed out from the other root group, and this state was observed. Also, the efflux of potassium from the root was observed. (1) The Na efflux was small in the culture ground with dilute hydrochloric acid, and larger in that with AlCl 3 or phosphate. (2) The K efflux was large under short-day condition. (3) Under short-day condition, in the culture ground with soluble Al, the K efflux was promoted by nitrogen-source addition, but the Na efflux was suppressed. (Mori, K.)

  16. A root hairless barley mutant for elucidating genetic of root hairs and phosphorus uptake (Correction in v. 242, 2002, p. 299)

    DEFF Research Database (Denmark)

    Gahoonia, T.S.; Nielsen, N.E.; Priyavadan, A.J.

    2001-01-01

    This paper reports a new barley mutant missing root hairs. The mutant was spontaneously discovered among the population of wild type (Pallas, a spring barley cultivar), producing normal, 0.8 mm long root hairs. We have called the mutant bald root barley (brb). Root anatomical studies confirmed...

  17. Labeled Azospirillum brasilense wild type and excretion-ammonium strains in association with barley roots.

    Science.gov (United States)

    Santos, Adrian Richard Schenberger; Etto, Rafael Mazer; Furmam, Rafaela Wiegand; Freitas, Denis Leandro de; Santos, Karina Freire d'Eça Nogueira; Souza, Emanuel Maltempi de; Pedrosa, Fábio de Oliveira; Ayub, Ricardo Antônio; Steffens, Maria Berenice Reynaud; Galvão, Carolina Weigert

    2017-09-01

    Soil bacteria colonization in plants is a complex process, which involves interaction between many bacterial characters and plant responses. In this work, we labeled Azospirillum brasilense FP2 (wild type) and HM053 (excretion-ammonium) strains by insertion of the reporter gene gusA-kanamycin into the dinitrogenase reductase coding gene, nifH, and evaluated bacteria colonization in barley (Hordeum vulgare). In addition, we determined inoculation effect based on growth promotion parameters. We report an uncommon endophytic behavior of A. brasilense Sp7 derivative inside the root hair cells of barley and highlight the promising use of A. brasilense HM053 as plant growth-promoting bacterium. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  18. Temporal and spatial distribution of roots and competition for nitrogen in pea-barley intercrops - a field study employing P-32 technique

    DEFF Research Database (Denmark)

    Hauggaard-Nielsen, H.; Ambus, P.; Jensen, E.S.

    2001-01-01

    was the dominant component of the pea-barley intercrop, obtaining 90% of its sole crop yield, while pea produced only 15% of the grains of a sole crop pea. Intercropping of pea and barley improved the utilization of plant growth resources (LER > 1) as compared to sole crops. Root system distribution in time...... and space can partly explain interspecific competition. The P-32 methodology proved to be a valuable tool for determining root dynamics in intercropping systems....

  19. The composite water and solute transport of barley (Hordeum vulgare) roots: effect of suberized barriers.

    Science.gov (United States)

    Ranathunge, Kosala; Kim, Yangmin X; Wassmann, Friedrich; Kreszies, Tino; Zeisler, Viktoria; Schreiber, Lukas

    2017-03-01

    Roots have complex anatomical structures, and certain localized cell layers develop suberized apoplastic barriers. The size and tightness of these barriers depend on the growth conditions and on the age of the root. Such complex anatomical structures result in a composite water and solute transport in roots. Development of apoplastic barriers along barley seminal roots was detected using various staining methods, and the suberin amounts in the apical and basal zones were analysed using gas chromatography-mass spectometry (GC-MS). The hydraulic conductivity of roots ( Lp r ) and of cortical cells ( Lp c ) was measured using root and cell pressure probes. When grown in hydroponics, barley roots did not form an exodermis, even at their basal zones. However, they developed an endodermis. Endodermal Casparian bands first appeared as 'dots' as early as at 20 mm from the apex, whereas a patchy suberin lamellae appeared at 60 mm. The endodermal suberin accounted for the total suberin of the roots. The absolute amount in the basal zone was significantly higher than in the apical zone, which was inversely proportional to the Lp r . Comparison of Lp r and Lp c suggested that cell to cell pathways dominate for water transport in roots. However, the calculation of Lp r from Lp c showed that at least 26 % of water transport occurs through the apoplast. Roots had different solute permeabilities ( P sr ) and reflection coefficients ( σ sr ) for the solutes used. The σ sr was below unity for the solutes, which have virtually zero permeability for semi-permeable membranes. Suberized endodermis significantly reduces Lp r of seminal roots. The water and solute transport across barley roots is composite in nature and they do not behave like ideal osmometers. The composite transport model should be extended by adding components arranged in series (cortex, endodermis) in addition to the currently included components arranged in parallel (apoplastic, cell to cell pathways). © The

  20. CRESCIMENTO RADICULAR E NUTRIÇÃO DA CEVADA EM FUNÇÃO DA CALAGEM E APLICAÇÃO DE GESSO BARLEY NUTRITION AND ROOT GROWTH AS AFFECTED BY LIME AND GYPSUM APPLICATIONS

    Directory of Open Access Journals (Sweden)

    EDUARDO FÁVERO CAIRES

    2001-01-01

    growth can be affected by chemical modifications in the soil profile due to lime and gypsum applications. A field trial was carried out on a dystrophic Clay Rhodic Hapludox at Ponta Grossa, State of Paraná, Brazil, aiming at evaluating lime and gypsum effects on root growth and plant chemical traits of barley, cv. BR 2 (Al susceptible. A randomized complete block design was used, with three replications, in a split-plot layout. The main plots received dolomitic limestone treatments (no lime and 4.5 t.ha-1 of lime-on the surface or incorporated into the soil and the subplots, the rates of gypsum (0, 3, 6 and 9 t.ha-1, applied in the installation of a no-tillage system, in 1998. Barley was grown during the 1999 winter season, after the soybean crop. Liming (whether surface applied or incorporated into the soil, and gypsum rates did not significantly affected barley root growth, although gypsum provided better root relative distribution in the soil profile, mainly when associated to liming. Under severe water stress conditions there was no limitation to barley root growth in depth (for 6 mmol c.dm-3 exchangeable Ca and 35% Al saturation. Lime incorporation improved the plant nutrition as to N and K, but liming treatments did not affect grain yields-these were limited by the prolonged water deficit during flowering stage. However, gypsum increased N, P, K, Ca and S plant levels, even under water stress conditions, with significant effects on grain yields, due to increases in the exchangeable Ca, Ca/Mg relationships and S-SO4(2- levels available in the soil.

  1. Suberized transport barriers in Arabidopsis, barley and rice roots: From the model plant to crop species.

    Science.gov (United States)

    Kreszies, Tino; Schreiber, Lukas; Ranathunge, Kosala

    2018-02-07

    Water is the most important prerequisite for life and plays a major role during uptake and transport of nutrients. Roots are the plant organs that take up the major part of water, from the surrounding soil. Water uptake is related to the root system architecture, root growth, age and species dependent complex developmental changes in the anatomical structures. The latter is mainly attributed to the deposition of suberized barriers in certain layers of cell walls, such as endo- and exodermis. With respect to water permeability, changes in the suberization of roots are most relevant. Water transport or hydraulic conductivity of roots (Lp r ) can be described by the composite transport model and is known to be very variable between plant species and growth conditions and root developmental states. In this review, we summarize how anatomical structures and apoplastic barriers of roots can diversely affect water transport, comparing the model plant Arabidopsis with crop plants, such as barley and rice. Results comparing the suberin amounts and water transport properties indicate that the common assumption that suberin amount negatively correlates with water and solute transport through roots may not always be true. The composition, microstructure and localization of suberin may also have a great impact on the formation of efficient barriers to water and solutes. Copyright © 2018 The Authors. Published by Elsevier GmbH.. All rights reserved.

  2. Fungal growth during malting of barley

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    Kocić-Tanackov Sunčica D.

    2005-01-01

    Full Text Available Fungi were isolated and identified in two samples of winter two-row barley (SSK3 and SSK6 harvested in 2003, Kragujevac location, during micromalting. Fungi were isolated and identified in barley before the micromalting, after the 1st, 2nd and 3rd day of steeping, the first day and after the germination after kilning and after malt degermination. The total fungi count was followed in both barley samples, during the mentioned phases. The total count of fungi was also determined in the steeping water, and the isolation and identification was performed after the steeping process. Change of the total count of fungi during barley micromalting was exponentional. During barley micromalting nine fungi genera were isolated: Phoma, Alternaria, Fusarium aspergillus, Cladosporium, Geotrichum, Scopulariopsis, Aureobasidium and Mucor. The most frequent genera were: Phoma, Alternaria and Fusarium. In water for steeping, five genera were identified: Geotrichum, Fusarium, Phoma Cladosporium and Mucor. The most frequent genera was Phoma.

  3. Changes of Root Hydraulic Conductivity and Root/Shoot Ratio of Durum Wheat and Barley in Relation to Nitrogen Availability and Mercury Exposure

    Directory of Open Access Journals (Sweden)

    Giovanna Angelino

    2011-02-01

    Full Text Available The aim of this research was to verify, on whole plant level and during all the plant cycle, the hypothesis that nitrogen deficiency reduces root hydraulic conductivity through the water channels (aquaporins activity, and that the plant reacts by changing root/shoot ratio. Root hydraulic conductivity, plant growth, root/shoot ratio and plant water status were assessed for durum wheat (Triticum durum Desf. and barley (Hordeum vulgare L., as influenced by nitrogen availability and HgCl2 treatment. On both species during the plant cycle, nitrogen deficiency induced lower root hydraulic conductivity (-49 and -66% respectively for barley and wheat and lower plant growth. On wheat was also observed cycle delay, lower plant nitrogen content, but not lower leaf turgor pressure and epidermic cell dimension. The lower plant growth was due to lower plant dimension and lower tillering. Root /shoot ratio was always higher for nitrogen stressed plants, whether on dry matter or on surface basis. This was due to lower effect of nitrogen stress on root growth than on shoot growth. On wheat HgCl2 treatment determined lower plant growth, and more than nitrogen stress, cycle delay and higher root/shoot ratio. The mercury, also, induced leaf rolling, lower turgor pressure, lower NAR, higher root cell wall lignification and lower epidermic cell number per surface unity. In nitrogen fertilized plants root hydraulic conductivity was always reduced by HgCl2 treatment (-61 and 38%, respectively for wheat and barley, but in nitrogen unfertilized plants this effect was observed only during the first plant stages. This effect was higher during shooting and caryopsis formation, lower during tillering. It is concluded that barley and durum wheat react to nitrogen deficiency and HgCl2 treatment by increasing the root/shoot ratio, to compensate water stress due to lower water root conductivity probably induced by lower aquaporin synthesis or inactivation. However, this

  4. Changes of Root Hydraulic Conductivity and Root/Shoot Ratio of Durum Wheat and Barley in Relation to Nitrogen Availability and Mercury Exposure

    Directory of Open Access Journals (Sweden)

    Celestino Ruggiero

    2007-09-01

    Full Text Available The aim of this research was to verify, on whole plant level and during all the plant cycle, the hypothesis that nitrogen deficiency reduces root hydraulic conductivity through the water channels (aquaporins activity, and that the plant reacts by changing root/shoot ratio. Root hydraulic conductivity, plant growth, root/shoot ratio and plant water status were assessed for durum wheat (Triticum durum Desf. and barley (Hordeum vulgare L., as influenced by nitrogen availability and HgCl2 treatment. On both species during the plant cycle, nitrogen deficiency induced lower root hydraulic conductivity (-49 and -66% respectively for barley and wheat and lower plant growth. On wheat was also observed cycle delay, lower plant nitrogen content, but not lower leaf turgor pressure and epidermic cell dimension. The lower plant growth was due to lower plant dimension and lower tillering. Root /shoot ratio was always higher for nitrogen stressed plants, whether on dry matter or on surface basis. This was due to lower effect of nitrogen stress on root growth than on shoot growth. On wheat HgCl2 treatment determined lower plant growth, and more than nitrogen stress, cycle delay and higher root/shoot ratio. The mercury, also, induced leaf rolling, lower turgor pressure, lower NAR, higher root cell wall lignification and lower epidermic cell number per surface unity. In nitrogen fertilized plants root hydraulic conductivity was always reduced by HgCl2 treatment (-61 and 38%, respectively for wheat and barley, but in nitrogen unfertilized plants this effect was observed only during the first plant stages. This effect was higher during shooting and caryopsis formation, lower during tillering. It is concluded that barley and durum wheat react to nitrogen deficiency and HgCl2 treatment by increasing the root/shoot ratio, to compensate water stress due to lower water root conductivity probably induced by lower aquaporin synthesis or inactivation. However, this

  5. Dominant Groups of Potentially Active Bacteria Shared by Barley Seeds become Less Abundant in Root Associated Microbiome

    OpenAIRE

    Yang, Luhua; Danzberger, Jasmin; Schöler, Anne; Schröder, Peter; Schloter, Michael; Radl, Viviane

    2017-01-01

    Endophytes are microorganisms colonizing plant internal tissues. They are ubiquitously associated with plants and play an important role in plant growth and health. In this work, we grew five modern cultivars of barley in axenic systems using sterile sand mixture as well as in greenhouse with natural soil. We characterized the potentially active microbial communities associated with seeds and roots using rRNA based amplicon sequencing. The seeds of the different cultivars share a great part o...

  6. Variation in activity of root extracellular phytase between genotypes of barley

    DEFF Research Database (Denmark)

    Asmar, Mohammad Farouq

    1997-01-01

    Barley genotypes grown in nutrient solution under P nutrient stress and sterile conditions were compared in activity of root-associated and root-released extracellular phytase. The activity of root-associated phytase of all genotypes was about 10 times higher than that of root-released phytase...... and the genotypes performed differently with regard to the activity of the enzymes. The winter barley genotype, Marinka had the highest activity of root-associated extracellular phytase which differed significantly from Alexis and Senate, but not from Regatta. Alexis showed the lowest activity of root......-released extracellular phytase which differed significantly from those of Marinka and Regatta, but not from Senate. Generally, there was a significant correlation between the activity of root-associated and released extracellular phytase....

  7. Transfer of N and P from intact or decomposing roots of pea to barley interconnected by an arbuscular mycorrhizal fungus

    DEFF Research Database (Denmark)

    Johansen, A.; Jensen, E.S.

    1996-01-01

    of growth. In half of the containers, the donor-plant shoot was removed 42 d after the start of labelling and the roots were left in the soil to decompose. The reverse transfer of N and P, from barley donor to pea receiver plants was also measured to allow calculation of the net transfer through hyphae...... by G, intraradices. The results for P transfer followed the same patterns as was observed for N, although in smaller proportions. The results indicate that arbuscular mycorrhizas may play a significant role in the flow of N and P between two plants interconnected by hyphae, when the root system of one...

  8. Luteibacter rhizovicinus MIMR1 promotes root development in barley (Hordeum vulgare L.) under laboratory conditions.

    Science.gov (United States)

    Guglielmetti, Simone; Basilico, Roberto; Taverniti, Valentina; Arioli, Stefania; Piagnani, Claudia; Bernacchi, Andrea

    2013-11-01

    In order to preserve environmental quality, alternative strategies to chemical-intensive agriculture are strongly needed. In this study, we characterized in vitro the potential plant growth promoting (PGP) properties of a gamma-proteobacterium, named MIMR1, originally isolated from apple shoots in micropropagation. The analysis of the 16S rRNA gene sequence allowed the taxonomic identification of MIMR1 as Luteibacter rhizovicinus. The PGP properties of MIMR1 were compared to Pseudomonas chlororaphis subsp. aurantiaca DSM 19603(T), which was selected as a reference PGP bacterium. By means of in vitro experiments, we showed that L. rhizovicinus MIMR1 and P. chlororaphis DSM 19603(T) have the ability to produce molecules able to chelate ferric ions and solubilize monocalcium phosphate. On the contrary, both strains were apparently unable to solubilize tricalcium phosphate. Furthermore, the ability to produce 3-indol acetic acid by MIMR1 was approximately three times higher than that of DSM 19603(T). By using fluorescent recombinants of strains MIMR1 and DSM 19603(T), we also demonstrated that both bacteria are able to abundantly proliferate and colonize the barley rhizosphere, preferentially localizing on root tips and in the rhizoplane. Finally, we observed a negative effect of DSM 19603(T) on barley seed germination and plant growth, whereas MIMR1, compared to the control, determined a significant increase of the weight of aerial part (+22 %), and the weight and length of roots (+53 and +32 %, respectively). The results obtained in this work make L. rhizovicinus MIMR1 a good candidate for possible use in the formulation of bio-fertilizers.

  9. Dominant Groups of Potentially Active Bacteria Shared by Barley Seeds become Less Abundant in Root Associated Microbiome

    Directory of Open Access Journals (Sweden)

    Luhua Yang

    2017-06-01

    Full Text Available Endophytes are microorganisms colonizing plant internal tissues. They are ubiquitously associated with plants and play an important role in plant growth and health. In this work, we grew five modern cultivars of barley in axenic systems using sterile sand mixture as well as in greenhouse with natural soil. We characterized the potentially active microbial communities associated with seeds and roots using rRNA based amplicon sequencing. The seeds of the different cultivars share a great part of their microbiome, as we observed a predominance of a few bacterial OTUs assigned to Phyllobacterium, Paenibacillus, and Trabusiella. Seed endophytes, particularly members of the Enterobacteriacea and Paenibacillaceae, were important members of root endophytes in axenic systems, where there were no external microbes. However, when plants were grown in soil, seed endophytes became less abundant in root associated microbiome. We observed a clear enrichment of Actinobacteriacea and Rhizobiaceae, indicating a strong influence of the soil bacterial communities on the composition of the root microbiome. Two OTUs assigned to Phyllobacteriaceae were found in all seeds and root samples growing in soil, indicating a relationship between seed-borne and root associated microbiome in barley. Even though the role of endophytic bacteria remains to be clarified, it is known that many members of the genera detected in our study produce phytohormones, shape seedling exudate profile and may play an important role in germination and establishment of the seedlings.

  10. Dominant Groups of Potentially Active Bacteria Shared by Barley Seeds become Less Abundant in Root Associated Microbiome.

    Science.gov (United States)

    Yang, Luhua; Danzberger, Jasmin; Schöler, Anne; Schröder, Peter; Schloter, Michael; Radl, Viviane

    2017-01-01

    Endophytes are microorganisms colonizing plant internal tissues. They are ubiquitously associated with plants and play an important role in plant growth and health. In this work, we grew five modern cultivars of barley in axenic systems using sterile sand mixture as well as in greenhouse with natural soil. We characterized the potentially active microbial communities associated with seeds and roots using rRNA based amplicon sequencing. The seeds of the different cultivars share a great part of their microbiome, as we observed a predominance of a few bacterial OTUs assigned to Phyllobacterium , Paenibacillus , and Trabusiella . Seed endophytes, particularly members of the Enterobacteriacea and Paenibacillaceae, were important members of root endophytes in axenic systems, where there were no external microbes. However, when plants were grown in soil, seed endophytes became less abundant in root associated microbiome. We observed a clear enrichment of Actinobacteriacea and Rhizobiaceae, indicating a strong influence of the soil bacterial communities on the composition of the root microbiome. Two OTUs assigned to Phyllobacteriaceae were found in all seeds and root samples growing in soil, indicating a relationship between seed-borne and root associated microbiome in barley. Even though the role of endophytic bacteria remains to be clarified, it is known that many members of the genera detected in our study produce phytohormones, shape seedling exudate profile and may play an important role in germination and establishment of the seedlings.

  11. Dominant Groups of Potentially Active Bacteria Shared by Barley Seeds become Less Abundant in Root Associated Microbiome

    Science.gov (United States)

    Yang, Luhua; Danzberger, Jasmin; Schöler, Anne; Schröder, Peter; Schloter, Michael; Radl, Viviane

    2017-01-01

    Endophytes are microorganisms colonizing plant internal tissues. They are ubiquitously associated with plants and play an important role in plant growth and health. In this work, we grew five modern cultivars of barley in axenic systems using sterile sand mixture as well as in greenhouse with natural soil. We characterized the potentially active microbial communities associated with seeds and roots using rRNA based amplicon sequencing. The seeds of the different cultivars share a great part of their microbiome, as we observed a predominance of a few bacterial OTUs assigned to Phyllobacterium, Paenibacillus, and Trabusiella. Seed endophytes, particularly members of the Enterobacteriacea and Paenibacillaceae, were important members of root endophytes in axenic systems, where there were no external microbes. However, when plants were grown in soil, seed endophytes became less abundant in root associated microbiome. We observed a clear enrichment of Actinobacteriacea and Rhizobiaceae, indicating a strong influence of the soil bacterial communities on the composition of the root microbiome. Two OTUs assigned to Phyllobacteriaceae were found in all seeds and root samples growing in soil, indicating a relationship between seed-borne and root associated microbiome in barley. Even though the role of endophytic bacteria remains to be clarified, it is known that many members of the genera detected in our study produce phytohormones, shape seedling exudate profile and may play an important role in germination and establishment of the seedlings. PMID:28663753

  12. Responses of soil respiration and barley growth to modified supply of oxygen in the soil

    Directory of Open Access Journals (Sweden)

    A. SIMOJOKI

    2008-12-01

    Full Text Available Roots of dry-land plants are supplied with oxygen mainly by molecular diffusion from soil air. Roots may suffer from hypoxia if soil aeration is reduced by compaction and wetting. Although the mechanisms involved are well known, more research is needed to relate soil aeration status to plant growth. The effects of reduced oxygen supply on soil respiration and the growth of barley seedlings were studied in pot experiments with fine sand soil, where the soil air composition was varied by flushing the soil with gas streams containing 0%, 2%, 6%, 10% or 20% O2 independently of compactness (bulk density 1.4, 1.6 Mg m-3 and wetness (air space 0-5%, >5%. Plant growth decreased only at 0-2% O2 in the loose moist soil but as early as 20% O2 in the wet soil. Soil compaction impaired plant growth regardless of wetting and aeration. In the loose moist soil cropped with barley, the respiration rate (emission of CO2 did not decrease at 6% O2 but decreased clearly at 0-2% O2. The results compared fairly well with the critical oxygen concentrations calculated by a simple multicylindrical model, in which the water-film thickness around the roots was estimated using soil water retention data.

  13. Irradiation seed treatment reduces scald, common root rot and increases phosphorus absorption of barley

    International Nuclear Information System (INIS)

    Arabi, M.I.E.; Jawhar, M.

    2003-01-01

    The effect of low doses of gamma irradiation on severity of barley to scald and common root rot diseases, and phosphorus absorption was studied seeds were exposed to doses of 0, 10, 15, 20, 30, 40 and 50 Gy. A stimulatory effect was observed at irradiation doses of 30 and 40 Gy, which decreased the severity of barley to scald by 34% and 31% respectively. On the other hand, doses 20 and 30 Gy decreased the severity to CRR by 54% and 49% respectively, whereas, phosphorus absorption was significantly increased at doses of 15 and 20 Gy

  14. Dynamics of plant nutrient uptake as affected by biopore-associated root growth in arable subsoil

    DEFF Research Database (Denmark)

    Han, Eusun; Kautz, Timo; Huang, Ning

    2017-01-01

    %) precrops, respectively. On average root diameter and root dry mass of following crops were greater by 11 and 15 % after chicory than tall fescue. At anthesis chicory-barley treatment accumulated 10 % more K in comparison to tall fescue-barley treatment. P uptake of canola was greater (7 %) after tall...... fescue compared with chicory at the stage of fruit development. Conclusions: Our results suggest that the subsoil heterogenization by altered soil biopores hold relevance for plant root growth and overall crop performance. However, the effects depended on biopore size classes, root characteristics...

  15. Some Root Traits of Barley (Hordeum vulgare L. as Affected by Mycorrhizal Symbiosis under Drought Stress

    Directory of Open Access Journals (Sweden)

    R. Bayani

    2016-05-01

    Full Text Available The effect of drought stress and mycorrhizal symbiosis on the colonization, root and leaf phosphorous content, root and leaf phosphatase activity, root volume and area as well as shoot dry weight of a variety of hulless barley were evaluated using a completely randomized experimental design (CRD with 3 replications. Treatments were three levels of drought stress of 30, 60 and 90% field capacity and two levels of mycorrhizal with and without inoculation. According to the results, the highest value of leaf phosphorous (1.54 mg/g was observed at mycorrhizal symbiosis against severe drought treatment. Root phosphatase activity was highest (297.9 OD min -1 FW-1 at severe drought stress with mycorrhizal symbiosis which in comparison with mild stress in the presence of mycorrhiza showed 16.6 fold increasing. The control and non-mycorrhizal symbiosis treatments had highest root dry weight (0.091 g. The lowest root volume (0.016 cm2 observed at mycorrhizal symbiosis × severe drought treatment. Generally, Inoculation of barley seed with mycorrhiza at severe water stress could transport more phosphorous to shoot, especially leaf via inducing of leaf and root phosphatase activity. Also, in addition to supply of nutrient sources especially phosphorous for plant, mycorrhizal symbiosis could play an important role in withstanding water stress in plant via increasing of root dry weight and area.

  16. Huge increases in bacterivores on freshly killed barley roots

    DEFF Research Database (Denmark)

    Christensen, S.; Griffiths, B.; Ekelund, Flemming

    1992-01-01

    Adding fresh roots to intact soil cores resulted in marked increases in microbial and microfaunal activity at the resource islands. Microbial activity increased in two phases following root addition. Respiratory activity and concentration of respiratory enzyme (dehydrogenase) in soil adhering to ...

  17. Effect of gamma-radiation of pollen tube growth and seed set in barley-rye crosses

    International Nuclear Information System (INIS)

    Rohilla, J.S.; Khanna, V.K.

    1993-01-01

    One variety of barley and one variety of rye were taken to study the effect of gamma-radiation on pollen germination, pollen tube growth and seed set in barley-rye crosses. There was an increase in pollen germination and pollen tube growth over control at 1 kR dose but it was reduced at higher doses. Seed set was maximum at 1 kR and it was more than control from 1-5 kR. Only seeds of the cross Karan - 4 (1 kR)*MRSP-992 were able to germinate. In these germinated seeds the root growth was arrested after the fourth day of germination and they turned brown. The shoot growth was also very poor and it stopped after a week. (author) 11 refs.; 2 tabs

  18. Estimating Leaching Requirements for Barley Growth under Saline Irrigation

    Directory of Open Access Journals (Sweden)

    Ahmed Al-Busaidi

    2012-01-01

    Full Text Available The utilization of marginal water resources for agriculture is receiving considerable attention. The lands irrigated with saline water are required to reduce salt accumulations through leaching and/or drainage practices. A field experiment was carried out to investigate the effect of saline irrigation and leaching fraction on barley (Hordeum vulgare L. growth. For this purpose highly saline water was diluted to the salinity levels of 3, 6 and 9 dS m-1 and applied by drip irrigation at 0.0, 0.15, 0.20 and 0.25 leaching fractions (LF. The results of the experiment showed that both quantity and quality of water regulated salts distribution within the soil in the following manner: a the salts were found higher near or immediate below the soil surface; b an enhanced LF carried more salts down the soil horizon but there was no significant difference in plant yield between different treatments of leaching fractions. Salinity of water significantly impaired barley growth. The good drainage of sandy soil enhanced the leaching process and minimized the differences between leaching fractions. The increment in saline treatments (3, 6 and 9 dS m-1 added more salts and stressed plant growth. However, the conjunctive use of marginal water at proportional LF could be effective in enhancing the yield potential of crops in water-scarce areas.

  19. Intercropping effect on root growth and nitrogen uptake at different nitrogen levels

    DEFF Research Database (Denmark)

    Ramirez-Garcia, Javier; Martens, Helle Juel; Quemada, Miguel

    2015-01-01

    of root growth and N foraging for barley (Hordeum vulgare L.) and vetch (Vicia sativa L.), frequently grown in mixtures as cover crops. N was added at 0 (N0), 50 (N1) and 150 (N2) kg N ha−1. The roots discrimination relying on the anatomical and morphological differences observed between dicots......Aims Intercropping legumes and non-legumes may affect the root growth of both components in the mixture, and the non-legume is known to be strongly favored by increasing nitrogen (N) supply. The knowledge of how root systems affect the growth of the individual species is useful for understanding...... the interactions in intercrops as well as for planning cover cropping strategies. The aim of this work was (i) to determine if different levels of N in the topsoil influence root depth (RD) and intensity of barley and vetch as sole crops or as an intercropped mixture and (ii) to test if the choice of a mixture...

  20. A Simple Method for Assessing Severity of Common Root Rot on Barley

    Directory of Open Access Journals (Sweden)

    Mohammad Imad Eddin Arabi

    2013-12-01

    Full Text Available Common root rot caused by Cochliobolus sativus is a serious disease of barley. A simple and reliable method for assessing this disease would enhance our capacity in identifying resistance sources and developing resistant barley cultivars. In searching for such a method, a conidial suspension of C. sativus was dropped onto sterilized elongated subcrown internodes and incubated in sandwich filter paper using polyethylene transparent envelopes. Initial disease symptoms were easily detected after 48h of inoculation. Highly significant correlation coefficients were found in each experiment (A, B and C between sandwich filter paper and seedling assays, indicating that this testing procedure was reliable. The method presented facilitates a rapid pre-selection under uniform conditions which is of importance from a breeder’s point of view.

  1. Growth curve registration for evaluating salinity tolerance in barley

    KAUST Repository

    Meng, Rui

    2017-03-23

    Background: Smarthouses capable of non-destructive, high-throughput plant phenotyping collect large amounts of data that can be used to understand plant growth and productivity in extreme environments. The challenge is to apply the statistical tool that best analyzes the data to study plant traits, such as salinity tolerance, or plant-growth-related traits. Results: We derive family-wise salinity sensitivity (FSS) growth curves and use registration techniques to summarize growth patterns of HEB-25 barley families and the commercial variety, Navigator. We account for the spatial variation in smarthouse microclimates and in temporal variation across phenotyping runs using a functional ANOVA model to derive corrected FSS curves. From FSS, we derive corrected values for family-wise salinity tolerance, which are strongly negatively correlated with Na but not significantly with K, indicating that Na content is an important factor affecting salinity tolerance in these families, at least for plants of this age and grown in these conditions. Conclusions: Our family-wise methodology is suitable for analyzing the growth curves of a large number of plants from multiple families. The corrected curves accurately account for the spatial and temporal variations among plants that are inherent to high-throughput experiments.

  2. Growth curve registration for evaluating salinity tolerance in barley

    KAUST Repository

    Meng, Rui; Saade, Stephanie; Kurtek, Sebastian; Berger, Bettina; Brien, Chris; Pillen, Klaus; Tester, Mark A.; Sun, Ying

    2017-01-01

    Background: Smarthouses capable of non-destructive, high-throughput plant phenotyping collect large amounts of data that can be used to understand plant growth and productivity in extreme environments. The challenge is to apply the statistical tool that best analyzes the data to study plant traits, such as salinity tolerance, or plant-growth-related traits. Results: We derive family-wise salinity sensitivity (FSS) growth curves and use registration techniques to summarize growth patterns of HEB-25 barley families and the commercial variety, Navigator. We account for the spatial variation in smarthouse microclimates and in temporal variation across phenotyping runs using a functional ANOVA model to derive corrected FSS curves. From FSS, we derive corrected values for family-wise salinity tolerance, which are strongly negatively correlated with Na but not significantly with K, indicating that Na content is an important factor affecting salinity tolerance in these families, at least for plants of this age and grown in these conditions. Conclusions: Our family-wise methodology is suitable for analyzing the growth curves of a large number of plants from multiple families. The corrected curves accurately account for the spatial and temporal variations among plants that are inherent to high-throughput experiments.

  3. Efflux of inorganic substances from young barley roots. II. Movement in roots and efflux of sodium in plants with divided root systems

    Energy Technology Data Exchange (ETDEWEB)

    Fujimoto, H; Kojima, S [Radiation Center of Osaka Prefecture, Sakai (Japan)

    1977-09-01

    The root system of young barley was almost halved, and the two portions were planted in culture grounds with different composition after severing the capillary connection between both root groups. With one portion in the acid medium solution of various compositions and the other in the /sup 22/Na-absorbing medium solution, the sodium absorbed from one root group moved to and flowed out from the other root group, and this state was observed. Also, the efflux of potassium from the root was observed. (1) The Na efflux was small in the culture ground with dilute hydrochloric acid, and larger in that with AlCl/sub 3/ or phosphate. (2) The K efflux was large under short-day condition. (3) Under short-day condition, in the culture ground with soluble Al, the K efflux was promoted by nitrogen-source addition, but the Na efflux was suppressed.

  4. Phosphorus Acquisition Efficiency Related to Root Traits: Is Mycorrhizal Symbiosis a Key Factor to Wheat and Barley Cropping?

    Science.gov (United States)

    Campos, Pedro; Borie, Fernando; Cornejo, Pablo; López-Ráez, Juan A.; López-García, Álvaro; Seguel, Alex

    2018-01-01

    Wheat (Triticum aestivum L.) and barley (Hordeum vulgare L.) are major crops cultivated around the world, thus playing a crucial role on human diet. Remarkably, the growing human population requires a significant increase in agricultural production in order to feed everybody. In this context, phosphorus (P) management is a key factor as it is component of organic molecules such as nucleic acids, ATP and phospholipids, and it is the most abundant macronutrient in biomass after nitrogen (N), although being one of the scarcest elements in the lithosphere. In general, P fertilization has low efficiency, as only a fraction of the applied P is acquired by roots, leaving a substantial amount to be accumulated in soil as not readily available P. Breeding for P-efficient cultivars is a relatively low cost alternative and can be done through two mechanisms: i) improving P use efficiency (PUE), and/or ii) P acquisition efficiency (PAE). PUE is related to the internal allocation/mobilization of P, and is usually represented by the amount of P accumulated per biomass. PAE relies on roots ability to acquire P from the soil, and is commonly expressed as the relative difference of P acquired under low and high P availability conditions. In this review, plant adaptations related to improved PAE are described, with emphasis on arbuscular mycorrhizal (AM) symbiosis, which is generally accepted to enhance plant P acquisition. A state of the art (1980–2018) of AM growth responses and P uptake in wheat and barley is made to discuss about the commonly accepted growth promoting effect and P increased uptake by AM fungi and the contrasting evidence about the generally accepted lack of positive responses in both plant species. Finally, the mechanisms by which AM symbiosis can affect wheat and barley PAE are discussed, highlighting the importance of considering AM functional diversity on future studies and the necessity to improve PAE definition by considering the carbon trading between

  5. Toxicity Thresholds Based on EDTA Extractable Nickel and Barley Root Elongation in Chinese Soils

    Directory of Open Access Journals (Sweden)

    Guangyun Zhu

    2018-04-01

    Full Text Available The uncertainty in the risk assessment of trace metal elements in soils when total metal contents are used can be decreased by assessing their availability and/or extractability when the soils have a high background value or different sources of trace metal elements. In this study, the added water-soluble nickel (Ni toxicity to barley root elongation was studied in 17 representative Chinese soil samples with and without artificial rainwater leaching. The extractability of added Ni in soils was estimated by three sequential extractions with ethylenediaminetetraacetic acid (EDTA. The results showed that the effective concentration of EDTA extractable Ni (EC50, which caused 50% inhibition of barley root elongation, ranged from 46 to 1019 mg/kg in unleached soils and 24 to 1563 mg/kg in leached soils. Regression models for EDTA extractable Ni and total Ni added to soils against soil properties indicated that EDTA extractable Ni was significantly correlated with the total Ni added to soils and that pH was the most important control factor. Regression models for toxicity thresholds based on EDTA extractable Ni against soil properties showed that soil citrate dithionate extractable Fe was more important than soil pH in predicting Ni toxicity. These results can be used to accurately assess the risk of contaminated soils with high background values and/or different Ni sources.

  6. Barley Seed Germination/Root Elongation Toxicity Test For Evaluation Of Sludge Pre-Treatment

    DEFF Research Database (Denmark)

    Eriksson, Eva; Kusk, Kresten Ole; Barrett Sørensen, Mie

    Application of sludge from wastewater treatment plants (WWTPs) on agricultural land is an approach for nutrient recycling that rise challenges due to recalcitrant and harmful pollutants. In this study we assessed the feasibility of a seed germination test to evaluate sludge ecotoxicity and compared...... germination responses from two test parameters, root elongation and seed germination (sprouts elongation) of the barley (Hordeum vulgare). 2nd objective was to evaluate sewage sludge pre-treatments at batch-scale of sludge samples from two WWTPs using anaerobic digestion, and thermal and ozonation pre......-treatments. Glyphosate and eco-labelled soil were used as references. Inhibition of germination of seeds exposed to the glyphosate and sludge was registered and thus germination was successfully applied for sludge ecotoxicity assessment, and using the root elongation as the end-point was both faster and more precise...

  7. Effects of salt on the pattern of protein synthesis in barley roots

    International Nuclear Information System (INIS)

    Hurkman, W.J.; Tanaka, C.K.

    1987-01-01

    The effect of salt stress on the incorporation of [ 3 5 S]methionine into protein was examined in roots of barley (Hordeum vulgare L.cv California Mariout 72). Plants were grown in nutrient solution with or without 200 millimolar NaCl. Roots of intact plants were labeled in vivo and proteins were extracted and analyzed by fluorography of two-dimensional gels. Although the protein patterns for control and salt-stressed plants were qualitatively similar, the net synthesis of a number of proteins was quantitatively changed. The most striking change was a significant increase of label in two protein pairs that had pls of approximately 6.3 and 6.5. Each pair consisted of proteins of approximately 26 and 27 kilodaltons (kD). In roots of control plants, the 27-kD proteins were more heavily labeled in the microsomal fraction relative to the 26-kD proteins, whereas the 26-kD proteins were enriched in the post 178,000g supernatant fraction; in roots of salt treated plants, the 26- and 27-kD proteins were more intensely labeled in both fractions. Labeling of the 26- and 27-kD proteins returned to control levels when salt-stressed plants were transferred to nutrient solution without NaCl. No cross-reaction was detected between the antibody to the 26-kD protein from salt-adapted tobacco cells and the 26- and 27-kD proteins of barley

  8. Potassium-dependent changes in the expression of membrane-associated proteins in barley roots

    International Nuclear Information System (INIS)

    Fernando, M.; Kulpa, J.; Siddiqi, M.Y.; Glass, A.D.M.

    1990-01-01

    Barley (Hordeum vulgare L. cv Halcyon) seedlings which has been grown in full strength complete inorganic nutrient media (containing 6 millimolar K + ) had high internal K + concentrations and low values of K + ( 86 Rb + ) influx when influx was measured from solutions containing 100 micromolar K + . Transfer of these plants to solutions lacking K + resulted in significant reductions of root and shoot K + concentrations and values of K + ( 86 Rb + ) influx increased by greater than 10-fold within 3 days. When plants treated in this way were returned to complete solutions, containing K + , the changes induced by K + deprivation were reversed. Parallel studies of microsomal membranes by means of SDS-PAGE demonstrated that the expression of a group of polypeptides increased or decreased in parallel with changes of K + ( 86 Rb + ) influx. Most prominent of these were 45 and 34 kilodalton polypeptides which specifically responded to K + status of the barley plants; their expression was not enhanced by N or P deprivation. The 45 kilodalton polypeptide was susceptible to degradation by a membrane associated protease when microsomes were washing in buffer containing 0.2 millimolar PMSF. This loss was prevented by increasing PMSF concentration to 2 millimolar

  9. Efflux of inorganic substances from young barley roots. I. Efflux in water culture under various conditions

    Energy Technology Data Exchange (ETDEWEB)

    Fujimoto, H; Kojima, S [Radiation Center of Osaka Prefecture, Sakai (Japan)

    1977-09-01

    The efflux of elements from the roots of hydropomically grown young barley plants was studied. The effects of different mutrient compositions and pH values of the solutions was also studied using /sup 22/Na and /sup 45/Ca as the indexes. In all culture conditions, there was efflux of both elements. In two media with dilute hydrochloric acid and AlCl/sub 3/, respectively, the tendencies of Na and Ca efflux were similar in both media at first, but after 72 hr, the Na efflux in AlCl/sub 3/ decreased and that in dilute hydrochloric acid medium increased. The Ca efflux was high in AlCl/sub 3/ medium,however. The efflux of both Na and Ca was higher in the standard medium than in the media with some bases of high concentrations.

  10. The effect of some growth regulators on enzyme systems in irradiated barley grain using disinfestation doses

    International Nuclear Information System (INIS)

    Bachman, S.

    1973-01-01

    Disinfestation doses of 20 to 100 krad may cause changes in the biological systems of barley grain and, therefore, may influence undesirably the technological quality of malted grain. The effect of some growth regulators on irradiated grain has been investigated. The experiments have been carried out on brewery barley var. Visa Breuns. Following growth-regulators were used: gibberellic acid (Polish preparation ''Gibrescol''), kinetin (6-furfurylo-aminopurin), CCC (2-chloroethyl trimethyl ammonium chloride), and betaine hydrochloride. By treating the irradiated barley with solutions of growth regulators it was possible to diminish the loss of enzyme activity. A ''regenerating'' effect of growth substances, mainly gibberellic acid and betain hydrochloride in 10 -4 M solutions, was observed. Amylolytic activity decreased immediately after irradiation but in samples treated with growth regulators it was higher than in those without regulators. The results may have a practical importance since gibberellic acid has just been introduced into the brewery industry. (F.J.)

  11. Calibration and validation of the crop growth model daisy for spring barley in the Czech Republic

    Czech Academy of Sciences Publication Activity Database

    Pohanková, Eva; Hlavinka, Petr; Takáč, J.; Žalud, Zdeněk; Trnka, Miroslav

    2015-01-01

    Roč. 63, č. 4 (2015), s. 1177-1186 ISSN 1211-8516 R&D Projects: GA MŠk(CZ) LD13030; GA MŠk(CZ) LO1415 Institutional support: RVO:67179843 Keywords : Tolar * Crop growth model * daisy * Field experiments * Growth dynamics * Phenology * Spring barley Subject RIV: EH - Ecology, Behaviour

  12. A proteomics approach to study the molecular basis of enhanced salt tolerance in barley (Hordeum vulgare L.) conferred by the root mutualistic fungus Piriformospora indica.

    Science.gov (United States)

    Alikhani, Mehdi; Khatabi, Behnam; Sepehri, Mozhgan; Nekouei, Mojtaba Khayam; Mardi, Mohsen; Salekdeh, Ghasem Hosseini

    2013-06-01

    Piriformospora indica is a root-interacting mutualistic fungus capable of enhancing plant growth, increasing plant resistance to a wide variety of pathogens, and improving plant stress tolerance under extreme environmental conditions. Understanding the molecular mechanisms by which P. indica can improve plant tolerance to stresses will pave the way to identifying the major mechanisms underlying plant adaptability to environmental stresses. We conducted greenhouse experiments at three different salt levels (0, 100 and 300 mM NaCl) on barley (Hordeum vulgare L.) cultivar "Pallas" inoculated with P. indica. Based on the analysis of variance, P. indica had a significant impact on the barley growth and shoot biomass under normal and salt stress conditions. P. indica modulated ion accumulation in colonized plants by increasing the foliar potassium (K(+))/sodium (Na(+)) ratio, as it is considered a reliable indicator of salt stress tolerance. P. indica induced calcium (Ca(2+)) accumulation and likely influenced the stress signal transduction. Subsequently, proteomic analysis of the barley leaf sheath using two-dimensional electrophoresis resulted in detection of 968 protein spots. Of these detected spots, the abundance of 72 protein spots changed significantly in response to salt treatment and P. indica-root colonization. Mass spectrometry analysis of responsive proteins led to the identification of 51 proteins. These proteins belonged to different functional categories including photosynthesis, cell antioxidant defense, protein translation and degradation, energy production, signal transduction and cell wall arrangement. Our results showed that P. indica induced a systemic response to salt stress by altering the physiological and proteome responses of the plant host.

  13. Whole Tibetan Hull-Less Barley Exhibit Stronger Effect on Promoting Growth of Genus Bifidobacterium than Refined Barley In Vitro.

    Science.gov (United States)

    Gong, Lingxiao; Cao, Wenyan; Gao, Jie; Wang, Jing; Zhang, Huijuan; Sun, Baoguo; Yin, Meng

    2018-04-01

    The gut microbiota has recently become a new route for research at the intersection of diet and human health. The aim of this study was to investigate whether whole Tibetan hull-less barley (WHB) and refined Tibetan hull-less barley (RHB) caused differentiation of the fecal microbiota in vitro. The microbiota-accessible ingredients in the 2 barley samples were studied using an in vitro enzymatic digestion procedure. After in vitro digestion, insoluble dietary fiber, phenolic compounds, proteins, and β-glucans were 93.2%, 103.4%. 18.8%, and 10.2% higher provided by WHB flour as compared with RHB flour based on the same mass amount. However, due to the significantly higher content of insoluble dietary fiber, WHB digesta had lower percentage contents of fast fermentable substrates including dietary fiber and starch as compared with RHB digesta. The results of Next-generation sequencing of the bacterial 16SrRNA gene showed that both WHB and RHB fermentation had significantly promoted the growth of Bifidobacterium and inhibited the growth of pathogenic bacteria such as Dorea, Escherichia, Oscillopira, and Ruminococcus. Moreover, in response to WHB fermentation, the relative abundance of Bifidobacterium increased by 78.5% and 92.8% as compared with RHB and fructo-oligosaccharides (FOs). Both WHB and RHB are good sources of fermentable dietary fiber with the ability to yield high concentration of short chain fatty acids (SCFAs) as compared to FOs. However, the higher fraction of soluble fiber in RHB digesta increase higher amounts of SCFA compared with WHB digesta. Our findings shed light on the complex interactions of whole cereals with gut microbiota and the possible impact on host health. Until now, only few reports have regarded the impact of in vitro digestion in components of whole grain with complex food matrix. Moreover, our findings shed light on the complex interactions of whole cereals with gut microbiota and the possible impact on host health. © 2018

  14. Effects of catch crop type and root depth on nitrogen leaching and yield of spring barley

    DEFF Research Database (Denmark)

    Sapkota, Tek Bahadur; Askegaard, Margrethe; Lægdsmand, Mette

    2012-01-01

    [chicory (Cichorium intybus L.), fodder radish (Raphanus sativus L.) and perennial ryegrass (Lolium perenne L.)] and their effect on soil mineral N (NO3− and NH4+) in different soil layers by using the FASSET model. The simulated results of catch crop biomass and root growth and mineral N in the soil...

  15. Quantifying biological nitrogen fixation of different catch crops, and residual effects of roots and tops on nitrogen uptake in barley using in-situ 15N labelling

    DEFF Research Database (Denmark)

    Li, Xiaoxi; Sørensen, Peter; Li, F C

    2015-01-01

    –46 % in macro-roots (0–18 cm soil). Macro-roots represented 31–50 % of total plant N. LBCCs showed similar capacity for soil N extraction as non-LBCCs. After incorporation of LBCC residues, the dry matter and N yields of spring barley were comparable to the effect of 50 kg N fertilisation ha−1, whereas no extra...

  16. Response-based selection of barley cultivars and legume species for complementarity: Root morphology and exudation in relation to nutrient source.

    Science.gov (United States)

    Giles, Courtney D; Brown, Lawrie K; Adu, Michael O; Mezeli, Malika M; Sandral, Graeme A; Simpson, Richard J; Wendler, Renate; Shand, Charles A; Menezes-Blackburn, Daniel; Darch, Tegan; Stutter, Marc I; Lumsdon, David G; Zhang, Hao; Blackwell, Martin S A; Wearing, Catherine; Cooper, Patricia; Haygarth, Philip M; George, Timothy S

    2017-02-01

    Phosphorus (P) and nitrogen (N) use efficiency may be improved through increased biodiversity in agroecosystems. Phenotypic variation in plants' response to nutrient deficiency may influence positive complementarity in intercropping systems. A multicomponent screening approach was used to assess the influence of P supply and N source on the phenotypic plasticity of nutrient foraging traits in barley (H. vulgare L.) and legume species. Root morphology and exudation were determined in six plant nutrient treatments. A clear divergence in the response of barley and legumes to the nutrient treatments was observed. Root morphology varied most among legumes, whereas exudate citrate and phytase activity were most variable in barley. Changes in root morphology were minimized in plants provided with ammonium in comparison to nitrate but increased under P deficiency. Exudate phytase activity and pH varied with legume species, whereas citrate efflux, specific root length, and root diameter lengths were more variable among barley cultivars. Three legume species and four barley cultivars were identified as the most responsive to P deficiency and the most contrasting of the cultivars and species tested. Phenotypic response to nutrient availability may be a promising approach for the selection of plant combinations for minimal input cropping systems. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  17. Investigations of barley stripe mosaic virus as a gene silencing vector in barley roots and in Brachypodium distachyon and oat

    DEFF Research Database (Denmark)

    Pacak, Andrzej; Geisler, Katrin; Jørgensen, Bodil

    2010-01-01

    -expressed genes we wanted to explore the potential of BSMV for silencing genes in root tissues. Furthermore, the newly completed genome sequence of the emerging cereal model species Brachypodium distachyon as well as the increasing amount of EST sequence information available for oat (Avena species) have created...

  18. Study the Reaction of Some Barley Cultivars to Rhizoctonia solani AG-8, the Causal Agent of Root Rot Disease

    Directory of Open Access Journals (Sweden)

    M. Yazdani Kohanstani

    2016-03-01

    Full Text Available Introduction: Barley is one of the important agricultural products, mostly as livestock feed, and secondly for its important role in human nutrition as bread, soups, baby food and etc. It has the second-largest rank of cultivation area and yield of the national grain production and the Isfahan province, with production 5% of total barley yield, has been ranked eighth in 2010. Because its consumption exceed over the production, barley is one of the major imports to the country. In addition to, agronomy operations, plant diseases are important factors in yield loss. Rhizoctonia root rot (caused by soil-inhabiting fungus Rhizoctonia solani is one of the important diseases of cereals include barley over the worldwide cultivation area. Apropriate soil fertility, delaying planting dates, crop rotation with insensitive crops such as legumes, planting resistant varieties and fungicide seed dressing are recommended methods to reduce disease damage. Chemical control of this disease is difficult because of its soil-born the pathogen. Therefore, reducing disease level requires application of other methods especially resistance cultivars. Materials and Methods In this research, the reaction of 8 barley cultivars were examined against root rot disease in greenhouse conditions, in the winter of 2009. Fifteen isolates of the fungus were isolated from infected barley fields in the Isfahan province and their pathogenicity was examined on barley. One isolate with the highest pathogenicity potential was selected and special tests showed that the isolate was Rhizoctonia solani AG-8. The experiment was conducted in a completely randomized design with 4 replications. The test plants were harvested at two times of 4 & 8 weeks after planting. Following parameters were measured: 1- dry weight of plant root and aerial part, 2- disease severity as an index of subcrown internodes infection. Results and discussion Statistical analysis of recorded data showed that there were

  19. Long-term control of root growth

    Science.gov (United States)

    Burton, Frederick G.; Cataldo, Dominic A.; Cline, John F.; Skiens, W. Eugene

    1992-05-26

    A method and system for long-term control of root growth without killing the plants bearing those roots involves incorporating a 2,6-dinitroaniline in a polymer and disposing the polymer in an area in which root control is desired. This results in controlled release of the substituted aniline herbicide over a period of many years. Herbicides of this class have the property of preventing root elongation without translocating into other parts of the plant. The herbicide may be encapsulated in the polymer or mixed with it. The polymer-herbicide mixture may be formed into pellets, sheets, pipe gaskets, pipes for carrying water, or various other forms. The invention may be applied to other protection of buried hazardous wastes, protection of underground pipes, prevention of root intrusion beneath slabs, the dwarfing of trees or shrubs and other applications. The preferred herbicide is 4-difluoromethyl-N,N-dipropyl-2,6-dinitro-aniline, commonly known as trifluralin.

  20. Root-growth-inhibiting sheet

    Science.gov (United States)

    Burton, F.G.; Cataldo, D.A.; Cline, J.F.; Skiens, W.E.; Van Voris, P.

    1993-01-26

    In accordance with this invention, a porous sheet material is provided at intervals with bodies of a polymer which contain a 2,6-dinitroaniline. The sheet material is made porous to permit free passage of water. It may be either a perforated sheet or a woven or non-woven textile material. A particularly desirable embodiment is a non-woven fabric of non-biodegradable material. This type of material is known as a geotextile'' and is used for weed control, prevention of erosion on slopes, and other landscaping purposes. In order to obtain a root repelling property, a dinitroaniline is blended with a polymer which is attached to the geotextile or other porous material.

  1. Root-growth-inhibiting sheet

    Science.gov (United States)

    Burton, Frederick G.; Cataldo, Dominic A.; Cline, John F.; Skiens, W. Eugene; Van Voris, Peter

    1993-01-01

    In accordance with this invention, a porous sheet material is provided at intervals with bodies of a polymer which contain a 2,6-dinitroaniline. The sheet material is made porous to permit free passage of water. It may be either a perforated sheet or a woven or non-woven textile material. A particularly desirable embodiment is a non-woven fabric of non-biodegradable material. This type of material is known as a "geotextile" and is used for weed control, prevention of erosion on slopes, and other landscaping purposes. In order to obtain a root repelling property, a dinitroaniline is blended with a polymer which is attached to the geotextile or other porous material.

  2. Effect of saline stress on plasma membrane structure and function of barley roots

    International Nuclear Information System (INIS)

    Rahmani, F. H.

    2000-01-01

    Barely (Hordeum vulgare L. c v. Black Local) plants were grown hydroponic ally under different saline stresses (50, 100, 150 And 200 mm NaCI. The adverse effect of each saline stress on the structure and function of root cells plasma membrane was studied in terms of root surface ATPase activation by NaCI in the reaction mixture. Was 0, 50, 100. 150 and 200mM. ATPase activity was found to be increased gradually at certain concentrations of NaCI. For control and 50mM stressed plants, the increase in root surface ATPase activity was started at 150mM NaCI. For 100mM stressed plants it was started at 100mM NaCI. For 150 and 200mM stressed plants it was stated at 50mM NaCI Results indicated that the adverse effect of the growth medium saline stresses on the integrity of the plasma membrane was started at 100mM saline stress. Accordingly the role of plasma membrane bound ATPase in active ion transport was disturbed at 100mM saline stress and may be impaired at 150 and 200mM saline stresses. It was suggested that the lipid environment of the plasma membrane surrounding ATPase was modified by the saline stresses 100-200mM. (author). 38 refs., 2 figs., 2 tabs

  3. Root-zone temperature and water availability affect early root growth of planted longleaf pine

    Science.gov (United States)

    M.A. Sword

    1995-01-01

    Longleaf pine seedlings from three seed sources were exposed to three root-zone temperatures and three levels of water availability for 28 days. Root growth declined as temperature and water availability decreased. Root growth differed by seed source. Results suggest that subtle changes in the regeneration environment may influence early root growth of longleaf pine...

  4. Shoot-derived abscisic acid promotes root growth.

    Science.gov (United States)

    McAdam, Scott A M; Brodribb, Timothy J; Ross, John J

    2016-03-01

    The phytohormone abscisic acid (ABA) plays a major role in regulating root growth. Most work to date has investigated the influence of root-sourced ABA on root growth during water stress. Here, we tested whether foliage-derived ABA could be transported to the roots, and whether this foliage-derived ABA had an influence on root growth under well-watered conditions. Using both application studies of deuterium-labelled ABA and reciprocal grafting between wild-type and ABA-biosynthetic mutant plants, we show that both ABA levels in the roots and root growth in representative angiosperms are controlled by ABA synthesized in the leaves rather than sourced from the roots. Foliage-derived ABA was found to promote root growth relative to shoot growth but to inhibit the development of lateral roots. Increased root auxin (IAA) levels in plants with ABA-deficient scions suggest that foliage-derived ABA inhibits root growth through the root growth-inhibitor IAA. These results highlight the physiological and morphological importance, beyond the control of stomata, of foliage-derived ABA. The use of foliar ABA as a signal for root growth has important implications for regulating root to shoot growth under normal conditions and suggests that leaf rather than root hydration is the main signal for regulating plant responses to moisture. © 2015 John Wiley & Sons Ltd.

  5. Root plasma membrane transporters controlling K+/Na+ homeostasis in salt-stressed bBarley1[C][W

    DEFF Research Database (Denmark)

    Chen, Zhonghua; Pottosin, Igor I.; Cuin, Tracey A.

    2007-01-01

    are well combined to withstand saline conditions. These mechanisms include: (1) better control of membrane voltage so retaining a more negative membrane potential; (2) intrinsically higher H1 pump activity; (3) better ability of root cells to pump Na1 from the cytosol to the external medium; and (4) higher......Plant salinity tolerance is a polygenic trait with contributions from genetic, developmental, and physiological interactions, in addition to interactions between the plant and its environment. In this study, we show that in salt-tolerant genotypes of barley (Hordeum vulgare), multiple mechanisms...... of the cytosolic K1-to-Na1 ratio being a key determinant of plant salinity tolerance, and suggest multiple pathways of controlling that important feature in salt-tolerant plants....

  6. In vitro and in vivo phosphorylation of polypeptides in plasma membrane and tonoplast-enriched fractions from barley roots

    International Nuclear Information System (INIS)

    Garbarino, J.E.; Hurkman, W.J.; Tanaka, C.K.; DuPont, F.M.

    1991-01-01

    Phosphorylation of polypeptides in membrane fractions from barley (Hordeum vulgare L. cv CM 72) roots was compared in in vitro and in vivo assays to assess the potential role of protein kinases in modification of membrane transport. Membrane fractions enriched in endoplasmic reticulum, tonoplast, and plasma membrane were isolated using sucrose gradients and the membrane polypeptides separated using sodium dodecyl sulfate polyacrylamide gel electrophoresis. When the membrane fractions were incubated with γ[p 32 P]ATP, phosphorylation occurred almost exclusively in the plasma membrane fraction. Phosphorylation of a band at 38 kilodaltons increased as the concentration of Mg 2+ was decreased from millimolar to micromolar levels. Phosphorylation of bands at 125, 86, 58, 46 and 28 kilodaltons required millimolar Mg 2+ concentrations and was greatly enhanced by Ca 2+ . When roots of intact plants were labeled with [ 32 P]orthophosphate, polypeptides at approximately 135, 166, 90, 46 to 53, 32, 28, and 19 kilodaltons were labeled in the plasma membrane fraction and polypeptides at approximately 73, 66, and 48 kilodaltons were labeled in the tonoplast fraction. Treatment of the roots of intact plants with 150 millimolar NaCl resulted in increased phosphorylation of some polypeptides while treatment with 100 mM NaCl had no effect

  7. Influence of bacterial N-acyl-homoserinelactones on growth parameters, pigments, antioxidative capacities and the xenobiotic phase II detoxification enzymes in barley and yam bean

    Directory of Open Access Journals (Sweden)

    Christine eGoetz-Roesch

    2015-04-01

    Full Text Available Bacteria are able to communicate with each other and sense their environment in a population density dependent mechanism known as quorum sensing (QS. N-acyl-homoserine lactones (AHLs are the QS signalling compounds of Gram-negative bacteria which are frequent colonizers of rhizospheres. While cross-kingdom signalling and AHL-dependent gene expression in plants has been confirmed, the responses of enzyme activities in the eukaryotic host upon AHLs are unknown. Since AHL are thought to be used as so-called plant boosters or strengthening agents, which might change their resistance towards radiation and/or xenobiotic stress, we have examined the plants’ pigment status and their antioxidative and detoxifying capacities upon AHL treatment. Because the yield of a crop plant should not be negatively influenced, we have also checked for growth and root parameters.We investigated the influence of three different AHLs, namely N-hexanoyl- (C6-HSL, N-octanoyl- (C8-HSL and N-decanoyl- homoserine lactone (C10-HSL on two agricultural crop plants. The AHL-effects on Hordeum vulgare (L. as an example of a monocotyledonous crop and on the tropical leguminous crop plant Pachyrhizus erosus (L were compared. While plant growth and pigment contents in both plants showed only small responses to the applied AHLs, AHL treatment triggered tissue- and compound-specific changes in the activity of important detoxification enzymes. The activity of dehydroascorbate reductase (DHAR in barley shoots after C10-HSL treatment for instance increased up to 384% of control plant levels, whereas superoxide dismutase (SOD activity in barley roots was decreased down to 23% of control levels upon C6-HSL treatment. Other detoxification enzymes reacted similarly within this range, with interesting clusters of positive or negative answers towards AHL treatment. In general the changes on the enzyme level were more severe in barley than in yam bean which might be due to the different

  8. From oil spills to barley growth - oil-degrading soil bacteria and their promoting effects.

    Science.gov (United States)

    Mikolasch, Annett; Reinhard, Anne; Alimbetova, Anna; Omirbekova, Anel; Pasler, Lisa; Schumann, Peter; Kabisch, Johannes; Mukasheva, Togzhan; Schauer, Frieder

    2016-11-01

    Heavy contamination of soils by crude oil is omnipresent in areas of oil recovery and exploitation. Bioremediation by indigenous plants in cooperation with hydrocarbon degrading microorganisms is an economically and ecologically feasible means to reclaim contaminated soils. To study the effects of indigenous soil bacteria capable of utilizing oil hydrocarbons on biomass production of plants growing in oil-contaminated soils eight bacterial strains were isolated from contaminated soils in Kazakhstan and characterized for their abilities to degrade oil components. Four of them, identified as species of Gordonia and Rhodococcus turned out to be effective degraders. They produced a variety of organic acids from oil components, of which 59 were identified and 7 of them are hitherto unknown acidic oil metabolites. One of them, Rhodococcus erythropolis SBUG 2054, utilized more than 140 oil components. Inoculating barley seeds together with different combinations of these bacterial strains restored normal growth of the plants on contaminated soils, demonstrating the power of this approach for bioremediation. Furthermore, we suggest that the plant promoting effect of these bacteria is not only due to the elimination of toxic oil hydrocarbons but possibly also to the accumulation of a variety of organic acids which modulate the barley's rhizosphere environment. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Growth, Carbon Isotope Discrimination and Nitrogen Uptake in Silicon and/or Potassium Fed barley Grown under Two Watering Regimes

    OpenAIRE

    Kurdali, Fawaz; Al-Chammaa, Mohammad

    2013-01-01

    The present pot experiment was an attempt to monitor the beneficial effects of silicon (Si) and/or potassium (K) applications on growth and nitrogen uptake in barley plants grown under water (FC1) and non water (FC2) stress conditions using 15N and 13C isotopes. Three fertilizer rates of Si (Si 50, Si 100 and Si 200) and one fertilizer rate of K were used. Dry matter (DM) and N yield (NY) in different plant parts of barley plants was affected by Si and/ or K fertilization as well as by the wa...

  10. Aluminium localization and toxicity symptoms related to root growth ...

    Indian Academy of Sciences (India)

    We correlated root growth inhibition with aluminium (Al3+) localization and toxicity symptoms in rice roots using seedlings of two genotypes (tolerant and sensitive) that were exposed to different AlCl3 concentrations. Al3+ localization was evaluated by hematoxylin in primary roots and by morin in cross-sections of the root ...

  11. Root~Shoot Growth Interactions of Sorghmn (Sorghwn Bicolor L ...

    African Journals Online (AJOL)

    growth. Studies on root-shoot intera'ctions in relation to mechanical impedance have only investigated the effect on shoots of ... growth regulators that may be responsible. Studies of root-shoot ... of germinating seeds to MI leaving roots in rela-.

  12. Influence of Both Gamma Radiation and Nitrogen Fertilizer Levels on Growth and Productivity of Barley

    International Nuclear Information System (INIS)

    El-Khawaga, A.A.H.; Farag, I.A.A.; Eliwa, N.E.

    2013-01-01

    Influences of gamma irradiation doses (zero, 10, 20 and 30 Gy) as well as nitrogen fertilizer levels (zero, 50, 70 and 90 kg N/fad) on growth, yield and yield components of barley cultivar Giza 123 were studied during 2009-2010 and 2010-2011 seasons. The study was conducted in an extension field at Belbees District, Sharkia Governorate, Egypt. Irradiation with the lowest gamma does gave the highest value for each of emergence/m 2 , plant height at heading (cm), flag leaf area at heading (cm 2 ), spike length (cm), number of grains/spike and weight of grains/spike. Nitrogen application significantly increased emergence/m 2 , plant height, flag leaf area (cm 2 ), number of grains/spike, number of spikes/m2 as well as grain, straw and biological yields (kg/fad). Accepted September 2013.

  13. Supplementary Material for: Growth curve registration for evaluating salinity tolerance in barley

    KAUST Repository

    Meng, Rui

    2017-01-01

    Abstract Background Smarthouses capable of non-destructive, high-throughput plant phenotyping collect large amounts of data that can be used to understand plant growth and productivity in extreme environments. The challenge is to apply the statistical tool that best analyzes the data to study plant traits, such as salinity tolerance, or plant-growth-related traits. Results We derive family-wise salinity sensitivity (FSS) growth curves and use registration techniques to summarize growth patterns of HEB-25 barley families and the commercial variety, Navigator. We account for the spatial variation in smarthouse microclimates and in temporal variation across phenotyping runs using a functional ANOVA model to derive corrected FSS curves. From FSS, we derive corrected values for family-wise salinity tolerance, which are strongly negatively correlated with Na but not significantly with K, indicating that Na content is an important factor affecting salinity tolerance in these families, at least for plants of this age and grown in these conditions. Conclusions Our family-wise methodology is suitable for analyzing the growth curves of a large number of plants from multiple families. The corrected curves accurately account for the spatial and temporal variations among plants that are inherent to high-throughput experiments.

  14. Evaluation of the allelopathic potential of water-soluble compounds of barley (Hordeum vulgare L. subsp.vulgare and great brome (Bromus diandrus Roth. using a modified bioassay

    Directory of Open Access Journals (Sweden)

    Bouhaouel, I.

    2016-01-01

    Full Text Available Description of the subject. The present study focuses on the description of the allelopathic interactions between wild and crop species that may occur in a given ecosystem. Objectives. The objective is the evaluation of the allo- and autoinhibition activity of root exudates of barley (Hordeum vulgare L. subsp. vulgare and great brome (Bromus diandrus Roth. seedlings by water-soluble allelochemicals. Method. The allelopathic activities of five Tunisian barley genotypes (modern varieties and landraces, one Saudi Arabian barley landrace and great brome were assessed using a modified laboratory bioassay named "seedling-after-seedling agar method". Results. The barley or the great brome reduced, to a greater extent, the root growth compared to the shoot growth of receiver species. The response of the root system architecture of the great brome towards barley root exudates was studied in detail. All the measured root traits were highly sensitive to the presence of barley. In our conditions, the allelopathic activity of barley root exudates had no apparent relationship with the size of the root and a prominent action of genetic determinants in the allelopathic potential between genotypes is proposed. The alloinhibitory activity of barley or great brome root exudates deferred between the receiver species but was always higher than the autoinhibition potential. The autoinhibition in barley proved to depend on whether the genotypes used as donor and receiver are identical or different, suggesting a specific interaction of allelochemicals with the receiver plant. These molecules seem to be the main actors in the allelopathic barley potential as external factors such variations of pH have no evident relevance in the inhibition process. Conclusions. Barley and great brome exude molecules in their surroundings. This affects the growth of the receiver plants, suggesting that these compounds might contribute to the plant community dynamics.

  15. Biochar amendment to coarse sandy subsoil improves root growth and increases water retention

    DEFF Research Database (Denmark)

    Bruun, Esben; Petersen, C. T.; Hansen, E.

    2014-01-01

    Crop yields and yield potentials on Danish coarse sandy soils are strongly limited due to restricted root growth and poor water and nutrient retention. We investigated if biochar amendment to subsoil can improve root development in barley and significantly increase soil water retention. Spring...... barley (Hordeum vulgare cv. Anakin) was grown in soil columns (diameter: 30 cm) prepared with 25 cm topsoil, 75 cm biochar-amended subsoil, and 30 cm un-amended subsoil lowermost placed on an impervious surface. Low-temperature gasification straw-biochar (at 0, 0.50, 1.0, 2.0, and 4.0 wt%) and slow...... pyrolysis hardwood-biochar (at 2 wt%) were investigated. One wt% can be scaled up to 102 Mg/ha of char. After full irrigation and drainage, the in-situ moisture content at 30-80 cm depth increased linearly (R2 = 0.99) with straw-biochar content at a rate corresponding to 0.029 m3/m3/%. The lab determined...

  16. Two-dimensional Root Phenotyping System Based on Root Growth on Black Filter Paper and Recirculation Micro-irrigation

    Czech Academy of Sciences Publication Activity Database

    Rattanapichai, W.; Klem, Karel

    2016-01-01

    Roč. 52, č. 2 (2016), s. 64-70 ISSN 1212-1975 R&D Projects: GA MŠk(CZ) LO1415 Institutional support: RVO:67179843 Keywords : image analysis * nutrient deficiency * root system architecture * spring barley Subject RIV: EH - Ecology, Behaviour Impact factor: 0.532, year: 2016

  17. Growth and yield of barley (Hordeum vulgare L.) as affected by ...

    African Journals Online (AJOL)

    Bheema

    (2003) reported that about 65% of grain yield variability in barley was attributed to ... of those of the respective non-stressed environments (Cantero-Martínez et ... production stability of barley (Fekadu and Skjelvåg, 2002) and nitrogen and phosphorus are .... of SAS version 9.1 for analysis of variance of non-orthogonal data.

  18. Growth, Carbon Isotope Discrimination and Nitrogen Uptake in Silicon and/or Potassium Fed barley Grown under Two Watering Regimes

    Directory of Open Access Journals (Sweden)

    Kurdali, Fawaz

    2013-02-01

    Full Text Available The present pot experiment was an attempt to monitor the beneficial effects of silicon (Si and/or potassium (K applications on growth and nitrogen uptake in barley plants grown under water (FC1 and non water (FC2 stress conditions using 15N and 13C isotopes. Three fertilizer rates of Si (Si50, Si100 and Si200 and one fertilizer rate of K were used. Dry matter (DM and N yield (NY in different plant parts of barley plants was affected by Si and/ or K fertilization as well as by the watering regime level under which the plants have been grown. Solely added K or in combination with adequate rate of Si (Si 100 were more effective in alleviating water stress and producing higher yield in barley plants than solely added Si. However, the latter nutrient was found to be more effective than the former in producing higher spike's N yield. Solely added Si or in combination with K significantly reduced leaves ∆13 C reflecting their bifacial effects on water use efficiency (WUE, particularly in plants grown under well watering regime. This result indicated that Si might be involved in saving water loss through reducing transpiration rate and facilitating water uptake; consequently, increasing WUE. Although the rising of soil humidity generally increased fertilizer nitrogen uptake (Ndff and its use efficiency (%NUE in barley plants, applications of K or Si fertilizers to water stressed plants resulted in significant increments of these parameters as compared with the control. Our results highlight that Si or K is not only involved in amelioration of growth of barley plants, but can also improve nitrogen uptake and fertilizer nitrogen use efficiency particularly under water deficit conditions.

  19. EFFECTS OF SOME PLANT GROWTH REGULATORS ON JASMONIC ACID INDUCED INHIBITION OF SEED GERMINATION AND SEEDLING GROWTH OF BARLEY

    Directory of Open Access Journals (Sweden)

    Kürşat ÇAVUŞOĞLU

    2009-02-01

    Full Text Available Abstract: The effects of gibberellic acid, kinetin, benzyladenine, ethylene, 24-epibrassinolide and polyamines (spermine, spermidine, putrescine, cadaverine on jasmonic acid inhibition of seed germination and seedling growth of barley were studied. All of the plant growth regulators studied were determined to have a succesful performance in reversing of the inhibitory effects of jasmonic acid on the seed germination and seedling growth. Moreover, the above mentioned growth regulators overcame the inhibitory effect of JA on the percentages of germination and coleoptile emergence in the same ratio, while GA3 was the most successful hormone on the fresh weight and radicle and coleoptile elongation in comparison with the other growth regulators. Key words: Barley, jasmonic acid, plant growth regulator, seed germination, seedling growth ARPANIN TOHUM ÇİMLENMESİ VE FİDE BÜYÜMESİNİN JASMONİK ASİT TEŞVİKLİ İNHİBİSYONU ÜZERİNE BAZI BİTKİ BÜYÜME DÜZENLEYİCİLERİNİN ETKİLERİ Özet: Arpanın tohum çimlenmesi ve fide büyümesinin jasmonik asit inhibisyonu üzerine gibberellik asit, kinetin, benziladenin, etilen, 24-epibrassinolit ve poliaminlerin (spermin, spermidin, putressin, kadaverin etkileri araştırılmıştır. Çalışılan bitki büyüme düzenleyicilerinin tümünün tohum çimlenmesi ve fide büyümesi üzerinde jasmonik asitin engelleyici etkisini tersine çevirmede başarılı bir performansa sahip oldukları belirlenmiştir. Dahası, yukarıda sözü edilen büyüme düzenleyicileri çimlenme ve koleoptil çıkış yüzdeleri üzerinde aynı oranda etkili olurken, taze ağırlık ve radikula ve koleoptil uzaması üzerinde diğer büyüme düzenleyicileri ile karşılaştırıldığında en başarılı hormon GA3 olmuştur. Anahtar kelimeler: Arpa, jasmonik asit, bitki büyüme düzenleyicisi, tohum çimlenmesi, fide büyümesi

  20. Root growth in corn and soybeans: effects of cadmium and lead on lateral root initiation

    Energy Technology Data Exchange (ETDEWEB)

    Malone, C P; Miller, R J; Koeppe, D E

    1978-02-01

    This study examines the previously reported inhibitory effects of Cd on root growth. In hydroponic experiments, 100 ..mu..g Cd/l effected a 33% inhibition of lateral root initiation of corn. The growth of corn and soybean primary roots was not reduced at Cd concentrations of 1 mg/l, and the number of lateral root initials in soybeans was not reduced at 2 mg Cd/l. The toxic effects of Cd were ameliorated by additions of Zn or by additions of Fe citrate to nutrient growth solutions. While both Zn and Fe additions did result in increased lateral root initiation, the number of initials was significantly lower than the controls. Lead had no effect on the initiation of soybean lateral roots at a concentration of 100 ..mu..g Pb/l. However, 5 mg Pb/l did effect a 21% decrease in corn lateral root initials, but this decrease could not be demonstrated with higher Pb concentrations.

  1. [Effects nutrients on the seedlings root hair development and root growth of Poncirus trifoliata under hydroponics condition].

    Science.gov (United States)

    Cao, Xiu; Xia, Ren-Xue; Zhang, De-Jian; Shu, Bo

    2013-06-01

    Ahydroponics experiment was conducted to study the effects of nutrients (N, P, K, Ca, Mg, Fe, and Mn) deficiency on the length of primary root, the number of lateral roots, and the root hair density, length, and diameter on the primary root and lateral roots of Poncirus trifoliata seedlings. Under the deficiency of each test nutrient, root hair could generate, but was mainly concentrated on the root base and fewer on the root tip. The root hair density on lateral roots was significantly larger than that on primary root, but the root hair length was in adverse. The deficiency of each test nutrient had greater effects on the growth and development of root hairs, with the root hair density on primary root varied from 55.0 to 174.3 mm(-2). As compared with the control, Ca deficiency induced the significant increase of root hair density and length on primary root, P deficiency promoted the root hair density and length on the base and middle part of primary root and on the lateral roots significantly, Fe deficiency increased the root hair density but decreased the root hair length on the tip of primary root significantly, K deficiency significantly decreased the root hair density, length, and diameter on primary root and lateral roots, whereas Mg deficiency increased the root hair length of primary root significantly. In all treatments of nutrient deficiency, the primary root had the similar growth rate, but, with the exceptions of N and Mg deficiency, the lateral roots exhibited shedding and regeneration.

  2. Quantification of water uptake by arbuscular mycorrhizal hyphae and its significance for leaf growth, water relations, and gas exchange of barley subjected to drought stress.

    Science.gov (United States)

    Khalvati, M A; Hu, Y; Mozafar, A; Schmidhalter, U

    2005-11-01

    Arbuscular mycorrhizal fungi alleviate drought stress in their host plants via the direct uptake and transfer of water and nutrients through the fungal hyphae to the host plants. To quantify the contribution of the hyphae to plant water uptake, a new split-root hyphae system was designed and employed on barley grown in loamy soil inoculated with Glomus intraradices under well-watered and drought conditions in a growth chamber with a 14-h light period and a constant temperature (15 degrees C; day/night). Drought conditions were initiated 21 days after sowing, with a total of eight 7-day drying cycles applied. Leaf water relations, net photosynthesis rates, and stomatal conductance were measured at the end of each drying cycle. Plants were harvested 90 days after sowing. Compared to the control treatment, the leaf elongation rate and the dry weight of the shoots and roots were reduced in all plants under drought conditions. However, drought resistance was comparatively increased in the mycorrhizal host plants, which suffered smaller decreases in leaf elongation, net photosynthetic rate, stomatal conductance, and turgor pressure compared to the non-mycorrhizal plants. Quantification of the contribution of the arbuscular mycorrhizal hyphae to root water uptake showed that, compared to the non-mycorrhizal treatment, 4 % of water in the hyphal compartment was transferred to the root compartment through the arbuscular mycorrhizal hyphae under drought conditions. This indicates that there is indeed transport of water by the arbuscular mycorrhizal hyphae under drought conditions. Although only a small amount of water transport from the hyphal compartment was detected, the much higher hyphal density found in the root compartment than in the hyphal compartment suggests that a larger amount of water uptake by the arbuscular mycorrhizal hyphae may occur in the root compartment.

  3. Aluminium localization and toxicity symptoms related to root growth ...

    Indian Academy of Sciences (India)

    2012-10-26

    Oct 26, 2012 ... Aluminium localization and toxicity symptoms related to root growth inhibition in rice (Oryza sativa ... growth of this cultivar when submitted to Al3+ stress. Moreover ..... Caiapó. Previous work has shown the IAC cultivar to be.

  4. Partial substitution of barley for corn: effect on "Hamra" lamb growth performance, carcass and meat characteristics.

    Science.gov (United States)

    Ziani, Kaddour; Khaled, Méghit Boumédiène

    2016-03-01

    The aim of this study was to investigate the effect of two kinds of given diets on growth, on some carcass characteristics and on the major meat nutrients of local Algerian sheep breed. The investigated sheep breed called "Hamra" is one of the most famous breeds in Algeria. Among one 106 animals, 40 lambs were selected according to their age, similar livestock characteristics and body weight. The samples were divided into two equal groups: control and experimental lambs according to their live weight; 24.63 ± 0.47 and 24.35 ± 0.64 kg, respectively. Both groups were fed with two varieties of concentrate diets: corn diet based for the first group of control lambs (n = 20) and corn substituted by barley (Variety Saïda 183) for the second experimental group lambs (n = 20). Both diets were supplemented with 200 g straw of barley/animal/ration. The chemical analysis of diets showed an elevated crude fibre content in the commercial concentrate. However, the experimental concentrate contained higher amounts of calcium. After 59 days of fattening, no significant difference was found among the two studied groups on the growth performance (p > 0.05), showing the same final body weight. In contrast, a significant difference was found (p ≤ 0.001) in relation to the cost of the given diet. This could affect the price of the produced meat. At 37.85 ± 0.78 kg live weight, 10 lambs fed with experimental concentrate were slaughtered. The dressing percentage was 46.65 %, with 2.49 % of carcass shrink. Furthermore, an interesting percentage of total muscle was obtained (63.73 %) with a good carcass conformation scoring 9.56. Compared to other breed sheep, Hamra carcass could be considered as the most valuable one economically.

  5. Root Growth and Water distribution in living walls

    DEFF Research Database (Denmark)

    Jørgensen, Lars

    of functional living walls and this thesis is a first step of understanding the essential but hidden part inside the growing medium, i.e. the roots. Ensuring successful performance of the plants in a living wall is complex and the choice of growing medium, plant species and planting position are important....... for root growth. This thesis investigates the correlations between the growing media and root and shoots growth, and studies root growth patterns of different plant species and effects of planting position and root interactions of plants growing in living walls. There are a number of challenges with living...... walls; the vertical orientation of the growing medium, plants are growing vertically above or below each other in a limited rooting volume; there is an increased exposure to weather and the plants can react differently to water conditions and competition from other plants. Plant growth is the core...

  6. [The influence of root excretions of germinating barley seed (Hordeum vulgare L.) on qualitative and quantitative composition of soil organic components].

    Science.gov (United States)

    Volkov, O I

    2010-01-01

    The data from scientific publications on excretory activity of herbs root endings were analyzed, along with the data on the role of polyvalent metals cations in stabilization of humus substances (HS) of soil organic mineral complex. On the base of the analysis a working hypothesis was proposed considering root endings influence on fractional composition of soil organic components. To detect the changes taking place in soil HS, the chromatographic fractionation method was chosen. The soil aggregates stuck to root endings of germinating barley seed were washed off, and the washouts were used as the samples for the analysis. The soil from the weighed portion was dissolved directly with extenuating concentrations of LiCl and Li2SO4 alkaline solution. The fractionation was carried out in a chromatographic column. Some changes were detected in optical density of chernozem and dark-grey forest soil leached out after 1-2 days of barley seeds germination. Besides, the experiment showed that the content of organic carbon in HS changes as well.

  7. Nematode assemblages in the rhizosphere of spring barley (Hordeum vulgare L.) depended on fertilisation and plant growth phase

    DEFF Research Database (Denmark)

    Madsen, Mette Vestergård

    2004-01-01

    rhizosphere; nitrogen and phosphorus fertilisation; nematode assemblages; plant parasites; barley......rhizosphere; nitrogen and phosphorus fertilisation; nematode assemblages; plant parasites; barley...

  8. Root growth, secondary root formation and root gravitropism in carotenoid-deficient seedlings of Zea mays L

    Science.gov (United States)

    Ng, Y. K.; Moore, R.

    1985-01-01

    The effect of ABA on root growth, secondary-root formation and root gravitropism in seedlings of Zea mays was investigated by using Fluridone-treated seedlings and a viviparous mutant, both of which lack carotenoids and ABA. Primary roots of seedlings grown in the presence of Fluridone grew significantly slower than those of control (i.e. untreated) roots. Elongation of Fluridone-treated roots was inhibited significantly by the exogenous application of 1 mM ABA. Exogenous application of 1 micromole and 1 nmole ABA had either no effect or only a slight stimulatory effect on root elongation, depending on the method of application. The absence of ABA in Fluridone-treated plants was not an important factor in secondary-root formation in seedlings less than 9-10 d old. However, ABA may suppress secondary-root formation in older seedlings, since 11-d-old control seedlings had significantly fewer secondary roots than Fluridone-treated seedlings. Roots of Fluridone-treated and control seedlings were graviresponsive. Similar data were obtained for vp-9 mutants of Z. mays, which are phenotypically identical to Fluridone-treated seedlings. These results indicate that ABA is necessary for neither secondary-root formation nor for positive gravitropism by primary roots.

  9. Supplementary Material for: Growth curve registration for evaluating salinity tolerance in barley

    KAUST Repository

    Meng, Rui; Saade, Stephanie; Kurtek, Sebastian; Berger, Bettina; Brien, Chris; Pillen, Klaus; Tester, Mark A.; Sun, Ying

    2017-01-01

    of HEB-25 barley families and the commercial variety, Navigator. We account for the spatial variation in smarthouse microclimates and in temporal variation across phenotyping runs using a functional ANOVA model to derive corrected FSS curves. From FSS, we

  10. GROWTH PERFORMANCE AND CARCASS COMPOSITION OF RABBITS FED ON DIETS OF GRADUAL LEVELS OF BARLEY GRAIN

    Directory of Open Access Journals (Sweden)

    M.M. El-Adawy

    2012-05-01

    Full Text Available Forty-eight male New Zealand White rabbits of 6 weeks age (BW 875 ± 28.3 g were randomly allocated among six groups in different levels of barley grains (BG; 0 (B0, 5 (B5, 10 (B10, 15 (B15, 20 (B20, 25% (B25 of the total diet on growth performance and carcass composition of rabbits . The highest live BW value (P < 0.05 was obtained in B20 rabbits, whereas the highest feed intake (P < 0.05 value was obtained in B25 rabbits followed by those fed on the other diets. The better-feed conversion ratio (FCR was obtained in B20 rabbits followed by those of B15 and B25. Animals of B20 had better FCR than those of the other experimental diets. The relative contribution of soft feces to dry matter or crude protein intake differed (P < 0.05 among the experimental diets. The caecal turnover rate was increased (P < 0.05 in B15 and B20 rabbits than those other diets. The per-slaughter weight, hot and cold carcass weight and dressing percentage were differed (P < 0.05 among the experimental groups and highest values were recorded in B20 rabbits. Data suggested that a partial replacement of corn grains (CG by 20% BG in rabbit diets was increased live body weight, feed intake and feed conversion ratio.

  11. QTL mapping of root traits in phosphorus-deficient soils reveals important genomic regions for improving NDVI and grain yield in barley.

    Science.gov (United States)

    Gong, Xue; McDonald, Glenn

    2017-09-01

    Major QTLs for root rhizosheath size are not correlated with grain yield or yield response to phosphorus. Important QTLs were found to improve phosphorus efficiency. Root traits are important for phosphorus (P) acquisition, but they are often difficult to characterize and their breeding values are seldom assessed under field conditions. This has shed doubts on using seedling-based criteria of root traits to select and breed for P efficiency. Eight root traits were assessed under controlled conditions in a barley doubled-haploid population in soils differing in P levels. The population was also phenotyped for grain yield, normalized difference vegetation index (NDVI), grain P uptake and P utilization efficiency at maturity (PutE GY ) under field conditions. Several quantitative traits loci (QTLs) from the root screening and the field trials were co-incident. QTLs for root rhizosheath size and root diameter explained the highest phenotypic variation in comparison to QTLs for other root traits. Shared QTLs were found between root diameter and grain yield, and total root length and PutE GY . A common major QTL for rhizosheath size and NDVI was mapped to the HvMATE gene marker on chromosome 4H. Collocations between major QTLs for NDVI and grain yield were detected on chromosomes 6H and 7H. When results from BIP and MET were combined, QTLs detected for grain yield were also those QTLs found for NDVI. QTLs qGY5H, qGY6H and qGY7Hb on 7H were robust QTLs in improving P efficiency. A selection of multiple loci may be needed to optimize the breeding outcomes due to the QTL x Environment interaction. We suggest that rhizosheath size alone is not a reliable trait to predict P efficiency or grain yield.

  12. Jasmonic Acid Enhances Al-Induced Root Growth Inhibition.

    Science.gov (United States)

    Yang, Zhong-Bao; He, Chunmei; Ma, Yanqi; Herde, Marco; Ding, Zhaojun

    2017-02-01

    Phytohormones such as ethylene and auxin are involved in the regulation of the aluminum (Al)-induced root growth inhibition. Although jasmonate (JA) has been reported to play a crucial role in the regulation of root growth and development in response to environmental stresses through interplay with ethylene and auxin, its role in the regulation of root growth response to Al stress is not yet known. In an attempt to elucidate the role of JA, we found that exogenous application of JA enhanced the Al-induced root growth inhibition. Furthermore, phenotype analysis with mutants defective in either JA biosynthesis or signaling suggests that JA is involved in the regulation of Al-induced root growth inhibition. The expression of the JA receptor CORONATINE INSENSITIVE1 (COI1) and the key JA signaling regulator MYC2 was up-regulated in response to Al stress in the root tips. This process together with COI1-mediated Al-induced root growth inhibition under Al stress was controlled by ethylene but not auxin. Transcriptomic analysis revealed that many responsive genes under Al stress were regulated by JA signaling. The differential responsive of microtubule organization-related genes between the wild-type and coi1-2 mutant is consistent with the changed depolymerization of cortical microtubules in coi1 under Al stress. In addition, ALMT-mediated malate exudation and thus Al exclusion from roots in response to Al stress was also regulated by COI1-mediated JA signaling. Together, this study suggests that root growth inhibition is regulated by COI1-mediated JA signaling independent from auxin signaling and provides novel insights into the phytohormone-mediated root growth inhibition in response to Al stress. © 2017 American Society of Plant Biologists. All Rights Reserved.

  13. Root growth during molar eruption in extant great apes.

    Science.gov (United States)

    Kelley, Jay; Dean, Christopher; Ross, Sasha

    2009-01-01

    While there is gradually accumulating knowledge about molar crown formation and the timing of molar eruption in extant great apes, very little is known about root formation during the eruption process. We measured mandibular first and second molar root lengths in extant great ape osteological specimens that died while either the first or second molars were in the process of erupting. For most specimens, teeth were removed so that root lengths could be measured directly. When this was not possible, roots were measured radiographically. We were particularly interested in the variation in the lengths of first molar roots near the point of gingival emergence, so specimens were divided into early, middle and late phases of eruption based on the number of cusps that showed protein staining, with one or two cusps stained equated with immediate post-gingival emergence. For first molars at this stage, Gorilla has the longest roots, followed by Pongo and Pan. Variation in first molar mesial root lengths at this stage in Gorilla and Pan, which comprise the largest samples, is relatively low and represents no more than a few months of growth in both taxa. Knowledge of root length at first molar emergence permits an assessment of the contribution of root growth toward differences between great apes and humans in the age at first molar emergence. Root growth makes up a greater percentage of the time between birth and first molar emergence in humans than it does in any of the great apes. Copyright (c) 2009 S. Karger AG, Basel.

  14. Influence of PEG induced drought stress on molecular and biochemical constituents and seedling growth of Egyptian barley cultivars

    Directory of Open Access Journals (Sweden)

    F.A. Hellal

    2018-06-01

    Full Text Available In order to investigate the effects of drought stress on germination components of barley cultivars, a laboratory experiment was conducted in a factorial randomized complete design with four replications. The controlled experiment included ten of Egyptian barley cultivars namely; (Giza 123, 124, 125, 126, 127, 129, 130, 134, 135 and 2000 as first factor. The second factor included 4 levels of drought stress inducer by applying 0, 5, 10 and 20% of polyethylene glycol-6000 (PEG which is equivalent to four osmotic potential levels including −0.001, −0.27, −0.54 and −1.09 MPa, respectively. The results showed that, the highest reduction was related to the drought level of 20% PEG among the barley cultivars. The best cultivars in terms of germination traits were Giza 134, Giza 127, and Giza 126 this indicate their tolerance to drought stress and Giza 130, 135, 2000 cultivars was moderately tolerance and remaining is less tolerance. The protein band 27 kDa and 78 kDa showed high intensity after stress in almost all cultivars. Those two protein bands their exciting was very clear in treated barley leaf tissue. It could be related to dehydrine and oxygen evolving enhancer protein 2 (OEE2 which involved in drought stress tolerance response. Cultivars Giza 127, 130 and 134 showed highest tolerance response under drought stress. The antioxidant enzymes PAGE pattern of Peroxidase (POX, Sodium dismutase (SOD and Ascorbate peroxidase (APX for Barley cultivars under drought stress revealed a high activities for Giza 126, 127, 134, 136 and 2000 under −0.5 MPa osmotic stress by PEG in most of their isoforms. Based on similarity coefficient values the highest values were 1.0 with 100% similarly between tolerant cultivars Giza 130 and Giza 127. Similarly between the susceptible cultivars 125 and Giza 129 was 60%.These data confirmed by the growth parameters which we ranked as tolerant to drought stress. Keywords: Barley, Drought stress, Seed germination

  15. Root morphology and growth of bare-root seedlings of Oregon white oak

    Science.gov (United States)

    Peter J. Gould; Constance A. Harrington

    2009-01-01

    Root morphology and stem size were evaluated as predictors of height and basal-area growth (measured at groundline) of 1-1 Oregon white oak (Quercus garryana Dougl. ex Hook.) seedlings planted in raised beds with or without an additional irrigation treatment. Seedlings were classified into three root classes based on a visual assessment of the...

  16. Jatropha curcas L. Root Structure and Growth in Diverse Soils

    Science.gov (United States)

    Valdés-Rodríguez, Ofelia Andrea; Sánchez-Sánchez, Odilón; Pérez-Vázquez, Arturo; Caplan, Joshua S.; Danjon, Frédéric

    2013-01-01

    Unlike most biofuel species, Jatropha curcas has promise for use in marginal lands, but it may serve an additional role by stabilizing soils. We evaluated the growth and structural responsiveness of young J. curcas plants to diverse soil conditions. Soils included a sand, a sandy-loam, and a clay-loam from eastern Mexico. Growth and structural parameters were analyzed for shoots and roots, although the focus was the plasticity of the primary root system architecture (the taproot and four lateral roots). The sandy soil reduced the growth of both shoot and root systems significantly more than sandy-loam or clay-loam soils; there was particularly high plasticity in root and shoot thickness, as well as shoot length. However, the architecture of the primary root system did not vary with soil type; the departure of the primary root system from an index of perfect symmetry was 14 ± 5% (mean ± standard deviation). Although J. curcas developed more extensively in the sandy-loam and clay-loam soils than in sandy soil, it maintained a consistent root to shoot ratio and root system architecture across all types of soil. This strong genetic determination would make the species useful for soil stabilization purposes, even while being cultivated primarily for seed oil. PMID:23844412

  17. Jatropha curcas L. root structure and growth in diverse soils.

    Science.gov (United States)

    Valdés-Rodríguez, Ofelia Andrea; Sánchez-Sánchez, Odilón; Pérez-Vázquez, Arturo; Caplan, Joshua S; Danjon, Frédéric

    2013-01-01

    Unlike most biofuel species, Jatropha curcas has promise for use in marginal lands, but it may serve an additional role by stabilizing soils. We evaluated the growth and structural responsiveness of young J. curcas plants to diverse soil conditions. Soils included a sand, a sandy-loam, and a clay-loam from eastern Mexico. Growth and structural parameters were analyzed for shoots and roots, although the focus was the plasticity of the primary root system architecture (the taproot and four lateral roots). The sandy soil reduced the growth of both shoot and root systems significantly more than sandy-loam or clay-loam soils; there was particularly high plasticity in root and shoot thickness, as well as shoot length. However, the architecture of the primary root system did not vary with soil type; the departure of the primary root system from an index of perfect symmetry was 14 ± 5% (mean ± standard deviation). Although J. curcas developed more extensively in the sandy-loam and clay-loam soils than in sandy soil, it maintained a consistent root to shoot ratio and root system architecture across all types of soil. This strong genetic determination would make the species useful for soil stabilization purposes, even while being cultivated primarily for seed oil.

  18. Jatropha curcas L. Root Structure and Growth in Diverse Soils

    Directory of Open Access Journals (Sweden)

    Ofelia Andrea Valdés-Rodríguez

    2013-01-01

    Full Text Available Unlike most biofuel species, Jatropha curcas has promise for use in marginal lands, but it may serve an additional role by stabilizing soils. We evaluated the growth and structural responsiveness of young J. curcas plants to diverse soil conditions. Soils included a sand, a sandy-loam, and a clay-loam from eastern Mexico. Growth and structural parameters were analyzed for shoots and roots, although the focus was the plasticity of the primary root system architecture (the taproot and four lateral roots. The sandy soil reduced the growth of both shoot and root systems significantly more than sandy-loam or clay-loam soils; there was particularly high plasticity in root and shoot thickness, as well as shoot length. However, the architecture of the primary root system did not vary with soil type; the departure of the primary root system from an index of perfect symmetry was 14±5% (mean ± standard deviation. Although J. curcas developed more extensively in the sandy-loam and clay-loam soils than in sandy soil, it maintained a consistent root to shoot ratio and root system architecture across all types of soil. This strong genetic determination would make the species useful for soil stabilization purposes, even while being cultivated primarily for seed oil.

  19. Root Exudate Effect on Germination and Mycelial Growth of ...

    African Journals Online (AJOL)

    The effect of some root exudates on the germination and mycelial growth of sclerotia of Sclerotium rolfsii Sacc. was studied. Root exudates of 5 – 10 days old seedlings from five plants viz: - tomato (Lycopersicum esculenta) maize (Zea mays), garden egg (Solanum melongena), pigeon pea (Cajanus cajan), and pepper ...

  20. Effects of Vietnamese Sophora root on growth, adhesion, invasion ...

    African Journals Online (AJOL)

    Background: Vietnamese Sophora Root mainly contains active constituents such as alkaloids, and it has anti-tumour, antibacterial, and anti-inflammatory effects. The objective of the paper was to study the effects of Vietnamese Sophora Root on growth, adhesion, invasion and motility of mouse melanoma B16BL6 cells, and ...

  1. Isolation and characterization of altered root growth behavior and ...

    African Journals Online (AJOL)

    Ezedom Theresa

    2013-10-02

    Oct 2, 2013 ... contrasting root growth behavior and salinity tolerance in rice will help us to identify key genes controlling ..... In order to screen plants showing altered response ... were found to remain green even after 15 days of salinity.

  2. Uptake of [14C]triadimenol via grain and root after seed treatment of winter barley with a flowable seed dressing: Influence of soil moisture and sowing date on the distribution of radioactivity and active ingredient content in plant and soil

    International Nuclear Information System (INIS)

    Schneider, M.

    1988-12-01

    Winter barley seed of the 'Vogelsander Gold' variety was shown in a total of 7 lysimeters after seed treatment with [benzene ring-U- 14 C]triadimenol in the formulation as [ 14 C]Baytan 075 FS and [ 14 C]Baytan 25 DS at an early (September) and a late date (October). After both dates of sowing, the FS-treated winter barley developed under 3 different soil moisture conditions. The radioactivity and active ingredient contents in plants and soil were recorded until tillering as a function of low, high and natural precipitation after sowing. Details on the uptake of radioactivity via grain and roots were quantitatively and qualitatively studied in two further lysimeters, a pot experiment as well as experiments in the growth chamber. The results are presented and discussed in detail. (orig./MG) [de

  3. Winter Wheat Root Growth and Nitrogen Relations

    DEFF Research Database (Denmark)

    Rasmussen, Irene Skovby

    in winter wheat (Triticum aestivum L). Field experiments on the effect of sowing date, N fertilization and cultivars were conducted on a sandy loam soil in Taastrup, Denmark. The root studies were conducted by means of the minirhizotron method. Also, a field experiment on the effect of defoliation and N...

  4. Genetic variability in uptake of nitrogen at various growth stages of barley and wheat under dryland conditions

    International Nuclear Information System (INIS)

    Della, A.; Hadjichristodoulou, A.

    1976-01-01

    Protein and dry matter in a number of high protein and commercial varieties of barley and wheat were tested at various growth stages and at two locations. Large genetic variability was found in uptake of nitrogen, which was taken up generally before heading. High protein yields were not associated with high protein content but with higher dry matter yields. Nitrogen fertilization increased protein content and protein yield at a low protein location only. It was concluded that it is possible to breed for both high grain and high straw protein varieties. (author)

  5. Barley uptake of N deposited in the rhizosphere of associated field pea

    DEFF Research Database (Denmark)

    Jensen, E.S.

    1996-01-01

    N deposited in the rhizosphere of a legume may contribute to the N-nutrition of an intercropped non-legume. The process of deposition and subsequent uptake by a neighbouring plant is often termed N-transfer. The N-transfer from field pea (Pisum sativum L.) to associated spring barley (Hordeum...... debris. Separating the root systems reduced the barley recovery of pea-derived N to about half the amount recovered in the association where root systems grew in the same compartment. The death of pea, caused by spraying with a herbicide, increased the amount of N recovered in barley, whereas shading...... the pea plant had no effect on the amount of pea-derived N taken up in barley. The N deposited up to 45 days of growth contributed

  6. Root distribution and its association with bean growth habit

    Directory of Open Access Journals (Sweden)

    LUIS P.S. VELHO

    2018-04-01

    Full Text Available ABSTRACT Associations between root distribution and bean growth habit may contribute to the selection of genotypes adapted to restrictive environments. The present work aimed to relate and compare root distribution with the growth habit in beans. 10 bean genotypes of different growth habits (I, II and III were evaluated for root distribution in two agricultural years (2014/15 and 2015/16. The genotypes responded similarly for the trait root distribution throughout the agricultural years, without any simple effect of the genotype x year interaction. The factors genotype and years were significant for the trait. The genotypes of a determinate habit showed significant differences compared to other genotypes (II and III, which were ascribed to their poor performance in the average of years. They include the Carioca Precoce, which showed a behavior similar to the other habits. It could be considered a “plastic” genotype under restrictive conditions. The contrasts revealed significant differences between the growth habits II vs I (2.87 and III vs I (3.64 for root distribution. The differences were also significant for grain yield. Thus, genotypes of indeterminate growth habit show greater root distribution than those of a determinate habit, regardless of the agricultural years. Therefore, they are promising for use in blocks of crosses, when the purpose is the selection of cultivars adapted to low input environments.

  7. Exogenous nitrate induces root branching and inhibits primary root growth in Capsicum chinense Jacq.

    Science.gov (United States)

    Celis-Arámburo, Teresita de Jesús; Carrillo-Pech, Mildred; Castro-Concha, Lizbeth A; Miranda-Ham, María de Lourdes; Martínez-Estévez, Manuel; Echevarría-Machado, Ileana

    2011-12-01

    The effects of nitrate (NO₃⁻) on the root system are complex and depend on several factors, such as the concentration available to the plant, endogenous nitrogen status and the sensitivity of the species. Though these effects have been widely documented on Arabidopsis and cereals, no reports are available in the Capsicum genus. In this paper, we have determined the effect of an exogenous in vitro application of this nutrient on root growth in habanero pepper (Capsicum chinense Jacq.). Exposure to NO₃⁻ inhibited primary root growth in both, dose- and time-dependent manners. The highest inhibition was attained with 0.1 mM NO₃⁻ between the fourth and fifth days of treatment. Inhibition of primary root growth was observed by exposing the root to both homogeneous and heterogeneous conditions of the nutrient; in contrast, ammonium was not able to induce similar changes. NO₃⁻-induced inhibition of primary root growth was reversed by treating the roots with IAA or NPA, a polar auxin transport inhibitor. Heterogeneous NO₃⁻ application stimulated the formation and elongation of lateral roots in the segment where the nutrient was present, and this response was influenced by exogenous phytohormones. These results demonstrate that habanero pepper responds to NO₃⁻ in a similar fashion to other species with certain particular differences. Therefore, studies in this model could help to elucidate the mechanisms by which roots respond to NO₃⁻ in fluctuating soil environments. Copyright © 2011 Elsevier Masson SAS. All rights reserved.

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

    Science.gov (United States)

    Gerbode, Sharon; Noar, Roslyn; Harrison, Maria

    2009-03-01

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

  9. Field grown Acacia Mangium: how intensive is root growth?

    International Nuclear Information System (INIS)

    Wan Rasidah Kadir; Azizol Abdul Kadir; Van Cleemput, O.; Zaharah Abdul Rahman

    1998-01-01

    Under rainfed conditions, root development of trees can be very unpredictable and variable, depending on the amount and distribution of rainfall received. This becomes more critical when the rainfall is seasonal and the soil has a high clay content. Our investigation dealt with the root development of Acacia mangium established as plantation forest on a soil with heavy clay texture in Kemasul Forest Reserve, Malaysia. The distribution of active roots was measured at 9- and 21- month-old plantations using the radioactive P injection method. Growth at different distances from the tree base and at different soil depths was studied. After nine months of field planting, we found that roots were mostly concentrated at the surface within 1000 mm distance from the tree base. At one year after the first measurement, roots were traced as far as 6400 mm away. A large part of these roots, however, were detected within 3700 mm distance in the upper 300 mm soil. At this stage, roots can still did not go deeper than 450 mm depth, probably due to the high clay content at lower depth and low pH. This rapid root growth indicates that below-ground competition can be very intense if this species is established as a mixed-species plantation

  10. Root Growth Optimizer with Self-Similar Propagation

    Directory of Open Access Journals (Sweden)

    Xiaoxian He

    2015-01-01

    Full Text Available Most nature-inspired algorithms simulate intelligent behaviors of animals and insects that can move spontaneously and independently. The survival wisdom of plants, as another species of biology, has been neglected to some extent even though they have evolved for a longer period of time. This paper presents a new plant-inspired algorithm which is called root growth optimizer (RGO. RGO simulates the iterative growth behaviors of plant roots to optimize continuous space search. In growing process, main roots and lateral roots, classified by fitness values, implement different strategies. Main roots carry out exploitation tasks by self-similar propagation in relatively nutrient-rich areas, while lateral roots explore other places to seek for better chance. Inhibition mechanism of plant hormones is applied to main roots in case of explosive propagation in some local optimal areas. Once resources in a location are exhausted, roots would shrink away from infertile conditions to preserve their activity. In order to validate optimization effect of the algorithm, twelve benchmark functions, including eight classic functions and four CEC2005 test functions, are tested in the experiments. We compared RGO with other existing evolutionary algorithms including artificial bee colony, particle swarm optimizer, and differential evolution algorithm. The experimental results show that RGO outperforms other algorithms on most benchmark functions.

  11. On the influence of abiotic stress conditions on growth of barley and bean and their predisposition for pathogens

    Energy Technology Data Exchange (ETDEWEB)

    Oerke, E.C.; Schoenbeck, F.

    1986-01-01

    Shorttime changes of environmental conditions stressed barley and bean and affected plant growth and their predisposition for various pathogens. Moderate stress intensities as low or high temperatures, water or light deficits, increased the susceptibility to Erysiphe graminis var. hordei or Uromyces phaseoli and reduced disease level of spot blotch caused by Cochliobolus sativus, respectively. There was only little effect on plant growth in that case. Intensive stress as a result of combinations of unfavorable environmental conditions or longtime continuance of moderate stress reduced the plant growth and turned the predisposing effect to the opposite: after the treatment, plants were more resistent to diseases caused by biotrophic fungi, whereas there was increased susceptibility to the perthotrophic fungus. High intensities of fertilization acted as an additional stress and intensified the plant reaction to environmental alterations. The variation of the predisposition is discussed in relation to stress intensity.

  12. Hair Growth Promotant Activity of Petroleum Ether Root Extract of ...

    African Journals Online (AJOL)

    Purpose: To investigate the effect of Glycyrrhiza glabra root extract on hair growth in female Wistar rats. Methods: Female Wistar rats were used for the hair growth promotion studies. They were divided into three groups(n = 6) and their dorsal skin was completely denuded to completely remove hair. Paraffin oil (control), 2 ...

  13. Effects of Growth Hormones on Sprouting and Rooting of Jatropha ...

    African Journals Online (AJOL)

    MICHAEL HORSFALL

    ABSTRACT: This study was conducted to assess the effect of growth hormone on sprouting and rooting ability of Jatropha curcas (L). Stem cuttings from mature plants were treated with two types of growth hormones: Naphthalene Acetic Acid and Indole-3-Butyric Acid while the untreated cuttings were used as control.

  14. High temperature combined with drought affect rainfed spring wheat and barley in South-Eastern Russia: I. Phenology and growth

    Science.gov (United States)

    Hossain, Akbar; Teixeira da Silva, Jaime A.; Lozovskaya, Marina Viacheslavovna; Zvolinsky, Vacheslav Petrovich

    2012-01-01

    Heat stress, when combined with drought, is one of the major limitations to food production worldwide, especially in areas that use rainfed agriculture. As the world population continues to grow, and water resources for the crop production decline and temperature increases, so the development of heat- and drought-tolerant cultivars is an issue of global concern. In this context, four barley and two wheat genotypes were evaluated in south-eastern Russia to identify heat- and drought-tolerant genotypes for future breeding programmes by identifying suitable sowing times for specific genotypes. High temperature stress, when combined with drought during late sowing, decreased the days to visible awns, days to heading and days to ripe harvest, finally negatively affecting the growth and development of plants and resulting in a lower plant population m−2, tillers plant−1, plant height and dry matter production m−2. On the other hand, low temperature in combination with early sowing increased the number of days to germination, reduced seedling stand establishment and tillering capacity, finally affecting the growth and development of the crops. Compared to overall performance and optimum sowing date, barley genotypes ‘Zernograd.770’ and ‘Nutans’, and wheat genotype ‘Line4’ performed best in both late (high temperature with drought) and early (low temperature) stress conditions. PMID:23961209

  15. Synergic effect of. gamma. irradiation and formaldehyde on growth of barley seedlings after caryopse treatment

    Energy Technology Data Exchange (ETDEWEB)

    Silvy, A; Maltet, P; Jonard, R [CEA Centre d' Etudes Nucleaires de Cadarache, 13 - Saint-Paul-les-Durance (France). Service de Radio-Agronomie; Montpellier-1 Univ., 34 (France))

    1980-06-30

    A synergic effect is observed on the shortening of first leaf of seedlings following combined treatments with ..gamma.. irradiation before or during exposure to formaldehyde in gaseous phase on barley caryopses with low water content (4,7%) under anoxic conditions. This effect being attributed to the great reactivity of free radicals in such dry and anoxic systems, new methods of mutagenic treatment can therefore be envisaged for higher plants.

  16. Synergic effect of γ irradiation and formaldehyde on growth of barley seedlings after caryopse treatment

    International Nuclear Information System (INIS)

    Silvy, Andre; Maltet, Patrick; Jonard, Robert

    1980-01-01

    A synergic effect is observed on the shortening of first leaf of seedlings following combined treatments with γ irradiation before or during exposure to formaldehyde in gaseous phase on barley caryopses with low water content (4,7%) under anoxic conditions. This effect being attributed to the great reactivity of free radicals in such dry and anoxic systems, new methods of mutagenic treatment can therefore be envisaged for higher plants [fr

  17. Primary assimilation process of triply (/sup 15/N, /sup 14/C and /sup 3/H) labeled arginine in the roots of arginine-fed barley

    Energy Technology Data Exchange (ETDEWEB)

    Mori, Satoshi [Tokyo Univ. (Japan). Faculty of Agriculture

    1981-03-01

    To clarify the mechanism of arginine utilization in barley roots, triply labeled (ureido-/sup 15/N, ureido-/sup 14/C and 5-/sup 3/H) arginine was applied to plants precultured with arginine (Arg-plants). (5-/sup 3/H) Arginine was incorporated mainly into ornithine, suggesting that arginase contributes in the first step of arginine metabolism. The arginase activity in the tissues was greatly enhanced by continuous supply of arginine, whereas urease activity was not by the same treatment. The amount of /sup 14/CO/sub 2/ evolved from (ureido-/sup 14/C) arginine in the Arg-plants was several times higher than that in plants treated with NO/sub 3//sup -/(NO/sub 3/-plants), and most /sup 14/C-urea exogenously supplied to detached roots of Arg-plants was immediately decomposed to /sup 14/CO/sub 2/. The urea released from arginine by arginase was cleaved to /sup 15/NH/sub 4//sup +/ + /sup 14/CO/sub 2/ by urease. Most of the /sup 14/CO/sub 2/ was then lost from the root system. On the other hand, the released /sup 15/NH/sub 4//sup +/ was reassimilated into amino acids probably through the pathway of ammonia assimilation. Released (5-/sup 3/H) ornithine was metabolized dominantly to proline.

  18. Regeneration of roots from callus reveals stability of the developmental program for determinate root growth in Sonoran Desert Cactaceae.

    Science.gov (United States)

    Shishkova, Svetlana; García-Mendoza, Edith; Castillo-Díaz, Vicente; Moreno, Norma E; Arellano, Jesús; Dubrovsky, Joseph G

    2007-05-01

    In some Sonoran Desert Cactaceae the primary root has a determinate root growth: the cells of the root apical meristem undergo only a few cell division cycles and then differentiate. The determinate growth of primary roots in Cactaceae was found in plants cultivated under various growth conditions, and could not be reverted by any treatment tested. The mechanisms involved in root meristem maintenance and determinate root growth in plants remain poorly understood. In this study, we have shown that roots regenerated from the callus of two Cactaceae species, Stenocereus gummosus and Ferocactus peninsulae, have a determinate growth pattern, similar to that of the primary root. To demonstrate this, a protocol for root regeneration from callus was established. The determinate growth pattern of roots regenerated from callus suggests that the program of root development is very stable in these species. These findings will permit future analysis of the role of certain Cactaceae genes in the determinate pattern of root growth via the regeneration of transgenic roots from transformed calli.

  19. Evaluation of growth, metabolism and production of potentially bioactive components during fermentation of barley with Lactobacillus reuteri.

    Science.gov (United States)

    Pallin, Anton; Agback, Peter; Jonsson, Hans; Roos, Stefan

    2016-08-01

    Eighteen bacterial isolates from millet, buckwheat and rye flour were identified as Lactobacillus reuteri. Genomic fingerprinting (rep-PCR) revealed that they represented five strains and phylogenetic analyses using multi locus sequence analysis (MLSA) showed that all clustered with strains of rodent origin. Two strains (SU12-3 and SU18-3) from different phylogenetic clades were used in fermentations of six varieties of barley, both untreated and heat-treated (with inactivated indigenous enzymes) flour. They were compared with two probiotic strains of human origin (DSM 17938 and ATCC PTA 6475), one previously isolated sourdough strain (LTH 5531) and one strain of Lactobacillus plantarum (36E). Analyses of growth (CFU) and metabolism (1H-NMR) revealed differences at species level, with L. plantarum showing a higher capacity to assimilate nutrients without help of the cereal enzymes. Similarities were observed between L. reuteri strains isolated from sourdough, while the greatest differences between L. reuteri strains were observed between strains 6475 and 17938. Multivariate analysis of the metabolic profiles revealed clear clustering according to flour treatment, species of bacteria and barley variety and to some extent also bacterial strain. Possible bioactive compounds such as γ-aminobutyric acid (GABA), 1,3- propanediol (sign of reuterin production) and histamine were identified and quantified. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. Evaluation of the ability of barley genotypes containing different amounts of ß-glucan to alter growth and disease resistance of rainbow trout Oncorhynchus mykiss.

    Science.gov (United States)

    A feeding trial was performed to screen three barley genotypes containing different levels of '-glucan for their ability to influence growth, immune function, and disease resistance of rainbow trout. Three experimental diets were prepared by substituting each of three barely genotypes containing dif...

  1. Allelopathic effect of ryegrass (lolium persicum) and wild mustard (sinapis arvensis) on barley

    International Nuclear Information System (INIS)

    Baziar, M.R.; Farahvash, F.; Mirshekari, B.; Rashidi, V.

    2014-01-01

    Most crop plants and weeds have allelopathic effects and analysis of these effects on plants in crop alteration and successive planting is very important. In this research the allelopathic ability of different parts and concentrations of two weeds, Lolium Persicum (Ryegrass) and Sinapis arvensis (wild mustered), on growth characteristics of two barley varieties was studied in the greenhouse using a completely randomized design with four replications. Test factors consisted of two barley varieties (Valfajr and Rehane), three weed organs (root, stalk, leaf) and four concentrations of extracts of weed organs (25, 50, 75 and control or distilled water). After the preparation of extracts of different weed organs with different concentrations, their effect on growth characteristics of barley plant was evaluated. Finally, seedling length, rootlet length caulicle length, wet weight of seedling, dry weight of seedling were measured. Also, the above two seeds had significant effects on the two strains of barley and could influence growth characteristics of barley. Based on the results of present study, one can argue that Ryegrass (Lolium Persicum) and wild mustard (Sinapis arvensis) can strongly affect germination, growth and performance of barley through production of chemical materials with allelopathic properties, leading unfavorable growth and product yield. (author)

  2. Barley growth and plant mineral content of plant grown from seeds irradiated by low doses of gamma irradiated and cultured on salt media

    International Nuclear Information System (INIS)

    Charbaji, T.; Arabi, M.I.; Jawhar, M.

    2000-02-01

    Seeds of two barley White Arabi (WA) Pakistani PK30163 (PK) were irradiated with three doses 0,15 and 20 Gy of gamma irradiation. Then they were cultured on (Coic-Lesaint) nutrient media containing several concentrations of NaCl (0, 10, 50, and 100 mmol). The irradiation doses did not affect the shoot growth of plants, whereas the combination between 15 Gy and 50 and 100 mmol NaCl decreased significantly the root growth. Doses of 0 and 20 Gy and 10 mmol NaCl had a positive effect on WA variety wet weight. The 20 Gy and 10 and 50 mmol NaCl significantly reduced the wet weight of PK variety. Dry weight of WA variety was decreased, when the seeds were irradiated by 15 Gy and cultured on media containing 10 and 50 mmol NaCl. WA and PK content of Ca ++ increased when weeds were irradiated by 15 Gy (WA) and 20 Gy (PK) and grown on media containing 10 mmol NaCl. The content of Mg ++ and K ++ of 2 varieties were increased, when seeds were cultured on media containing 10 mmol NaCl. Positive relationship was noticed between Na + and Cl - contents and NaCl concentrations in the media. The NaCl concentrations correlated with the irradiation, negatively effected the total N % of the WA variety, whereas in the absence of irradiation, 10 and 50 mmol NaCl had a positive effect on the total N % of PK variety. Similar effects were produced for the last variety with the dose of 15 Gy and NaCl concentrations in the media. Concentration of 100 mmol NaCl positively affect PO4 -- of unirradiated WA variety, but PO -- of all plants of PK variety was increased with 10 and 50 mmol NaCl. The content of SO4 -- of 2 varieties was increased, when the seeds were exposed to the irradiation of 15 and 20 Gy and cultured on a media containing 10 and 50 mmol NaCl. The ratio of Na/Cl, was generally different from 1 and the Cl - content was higher than Na + content, in seedlings of both barley varieties. (author)

  3. Barley growth and plant mineral content of plant grown from seeds irradiated by low doses of gamma irradiated and cultured on salt media

    Energy Technology Data Exchange (ETDEWEB)

    Charbaji, T; Arabi, M I; Jawhar, M [Atomic Energy Commission, Damascus (Syrian Arab Republic). Dept. of Agriculture

    2000-02-01

    Seeds of two barley White Arabi (WA) Pakistani PK30163 (PK) were irradiated with three doses 0,15 and 20 Gy of gamma irradiation. Then they were cultured on (Coic-Lesaint) nutrient media containing several concentrations of NaCl (0, 10, 50, and 100 mmol). The irradiation doses did not affect the shoot growth of plants, whereas the combination between 15 Gy and 50 and 100 mmol NaCl decreased significantly the root growth. Doses of 0 and 20 Gy and 10 mmol NaCl had a positive effect on WA variety wet weight. The 20 Gy and 10 and 50 mmol NaCl significantly reduced the wet weight of PK variety. Dry weight of WA variety was decreased, when the seeds were irradiated by 15 Gy and cultured on media containing 10 and 50 mmol NaCl. WA and PK content of Ca{sup ++} increased when weeds were irradiated by 15 Gy (WA) and 20 Gy (PK) and grown on media containing 10 mmol NaCl. The content of Mg{sup ++} and K{sup ++} of 2 varieties were increased, when seeds were cultured on media containing 10 mmol NaCl. Positive relationship was noticed between Na{sup +} and Cl{sup -} contents and NaCl concentrations in the media. The NaCl concentrations correlated with the irradiation, negatively effected the total N % of the WA variety, whereas in the absence of irradiation, 10 and 50 mmol NaCl had a positive effect on the total N % of PK variety. Similar effects were produced for the last variety with the dose of 15 Gy and NaCl concentrations in the media. Concentration of 100 mmol NaCl positively affect PO4{sup --} of unirradiated WA variety, but PO{sup --} of all plants of PK variety was increased with 10 and 50 mmol NaCl. The content of SO4{sup --} of 2 varieties was increased, when the seeds were exposed to the irradiation of 15 and 20 Gy and cultured on a media containing 10 and 50 mmol NaCl. The ratio of Na/Cl, was generally different from 1 and the Cl{sup -} content was higher than Na{sup +} content, in seedlings of both barley varieties. (author)

  4. Development of test method for evaluating root resistance of pavement used for roof garden caused by thickening growth of root

    Energy Technology Data Exchange (ETDEWEB)

    Ishihara, Saori; Tanaka, Kyoji [Tokyo Institute of Technology, Tokyo, (Japan)

    2010-07-01

    The growth of roots of plants can damage roof garden components, such as pavements. This paper developed a test method for evaluating the resistance of pavement used in roof gardens to damage from a thickening growth of roots. The study assessed the behaviour of plant roots and evaluated the force of root growth subjected to hypertrophy. A system to measure the enlargement force of roots was designed and used for measurements over a period of 8 months on a cherry blossom of 21 years growth. The enlargement force was approximately 440 N/cm. A mechanical simulated root was designed and used to carry out experimental tests on asphalt pavements. The tests results demonstrated the viability of simulated root for evaluation of root resistances in pavements and various components of roof gardens.

  5. Isolation and characterization of altered root growth behavior and ...

    African Journals Online (AJOL)

    Generation, screening and isolating mutants for any developmental and adaptive traits plays a major role in plant functional genomics research. Identification and exploitation of mutants possessing contrasting root growth behavior and salinity tolerance in rice will help us to identify key genes controlling these traits and in ...

  6. ROOT-GROWTH AND FUNCTIONING UNDER ATMOSPHERIC CO2 ENRICHMENT

    NARCIS (Netherlands)

    STULEN, [No Value; DENHERTOG, J

    This paper examines the extent to which atmospheric CO2 enrichment may influence growth of plant roots and function in terms of uptake of water and nutrients, and carbon allocation towards symbionts. It is concluded that changes in dry matter allocation greatly depend on the experimental conditions

  7. Effect of organic root plus (biostimulant) on the growth, nutrient ...

    African Journals Online (AJOL)

    The effectiveness of organic root plus (biostimulant) was compared with conventional fertilizer on the growth and yield of amaranthus in a glass house study. The treatments consisted of control, full rate each of biostimulant and fertilizer, and combination of fertilizer with biostimulant at full and half rates. The urea, single ...

  8. Aphid effects on rhizosphere microorganisms and microfauna depend more on barley growth phase than on soil fertilization

    DEFF Research Database (Denmark)

    Madsen, Mette Vestergård; Strandmark, Lisa Bjørnlund; Christensen, Søren

    2004-01-01

    This paper gives the first reports on aphid effects on rhizosphere organisms as influenced by soil nutrient status and plant development. Barley plants grown in pots fertilized with N but without P (N), with N and P (NP), or not fertilized (0) were sampled in the early growth phase (day 25), 1 week...... before and 1 week after spike emergence. Aphids were added 16 days before sampling was carried out. In a separate experiment belowground respiration was measured on N and NP fertilized plant–soil systems with aphid treatments comparable to the first experiment. Aphids reduced numbers of rhizosphere...... experimental conditions with nematodes being the dominant bacterial grazers at N fertilization and Protozoa in the NP treatment before spike emergence....

  9. Flavonoids modify root growth and modulate expression of SHORT-ROOT and HD-ZIP III.

    Science.gov (United States)

    Franco, Danilo Miralha; Silva, Eder Marques; Saldanha, Luiz Leonardo; Adachi, Sérgio Akira; Schley, Thayssa Rabelo; Rodrigues, Tatiane Maria; Dokkedal, Anne Ligia; Nogueira, Fabio Tebaldi Silveira; Rolim de Almeida, Luiz Fernando

    2015-09-01

    Flavonoids are a class of distinct compounds produced by plant secondary metabolism that inhibit or promote plant development and have a relationship with auxin transport. We showed that, in terms of root development, Copaifera langsdorffii leaf extracts has an inhibitory effect on most flavonoid components compared with the application of exogenous flavonoids (glycosides and aglycones). These compounds alter the pattern of expression of the SHORT-ROOT and HD-ZIP III transcription factor gene family and cause morpho-physiological alterations in sorghum roots. In addition, to examine the flavonoid auxin interaction in stress, we correlated the responses with the effects of exogenous application of auxin and an auxin transport inhibitor. The results show that exogenous flavonoids inhibit primary root growth and increase the development of lateral roots. Exogenous flavonoids also change the pattern of expression of specific genes associated with root tissue differentiation. These findings indicate that flavonoid glycosides can influence the polar transport of auxin, leading to stress responses that depend on auxin. Copyright © 2015 Elsevier GmbH. All rights reserved.

  10. Importance of growth characteristics for yield of barley in different growing systems: will growth characteristics describe yield diffently in different growing systems?

    DEFF Research Database (Denmark)

    Kristensen, Kristian; Ericson, Lars

    2008-01-01

    The interest in organic grown cereals has increased the need for variety tests under organic growing systems and/or the knowledge on whether growth characteristics describe yield differently under conventional and organic conditions. This paper is a contribution to that question by examining...... the relationships between some important growth characteristics in barley trials in both systems in Northern Sweden and in Denmark. Mixed model analyses were used for regressions of growth characteristics (or transformations of those) on yield (and log-transformed yield), allowing the slope to depend on the growing...... system. The analyses showed that diseases seemed to have a less negative effect on yield in the organic growing system than in the conventional growing system if pesticides were not applied. For other characteristics the effect depended on the country. This was the case for grain characteristics where...

  11. Effects of plant growth promoting rhizobacteria (PGPR on rooting and root growth of kiwifruit (Actinidia deliciosa stem cuttings

    Directory of Open Access Journals (Sweden)

    YASAR ERTURK

    2010-01-01

    Full Text Available The effects of plant growth promoting rhizobacteria (PGPR on the rooting and root growth of semi-hardwood and hardwood kiwifruit stem cuttings were investigated. The PGPR used were Bacillus RC23, Paenibacillus polymyxa RC05, Bacillus subtilis OSU142, Bacillus RC03, Comamonas acidovorans RC41, Bacillus megaterium RC01 and Bacillus simplex RC19. All the bacteria showed indole-3-acetic acid (IAA producing capacity. Among the PGPR used, the highest rooting ratios were obtained at 47.50% for semi-hardwood stem cuttings from Bacillus RC03 and Bacillus simplex RC19 treatments and 42.50% for hardwood stem cuttings from Bacillus RC03. As well, Comamonas acidovorans RC41 inoculations indicated higher value than control treatments. The results suggest that these PGPR can be used in organic nursery material production and point to the feasibility of synthetic auxin (IBA replacement by organic management based on PGPR.

  12. Expression patterns of HvCKX genes indicate their role in growth and reproductive development of barley.

    Directory of Open Access Journals (Sweden)

    Wojciech Zalewski

    Full Text Available Cytokinin oxidase/dehydrogenase proteins (CKX are encoded by a multigene family of CKX genes with a varying number of members depending on species. For some of the genes, spectacular effects on grain production in selected cereals have been observed. Despite the fact that partial or full length sequences of most HvCKX genes in barley (Hordeum vulgare have already been published, in most cases their specific biological functions have not been reported. Detailed expression patterns for five HvCKX genes in different organs/tissues of developing barley plants coupled with analysis of RNAi silent for two genes are presented to test the hypothesis that these expression profiles might indicate their function. Elevated expression for four of them - HvCKX1, HvCKX9, HvCKX4, and HvCKX11 - was found in developing kernels of wild-type plants compared to other tissues. HvCKX5 was mainly expressed in leaf tissue. Lower expression was noted for HvCKX1 in seedling roots and for HvCKX9 in leaves. The documented effect of RNAi silencing of HvCKX1 and a trend for HvCKX9 was higher plant productivity, and the trait was inherited through four generations. Higher plant yield was determined by higher numbers of seeds and spikes. Increased productivity was significantly greater in HvCKX1 silenced plants showing higher relative expression of HvCKX1 in developing kernels of wild-type plants compared to the expression of HvCKX9. Both HvCKX1 silenced T1 seedlings of cv. Golden Promise and the newly transformed breeding line STH7308 showed greater root mass, but this trait was not inherited in the next generation. Similarly HvCKX9 silenced T1 seedlings exhibited greater plant height without inheritance in the next generation. It is suggested that these effects were not inherited because of compensation by other genes co-ordinately regulating reproductive development. One line with untypically changed, inherited phenotype, which was selected from several dozen silenced lines

  13. Phytotoxicity of nanoparticles: Inhibition of seed germination and root growth

    International Nuclear Information System (INIS)

    Lin Daohui; Xing Baoshan

    2007-01-01

    Plants need to be included to develop a comprehensive toxicity profile for nanoparticles. Effects of five types of nanoparticles (multi-walled carbon nanotube, aluminum, alumina, zinc, and zinc oxide) on seed germination and root growth of six higher plant species (radish, rape, ryegrass, lettuce, corn, and cucumber) were investigated. Seed germination was not affected except for the inhibition of nanoscale zinc (nano-Zn) on ryegrass and zinc oxide (nano-ZnO) on corn at 2000 mg/L. Inhibition on root growth varied greatly among nanoparticles and plants. Suspensions of 2000 mg/L nano-Zn or nano-ZnO practically terminated root elongation of the tested plant species. Fifty percent inhibitory concentrations (IC 50 ) of nano-Zn and nano-ZnO were estimated to be near 50 mg/L for radish, and about 20 mg/L for rape and ryegrass. The inhibition occurred during the seed incubation process rather than seed soaking stage. These results are significant in terms of use and disposal of engineered nanoparticles. - Engineered nanoparticles can inhibit the seed germination and root growth

  14. Phytotoxicity of nanoparticles: Inhibition of seed germination and root growth

    Energy Technology Data Exchange (ETDEWEB)

    Lin Daohui [Department of Environmental Science, Zhejiang University, Hangzhou 310028 (China); Department of Plant, Soil and Insect Sciences, University of Massachusetts, Stockbridge Hall, Amherst, MA 01003 (United States); Xing Baoshan [Department of Plant, Soil and Insect Sciences, University of Massachusetts, Stockbridge Hall, Amherst, MA 01003 (United States)], E-mail: bx@pssci.umass.edu

    2007-11-15

    Plants need to be included to develop a comprehensive toxicity profile for nanoparticles. Effects of five types of nanoparticles (multi-walled carbon nanotube, aluminum, alumina, zinc, and zinc oxide) on seed germination and root growth of six higher plant species (radish, rape, ryegrass, lettuce, corn, and cucumber) were investigated. Seed germination was not affected except for the inhibition of nanoscale zinc (nano-Zn) on ryegrass and zinc oxide (nano-ZnO) on corn at 2000 mg/L. Inhibition on root growth varied greatly among nanoparticles and plants. Suspensions of 2000 mg/L nano-Zn or nano-ZnO practically terminated root elongation of the tested plant species. Fifty percent inhibitory concentrations (IC{sub 50}) of nano-Zn and nano-ZnO were estimated to be near 50 mg/L for radish, and about 20 mg/L for rape and ryegrass. The inhibition occurred during the seed incubation process rather than seed soaking stage. These results are significant in terms of use and disposal of engineered nanoparticles. - Engineered nanoparticles can inhibit the seed germination and root growth.

  15. The effect of concentration and exposure time on 15N uptake and incorporation from urea and ammonium nitrate by spring barley in the initial growth period

    International Nuclear Information System (INIS)

    Matula, J.; Knop, K.

    1978-01-01

    The uptake and incorporation of 15 N from urea and ammonium nitrate by spring barley were studied in aquaculture at three nitrogen concentrations in complex nutrient solutions (28, 140 and 700 mg N per 1 litre) and for three lengths of exposure to 15 N-labelled nutrient solutions. The 'Diamant' variety plants were precultivated up to the stage of the 3rd to 4th leaf in a complex nutrient solution, and five days prior to exposure to 15 N-labelled solutions the plants were cultivated in a nutrient solution without nitrogen. At a concentration of 28 mg N per litre the course of urea absorption was similar to the absorption of ammonium nitrate, but at a lower level. The results suggest that urea uptake is basically controlled by the metabolic requirement, particularly at lower concentrations. Only at the highest concentrations of nitrogen in the nutrient solutions did the 15 N of urea and ammonium nitrate penetrate into the roots, passive uptake being preferred. The uptake of urea is controlled by the metabolic requirement but its availability for barley metabolism is lower. Ammonium nitrate NO 3 - was taken up at a lower rate than NH 4 + from the same compound. Nitrate nitrogen was transported relatively more intensively to the above-ground parts of barley. The increasing concentration of nitrogen and exposure to nutrient solutions induced a rise in the proportion of ethanol-soluble forms of nitrogen, particularly in the roots. (author)

  16. Using low energy x-ray radiography to evaluate root initiation and growth of Populus

    Science.gov (United States)

    Ronald S., Jr. Zalesny; A. L. Friend; B. Kodrzycki; D.W. McDonald; R. Michaels; A.H. Wiese; J.W. Powers

    2007-01-01

    Populus roots have been studied less than aboveground tissues. However, there is an overwhelming need to evaluate root initiation and growth in order to understand the genetics and physiology of rooting, along with genotype x environment interactions.

  17. On the road to quantitative genetic/genomic analyses of root growth and development components underlying root architecture

    International Nuclear Information System (INIS)

    Draye, X.; Dorlodot, S. de; Lavigne, T.

    2006-01-01

    The quantitative genetic and functional genomic analyses of root development, growth and plasticity will be instrumental in revealing the major regulatory pathways of root architecture. Such knowledge, combined with in-depth consideration of root physiology (e.g. uptake, exsudation), form (space-time dynamics of soil exploration) and ecology (including root environment), will settle the bases for designing root ideotypes for specific environments, for low-input agriculture or for successful agricultural production with minimal impact on the environment. This report summarizes root research initiated in our lab between 2000 and 2004 in the following areas: quantitative analysis of root branching in bananas, high throughput characterisation of root morphology, image analysis, QTL mapping of detailed features of root architecture in rice, and attempts to settle a Crop Root Research Consortium. (author)

  18. Radiosensitivity study of cultured barley (hordeum vulgare)

    International Nuclear Information System (INIS)

    Wang Cailian; Shen Mei; Xu Gang; Zhao Kongnan; Chen Qiufang

    1991-07-01

    For studying the radioactivity, forty seven varieties of dormant barley seeds were irradiated with various doses (0 ∼ 400 Gy) of 137 Cs γ-rays. The results showed that the dose-effects relations of seedling growth inhibition could be fitted by an equation of F(D) = 1 - (1 - e -a 1 D ) N , and the dose-effects of cell-nucleus, the frequency of root tip cell with chromosome aberations and peroxidase isoenzyme band could be expressed by a linear regression equation Y = A + B · X. The radioactivity of naked barley was much higher than of covered barley. According to different radiosensitivities the varieties studied could be divided into five types i.e. extreme resistant, resistant, intermediate, sensitive, and extreme sensitive. The results also showed that there was close relationship between the DNA content of cell-nucleus, peroxidase isoenzyme zymogram and radioactivity. The radiosensitivty was proportional to the DNA content. The volume of cell-nucleus varied inversly as D 50 of nucleus volume and no obvious correlation with the D 50 of seedling growth inhibition

  19. Rhizodeposition of N by pea and barley and its effect on soil N dynamics

    DEFF Research Database (Denmark)

    Jensen, E.S.

    1996-01-01

    Rhizodeposition of N during plant growth influences the microbial activity in the rhizosphere and constitutes a source of labile organic N, but has not been quantified to the same degree as the rhizodeposition of C. The rhizodeposition of N, defined as root-derived N present in the soil after...... removal of visible roots and root fragments, was determined during field pea (Pisum sativum L.) and spring barley (Hordeum vulgare L.) growth in a sandy soil at a low concentration of mineral N using a continuous split-root N-15-labelling technique. The N rhizodeposition constituted 15 and 48......% of the below-ground N in pea when determined 7 and 14 (maturity) wk after planting (WAP), respectively. In barley 32 and 71% of the below-ground N were present in rhizodeposits at the two samplings. At maturity the rhizodeposition of N amounted to 19 mg N plant(-1) (7% of total plant N) for pea and 17 mg N...

  20. Evaluation of the tolerance of three cultivars of barley to Zn, Cd or Cr in a growth chamber experiment

    Directory of Open Access Journals (Sweden)

    González A.

    2013-04-01

    Full Text Available To evaluate the tolerance of three cultivars of barley for the phytoremediation of soils contaminated by metals, a growth chamber experiment with plants exposed to increasing concentrations of Zn, Cd and Cr was conducted. Growth parameters, chlorophyll content and chlorophyll fluorescence were measured at 15 and 29 days after treatment application. Metal concentration in the plant was also measured. In all cases, the amount of metal accumulated in the plant increased by increasing the concentration of the applied metal. Chlorophyll content and chlorophyll fluorescence were higher in the first sampling indicating the negative effect on these parameters of the highest metal concentrations. Cr treatments affected significantly plant growth. Height and dry weights plants were significantly lower (p <0.05 than those treated with Zn and Cd. Physiological parameters measured and water content were also lower in plants treated with Cr. Plaisant and Pedrezuela varieties accumulated more Zn and Cd than Reinette, which accumulated greater amount of Cr than the other two cultivars. This fact shows the interest in selecting the most tolerant varieties when using a crop for phytoremediation of contaminated soils.

  1. Impact of root growth and root hydraulic conductance on water availability of young walnut trees

    Science.gov (United States)

    Jerszurki, Daniela; Couvreur, Valentin; Hopmans, Jan W.; Silva, Lucas C. R.; Shackel, Kenneth A.; de Souza, Jorge L. M.

    2015-04-01

    Walnut (Juglans regia L.) is a tree species of high economic importance in the Central Valley of California. This crop has particularly high water requirements, which makes it highly dependent on irrigation. The context of decreasing water availability in the state calls for efficient water management practices, which requires improving our understanding of the relationship between water application and walnut water availability. In addition to the soil's hydraulic conductivity, two plant properties are thought to control the supply of water from the bulk soil to the canopy: (i) root distribution and (ii) plant hydraulic conductance. Even though these properties are clearly linked to crop water requirements, their quantitative relation remains unclear. The aim of this study is to quantitatively explain walnut water requirements under water deficit from continuous measurements of its water consumption, soil and stem water potential, root growth and root system hydraulic conductance. For that purpose, a greenhouse experiment was conducted for a two month period. Young walnut trees were planted in transparent cylindrical pots, equipped with: (i) rhizotron tubes, which allowed for non-invasive monitoring of root growth, (ii) pressure transducer tensiometers for soil water potential, (iii) psychrometers attached to non-transpiring leaves for stem water potential, and (iv) weighing scales for plant transpiration. Treatments consisted of different irrigation rates: 100%, 75% and 50% of potential crop evapotranspiration. Plant responses were compared to predictions from three simple process-based soil-plant-atmosphere models of water flow: (i) a hydraulic model of stomatal regulation based on stem water potential and vapor pressure deficit, (ii) a model of plant hydraulics predicting stem water potential from soil-root interfaces water potential, and (iii) a model of soil water depletion predicting the water potential drop between the bulk soil and soil-root interfaces

  2. Flavonols Mediate Root Phototropism and Growth through Regulation of Proliferation-to-Differentiation Transition

    OpenAIRE

    Silva, Javier; Moreno Risueño, Miguel Ángel; Manzano, Concepción; Téllez Robledo, Bárbara; Navarro Neila, Sara; Carrasco Loba, Víctor; Pollmann, Stephan; Gallego, Javier; Pozo Benito, Juan Carlos del

    2016-01-01

    Roots normally grow in darkness, but they may be exposed to light. After perceiving light, roots bend to escape from light (root light avoidance) and reduce their growth. How root light avoidance responses are regulated is not well understood. Here, we show that illumination induces the accumulation of flavonols in Arabidopsis thaliana roots. During root illumination, flavonols rapidly accumulate at the side closer to light in the transition zone. This accumulation promotes asymmetrical cell ...

  3. Number, Position, Diameter and Initial Direction of Growth of Primary Roots in Musa

    OpenAIRE

    LECOMPTE, FRANCOIS; VAUCELLE, AURELIEN; PAGES, LOIC; OZIER‐LAFONTAINE, HARRY

    2002-01-01

    To understand soil colonization by a root system, information is needed on the architecture of the root system. In monocotyledons, soil exploration is mainly due to the growth of adventitious primary roots. Primary root emergence in banana was quantified in relation to shoot and corm development. Root emergence kinetics were closely related to the development of aerial organs. Root position at emergence on the corm followed an asymptotic function of corm dry weight, so that the age of each ro...

  4. Growth performance, productivity and diseases susceptibility of barley varieties in Slovenia within the Cobra project’s site comparison

    Directory of Open Access Journals (Sweden)

    Grobelnik Mlakar Silva

    2016-12-01

    Full Text Available Different plant genotypes react differently in different climates. A field experiment was carried out to estimate the growth performance, productivity and diseases susceptibility of spring barley varieties in the Slovenian climate. We received some varieties, mainly of Nordic origin, from the Technical University of Denmark, a COBRA project partner, which were previously tested in estimated future climate in RERAF phytotron. Varieties of the highest grain yield (3,993 kg ha-1 in ‘Evergreen’ to 5,146 kg ha-1 in ‘Sebastian’ were rather shorter (58.7 cm to 67.1 cm and mostly had the highest specific grain weight (54.3 to 58.6 kg 100 L-1 and 1000-kernel weight (30.2 to 37.1 g. They developed 1,561 to 2,532 tillers m-2 and 515 to 840 ears m-2 and reached a heading stage between 13th and 25th of May. The tested varieties seem rather insusceptible to most common diseases, but susceptible to cereal leaf beetle attacks.

  5. Barley germination

    DEFF Research Database (Denmark)

    Daneri-Castro, Sergio N.; Svensson, Birte; Roberts, Thomas H.

    2016-01-01

    germination. Lastly, the application of metabolomics to barley grain germination provides essential data on biochemical processes, including insights into the formation of compounds that contribute to malt quality. To maximize the benefits of the 'omics' revolution to the malting industry, there is a need......Germination of barley grain is central to the malting industry and is a valuable model for cereal grain germination. Our current understanding of the complexity of germination at the molecular level is facilitated by access to genomic, transcriptomic, proteomic and metabolomic data. Here we review...... of germination in the context of industrial malting. For transcriptomics, recent advances in sequencing the barley genome allow next-generation sequencing approaches to reveal novel effects of variety and environment on germination. For proteomics, selection of the source tissue(s) and the protein extraction...

  6. Growth rate distribution in the forming lateral root of arabidopsis.

    Science.gov (United States)

    Szymanowska-Pułka, Joanna; Lipowczan, Marcin

    2014-10-01

    Microscopic observations of lateral roots (LRs) in Arabidopsis thaliana reveal that the cross-sectional shape of the organ changes from its basal to its apical region. The founder cells for LRs are elongated along the parent root axis, and thus from the site of initiation the base of LRs resemble an ellipse. The circumference of the apical part of LRs is usually a circle. The objective of this study was to analyse the characteristics of changes in the growth field of LRs possessing various shapes in their basal regions. The LRs of the wild type (Col-0) and two transgenic arabidopsis lines were analysed. On the basis of measurements of the long and short diameters (DL and DS, respectively) of the ellipse-like figure representing the bases of particular LRs, their asymmetry ratios (DL/DS) were determined. Possible differences between accessions were analysed by applying statistical methods. No significant differences between accessions were detected. Comparisons were therefore made of the maximal, minimal and mean value of the ratio of all the LRs analysed. Taking into consideration the lack of circular symmetry of the basal part, rates of growth were determined at selected points on the surface of LRs by the application of the growth tensor method, a mathematical tool previously applied only to describe organs with rotational symmetry. Maps showing the distribution of growth rates were developed for surfaces of LRs of various asymmetry ratios. The maps of growth rates on the surfaces of LRs having various shapes of the basal part show differences in both the geometry and the manner of growth, thus indicating that the manner of growth of the LR primordium is correlated to its shape. This is the first report of a description of growth of an asymmetric plant organ using the growth tensor method. The mathematical modelling adopted in the study provides new insights into plant organ formation and shape. © The Author 2014. Published by Oxford University Press on

  7. Root growth and physiology of potted and field-grown trembling aspen exposed to tropospheric ozone

    Science.gov (United States)

    M.D. Coleman; R.E. Dickson; J.G. Isebrands; D.F. Karnosky

    1996-01-01

    We studied root growth and respiration of potted plants and field-grown aspen trees (Populus tremuloides Michx.) exposed to ambient or twice-ambient ozone. Root dry weight of potted plants decreased up to 45% after 12 weeks of ozone treatment, and root system respiration decreased by 27%. The ozone-induced decrease in root system respiration of...

  8. Nitric Oxide is Required for Homeostasis of Oxygen and Reactive Oxygen Species in Barley Roots under Aerobic Conditions

    DEFF Research Database (Denmark)

    Gupta, Kapuganti J; Hebelstrup, Kim; Kruger, Nicholas J

    2014-01-01

    Oxygen, the terminal electron acceptor for mitochondrial electron transport, is vital for plants because of its role in the production of ATP by oxidative phosphorylation. While photosynthetic oxygen production contributes to the oxygen supply in leaves, reducing the risk of oxygen limitation of ...... electron transport chain (Gupta et al., 2011). Thus, NO could influence oxygen consumption under normal aerobic conditions in roots, and it is this specific function that is assessed here.......Oxygen, the terminal electron acceptor for mitochondrial electron transport, is vital for plants because of its role in the production of ATP by oxidative phosphorylation. While photosynthetic oxygen production contributes to the oxygen supply in leaves, reducing the risk of oxygen limitation...

  9. Suppression of Zn stress on barley by irradiated chitosan

    Energy Technology Data Exchange (ETDEWEB)

    Nagasawa, N.; Mitomo, H. [Gunma Univ., Faculty of Engineering, Department of Biological and Chemical Engineering, Kiryu, Gunma (Japan); Ha, P.T.L. [Nuclear Research Institute, Dalat (Viet Nam); Watanabe, S.; Ito, T.; Takeshita, H.; Yoshii, F.; Kume, T. [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment

    2001-03-01

    Chitosan was irradiated up to 1000 kGy in solid state. Irradiation of chitosan caused the reduction of molecular weight. The molecular weight of the chitosan reduced from ca. 4 x 10{sup 5} to ca. 6 x 10{sup 3} by irradiation at 1000 kGy. For the barley growth promotion, irradiated chitosan showed the significant effect and 1000 kGy irradiated chitosan improved 20% of growth. Using the positron emitting tracer imaging system (PETIS), the effect of chitosan on uptake and transportation of {sup 62}Zn in barley were investigated. It was found that the transportation of Zn from root to shoot and the damage of plant by Zn were suppressed with irradiated chitosan. (author)

  10. Suppression of Zn stress on barley by irradiated chitosan

    International Nuclear Information System (INIS)

    Nagasawa, N.; Mitomo, H.; Ha, P.T.L.; Watanabe, S.; Ito, T.; Takeshita, H.; Yoshii, F.; Kume, T.

    2001-01-01

    Chitosan was irradiated up to 1000 kGy in solid state. Irradiation of chitosan caused the reduction of molecular weight. The molecular weight of the chitosan reduced from ca. 4 x 10 5 to ca. 6 x 10 3 by irradiation at 1000 kGy. For the barley growth promotion, irradiated chitosan showed the significant effect and 1000 kGy irradiated chitosan improved 20% of growth. Using the positron emitting tracer imaging system (PETIS), the effect of chitosan on uptake and transportation of 62 Zn in barley were investigated. It was found that the transportation of Zn from root to shoot and the damage of plant by Zn were suppressed with irradiated chitosan. (author)

  11. Transcriptomics insights into the genetic regulation of root apical meristem exhaustion and determinate primary root growth in Pachycereus pringlei (Cactaceae).

    Science.gov (United States)

    Rodriguez-Alonso, Gustavo; Matvienko, Marta; López-Valle, Mayra L; Lázaro-Mixteco, Pedro E; Napsucialy-Mendivil, Selene; Dubrovsky, Joseph G; Shishkova, Svetlana

    2018-06-04

    Many Cactaceae species exhibit determinate growth of the primary root as a consequence of root apical meristem (RAM) exhaustion. The genetic regulation of this growth pattern is unknown. Here, we de novo assembled and annotated the root apex transcriptome of the Pachycereus pringlei primary root at three developmental stages, with active or exhausted RAM. The assembled transcriptome is robust and comprehensive, and was used to infer a transcriptional regulatory network of the primary root apex. Putative orthologues of Arabidopsis regulators of RAM maintenance, as well as putative lineage-specific transcripts were identified. The transcriptome revealed putative orthologues of most proteins involved in housekeeping processes, hormone signalling, and metabolic pathways. Our results suggest that specific transcriptional programs operate in the root apex at specific developmental time points. Moreover, the transcriptional state of the P. pringlei root apex as the RAM becomes exhausted is comparable to the transcriptional state of cells from the meristematic, elongation, and differentiation zones of Arabidopsis roots along the root axis. We suggest that the transcriptional program underlying the drought stress response is induced during Cactaceae root development, and that lineage-specific transcripts could contribute to RAM exhaustion in Cactaceae.

  12. Number, position, diameter and initial direction of growth of primary roots in Musa.

    Science.gov (United States)

    Lecompte, Francois; Vaucelle, Aurelien; Pages, Loic; Ozier-Lafontaine, Harry

    2002-07-01

    To understand soil colonization by a root system, information is needed on the architecture of the root system. In monocotyledons, soil exploration is mainly due to the growth of adventitious primary roots. Primary root emergence in banana was quantified in relation to shoot and corm development. Root emergence kinetics were closely related to the development of aerial organs. Root position at emergence on the corm followed an asymptotic function of corm dry weight, so that the age of each root at a given time could be deduced from its position. Root diameter at emergence was related to the position of the roots on the corm, with younger roots being thicker than older ones. However, root diameters were not constant along a given root, but instead decreased with the distance to the base; roots appear to be conical in their basal and apical parts. Root growth directions at emergence were variable, but a high proportion of the primary roots emerged with a low angle to the horizontal. Further research is needed to evaluate whether these initial trajectories are conserved during root development. Results presented in this study are in good agreement with those reported for other monocotyledons such as maize and rice. They give quantitative information that will facilitate the development of models of root system architecture in banana.

  13. Impact of non-selective fungicides on the growth and production of ochratoxin A by Aspergillus ochraceus and A. carbonarius in barley-based medium.

    Science.gov (United States)

    Mateo, Eva M; Valle-Algarra, F M; Mateo-Castro, R; Jimenez, M

    2011-01-01

    The aim of this study was to assess the influence of the non-selective fungicides mancozeb, copper oxychloride, and sulfur on the growth and capability for producing ochratoxin A (OTA) of ochratoxigenic isolates of Aspergillus carbonarius and A. ochraceus in barley-based medium. Lag phases and growth rates were determined for each fungicide at different doses, at 15°C and 25°C and at 0.97 a(w). Mancozeb at 40 mg l(-1 )inhibited fungal growth and provided lag phases >24 days at 10-20 mg l(-1) and 15°C. OTA was observed only at 25°C and doses Sulfur was inhibitory or provided large lag phases at 5-8 g l(-1) (at 15°C) while at 25°C growth took place even at 8 g l(-1), although OTA levels were low or undetectable. The antifungal activity decreased in the order mancozeb > copper oxychloride > sulfur, and was lower at 25°C than at 15°C. OTA accumulation was affected by the type of fungicide, dose, temperature and time. The efficacy of these fungicides on the growth of A. carbonarius and A. ochraceus and OTA production in barley-based medium is assessed for the first time.

  14. Colonization of Plant Growth Promoting Rhizobacteria (PGPR) on Two Different Root Systems

    International Nuclear Information System (INIS)

    Chaudhry, M. Z.; Naz, A. U.; Nawaz, A.; Nawaz, A.; Mukhtar, H.

    2016-01-01

    Phytohormones producing bacteria enhance the plants growth by positively affecting growth of the root. Plant growth promoting bacteria (PGPR) must colonize the plant roots to contribute to the plant's endogenous pool of phytohormones. Colonization of these plant growth promoting rhizobacteria isolated from rhizosplane and soil of different crops was evaluated on different root types to establish if the mechanism of host specificity exist. The bacteria were isolated from maize, wheat, rice, canola and cotton and phytohormone production was detected and quantified by HPLC. Bacteria were inoculated on surface sterilized seeds of different crops and seeds were germinated. After 7 days the bacteria were re-isolated from the roots and the effect of these bacteria was observed by measuring increase in root length. Bacteria isolated from one plant family (monocots) having fibrous root performed well on similar root system and failed to give significant results on other roots (tap root) of dicots. Some aggressive strains were able to colonize both root systems. The plant growth promoting activities of the bacteria were optimum on the same plant from whom roots they were isolated. The results suggest that bacteria adapt to the root they naturally inhabit and colonize the same plant root systems preferably. Although the observe trend indicate host specificity but some bacteria were aggressive colonizers which grew on all the plants used in experiment. (author)

  15. Vigorous root growth is a better indicator of early nutrient uptake than root hair traits in spring wheat grown under low fertility

    DEFF Research Database (Denmark)

    Wang, Yaosheng; Thorup-Kristensen, Kristian; Jensen, Lars Stoumann

    2016-01-01

    . Vigorous root growth, however, was a better indicator of early nutrient acquisition than RHL and RHD. Vigorous root growth and long and dense root hairs ensured efficient acquisition of macro- and micronutrients during early growth and a high root length to shoot dry matter ratio favored high macronutrient......A number of root and root hair traits have been proposed as important for nutrient acquisition. However, there is still a need for knowledge on which traits are most important in determining macro- and micronutrient uptake at low soil fertility. This study investigated the variations in root growth...... vigor and root hair length (RHL) and density (RHD) among spring wheat genotypes and their relationship to nutrient concentrations and uptake during early growth. Six spring wheat genotypes were grown in a soil with low nutrient availability. The root and root hair traits as well as the concentration...

  16. Advancements in Root Growth Measurement Technologies and Observation Capabilities for Container-Grown Plants

    Directory of Open Access Journals (Sweden)

    Lesley A. Judd

    2015-07-01

    Full Text Available The study, characterization, observation, and quantification of plant root growth and root systems (Rhizometrics has been and remains an important area of research in all disciplines of plant science. In the horticultural industry, a large portion of the crops grown annually are grown in pot culture. Root growth is a critical component in overall plant performance during production in containers, and therefore it is important to understand the factors that influence and/or possible enhance it. Quantifying root growth has varied over the last several decades with each method of quantification changing in its reliability of measurement and variation among the results. Methods such as root drawings, pin boards, rhizotrons, and minirhizotrons initiated the aptitude to measure roots with field crops, and have been expanded to container-grown plants. However, many of the published research methods are monotonous and time-consuming. More recently, computer programs have increased in use as technology advances and measuring characteristics of root growth becomes easier. These programs are instrumental in analyzing various root growth characteristics, from root diameter and length of individual roots to branching angle and topological depth of the root architecture. This review delves into the expanding technologies involved with expertly measuring root growth of plants in containers, and the advantages and disadvantages that remain.

  17. Advancements in Root Growth Measurement Technologies and Observation Capabilities for Container-Grown Plants.

    Science.gov (United States)

    Judd, Lesley A; Jackson, Brian E; Fonteno, William C

    2015-07-03

    The study, characterization, observation, and quantification of plant root growth and root systems (Rhizometrics) has been and remains an important area of research in all disciplines of plant science. In the horticultural industry, a large portion of the crops grown annually are grown in pot culture. Root growth is a critical component in overall plant performance during production in containers, and therefore it is important to understand the factors that influence and/or possible enhance it. Quantifying root growth has varied over the last several decades with each method of quantification changing in its reliability of measurement and variation among the results. Methods such as root drawings, pin boards, rhizotrons, and minirhizotrons initiated the aptitude to measure roots with field crops, and have been expanded to container-grown plants. However, many of the published research methods are monotonous and time-consuming. More recently, computer programs have increased in use as technology advances and measuring characteristics of root growth becomes easier. These programs are instrumental in analyzing various root growth characteristics, from root diameter and length of individual roots to branching angle and topological depth of the root architecture. This review delves into the expanding technologies involved with expertly measuring root growth of plants in containers, and the advantages and disadvantages that remain.

  18. Effects of N fertilizer on root growth in Zea mays L. seedlings

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Z. R.; Rui, Y. R.; Shen, J. B.; Zhang, F. S.

    2008-07-01

    This paper reports the effects of different nitrogen (N) fertilizer levels on the growth of maize (Zea mays L.) under field conditions. The N supply was found to influence the growth of the plants, especially the roots. A high N supply significantly inhibited root elongation, and was associated with reduced root dry weight compared to controls and to plants grown with smaller supplies of N. However, no differences were seen in lateral primary root density under the different N supply conditions, nor did plant N concentration increase with high N supply. In conclusion, a high N supply not only wastes resources and pollutes the environment, it may also inhibit root growth. (Author)

  19. Long-term Root Growth Response to Thinning, Fertilization, and Water Deficit in Plantation Loblolly Pine

    Science.gov (United States)

    M.A. Sword-Sayer; Z. Tang

    2004-01-01

    High water deficits limit the new root growth of loblolly pine (Pinus taeda L.), potentially reducing soil resource availability and stand growth. We evaluated new root growth and stand production in response to thinning and fertilization in loblolly pine over a 6-year period that consisted of 3 years of low water deficit followed by 3 years of high...

  20. The barley MATE gene, HvAACT1, increases citrate efflux and Al3+ tolerance when expressed in wheat and barley

    Science.gov (United States)

    Zhou, Gaofeng; Delhaize, Emmanuel; Zhou, Meixue; Ryan, Peter R.

    2013-01-01

    Background and Aims Aluminium is toxic in acid soils because the soluble Al3+ inhibits root growth. A mechanism of Al3+ tolerance discovered in many plant species involves the release of organic anions from root apices. The Al3+-activated release of citrate from the root apices of Al3+-tolerant genotypes of barley is controlled by a MATE gene named HvAACT1 that encodes a citrate transport protein located on the plasma membrane. The aim of this study was to investigate whether expressing HvAACT1 with a constitutive promoter in barley and wheat can increase citrate efflux and Al3+ tolerance of these important cereal species. Methods HvAACT1 was over-expressed in wheat (Triticum aestivum) and barley (Hordeum vulgare) using the maize ubiquitin promoter. Root apices of transgenic and control lines were analysed for HvAACT1 expression and organic acid efflux. The Al3+ tolerance of transgenic and control lines was assessed in both hydroponic solution and acid soil. Key Results and Conclusions Increased HvAACT1 expression in both cereal species was associated with increased citrate efflux from root apices and enhanced Al3+ tolerance, thus demonstrating that biotechnology can complement traditional breeding practices to increase the Al3+ tolerance of important crop plants. PMID:23798600

  1. Sprouted barley for dairy cows: Nutritional composition and digestibility

    Science.gov (United States)

    A 4-unit dual-flow continuous culture fermentor system was used to assess the effect of supplementing 7-d sprouted barley or barley grain with an haylage or pasture diet on nutrient digestibility and methane output. Barley grain was sprouted in climate controlled growth chambers, to be used as part ...

  2. Nitrogen uptake by Azospirillum brasilense inoculated barley (Hordeum vulgare L.) as influenced by N and P fertilization

    International Nuclear Information System (INIS)

    Negi, Mahima; Tilak, K.V.B.R.; Sachdev, M.S.

    1991-01-01

    Response of barley (Hordeum vulgare L.) in a sandy-loam soil under potted conditions revealed that application of nitrogen and phosphorus increased the population of Azospirillium in the barley rhizosphere. A two fold increase was observed in the Azospirillium population at 80 days compared to that at 40 days of plant growth. The unsterilized inoculated roots had more population than the surface sterilized inoculated roots. Increased drymatter production of barley was obtained in A. brasilense inoculated N 0 P 1 (0 kg N and 30 kg P 2 O 5 ha -1 ) treatment than uninoculated control. Also N and P uptake was higher in A. brasilense inoculated plants in the presence of both N and P fertilizers. The 15 N data revealed that at harvest nearly 36 per cent of the total N uptake was from the nitrogen fixed by A. brasilense irrespective of P treatment. (author). 16 refs., 4 tabs

  3. Disentangling the intertwined genetic bases of root and shoot growth in Arabidopsis.

    Directory of Open Access Journals (Sweden)

    Marie Bouteillé

    Full Text Available Root growth and architecture are major components of plant nutrient and water use efficiencies and these traits are the matter of extensive genetic analysis in several crop species. Because root growth relies on exported assimilate from the shoot, and changes in assimilate supply are known to alter root architecture, we hypothesized (i that the genetic bases of root growth could be intertwined with the genetic bases of shoot growth and (ii that the link could be either positive, with alleles favouring shoot growth also favouring root growth, or negative, because of competition for assimilates. We tested these hypotheses using a quantitative genetics approach in the model species Arabidopsis thaliana and the Bay-0 × Shahdara recombinant inbred lines population. In accordance with our hypothesis, root and shoot growth traits were strongly correlated and most root growth quantitative trait loci (QTLs colocalized with shoot growth QTLs with positive alleles originating from either the same or the opposite parent. In order to identify regions that could be responsible for root growth independently of the shoot, we generated new variables either based on root to shoot ratios, residuals of root to shoot correlations or coordinates of principal component analysis. These variables showed high heritability allowing genetic analysis. They essentially all yielded similar results pointing towards two regions involved in the root--shoot balance. Using Heterogeneous Inbred Families (a kind of near-isogenic lines, we validated part of the QTLs present in these two regions for different traits. Our study thus highlights the difficulty of disentangling intertwined genetic bases of root and shoot growth and shows that this difficulty can be overcome by using simple statistical tools.

  4. Hormone-mediated growth dynamics of the barley pericarp as revealed by magnetic resonance imaging and transcript profiling

    Czech Academy of Sciences Publication Activity Database

    Pielot, R.; Kohl, S.; Manz, B.; Rutten, T.; Weier, D.; Tarkowská, Danuše; Rolčík, Jakub; Strnad, Miroslav; Volke, F.; Weber, H.; Weschke, W.

    2015-01-01

    Roč. 66, č. 21 (2015), s. 6927-6943 ISSN 0022-0957 R&D Projects: GA MŠk(CZ) LO1204; GA ČR GA14-34792S Institutional support: RVO:61389030 Keywords : Auxin * barley pericarp * cell expansion Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 5.677, year: 2015

  5. Fine Root Growth Phenology, Production, and Turnover in a Northern Hardwood Forest Ecosystem

    Science.gov (United States)

    Dudley J. Raynal

    1994-01-01

    A large part of the nutrient flux in deciduous forests is through fine root turnover, yet this process is seldom measured. As part of a nutrient cycling study, fine root dynamics were studied for two years at Huntington Forest in the Adirondack Mountain region of New York, USA. Root growth phenology was characterized using field rhizotrons, three methods were used to...

  6. Spatial and temporal patterns of chickpea genotypes (Cicer arietinum L. root growth under waterlogging stress

    Directory of Open Access Journals (Sweden)

    ali ganjali

    2009-06-01

    Full Text Available The dynamic of root growth of chickpea genotypes; including Rupali (Desi and Flip 97-530 (Kabuli were evaluated under waterlogging stress in a Glasshouse experiment at CSIRO, Perth, WA. during 2005. Root growth boxes (0.1×0.24×1.0 m with one wall of glass were used as experimental units. Data were analyzed based on Randomized Complete Block Design with three replications. Waterlogging was induced when the first root reached 50cm. The water level was maintained on the soil surface for 12 days. After that, waterlogging was finished by draining the root growth boxes. In soil profile, root growth rate were calculated based on recorded information on transparent films during growing season. There was positive and strong linear correlation between the root traits that were measured in soil (direct measurment and transparent films (indirect measurment. Decay and death of roots caused a severe decrease on root growth rate during waterlogging, but root growth rate was sharply increased at the end of recovery period on 0-40 cm layer of soil surface. In both genotypes, spatial and temporal patterns of the root growth were different. Root growth rate was highest on distinc time for each layer of soil profile. In both genotypes, RLD decreased with increasing soil depth. Results showed that more distribution of root system on upper soil layers (0-40 cm is a strategy for chickpea plants, and so, soil management is very important on this layer. In stress and non stress environments, Flip 97-530 showed better root characteristics than the Rupali during growing season, so this genotype is probably more tolerate to water logging stress.

  7. Systemic responses of barley to the 3-hydroxy-decanoyl-homoserine lactone producing plant beneficial endophyte Acidovorax radicis N35

    Directory of Open Access Journals (Sweden)

    Shengcai Han

    2016-12-01

    Full Text Available Quorum sensing auto-inducers of the N-acyl homoserine lactone (AHL type produced by Gram-negative bacteria have different effects on plants including stimulation on root growth and/or priming or acquirement of systemic resistance in plants. In this communication the influence of AHL production of the plant growth promoting endophytic rhizosphere bacterium Acidovorax radicis N35 on barley seedlings was investigated. A. radicis N35 produces 3-hydroxy-C10-homoserine lactone (3-OH-C10-HSL as the major AHL compound. To study the influence of this QS autoinducer on the interaction with barley, the araI-biosynthesis gene was deleted. The comparison of inoculation effects of the A. radicis N35 wild type and the araI mutant resulted in remarkable differences. While the N35 wild type colonized plant roots effectively in microcolonies, the araI mutant occurred at the root surface as single cells. Furthermore, in a mixed inoculum the wild type was much more prevalent in colonization than the araI mutant documenting that the araI mutation affected root colonization. Nevertheless, a significant plant growth promoting effect could be shown after inoculation of barley with the wild type and the araI mutant in soil after two months cultivation. While A. radicis N35 wild type showed only a very weak induction of early defense responses in plant RNA expression analysis, the araI mutant caused increased expression of flavonoid biosynthesis genes. This was corroborated by the accumulation of several flavonoid compounds such as saponarin and lutonarin in leaves of root inoculated barley seedlings. Thus, although the exact role of the flavonoids in this plant response is not clear yet, it can be concluded, that the synthesis of AHLs by A. radicis has implications on the perception by the host plant barley and thereby contributes to the establishment and function of the bacteria-plant interaction.

  8. Early Arabidopsis root hair growth stimulation by pathogenic strains of Pseudomonas syringae.

    Science.gov (United States)

    Pecenková, Tamara; Janda, Martin; Ortmannová, Jitka; Hajná, Vladimíra; Stehlíková, Zuzana; Žárský, Viktor

    2017-09-01

    Selected beneficial Pseudomonas spp. strains have the ability to influence root architecture in Arabidopsis thaliana by inhibiting primary root elongation and promoting lateral root and root hair formation. A crucial role for auxin in this long-term (1week), long-distance plant-microbe interaction has been demonstrated. Arabidopsis seedlings were cultivated in vitro on vertical plates and inoculated with pathogenic strains Pseudomonas syringae pv. maculicola (Psm) and P. syringae pv. tomato DC3000 (Pst), as well as Agrobacterium tumefaciens (Atu) and Escherichia coli (Eco). Root hair lengths were measured after 24 and 48h of direct exposure to each bacterial strain. Several Arabidopsis mutants with impaired responses to pathogens, impaired ethylene perception and defects in the exocyst vesicle tethering complex that is involved in secretion were also analysed. Arabidopsis seedling roots infected with Psm or Pst responded similarly to when infected with plant growth-promoting rhizobacteria; root hair growth was stimulated and primary root growth was inhibited. Other plant- and soil-adapted bacteria induced similar root hair responses. The most compromised root hair growth stimulation response was found for the knockout mutants exo70A1 and ein2. The single immune pathways dependent on salicylic acid, jasmonic acid and PAD4 are not directly involved in root hair growth stimulation; however, in the mutual cross-talk with ethylene, they indirectly modify the extent of the stimulation of root hair growth. The Flg22 peptide does not initiate root hair stimulation as intact bacteria do, but pretreatment with Flg22 prior to Psm inoculation abolished root hair growth stimulation in an FLS2 receptor kinase-dependent manner. These early response phenomena are not associated with changes in auxin levels, as monitored with the pDR5::GUS auxin reporter. Early stimulation of root hair growth is an effect of an unidentified component of living plant pathogenic bacteria. The root

  9. Long-Term Effects of Season of Prescribed Burn on the Fine-Root Growth, Root Carbohydrates, and Foliar Dynamics of Mature Longleaf Pine

    Science.gov (United States)

    Eric A. Kuehler; Mary Anne Sword Sayer; James D. Haywood; C. Dan Andries

    2004-01-01

    Depending on the season and intensity of fire, as well as the phenology of foliage and new root growth, fire may damage foliage, and subsequently decrease whole-crown carbon fixation and allocation to the root system. In central Louisiana the authors investigated how season of prescribed burning affects fine-root dynamics, root carbohydrate relations, and leaf area...

  10. Effects of plant growth regulators on callus, shoot and root formation ...

    African Journals Online (AJOL)

    Root and stem explants of fluted pumpkin were cultured in medium containing different types and concentrations of plant growth regulators (PGRs). The explants were observed for callus, root and shoot formation parameters after four months. Differences among explants, plant growth regulators and their interaction were ...

  11. Root exudate-induced alterations in Bacillus cereus cell wall contribute to root colonization and plant growth promotion.

    Directory of Open Access Journals (Sweden)

    Swarnalee Dutta

    Full Text Available The outcome of an interaction between plant growth promoting rhizobacteria and plants may depend on the chemical composition of root exudates (REs. We report the colonization of tobacco, and not groundnut, roots by a non-rhizospheric Bacillus cereus (MTCC 430. There was a differential alteration in the cell wall components of B. cereus in response to the REs from tobacco and groundnut. Attenuated total reflectance infrared spectroscopy revealed a split in amide I region of B. cereus cells exposed to tobacco-root exudates (TRE, compared to those exposed to groundnut-root exudates (GRE. In addition, changes in exopolysaccharides and lipid-packing were observed in B. cereus grown in TRE-amended minimal media that were not detectable in GRE-amended media. Cell-wall proteome analyses revealed upregulation of oxidative stress-related alkyl hydroperoxide reductase, and DNA-protecting protein chain (Dlp-2, in response to GRE and TRE, respectively. Metabolism-related enzymes like 2-amino-3-ketobutyrate coenzyme A ligase and 2-methylcitrate dehydratase and a 60 kDa chaperonin were up-regulated in response to TRE and GRE. In response to B. cereus, the plant roots altered their exudate-chemodiversity with respect to carbohydrates, organic acids, alkanes, and polyols. TRE-induced changes in surface components of B. cereus may contribute to successful root colonization and subsequent plant growth promotion.

  12. Root and aerial growth in early-maturing peach trees under two crop load treatments

    Energy Technology Data Exchange (ETDEWEB)

    Abrisqueta, I.; Conejero, W.; López-Martínez, L.; Vera, J.; Ruiz Sánchez, M.C.

    2017-07-01

    The objectives of the paper were to study the pattern of root growth (measured by minirhizotrons) in relation to trunk, fruit and shoot growth and the effects of crop load on tree growth and yield in peach trees. Two crop load (commercial and low) treatments were applied in a mature early-maturing peach tree orchard growing in Mediterranean conditions. Root growth dynamics were measured using minirhizotrons during one growing season. Shoot, trunk and fruit growth were also measured. At harvest, all fruits were weighed, counted and sized. Roots grew throughout the year but at lower rates during the active fruit growth phase. Root growth was asynchronous with shoot growth, while root and trunk growth rates were highest after harvest, when the canopy was big enough to allocate the photo-assimilates to organs that would ensure the following season’s yield. Shoot and fruit growth was greater in the low crop load treatment and was accompanied by a non-significant increase in root growth. High level of fruit thinning decreased the current yield but the fruits were more marketable because of their greater size.

  13. Cotton growth potassium deficiency stress is influenced by photosynthetic apparatus and root system

    International Nuclear Information System (INIS)

    Hussain, Z.U.; Arshad, M.

    2010-01-01

    Due to rapid depletion of soil potassium (K) and increasing cost of K fertilizers in Pakistan, the K-use efficient crop genotypes become very important for agricultural sustain ability. However, limited research has been done on this important issue particularly in cotton, an important fibre crop. We studied the growth and biomass production of three cotton genotypes (CIM-506, NIAB- 78 and NIBGE-2) different in K-use efficiency in a K-deficient solution culture. Genotypes differed significantly for biomass production, absolute growth rates (shoot, root, leaf, total), leaf area, mean leaf area and relative growth rate of leaf under K deficiency stress, besides specific leaf area. The relative growth rate (shoot, root, total) did not differ significantly, except for leaf. For all these characters, NIBGE-2 was the best performer followed by NIAB-78 and CIM-506. Shoot dry weight was significantly related with (in decreasing order of significance): mean leaf area, leaf dry weight, leaf area, root dry weight, absolute growth rate of shoot, absolute growth rate of root, absolute growth rate total, absolute growth rate root, relative growth rate leaf, relative growth rate total and relative growth rate shoot. Hence, the enhanced biomass accumulation of cotton genotypes under K deficiency stress is related to their efficient photosynthetic apparatus and root system, appeared to be the most important morphological markers while breeding for K-use efficient cotton genotypes.(author)

  14. Relationship between root growth, temperature and anion uptake

    Energy Technology Data Exchange (ETDEWEB)

    Holobrada, M; Mistrik, I; Kolek, J [Institute of Experimental Biology and Ecology of the Slovak Academy of Sciences, Bratislava (Czechoslovakia)

    1980-01-01

    The uptake and release were studied of /sup 35/S-sulfate ions by whole intact roots of maize seedlings. From the total incorporated sulfur only 20% were released back to the unlabelled culture solution. In correspondence to the physiological and biochemical-structural vertical gradient of the growing differentiating roots, the release of /sup 35/S from the apical root part was much lower than from the differentiated tissues.

  15. The relationship between root growth, temperature and anion uptake

    International Nuclear Information System (INIS)

    Holobrada, M.; Mistrik, I.; Kolek, J.

    1980-01-01

    The uptake and release were studied of 35 S-sulfate ions by whole intact roots of maize seedlings. From the total incorporated sulfur only 20% were released back to the unlabelled culture solution. In correspondence to the physiological and biochemical-structural vertical gradient of the growing differentiating roots, the release of 35 S from the apical root part was much lower than from the differentiated tissues. (author)

  16. Brassinosteroid enhances resistance to fusarium diseases of barley.

    Science.gov (United States)

    Ali, Shahin S; Kumar, G B Sunil; Khan, Mojibur; Doohan, Fiona M

    2013-12-01

    Fusarium pathogens are among the most damaging pathogens of cereals. These pathogens have the ability to attack the roots, seedlings, and flowering heads of barley and wheat plants with disease, resulting in yield loss and head blight disease and also resulting in the contamination of grain with mycotoxins harmful to human and animal health. There is increasing evidence that brassinosteroid (BR) hormones play an important role in plant defense against both biotic and abiotic stress agents and this study set out to determine if and how BR might affect Fusarium diseases of barley. Application of the epibrassinolide (epiBL) to heads of 'Lux' barley reduced the severity of Fusarium head blight (FHB) caused by Fusarium culmorum by 86% and reduced the FHB-associated loss in grain weight by 33%. Growth of plants in soil amended with epiBL resulted in a 28 and 35% reduction in Fusarium seedling blight (FSB) symptoms on the Lux and 'Akashinriki' barley, respectively. Microarray analysis was used to determine whether growth in epiBL-amended soil changed the transcriptional profile in stem base tissue during the early stages of FSB development. At 24 and 48 h post F. culmorum inoculation, there were 146 epiBL-responsive transcripts, the majority being from the 48-h time point (n = 118). Real-time reverse-transcription polymerase chain reaction analysis validated the results for eight transcripts, including five defense genes. The results of gene expression studies show that chromatin remodeling, hormonal signaling, photosynthesis, and pathogenesis-related genes are activated in plants as a result of growth in epiBL.

  17. Plasma membrane and salinity tolerance of barley plants

    International Nuclear Information System (INIS)

    Al-Rahmani, F. H.; Al-Mashhadani, M. S.; Al-Delemee, N. H.

    1997-01-01

    Barley cultivar, California Mario ut, was grown in a nutrient solution containing increasing Nacl concentrations up to 250 mm. The effect of Nacl on growth, mineral compost ion ant integrity of the plasma membrane was studied. Growth of the shoot'and root was stimulated or little affected by 10 and 20 ml Nacl. Further increase in Nacl concentrations depressed the growth. The depression was conspicuous between 100 and 250 mm Nacl. Increasing Nacl concentration decreased potassium content in the shoots and roots and led to steep increase in sodium accumulation. The integrity of the plasma membrane was measured in term of potassium leakage from the root tips. Rapid leakage of potassium was obtained at Nacl concentrations ranging from 100 to 250 mm. At the same concentrations of Nacl, adenosine triphosphatase activity in the root tips was increased. Results indicate that the plasma membrane of root cells was damaged by the increased levels of salinity. It was concluded that the plasma membrane of root cells is the primary site of salinity toxicity. (authors). 40 refs., 5 tabs. 3 figs

  18. The Swedish mutant barley collection

    International Nuclear Information System (INIS)

    1989-01-01

    Full text: The Swedish mutation research programme in barley began about 50 years ago and has mainly been carried out at Svaloev in co-operation with the institute of Genetics at the University of Lund. The collection has been produced from different Swedish high-yielding spring barley varieties, using the following mutagens: X-rays, neutrons, several organic chemical compounds such as ethyleneimine, several sulfonate derivatives and the inorganic chemical mutagen sodium azide. Nearly 10,000 barley mutants are stored in the Nordic Gene Bank and documented in databases developed by Udda Lundquist, Svaloev AB. The collection consists of the following nine categories with 94 different types of mutants: 1. Mutants with changes in the spike and spikelets; 2. Changes in culm length and culm composition; 3. Changes in growth types; 4. Physiological mutants; 5. Changes in awns; 6. Changes in seed size and shape; 7. Changes in leaf blades; 8. Changes in anthocyanin and colour; 9. Resistance to barley powdery mildew. Barley is one of the most thoroughly investigated crops in terms of induction of mutations and mutation genetics. So far, about half of the mutants stored at the Nordic Gene Bank, have been analysed genetically; They constitute, however, only a minority of the 94 different mutant types. The genetic analyses have given valuable insights into the mutation process but also into the genetic architecture of various characters. A number of mutants of two-row barley have been registered and commercially released. One of the earliest released, Mari, an early maturing, daylength neutral, straw stiff mutant, is still grown in Iceland. The Swedish mutation material has been used in Sweden, but also in other countries, such as Denmark, Germany, and USA, for various studies providing a better understanding of the barley genome. The collection will be immensely valuable for future molecular genetical analyses of clone mutant genes. (author)

  19. The Swedish mutant barley collection

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1989-07-01

    Full text: The Swedish mutation research programme in barley began about 50 years ago and has mainly been carried out at Svaloev in co-operation with the institute of Genetics at the University of Lund. The collection has been produced from different Swedish high-yielding spring barley varieties, using the following mutagens: X-rays, neutrons, several organic chemical compounds such as ethyleneimine, several sulfonate derivatives and the inorganic chemical mutagen sodium azide. Nearly 10,000 barley mutants are stored in the Nordic Gene Bank and documented in databases developed by Udda Lundquist, Svaloev AB. The collection consists of the following nine categories with 94 different types of mutants: 1. Mutants with changes in the spike and spikelets; 2. Changes in culm length and culm composition; 3. Changes in growth types; 4. Physiological mutants; 5. Changes in awns; 6. Changes in seed size and shape; 7. Changes in leaf blades; 8. Changes in anthocyanin and colour; 9. Resistance to barley powdery mildew. Barley is one of the most thoroughly investigated crops in terms of induction of mutations and mutation genetics. So far, about half of the mutants stored at the Nordic Gene Bank, have been analysed genetically; They constitute, however, only a minority of the 94 different mutant types. The genetic analyses have given valuable insights into the mutation process but also into the genetic architecture of various characters. A number of mutants of two-row barley have been registered and commercially released. One of the earliest released, Mari, an early maturing, daylength neutral, straw stiff mutant, is still grown in Iceland. The Swedish mutation material has been used in Sweden, but also in other countries, such as Denmark, Germany, and USA, for various studies providing a better understanding of the barley genome. The collection will be immensely valuable for future molecular genetical analyses of clone mutant genes. (author)

  20. The influence of calcium and pH on growth in primary roots of Zea mays

    Science.gov (United States)

    Hasenstein, K. H.; Evans, M. L.

    1988-01-01

    We investigated the interaction of Ca2+ and pH on root elongation in Zea mays L. cv. B73 x Missouri 17 and cv. Merit. Seedlings were raised to contain high levels of Ca2+ (HC, imbibed and raised in 10 mM CaCl2) or low levels of Ca2+ (LC, imbibed and raised in distilled water). In HC roots, lowering the pH (5 mM MES/Tris) from 6.5 to 4.5 resulted in strong, long-lasting growth promotion. Surprisingly, increasing the pH from 6.5 to 8.5 also resulted in strong growth promotion. In LC roots acidification of the medium (pH 6.5 to 4.5) resulted in transient growth stimulation followed by a gradual decline in the growth rate toward zero. Exposure of LC roots to high pH (pH shift from 6.5 to 8.5) also promoted growth. Addition of EGTA resulted in strong growth promotion in both LC and HC roots. The ability of EGTA to stimulate growth appeared not to be related to H+ release from EGTA upon Ca2+ chelation since, 1) LC roots showed a strong and prolonged response to EGTA, but only a transient response to acid pH, and 2) promotion of growth by EGTA was observed in strongly buffered solutions. We also examined the pH dependence of the release of 45Ca2+ from roots of 3-day-old seedlings grown from grains imbibed in 45Ca2+. Release of 45Ca2+ from the root into agar blocks placed on the root surface was greater the more acidic the pH of the blocks. The results indicate that Ca2+ may be necessary for the acid growth response in roots.

  1. Root temperature effects on growth and bud break of Rosa hybrida in relation to cytokinin concentrations in xylem sap.

    NARCIS (Netherlands)

    Dieleman, J.A.; Verstappen, F.W.A.; Kuiper, D.

    1998-01-01

    The effects of three divergent root temperatures (11°C, 20°C and 26°C) on growth and bud break of Rosa hybrida were studied. Root morphology was changed considerably with root temperature. Roots at 11°C were white, succulent, short and sparsely branched, whereas at 26°C roots were long, brown, thin

  2. Root growth and hydraulic conductivity of southern pine seedlings in response to soil temperature and water availability after planting

    Science.gov (United States)

    Mary Anne Sword Sayer; John C. Brissette; James P. Barnett

    2005-01-01

    Comparison of the root system growth and water transport of southern pine species after planting in different root-zone environments is needed to guide decisions regarding when, and what species to plant. Evaluation of how seed source affects root system responses to soil conditions will allow seed sources to be matched to planting conditions. The root growth and...

  3. Growth is required for perception of water availability to pattern root branches in plants.

    Science.gov (United States)

    Robbins, Neil E; Dinneny, José R

    2018-01-23

    Water availability is a potent regulator of plant development and induces root branching through a process termed hydropatterning. Hydropatterning enables roots to position lateral branches toward regions of high water availability, such as wet soil or agar media, while preventing their emergence where water is less available, such as in air. The mechanism by which roots perceive the spatial distribution of water during hydropatterning is unknown. Using primary roots of Zea mays (maize) we reveal that developmental competence for hydropatterning is limited to the growth zone of the root tip. Past work has shown that growth generates gradients in water potential across an organ when asymmetries exist in the distribution of available water. Using mathematical modeling, we predict that substantial growth-sustained water potential gradients are also generated in the hydropatterning competent zone and that such biophysical cues inform the patterning of lateral roots. Using diverse chemical and environmental treatments we experimentally demonstrate that growth is necessary for normal hydropatterning of lateral roots. Transcriptomic characterization of the local response of tissues to a moist surface or air revealed extensive regulation of signaling and physiological pathways, some of which we show are growth-dependent. Our work supports a "sense-by-growth" mechanism governing hydropatterning, by which water availability cues are rendered interpretable through growth-sustained water movement. Copyright © 2018 the Author(s). Published by PNAS.

  4. Fagopyrum esculentum Alters Its Root Exudation after Amaranthus retroflexus Recognition and Suppresses Weed Growth.

    Science.gov (United States)

    Gfeller, Aurélie; Glauser, Gaétan; Etter, Clément; Signarbieux, Constant; Wirth, Judith

    2018-01-01

    Weed control by crops through growth suppressive root exudates is a promising alternative to herbicides. Buckwheat ( Fagopyrum esculentum ) is known for its weed suppression and redroot pigweed ( Amaranthus retroflexus ) control is probably partly due to allelopathic root exudates. This work studies whether other weeds are also suppressed by buckwheat and if the presence of weeds is necessary to induce growth repression. Buckwheat and different weeds were co-cultivated in soil, separating roots by a mesh allowing to study effects due to diffusion. Buckwheat suppressed growth of pigweed, goosefoot and barnyard grass by 53, 42, and 77% respectively without physical root interactions, probably through allelopathic compounds. Root exudates were obtained from sand cultures of buckwheat (BK), pigweed (P), and a buckwheat/pigweed mixed culture (BK-P). BK-P root exudates inhibited pigweed root growth by 49%. Characterization of root exudates by UHPLC-HRMS and principal component analysis revealed that BK and BK-P had a different metabolic profile suggesting that buckwheat changes its root exudation in the presence of pigweed indicating heterospecific recognition. Among the 15 different markers, which were more abundant in BK-P, tryptophan was identified and four others were tentatively identified. Our findings might contribute to the selection of crops with weed suppressive effects.

  5. Effect of microcystins on root growth, oxidative response, and exudation of rice (Oryza sativa).

    Science.gov (United States)

    Cao, Qing; Rediske, Richard R; Yao, Lei; Xie, Liqiang

    2018-03-01

    A 30 days indoor hydroponic experiment was carried out to evaluate the effect of microcystins (MCs) on rice root morphology and exudation, as well as bioaccumulation of MCs in rice. MCs were bioaccumulated in rice with the greatest concentrations being observed in the leaves (113.68μgg -1 Fresh weight (FW)) when exposed to 500μgL -1 MCs. Root activity at 500μgL -1 decreased 37%, compared to the control. MCs also induced disruption of the antioxidant system and lipid peroxidation in rice roots. Root growth was significantly inhibited by MCs. Root weight, length; surface area and volume were significantly decreased, as well as crown root number and lateral root number. After 30 days exposure to MCs, an increase was found in tartaric acid and malic acid while the other organic acids were not affected. Glycine, tyrosine, and glutamate were the only amino acids stimulated at MCs concentrations of 500μgL -1 . Similarly, dissolved organic carbon (DOC) and carbohydrate at 50 and 500μgL -1 treatments were significantly increased. The increase of DOC and carbohydrate in root exudates was due to rice root membrane permeability changes induced by MCs. Overall, this study indicated that MCs significantly inhibited rice root growth and affected root exudation. Copyright © 2017 Elsevier Inc. All rights reserved.

  6. Inheritance and gene expression of a root-growth inhibiting mutant in rice (Oryza sativa L.)

    International Nuclear Information System (INIS)

    Kitano, H.; Futsuhara, Y.

    1990-01-01

    Full text: A root-growth inhibiting mutant was induced in the dwarf mutant line, 'Fukei 71', through ethylene-imine. The mutant is characterised by the excessive inhibition of both seminal and crown roots elongation just after germination, although its shoots grow nearly normal. To study the genetics, the mutant was crossed with its original line 'Fukei 71' and some other normal cultivars. Results show that the root-growth inhibition is controlled by a recessive gene (rt), independent of the dwarf gene, d-50(t) locus in Fukei 71. For elucidating the gene action on root morphogenesis, histological and cytological experiments were carried out using a longitudinal and transverse thin section of seminal and/or crown root tips. Observations suggest that the rt gene affects the normal formation of the epidermal system which is differentiated from the protoderm of the root apical meristem. (author)

  7. Modeling Root Growth, Crop Growth and N Uptake of Winter Wheat Based on SWMS_2D: Model and Validation

    Directory of Open Access Journals (Sweden)

    Dejun Yang

    Full Text Available ABSTRACT Simulations for root growth, crop growth, and N uptake in agro-hydrological models are of significant concern to researchers. SWMS_2D is one of the most widely used physical hydrologically related models. This model solves equations that govern soil-water movement by the finite element method, and has a public access source code. Incorporating key agricultural components into the SWMS_2D model is of practical importance, especially for modeling some critical cereal crops such as winter wheat. We added root growth, crop growth, and N uptake modules into SWMS_2D. The root growth model had two sub-models, one for root penetration and the other for root length distribution. The crop growth model used was adapted from EU-ROTATE_N, linked to the N uptake model. Soil-water limitation, nitrogen limitation, and temperature effects were all considered in dry-weight modeling. Field experiments for winter wheat in Bouwing, the Netherlands, in 1983-1984 were selected for validation. Good agreements were achieved between simulations and measurements, including soil water content at different depths, normalized root length distribution, dry weight and nitrogen uptake. This indicated that the proposed new modules used in the SWMS_2D model are robust and reliable. In the future, more rigorous validation should be carried out, ideally under 2D situations, and attention should be paid to improve some modules, including the module simulating soil N mineralization.

  8. Genetic analysis of aluminum tolerance in Brazilian barleys

    Directory of Open Access Journals (Sweden)

    Minella Euclydes

    2002-01-01

    Full Text Available Aluminum (Al toxicity is a major factor limiting barley growth in acid soils, and genotypes with adequate level of tolerance are needed for improving barley adaptation in Brazil. To study the inheritance of Al tolerance in Brazilian barleys, cultivars Antarctica 1, BR 1 and FM 404 were crossed to sensitive Kearney and PFC 8026, and intercrossed. Parental, F1, F2 and F6 generations were grown in nutrient solution containing 0.03, 0.05 and 0.07 mM of Al and classified for tolerance by the root tip hematoxylin staining assay. Tolerant by sensitive F2 progenies segregated three tolerant to one sensitive, fitting the 3:1 ratio expected for a single gene. The F6 populations segregated one tolerant to one sensitive also fitting a monogenic ratio. The F2 seedlings from crosses among tolerant genotypes scored the same as the parents. Since the population size used would allow detection of recombination as low as 7%, the complete absence of Al sensitive recombinants suggests that tolerance in these cultivars is most probably, controlled by the same gene. Thus, the potential for improving Al tolerance through recombination of these genotypes is very low and different gene sources should be evaluated.

  9. Growth of bean and tomato plants as affected by root absorbed growth substances and atmospheric carbon dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Tognoni, F; Halevy, A H; Wittwer, S H

    1967-01-01

    Bean and tomato plants were grown in solution culture root media containing pre-determined concentrations of gibberellin A/sub 3/ (GA), 1-naphthalene-acetic acid (NAA), N/sup 6/-benzyladenine (BA), (2-chloroethyl)trimethylammonium chloride (CCC), and at atmospheric levels of 300 and 1000 ppm of CO/sub 2/. Net assimilation rates (NAR), relative growth rates (RGR), leaf area ratios (LAR), root to top dry weight ratios (R/T) and changes in dry weight, size, and form of each organ were recorded. Gibberellin had no effect on RGR of either plant species but increased the NAR of tomatoes at 1000 ppm CO/sub 2/. Total dry weight was only slightly affected by GA but root growth and R/T were markedly depressed. CCC had no effect on NAR, but decreased RGR and LAR. Root growth of beans and R/T in both plants were promoted by CCC. NAR and RGR were strongly inhibited by BA and NAA. Inhibition of stem and leaf growth by CCC and NAA was greater than that for roots; thus, R/T ratios were increased. Root branching was promoted by NAA. High (1000 ppm), compared to the low (300 ppm), atmospheric levels of CO/sub 2/ generally promoted root growth and produced an increase in the R/T, both in the absence and presence of chemical treatment. The multiplicity of effects of the root-absorbed chemical growth substances and CO/sub 2/ on growth and photosynthesis is discussed.

  10. Belowground uptake strategies: how fine-root traits determine tree growth

    NARCIS (Netherlands)

    Weemstra, Monique

    2017-01-01

    The growth of trees depends on photosynthetic carbon gain by the leaves, which in turn relies on water and nutrient acquisition by the fine roots. Because the availability of carbon, water and nutrients fluctuates, trees can adjust their leaf and fine-root functional traits to maintain their

  11. Inhibition of phospholipase C disrupts cytoskeletal organization and gravitropic growth in Arabidopsis roots.

    Science.gov (United States)

    Andreeva, Zornitza; Barton, Deborah; Armour, William J; Li, Min Y; Liao, Li-Fen; McKellar, Heather L; Pethybridge, Kylie A; Marc, Jan

    2010-10-01

    The phospholipase protein superfamily plays an important role in hormonal signalling and cellular responses to environmental stimuli. There is also growing evidence for interactions between phospholipases and the cytoskeleton. In this report we used a pharmacological approach to investigate whether inhibiting a member of the phospholipase superfamily, phospholipase C (PLC), affects microtubules and actin microfilaments as well as root growth and morphology of Arabidopsis thaliana seedlings. Inhibiting PLC activity using the aminosteroid U73122 significantly inhibited root elongation and disrupted root morphology in a concentration-dependent manner, with the response being saturated at 5 μM, whereas the inactive analogue U73343 was ineffective. The primary root appeared to lose growth directionality accompanied by root waving and formation of curls. Immunolabelling of roots exposed to increasingly higher U73122 concentrations revealed that the normal transverse arrays of cortical microtubules in the elongation zone became progressively more disorganized or depolymerized, with the disorganization appearing within 1 h of incubation. Likewise, actin microfilament arrays also were disrupted. Inhibiting PLC using an alternative inhibitor, neomycin, caused similar disruptions to both cytoskeletal organization and root morphology. In seedlings gravistimulated by rotating the culture plates by 90°, both U73122 and neomycin disrupted the normal gravitropic growth of roots and etiolated hypocotyls. The effects of PLC inhibitors are therefore consistent with the notion that, as with phospholipases A and D, PLC likewise interacts with the cytoskeleton, alters growth morphology, and is involved in gravitropism.

  12. Soil CO2 concentration does not affect growth or root respiration in bean or citrus

    NARCIS (Netherlands)

    Bouma, T.J.; Nielsen, K.F.; Eissenstat, D.M.; Lynch, J.P.

    1997-01-01

    Contrasting effects of soil CO2 concentration on root respiration rates during short-term CO2 exposure, and on plant growth during long-term CO2 exposure, have been reported, Here we examine the effects of both short-and long-term exposure to soil CO2 on the root respiration of intact plants and on

  13. Effect of soil acidification on root growth, nutrient and water uptake

    International Nuclear Information System (INIS)

    Marschner, H.

    1989-01-01

    Soil acidification poses various types of stress to plants, especially Al and H + toxicity in roots and Mg and Ca deficiency in roots and shoots. The importance of the various types of stress varies with plant species, location and time. Average data of the chemical composition of the bulk soil or of the molar Ca/Al or Mg/Al ratios in the soil solution without consideration of the Al species are of limited value for precise conclusions of the actual, or for predictions of the potential risk of soil-acidity-induced inhibition of root growth and of nutritional imbalances. The root-induced changes in the rhizosphere and the consequences for Al toxicity and nutrient acquisition by plants deserve more attention. Further it should be considered that roots are not only required for anchoring higher plants in the soil and for nutrient and water uptake. Roots are also important sites for synthesis of phytohormones, cytokinins and abscisic acid in particular, which are transported into the shoots and act either as signals for the water status at the soil-root interface (ABA) or as compounds required for growth and development. Inhibition in root growth may therefore affect shoot growth by means other than water and nutrient supply. (orig./vhe)

  14. Effect of modeled microgravity on radiation-induced adaptive response of root growth in Arabidopsis thaliana

    International Nuclear Information System (INIS)

    Deng, Chenguang; Wang, Ting; Wu, Jingjing; Xu, Wei; Li, Huasheng; Liu, Min

    2017-01-01

    Highlights: • The radio-adaptive response (RAR) of A. thaliana root growth is modulated in microgravity. • The DNA damage repairs in RAR are regulated by microgravity. • The phytohormone auxin plays a regulatory role in the modulation of microgravity on RAR of root growth. - Abstract: Space particles have an inevitable impact on organisms during space missions; radio-adaptive response (RAR) is a critical radiation effect due to both low-dose background and sudden high-dose radiation exposure during solar storms. Although it is relevant to consider RAR within the context of microgravity, another major space environmental factor, there is no existing evidence as to its effects on RAR. In the present study, we established an experimental method for detecting the effects of gamma-irradiation on the primary root growth of Arabidopsis thaliana, in which RAR of root growth was significantly induced by several dose combinations. Microgravity was simulated using a two-dimensional rotation clinostat. It was shown that RAR of root growth was significantly inhibited under the modeled microgravity condition, and was absent in pgm-1 plants that had impaired gravity sensing in root tips. These results suggest that RAR could be modulated in microgravity. Time course analysis showed that microgravity affected either the development of radio-resistance induced by priming irradiation, or the responses of plants to challenging irradiation. After treatment with the modeled microgravity, attenuation in priming irradiation-induced expressions of DNA repair genes (AtKu70 and AtRAD54), and reduced DNA repair efficiency in response to challenging irradiation were observed. In plant roots, the polar transportation of the phytohormone auxin is regulated by gravity, and treatment with an exogenous auxin (indole-3-acetic acid) prevented the induction of RAR of root growth, suggesting that auxin might play a regulatory role in the interaction between microgravity and RAR of root growth.

  15. Effect of modeled microgravity on radiation-induced adaptive response of root growth in Arabidopsis thaliana

    Energy Technology Data Exchange (ETDEWEB)

    Deng, Chenguang [Key Laboratory of Ion Beam Bioengineering, Hefei Institutes of Physical Science, Chinese Academy of Sciences (China); Key Laboratory of Environmental Toxicology and Pollution Control Technology of Anhui Province (China); Institute of Technical Biology and Agriculture Engineering, Chinese Academy of Sciences, 350 Shushanhu Road, Hefei 230031 (China); University of Science and Technology of China, Hefei 230026 (China); Wang, Ting [Key Laboratory of Ion Beam Bioengineering, Hefei Institutes of Physical Science, Chinese Academy of Sciences (China); Key Laboratory of Environmental Toxicology and Pollution Control Technology of Anhui Province (China); Institute of Technical Biology and Agriculture Engineering, Chinese Academy of Sciences, 350 Shushanhu Road, Hefei 230031 (China); Wu, Jingjing [Key Laboratory of Ion Beam Bioengineering, Hefei Institutes of Physical Science, Chinese Academy of Sciences (China); Key Laboratory of Environmental Toxicology and Pollution Control Technology of Anhui Province (China); Institute of Technical Biology and Agriculture Engineering, Chinese Academy of Sciences, 350 Shushanhu Road, Hefei 230031 (China); University of Science and Technology of China, Hefei 230026 (China); Xu, Wei [Key Laboratory of Ion Beam Bioengineering, Hefei Institutes of Physical Science, Chinese Academy of Sciences (China); Key Laboratory of Environmental Toxicology and Pollution Control Technology of Anhui Province (China); Institute of Technical Biology and Agriculture Engineering, Chinese Academy of Sciences, 350 Shushanhu Road, Hefei 230031 (China); Li, Huasheng; Liu, Min [China Space Molecular Biological Lab, China Academy of Space Technology, Beijing 100086 (China); and others

    2017-02-15

    Highlights: • The radio-adaptive response (RAR) of A. thaliana root growth is modulated in microgravity. • The DNA damage repairs in RAR are regulated by microgravity. • The phytohormone auxin plays a regulatory role in the modulation of microgravity on RAR of root growth. - Abstract: Space particles have an inevitable impact on organisms during space missions; radio-adaptive response (RAR) is a critical radiation effect due to both low-dose background and sudden high-dose radiation exposure during solar storms. Although it is relevant to consider RAR within the context of microgravity, another major space environmental factor, there is no existing evidence as to its effects on RAR. In the present study, we established an experimental method for detecting the effects of gamma-irradiation on the primary root growth of Arabidopsis thaliana, in which RAR of root growth was significantly induced by several dose combinations. Microgravity was simulated using a two-dimensional rotation clinostat. It was shown that RAR of root growth was significantly inhibited under the modeled microgravity condition, and was absent in pgm-1 plants that had impaired gravity sensing in root tips. These results suggest that RAR could be modulated in microgravity. Time course analysis showed that microgravity affected either the development of radio-resistance induced by priming irradiation, or the responses of plants to challenging irradiation. After treatment with the modeled microgravity, attenuation in priming irradiation-induced expressions of DNA repair genes (AtKu70 and AtRAD54), and reduced DNA repair efficiency in response to challenging irradiation were observed. In plant roots, the polar transportation of the phytohormone auxin is regulated by gravity, and treatment with an exogenous auxin (indole-3-acetic acid) prevented the induction of RAR of root growth, suggesting that auxin might play a regulatory role in the interaction between microgravity and RAR of root growth.

  16. The effects of solar ultraviolet-B radiation on the growth and yield of barley are accompanied by increased DNA damage and antioxidant responses

    International Nuclear Information System (INIS)

    Mazza, C.A.; Battista, D.; Zima, A.M.; Szwarcberg-Bracchitta, M.; Giordano, C.V.; Acevedo, A.; Scopel, A.L.; Ballare, C.L.

    1999-01-01

    There is limited information on the impacts of present-day solar ultraviolet-B radiation (UV-B) on biomass and grain yield of field crops and on the mechanisms that confer tolerance to UV-B radiation under field conditions. We investigated the effects of solar UV-B on aspects of the biochemistry, growth and yield of barley crops using replicated field plots and two barley strains, a catalase (CAT)-deficient mutant (RPr 79/4) and its wild-type mother line (Maris Mink). Solar UV-B reduced biomass accumulation and grain yield in both strains. The effects on crop biomass accumulation tended to be more severe in RPr 79/4 (≈ 32% reduction) than in the mother line (≈ 20% reduction). Solar UV-B caused measurable DNA damage in leaf tissue, in spite of inducing a significant increase in UV-absorbing sunscreens in the two lines. Maris Mink responded to solar UV-B with increased CAT and ascorbate peroxidase (APx) activity. No effects of UV-B on total superoxide dismutase (SOD) activity were detected. Compared with the wild type, RPr 79/4 had lower CAT activity, as expected, but higher APx activity. Neither of these activities increased in response to UV-B in RPr 79/4. These results suggest that growth inhibition by solar UV-B involves DNA damage and oxidative stress, and that constitutive and UV-B-induced antioxidant capacity may play an important role in UV-B tolerance. (author)

  17. Phytotoxic cyanamide affects maize (Zea mays) root growth and root tip function: from structure to gene expression.

    Science.gov (United States)

    Soltys, Dorota; Rudzińska-Langwald, Anna; Kurek, Wojciech; Szajko, Katarzyna; Sliwinska, Elwira; Bogatek, Renata; Gniazdowska, Agnieszka

    2014-05-01

    Cyanamide (CA) is a phytotoxic compound produced by four Fabaceae species: hairy vetch, bird vetch, purple vetch and black locust. Its toxicity is due to complex activity that involves the modification of both cellular structures and physiological processes. To date, CA has been investigated mainly in dicot plants. The goal of this study was to investigate the effects of CA in the restriction of the root growth of maize (Zea mays), representing the monocot species. CA (3mM) reduced the number of border cells in the root tips of maize seedlings and degraded their protoplasts. However, CA did not induce any significant changes in the organelle structure of other root cells, apart from increased vacuolization. CA toxicity was also demonstrated by its effect on cell cycle activity, endoreduplication intensity, and modifications of cyclins CycA2, CycD2, and histone HisH3 gene expression. In contrast, the arrangement of microtubules was not altered by CA. Treatment of maize seedlings with CA did not completely arrest mitotic activity, although the frequency of dividing cells was reduced. Furthermore, prolonged CA treatment increased the proportion of endopolyploid cells in the root tip. Cytological malformations were accompanied by an induction of oxidative stress in root cells, which manifested as enhanced accumulation of H2O2. Exposure of maize seedlings to CA resulted in an increased concentration of auxin and stimulated ethylene emission. Taken together, these findings suggested that the inhibition of root growth by CA may be a consequence of stress-induced morphogenic responses. Copyright © 2014. Published by Elsevier GmbH.

  18. Growth and microtubule orientation of Zea mays roots subjected to osmotic stress

    Science.gov (United States)

    Blancaflor, E. B.; Hasenstein, K. H.

    1995-01-01

    Previous work has shown that microtubule (MT) reorientation follows the onset of growth inhibition on the lower side of graviresponding roots, indicating that growth reduction can occur independently of MT reorientation. To test this observation further, we examined whether the reduction in growth in response to osmotic stress is correlated with MT reorientation. The distribution and rate of growth in maize roots exposed to 350 mOsm sorbitol and KCl or 5 mM Mes/Tris buffer were measured with a digitizer. After various times roots were processed for indirect immunofluorescence microscopy. Application of sorbitol or KCl had no effect on the organization of MTs in the apical 2 mm of the root but resulted in striking and different effects in the basal region of the root. Sorbitol treatment caused rapid appearance of oval to circular holes in the microtubular array that persisted for at least 9 h. Between 30 min and 4 h of submersion in KCl, MTs in cortical cells 4 mm and farther from the quiescent center began to reorient oblique to the longitudinal axis. After 9 h, the alignment of MTs had shifted to parallel to the root axis but MTs of the epidermal cells remained transverse. In KCl-treated roots MT reorientation appeared to follow a pattern of development similar to that in controls but without elongation. Our data provide additional evidence that MT reorientation is not the cause but a consequence of growth inhibition.

  19. Phenotypic plasticity of fine root growth increases plant productivity in pine seedlings

    Directory of Open Access Journals (Sweden)

    Grissom James E

    2004-09-01

    Full Text Available Abstract Background The plastic response of fine roots to a changing environment is suggested to affect the growth and form of a plant. Here we show that the plasticity of fine root growth may increase plant productivity based on an experiment using young seedlings (14-week old of loblolly pine. We use two contrasting pine ecotypes, "mesic" and "xeric", to investigate the adaptive significance of such a plastic response. Results The partitioning of biomass to fine roots is observed to reduce with increased nutrient availability. For the "mesic" ecotype, increased stem biomass as a consequence of more nutrients may be primarily due to reduced fine-root biomass partitioning. For the "xeric" ecotype, the favorable influence of the plasticity of fine root growth on stem growth results from increased allocation of biomass to foliage and decreased allocation to fine roots. An evolutionary genetic analysis indicates that the plasticity of fine root growth is inducible, whereas the plasticity of foliage is constitutive. Conclusions Results promise to enhance a fundamental understanding of evolutionary changes of tree architecture under domestication and to design sound silvicultural and breeding measures for improving plant productivity.

  20. Effect of Mycorrhizal Fungi and Trifluralin Herbicide on Emergence, Growth and Root Colonization of Clover (Trifolium repens L.

    Directory of Open Access Journals (Sweden)

    Hassan Shahgholi

    2016-09-01

    emergence increased significantly with increasing herbicide dose. The maximum emergence (Emax value and clover shoot dry matter was obtained with inoculation by mycorrhiza species in all levels of herbicide doses than non-inoculation treatments (figures 1 and 3. Inoculation of clover with G. intraradices increased root length by 34 and 57% at the herbicide doses of 1000 and 1500 ml ha-1 than non-inoculation treatments, respectively (figure 2. Results showed that, the root colonization percentage improved in low rate of Treflan by inoculation of mycorrhizal than non-inoculation treatment significantly (figure 4. These results are in agreement with the results reported by Garcia-Romeria et al. (14. They reported that shoot dry weights of AM fungi infected pea plants, were higher when the cyanazine was applied at the rate of 0.05mg ml -1 than applied at the rate of 0.1 ml per pot (14. Busse et al. (6, reported that triclorpyr, imazapyr and sulfometuron methyl herbicides did not alter the capability of mycorrhizal fungi to infect roots, even at concentrations detrimental to seedling growth. Makarian et al., (21 reported that herbicide application significantly decreased the growth (dry matter, chlorophyll content and height of maize and barley plants but mycorrhizal colonization increased plant growth at low levels of herbicide concentration. It seems that, one of the main reasons that enable the mycorrhizal plant to partially or completely overcome the stress of herbicides as compared with non-mycorrhizal plant is the enhanced nutrient uptake (6. Enhanced nutrients uptake is due, in part, to the hyphal extension into the soil and subsequent transfer of them back to the root (30. Recent researches have established that AM fungi are able to absorb organic compounds, macro and micro nutrients from the soil and transfer them to plants (29. Pesticides have also been reported to stimulate colonization of plant roots by AM fungi. This may be due to a reduction or elimination of

  1. Root-shoot growth responses during interspecific competition quantified using allometric modelling.

    Science.gov (United States)

    Robinson, David; Davidson, Hazel; Trinder, Clare; Brooker, Rob

    2010-12-01

    Plant competition studies are restricted by the difficulty of quantifying root systems of competitors. Analyses are usually limited to above-ground traits. Here, a new approach to address this issue is reported. Root system weights of competing plants can be estimated from: shoot weights of competitors; combined root weights of competitors; and slopes (scaling exponents, α) and intercepts (allometric coefficients, β) of ln-regressions of root weight on shoot weight of isolated plants. If competition induces no change in root : shoot growth, α and β values of competing and isolated plants will be equal. Measured combined root weight of competitors will equal that estimated allometrically from measured shoot weights of each competing plant. Combined root weights can be partitioned directly among competitors. If, as will be more usual, competition changes relative root and shoot growth, the competitors' combined root weight will not equal that estimated allometrically and cannot be partitioned directly. However, if the isolated-plant α and β values are adjusted until the estimated combined root weight of competitors matches the measured combined root weight, the latter can be partitioned among competitors using their new α and β values. The approach is illustrated using two herbaceous species, Dactylis glomerata and Plantago lanceolata. Allometric modelling revealed a large and continuous increase in the root : shoot ratio by Dactylis, but not Plantago, during competition. This was associated with a superior whole-plant dry weight increase in Dactylis, which was ultimately 2·5-fold greater than that of Plantago. Whole-plant growth dominance of Dactylis over Plantago, as deduced from allometric modelling, occurred 14-24 d earlier than suggested by shoot data alone. Given reasonable assumptions, allometric modelling can analyse competitive interactions in any species mixture, and overcomes a long-standing problem in studies of competition.

  2. Brewing with fractionated barley

    NARCIS (Netherlands)

    Donkelaar, van L.H.G.

    2016-01-01

    Brewing with fractionated barley

    Beer is a globally consumed beverage, which is produced from malted barley, water, hops and yeast. In recent years, the use of unmalted barley and exogenous enzymes have become more popular because they enable simpler processing and reduced environmental

  3. Influence of nitrogen and phosphorous on the growth and root morphology of Acer mono.

    Science.gov (United States)

    Razaq, Muhammad; Zhang, Peng; Shen, Hai-Long; Salahuddin

    2017-01-01

    Nitrogen and phosphorous are critical determinants of plant growth and productivity, and both plant growth and root morphology are important parameters for evaluating the effects of supplied nutrients. Previous work has shown that the growth of Acer mono seedlings is retarded under nursery conditions; we applied different levels of N (0, 5, 10, and 15 g plant-1) and P (0, 4, 6 and 8 g plant-1) fertilizer to investigate the effects of fertilization on the growth and root morphology of four-year-old seedlings in the field. Our results indicated that both N and P application significantly affected plant height, root collar diameter, chlorophyll content, and root morphology. Among the nutrient levels, 10 g N and 8 g P were found to yield maximum growth, and the maximum values of plant height, root collar diameter, chlorophyll content, and root morphology were obtained when 10 g N and 8 g P were used together. Therefore, the present study demonstrates that optimum levels of N and P can be used to improve seedling health and growth during the nursery period.

  4. The use of 32P to study root growth of soybean as affected by soil compaction

    International Nuclear Information System (INIS)

    Sisworo, Elsje L.; Sisworo, Widjang H.; Syaukat, Sri Harti; Wemay, Johannis; Haryanto

    1996-01-01

    Two greenhouse and two field experiments have been conducted to study the effect of soil compaction on root and plant growth of soybean, by using 32 P in the form of carrier free KH 2 32 PO 4 solution. In the greenhouse experiment it was clearly shown that by increasing soil compaction the growth of roots and shoots was increasingly inhibited. The growth of roots was expressed in √% arcsin converted from 32 P activity (counts per minute, cpm) in the shoots and 32 P activity in the shoots (cpm) without convertion. Plant growth was expressed in plant height, number of leaves, dry weight of pods and shoots. In the field experiment, it was shown distinctively that root growth in the 15 cm soil depth was inhibited whith the increase of soil compaction. Similar with the greenhouse experiments the of plants of roots was expressed in cpm 32 P of roots, shoots, and pods, while, the growth of plants was expressed in plant height, number of pods, and dry weight of pods, seeds, and stover. (author). 19 refs, 4 tabs, 6 figs

  5. Effect of Irrigation Timing on Root Zone Soil Temperature, Root Growth and Grain Yield and Chemical Composition in Corn

    Directory of Open Access Journals (Sweden)

    Xuejun Dong

    2016-05-01

    Full Text Available High air temperatures during the crop growing season can reduce harvestable yields in major agronomic crops worldwide. Repeated and prolonged high night air temperature stress may compromise plant growth and yield. Crop varieties with improved heat tolerance traits as well as crop management strategies at the farm scale are thus needed for climate change mitigation. Crop yield is especially sensitive to night-time warming trends. Current studies are mostly directed to the elevated night-time air temperature and its impact on crop growth and yield, but less attention is given to the understanding of night-time soil temperature management. Delivering irrigation water through drip early evening may reduce soil temperature and thus improve plant growth. In addition, corn growers typically use high-stature varieties that inevitably incur excessive respiratory carbon loss from roots and transpiration water loss under high night temperature conditions. The main objective of this study was to see if root-zone soil temperature can be reduced through drip irrigation applied at night-time, vs. daytime, using three corn hybrids of different above-ground architecture in Uvalde, TX where day and night temperatures during corn growing season are above U.S. averages. The experiment was conducted in 2014. Our results suggested that delivering well-water at night-time through drip irrigation reduced root-zone soil temperature by 0.6 °C, increase root length five folds, plant height 2%, and marginally increased grain yield by 10%. However, irrigation timing did not significantly affect leaf chlorophyll level and kernel crude protein, phosphorous, fat and starch concentrations. Different from our hypothesis, the shorter, more compact corn hybrid did not exhibit a higher yield and growth as compared with taller hybrids. As adjusting irrigation timing would not incur an extra cost for farmers, the finding reported here had immediate practical implications for farm

  6. Effect of plant growth promoting rhizobacteria on root morphology of ...

    African Journals Online (AJOL)

    Jane

    2011-10-03

    Oct 3, 2011 ... Plant growth promoting rhizobacteria improve the plant growth by a variety of ways like ... preparing textile dye in the Far East, Central and. Northern Asia and ... The experiment was carried out in complete randomized design.

  7. Determination of the Optimum Concentration and Time of Salicylic Acid Foliar Application for Improving Barley Growth under Non-Saline and Saline Conditions

    Directory of Open Access Journals (Sweden)

    GH. Ranjbar

    2017-02-01

    Full Text Available In a 2yrs field study the effect of concentration and time of salicylic acid (SA foliar application on growth of barley under non-saline and saline (2 and 12 dS m-1 of NaCl, respectively conditions was evaluated in National Salinity Research Center of Iran, Yazd, central Iran during 2012-2014 growing seasons. The treatments of SA (11 treatments included without SA and SA foliar application at 0.0, 0.35, 0.70, 1.05, 1.40 and 1.75 mM applied at tillering + stem elongation + ear emergence or stem elongation + ear emergence. Salt stress led to significant decreases in seed yield and yield components; however, grain yield of barley plants were considerably increased when subjected to SA. This positive impact of SA was due probably to its effect on grain number. Average of grain yield in 0.0, 0.35, 0.70, 1.05, 1.40 and 1.75 mM SA concentrations were 496.1, 539.7, 538.5, 553.8, 517.4 and 501.3 g m-2 under non-saline and 189.2, 212.5, 219.1, 206.9, 200.3 and 182.3 g m-2 under saline conditions, respectively. Considering the negative correlation between sodium concentration in shoot and grain yield, modulating role of exogenous SA on adverse effect of salinity might be related to a SA-induced lowered Na+ concentration in such organs. The appropriate treatment seems to be SA foliar application at 1.05 mM for non-saline and 0.70 mM for saline conditions applied at stem elongation + ear emergence, as they increased grain yield by 16.6% and 18.6%, respectively. The result of this study revealed that higher concentration or frequency of SA application could be associated with negative impacts on barley.

  8. Growth of plant root cultures in liquid- and gas-dispersed reactor environments.

    Science.gov (United States)

    McKelvey, S A; Gehrig, J A; Hollar, K A; Curtis, W R

    1993-01-01

    The growth of Agrobacterium transformed "hairy root" cultures of Hyoscyamus muticus was examined in various liquid- and gas-dispersed bioreactor configurations. Reactor runs were replicated to provide statistical comparisons of nutrient availability on culture performance. Accumulated tissue mass in submerged air-sparged reactors was 31% of gyratory shake-flask controls. Experiments demonstrate that poor performance of sparged reactors is not due to bubble shear damage, carbon dioxide stripping, settling, or flotation of roots. Impaired oxygen transfer due to channeling and stagnation of the liquid phase are the apparent causes of poor growth. Roots grown on a medium-perfused inclined plane grew at 48% of gyratory controls. This demonstrates the ability of cultures to partially compensate for poor liquid distribution through vascular transport of nutrients. A reactor configuration in which the medium is sprayed over the roots and permitted to drain down through the root tissue was able to provide growth rates which are statistically indistinguishable (95% T-test) from gyratory shake-flask controls. In this type of spray/trickle-bed configuration, it is shown that distribution of the roots becomes a key factor in controlling the rate of growth. Implications of these results regarding design and scale-up of bioreactors to produce fine chemicals from root cultures are discussed.

  9. Comparative effects of auxin and abscisic acid on growth, hydrogen ion efflux and gravitropism in primary roots of maize

    Science.gov (United States)

    Evans, M. L.; Mulkey, T. J.

    1984-01-01

    In order to test the idea that auxin action on root growth may be mediated by H(+) movement, the correlation of auxin action on growth and H(+) movement in roots was examined along with changes in H(+) efflux patterns associated with the asymmetric growth which occurs during gravitropism. The effects of indoleacetic acid (IAA) and abscisic acid (AbA) on growth, H(+) secretion, and gravitropism in roots were compared. Results show a close correlation existent between H(+) efflux and growth in maize roots. In intact roots there is strong H(+) efflux from the elongation zone. Growth-promoting concentrations of IAA stimulate H(+) efflux. During gravitropism the H(+) efflux from the elongation zone becomes asymmetric; the evidence indicates that auxin redistribution contributes to the development of acid efflux asymmetry. That AbA stimulates root growth is reflected in its ability to stimulate H(+) efflux from apical root segments.

  10. Artificial Plant Root System Growth for Distributed Optimization: Models and Emergent Behaviors

    Directory of Open Access Journals (Sweden)

    Su Weixing

    2016-01-01

    Full Text Available Plant root foraging exhibits complex behaviors analogous to those of animals, including the adaptability to continuous changes in soil environments. In this work, we adapt the optimality principles in the study of plant root foraging behavior to create one possible bio-inspired optimization framework for solving complex engineering problems. This provides us with novel models of plant root foraging behavior and with new methods for global optimization. This framework is instantiated as a new search paradigm, which combines the root tip growth, branching, random walk, and death. We perform a comprehensive simulation to demonstrate that the proposed model accurately reflects the characteristics of natural plant root systems. In order to be able to climb the noise-filled gradients of nutrients in soil, the foraging behaviors of root systems are social and cooperative, and analogous to animal foraging behaviors.

  11. The interaction between glucose and cytokinin signaling in controlling Arabidopsis thaliana seedling root growth and development.

    Science.gov (United States)

    Kushwah, Sunita; Laxmi, Ashverya

    2017-05-04

    Cytokinin (CK) and glucose (GLC) control several common responses in plants. There is an extensive overlap between CK and GLC signal transduction pathways in Arabidopsis. Physiologically, both GLC and CK could regulate root length in light. CK interacts with GLC via HXK1 dependent pathway for root length control. Wild-type (WT) roots cannot elongate in the GLC free medium while CK-receptor mutant ARABIDOPSIS HISTIDINE KINASE4 (ahk4) and type B ARR triple mutant ARABIDOPSIS RESPONSE REGULATOR1, 10,11 (arr1, 10,11) roots could elongate even in the absence of GLC as compared with the WT. The root hair initiation was also found defective in CK signaling mutants ahk4, arr1,10,11 and arr3,4,5,6,8,9 on increasing GLC concentration (up to 3%); and lesser number of root hairs were visible even at 5% GLC as compared with the WT. Out of 941 BAP regulated genes, 103 (11%) genes were involved in root growth and development. Out of these 103 genes, 60 (58%) genes were also regulated by GLC. GLC could regulate 5736 genes, which include 327 (6%) genes involved in root growth and development. Out of these 327 genes, 60 (18%) genes were also regulated by BAP. Both GLC and CK signaling cannot alter root length in light in auxin signaling mutant AUXIN RESPONSE3/INDOLE-3-ACETIC ACID17 (axr3/iaa17) suggesting that they may involve auxin signaling component as a nodal point. Therefore CK- and GLC- signaling are involved in controlling different aspects of root growth and development such as root length, with auxin signaling components working as downstream target.

  12. Root rots

    Science.gov (United States)

    Kathryn Robbins; Philip M. Wargo

    1989-01-01

    Root rots of central hardwoods are diseases caused by fungi that infect and decay woody roots and sometimes also invade the butt portion of the tree. By killing and decaying roots, root rotting fungi reduce growth, decrease tree vigor, and cause windthrow and death. The most common root diseases of central hardwoods are Armillaria root rot, lnonotus root rot, and...

  13. Evolutionary potential of root chemical defense: genetic correlations with shoot chemistry and plant growth.

    Science.gov (United States)

    Parker, J D; Salminen, J-P; Agrawal, Anurag A

    2012-08-01

    Root herbivores can affect plant fitness, and roots often contain the same secondary metabolites that act as defenses in shoots, but the ecology and evolution of root chemical defense have been little investigated. Here, we investigated genetic variance, heritability, and correlations among defensive phenolic compounds in shoot vs. root tissues of common evening primrose, Oenothera biennis. Across 20 genotypes, there were roughly similar concentrations of total phenolics in shoots vs. roots, but the allocation of particular phenolics to shoots vs. roots varied along a continuum of genotype growth rate. Slow-growing genotypes allocated 2-fold more of the potential pro-oxidant oenothein B to shoots than roots, whereas fast-growing genotypes had roughly equivalent above and belowground concentrations. Phenolic concentrations in both roots and shoots were strongly heritable, with mostly positive patterns of genetic covariation. Nonetheless, there was genotype-specific variation in the presence/absence of two major ellagitannins (oenothein A and its precursor oenothein B), indicating two different chemotypes based on alterations in this chemical pathway. Overall, the presence of strong genetic variation in root defenses suggests ample scope for the evolution of these compounds as defenses against root herbivores.

  14. Release of Growth Factors into Root Canal by Irrigations in Regenerative Endodontics.

    Science.gov (United States)

    Zeng, Qian; Nguyen, Sean; Zhang, Hongming; Chebrolu, Hari Priya; Alzebdeh, Dalia; Badi, Mustafa A; Kim, Jong Ryul; Ling, Junqi; Yang, Maobin

    2016-12-01

    The aim of this study was to investigate the release of growth factors into root canal space after the irrigation procedure of regenerative endodontic procedure. Sixty standardized root segments were prepared from extracted single-root teeth. Nail varnish was applied to all surfaces except the root canal surface. Root segments were irrigated with 1.5% NaOCl + 17% EDTA, 2.5% NaOCl + 17% EDTA, 17% EDTA, or deionized water. The profile of growth factors that were released after irrigation was studied by growth factor array. Enzyme-linked immunosorbent assay was used to validate the release of transforming growth factor (TGF)-β1 and basic fibroblast growth factor (bFGF) at 4 hours, 1 day, and 3 days after irrigation. The final concentrations were calculated on the basis of the root canal volume measured by cone-beam computed tomography. Dental pulp stem cell migration on growth factors released from root segments was measured by using Transwell assay. Total of 11 of 41 growth factors were detected by growth factors array. Enzyme-linked immunosorbent assay showed that TGF-β1 was released in all irrigation groups. Compared with the group with 17% EDTA (6.92 ± 4.49 ng/mL), the groups with 1.5% NaOCl + 17% EDTA and 2.5% NaOCl + 17% EDTA had significantly higher release of TGF-β1 (69.04 ± 30.41 ng/mL and 59.26 ± 3.37 ng/mL, respectively), with a peak release at day 1. The release of bFGF was detected at a low level in all groups (0 ng/mL to 0.43 ± 0.22 ng/mL). Migration assay showed the growth factors released from root segments induced dental pulp stem cell migration. The root segment model in present study simulated clinical scenario and indicated that the current irrigation protocol released a significant amount of TGF-β1 but not bFGF. The growth factors released into root canal space induced dental pulp stem cell migration. Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  15. Methylobacterium Species Promoting Rice and Barley Growth and Interaction Specificity Revealed with Whole-Cell Matrix-Assisted Laser Desorption/Ionization-Time-of-Flight Mass Spectrometry (MALDI-TOF/MS Analysis.

    Directory of Open Access Journals (Sweden)

    Akio Tani

    Full Text Available Methylobacterium species frequently inhabit plant surfaces and are able to utilize the methanol emitted from plants as carbon and energy sources. As some of the Methylobacterium species are known to promote plant growth, significant attention has been paid to the mechanism of growth promotion and the specificity of plant-microbe interactions. By screening our Methylobacterium isolate collection for the high growth promotion effect in vitro, we selected some candidates for field and pot growth tests for rice and barley, respectively. We found that inoculation resulted in better ripening of rice seeds, and increased the size of barley grains but not the total yield. In addition, using whole-cell matrix-assister laser desorption/ionization-time-of-flight mass spectrometry (MALDI-TOF/MS analysis, we identified and classified Methylobacterium isolates from Methylobacterium-inoculated rice plants. The inoculated species could not be recovered from the rice plants, and in some cases, the Methylobacterium community structure was affected by the inoculation, but not with predomination of the inoculated species. The isolates from non-inoculated barley of various cultivars grown in the same field fell into just two species. These results suggest that there is a strong selection pressure at the species level of Methylobacterium residing on a given plant species, and that selection of appropriate species that can persist on the plant is important to achieve growth promotion.

  16. A QTL for root growth angle on rice chromosome 7 is involved in the genetic pathway of DEEPER ROOTING 1.

    Science.gov (United States)

    Uga, Yusaku; Kitomi, Yuka; Yamamoto, Eiji; Kanno, Noriko; Kawai, Sawako; Mizubayashi, Tatsumi; Fukuoka, Shuichi

    2015-01-01

    Root growth angle (RGA) is an important trait that influences the ability of rice to avoid drought stress. DEEPER ROOTING 1 (DRO1), which is a major quantitative trait locus (QTL) for RGA, is responsible for the difference in RGA between the shallow-rooting cultivar IR64 and the deep-rooting cultivar Kinandang Patong. However, the RGA differences between these cultivars cannot be fully explained by DRO1. The objective of this study was to identify new QTLs for RGA explaining the difference in RGA between these cultivars. By crossing IR64 (which has a non-functional allele of DRO1) with Kinandang Patong (which has a functional allele of DRO1), we developed 26 chromosome segment substitution lines (CSSLs) that carried a particular chromosome segment from Kinandang Patong in the IR64 genetic background. Using these CSSLs, we found only one chromosomal region that was related to RGA: on chromosome 9, which includes DRO1. Using an F2 population derived from a cross between Kinandang Patong and the Dro1-NIL (near isogenic line), which had a functional DRO1 allele in the IR64 genetic background, we identified a new QTL for RGA (DRO3) on the long arm of chromosome 7. DRO3 may only affect RGA in plants with a functional DRO1 allele, suggesting that DRO3 is involved in the DRO1 genetic pathway.

  17. Elevated CO[sub 2] alters deployment of roots in small growth containers

    Energy Technology Data Exchange (ETDEWEB)

    Berntson, G M; McConnaughay, K D.M.; Bazzaz, F A [Harvard University, Cambridge, MA (United States). Dept. of Organismic and Evolutionary Biology

    1993-07-01

    Previously the authors examined how limited rooting space and nutrient supply influenced plant growth under elevated atmospheric CO[sub 2] concentrations. To gain insight into how elevated CO[sub 2] atmospheres affect how plants utilize available belowground space, when rooting space and nutrient supply are limited, they measured the deployment of roots within pots through time. Contrary to aboveground responses, patterns of belowground deployment were most strongly influenced by elevated CO[sub 2] in pots of different volume and shape. Further, elevated CO[sub 2] conditions interacted differently with limited belowground space for the two species studied, Abutilon theophrasti, a C[sub 3] dicot with a deep taproot, and Setaria faberii, a C4 monocot with a shallow fibrous root system. For Setaria, elevated CO[sub 2] increased the size of the largest region of low root density at the pot surface in larger rooting volumes independent of nutrient content, thereby decreasing their efficiency of deployment. For Abutilon, plants responded to elevated CO[sub 2] concentrations by equalizing the pattern of deployment in all the pots. Nutrient concentration, and not pot size or shape, greatly influenced the density of root growth. Root densities for Abutilon and Setaria were similar to those observed in field conditions, for annual dicots and monocots respectively, suggesting that studies using pots may successfully mimic natural conditions.

  18. Root growth of tomato seedlings intensified by humic substances from peat bogs

    Directory of Open Access Journals (Sweden)

    Alexandre Christofaro Silva

    2011-10-01

    Full Text Available Peats are an important reserve of humified carbon in terrestrial ecosystems. The interest in the use of humic substances as plant growth promoters is continuously increasing. The objective of this study was to evaluate the bioactivity of alkaline soluble humic substances (HS, humic (HA and fulvic acids (FA isolated from peats with different decomposition stages of organic matter (sapric, fibric and hemic in the Serra do Espinhaço Meridional, state of Minas Gerais. Dose-response curves were established for the number of lateral roots growing from the main plant axis of tomato seedlings. The bioactivity of HA was greatest (highest response in lateral roots at lowest concentration while FA did not intensify root growth. Both HS and HA stimulated root hair formation. At low concentrations, HS and HA induced root hair formation near the root cap, a typical hormonal imbalance effect in plants. Transgenic tomato with reporter gene DR5::GUS allowed the observation that the auxin-related signalling pathway was involved in root growth promotion by HA.

  19. Overexpression of Arabidopsis plasmodesmata germin-like proteins disrupts root growth and development.

    Science.gov (United States)

    Ham, Byung-Kook; Li, Gang; Kang, Byung-Ho; Zeng, Fanchang; Lucas, William J

    2012-09-01

    In plants, a population of non-cell-autonomous proteins (NCAPs), including numerous transcription factors, move cell to cell through plasmodesmata (PD). In many cases, the intercellular trafficking of these NCAPs is regulated by their interaction with specific PD components. To gain further insight into the functions of this NCAP pathway, coimmunoprecipitation experiments were performed on a tobacco (Nicotiana tabacum) plasmodesmal-enriched cell wall protein preparation using as bait the NCAP, pumpkin (Cucurbita maxima) PHLOEM PROTEIN16 (Cm-PP16). A Cm-PP16 interaction partner, Nt-PLASMODESMAL GERMIN-LIKE PROTEIN1 (Nt-PDGLP1) was identified and shown to be a PD-located component. Arabidopsis thaliana putative orthologs, PDGLP1 and PDGLP2, were identified; expression studies indicated that, postgermination, these proteins were preferentially expressed in the root system. The PDGLP1 signal peptide was shown to function in localization to the PD by a novel mechanism involving the endoplasmic reticulum-Golgi secretory pathway. Overexpression of various tagged versions altered root meristem function, leading to reduced primary root but enhanced lateral root growth. This effect on root growth was corrected with an inability of these chimeric proteins to form stable PD-localized complexes. PDGLP1 and PDGLP2 appear to be involved in regulating primary root growth by controlling phloem-mediated allocation of resources between the primary and lateral root meristems.

  20. Physiological minimum temperatures for root growth in seven common European broad-leaved tree species.

    Science.gov (United States)

    Schenker, Gabriela; Lenz, Armando; Körner, Christian; Hoch, Günter

    2014-03-01

    Temperature is the most important factor driving the cold edge distribution limit of temperate trees. Here, we identified the minimum temperatures for root growth in seven broad-leaved tree species, compared them with the species' natural elevational limits and identified morphological changes in roots produced near their physiological cold limit. Seedlings were exposed to a vertical soil-temperature gradient from 20 to 2 °C along the rooting zone for 18 weeks. In all species, the bulk of roots was produced at temperatures above 5 °C. However, the absolute minimum temperatures for root growth differed among species between 2.3 and 4.2 °C, with those species that reach their natural distribution limits at higher elevations also tending to have lower thermal limits for root tissue formation. In all investigated species, the roots produced at temperatures close to the thermal limit were pale, thick, unbranched and of reduced mechanical strength. Across species, the specific root length (m g(-1) root) was reduced by, on average, 60% at temperatures below 7 °C. A significant correlation of minimum temperatures for root growth with the natural high elevation limits of the investigated species indicates species-specific thermal requirements for basic physiological processes. Although these limits are not necessarily directly causative for the upper distribution limit of a species, they seem to belong to a syndrome of adaptive processes for life at low temperatures. The anatomical changes at the cold limit likely hint at the mechanisms impeding meristematic activity at low temperatures.

  1. Kinetics of nickel silicide growth in silicon nanowires: From linear to square root growth

    International Nuclear Information System (INIS)

    Yaish, Y. E.; Beregovsky, M.; Katsman, A.; Cohen, G. M.

    2011-01-01

    The common practice for nickel silicide formation in silicon nanowires (SiNWs) relies on axial growth of silicide along the wire that is initiated from nickel reservoirs at the source and drain contacts. In the present work the silicide intrusions were studied for various parameters including wire diameter (25-50 nm), annealing time (15-120 s), annealing temperature (300-440 deg. C), and the quality of the initial Ni/Si interface. The silicide formation was investigated by high-resolution scanning electron microscopy, high-resolution transmission electron microscopy (TEM), and atomic force microscopy. The main part of the intrusion formed at 420 deg. C consists of monosilicide NiSi, as was confirmed by energy dispersive spectroscopy STEM, selected area diffraction TEM, and electrical resistance measurements of fully silicided SiNWs. The kinetics of nickel silicide axial growth in the SiNWs was analyzed in the framework of a diffusion model through constrictions. The model calculates the time dependence of the intrusion length, L, and predicts crossover from linear to square root time dependency for different wire parameters, as confirmed by the experimental data.

  2. Toxic effects of Cu2+ on growth, nutrition, root morphology, and distribution of Cu in roots of Sabi grass

    International Nuclear Information System (INIS)

    Kopittke, P.M.; Asher, C.J.; Blamey, F.P.C.; Menzies, N.W.

    2009-01-01

    Sabi grass (Urochloa mosambicensis (Hack.) Dandy) (a C4 species of Poaceae) is commonly used to revegetate disturbed sites in low-rainfall environments, but comparatively little is known regarding copper (Cu) toxicity in this species. A dilute nutrient solution culture experiment was conducted for 10 d to examine the effects of elevated Cu 2+ activities ({Cu 2+ }) on the growth of Sabi grass. Growth was inhibited by high Cu in solution, with a 50% reduction in the relative fresh mass occurring at 1.0 μM {Cu 2+ } for the roots and 1.2 μM {Cu 2+ } for the shoots. In solutions containing 1.2-1.9 μM {Cu 2+ }, many of the roots ruptured due to the tearing and separation of the rhizodermis and outer cortex from the underlying tissues. Transmission electron microscopy revealed that Cu-rich deposits were found to accumulate predominantly within vacuoles. Due to limited translocation of Cu from the roots to the shoots, phytotoxicity is likely to be more of a problem in remediation of Cu-toxic sites than is Cu toxicity of fauna consuming the above-ground biomass.

  3. Boron toxicity tolerance in barley through reduced expression of the multifunctional aquaporin HvNIP2;1.

    Science.gov (United States)

    Schnurbusch, Thorsten; Hayes, Julie; Hrmova, Maria; Baumann, Ute; Ramesh, Sunita A; Tyerman, Stephen D; Langridge, Peter; Sutton, Tim

    2010-08-01

    Boron (B) toxicity is a significant limitation to cereal crop production in a number of regions worldwide. Here we describe the cloning of a gene from barley (Hordeum vulgare), underlying the chromosome 6H B toxicity tolerance quantitative trait locus. It is the second B toxicity tolerance gene identified in barley. Previously, we identified the gene Bot1 that functions as an efflux transporter in B toxicity-tolerant barley to move B out of the plant. The gene identified in this work encodes HvNIP2;1, an aquaporin from the nodulin-26-like intrinsic protein (NIP) subfamily that was recently described as a silicon influx transporter in barley and rice (Oryza sativa). Here we show that a rice mutant for this gene also shows reduced B accumulation in leaf blades compared to wild type and that the mutant protein alters growth of yeast (Saccharomyces cerevisiae) under high B. HvNIP2;1 facilitates significant transport of B when expressed in Xenopus oocytes compared to controls and to another NIP (NOD26), and also in yeast plasma membranes that appear to have relatively high B permeability. We propose that tolerance to high soil B is mediated by reduced expression of HvNIP2;1 to limit B uptake, as well as by increased expression of Bot1 to remove B from roots and sensitive tissues. Together with Bot1, the multifunctional aquaporin HvNIP2;1 is an important determinant of B toxicity tolerance in barley.

  4. CARRY-OVER EFFECTS OF OZONE ON ROOT GROWTH AND CARBOHYDRATE CONCENTRATIONS OF PONDEROSA PINE SEEDLINGS

    Science.gov (United States)

    Ozone exposure decreases belowground carbon allocation and root growth of plants;however,the extent to which these effects persist and the cumulative impact of ozone stress on plant growth are poorly understood.To evaluate the potential for plant compensation,we followed the prog...

  5. Influence of fertilizer placements on the root and shoot growth of soybean

    International Nuclear Information System (INIS)

    Sisworo, E.L.

    1983-01-01

    Two experiments have been carried out to obtain data of soybean growth in relation to fertilizer placements in the soil. Treatments in these two experiments were: fertilizer (N, P, and K) placements at the soil surface, 5, 10, and 15 cm beneath the soil surface and the plants were harvested at the age of 51, 58, and 65 days after seed planting, in the first experiment, and in the second experiment plants were harvested at the age of 37, 44, and 51 days after seed planting. The parameter for root growth was the percentage of roots in soil depths at: 0-5, 5-10, 10-15, and 15-20 cm, respectively, while for shoot growth the parameters were the dry weight of the shoot, plant height, and number of flowers and pods. Data obtained from these two experiments showed that fertilizer placements at several soil depths have no influence on the growth of root and shoot. The highest shoot growth was at 0-5 cm soil depth, but this does not cause highest shoot growth. Different harvest time do not effect root growth, but it has a highly siginificant on shoot growth. The soybean plants were planted in PVC pots with a 6 kg soil capacity, and the pots were placed outside the green house. (author)

  6. Trichoderma-Induced Acidification Is an Early Trigger for Changes in Arabidopsis Root Growth and Determines Fungal Phytostimulation

    Science.gov (United States)

    Pelagio-Flores, Ramón; Esparza-Reynoso, Saraí; Garnica-Vergara, Amira; López-Bucio, José; Herrera-Estrella, Alfredo

    2017-01-01

    Trichoderma spp. are common rhizosphere inhabitants widely used as biological control agents and their role as plant growth promoting fungi has been established. Although soil pH influences several fungal and plant functional traits such as growth and nutrition, little is known about its influence in rhizospheric or mutualistic interactions. The role of pH in the Trichoderma–Arabidopsis interaction was studied by determining primary root growth and lateral root formation, root meristem status and cell viability, quiescent center (QC) integrity, and auxin inducible gene expression. Primary root growth phenotypes in wild type seedlings and STOP1 mutants allowed identification of a putative root pH sensing pathway likely operating in plant–fungus recognition. Acidification by Trichoderma induced auxin redistribution within Arabidopsis columella root cap cells, causing root tip bending and growth inhibition. Root growth stoppage correlated with decreased cell division and with the loss of QC integrity and cell viability, which were reversed by buffering the medium. In addition, stop1, an Arabidopsis mutant sensitive to low pH, was oversensitive to T. atroviride primary root growth repression, providing genetic evidence that a pH root sensing mechanism reprograms root architecture during the interaction. Our results indicate that root sensing of pH mediates the interaction of Trichoderma with plants. PMID:28567051

  7. Root temperature and growth of young tomato plants

    NARCIS (Netherlands)

    Harssema, H.

    1978-01-01

    During recent years sophisticated techniques are applied in the glasshouse industry for the control of the glasshouse climate. Along with that development, extensive research programs were carried out to establish optimum conditions for growth. Air temperature, radiation, CO

  8. Cytosolic glutamine synthetase in barley

    DEFF Research Database (Denmark)

    Thomsen, Hanne Cecilie

    remobilisation from ageing plant parts. Thus, GS is highly involved in determining crop yield and NUE. The major objective of this PhD project was to investigate the NUE properties of transgenic barley designed to constitutively overexpress a GS1 isogene (HvGS1.1). These transgenic lines exhibited an increased...... for N demand. Of the GS isogenes, only the transcript levels of root HvGS1.1 increased when plants were transferred from high to low N. This change coincided with an increase in total GS activity. Pronounced diurnal variation was observed for root nitrate transporter genes and GS isogenes in both root...... fertilizer requirement. The enzyme glutamine synthetase (GS) has been a major topic in plant nitrogen research for decades due to its central role in plant N metabolism. The cytosolic version of this enzyme (GS1) plays an important role in relation to primary N assimilation as well as in relation to N...

  9. Radiomimetic effect of cisplatin on cucumber root development: the relationship between cell division and cell growth

    Energy Technology Data Exchange (ETDEWEB)

    Dubrovsky, J. G. [Division of Experimental Biology, Center for Biological Research (CIB), PO Box 128, La Paz, BCS 23000 (Mexico)

    1993-07-01

    Cisplatin [DDP, cis-dichlorodiammine platinum (II)], a strong cytostatic and antineoplastic agent, was tested on seedlings of cucumber Cucumis sativus L. for its general effect on root development and its particular effects on root cell division and cell growth. DDP was characterized as a radiomimetic compound since both DDP (1·3 × 10{sup -5} M) and γ-irradiation (2·5-10 kGy) drastically and irreversibly stopped development of embryonic lateral root primordia (LRPs) in the radicle by inhibiting both mitotic activity and cell growth. In 20% of the LRPs of DDP-treated roots, cells did not divide at all. Dividing cells completed no more than two cell cycles. These effects were specific because when DDP was available to the roots only at the onset of cell division, cell proliferation and cell growth were similar to that produced by constant incubation. Neither DDP nor γ-irradiation affected non-meristematic cell elongation. It was concluded that cell growth of meristematic cells is closely related to cell division. However, non-meristematic cell growth is independent of DNA damage. This suggests DDP as a tool to reveal these autonomous processes in plants development and to detect tissue compartments in mature plant embryos which contain potentially non-meristematic cells. (author)

  10. Sensitivity of root-knot nematodes to gamma irradiation, salinity and plant growth regulator, cycocel

    Energy Technology Data Exchange (ETDEWEB)

    Sweelam, M E [Econ. Entomology Dept., Fac. Agric. Menoufia University Shebin El-Kom, (Egypt)

    1995-10-01

    The experiment was carried out at the experimental station of the faculty of agriculture, Menoufia Univ. To determine the sensitivity of root-knot nematode, Meloidogyne Javanica infecting tomato plants exposed to different doses of gamma irradiation 0,20,40,60,80 Gy, salinity levels 0. 1000, 2000, 4000 ppm and the plant growth regulator cycocel 0,200 ppm. Treated seeds were planted clay pots and salinity levels and cycocel concentrations were applied. Fresh weights and nematode populations were computed 3 months after application. Results indicated that 20 Gy, 1000 ppm salinity and cycocel gave the highest fresh weight of shoots and roots. The developmental stages and egg-laying females of nematode decreased by the increasing of irradiation dose and salinity levels. Root-knot galls decreased with 40 and 60 Gy, while significant increase was observed with 0 and 80 Gy, salinity levels decreased root galls. Cycocel decreased nematode population, egg-lying females and root-knot galls.

  11. Sensitivity of root-knot nematodes to gamma irradiation, salinity and plant growth regulator, cycocel

    International Nuclear Information System (INIS)

    Sweelam, M.E.

    1995-01-01

    The experiment was carried out at the experimental station of the faculty of agriculture, Menoufia Univ. To determine the sensitivity of root-knot nematode, Meloidogyne Javanica infecting tomato plants exposed to different doses of gamma irradiation 0,20,40,60,80 Gy, salinity levels 0. 1000, 2000, 4000 ppm and the plant growth regulator cycocel 0,200 ppm. Treated seeds were planted clay pots and salinity levels and cycocel concentrations were applied. Fresh weights and nematode populations were computed 3 months after application. Results indicated that 20 Gy, 1000 ppm salinity and cycocel gave the highest fresh weight of shoots and roots. The developmental stages and egg-laying females of nematode decreased by the increasing of irradiation dose and salinity levels. Root-knot galls decreased with 40 and 60 Gy, while significant increase was observed with 0 and 80 Gy, salinity levels decreased root galls. Cycocel decreased nematode population, egg-lying females and root-knot galls

  12. Spatial Regulation of Root Growth: Placing the Plant TOR Pathway in a Developmental Perspective

    Science.gov (United States)

    Barrada, Adam; Montané, Marie-Hélène; Robaglia, Christophe; Menand, Benoît

    2015-01-01

    Plant cells contain specialized structures, such as a cell wall and a large vacuole, which play a major role in cell growth. Roots follow an organized pattern of development, making them the organs of choice for studying the spatio-temporal regulation of cell proliferation and growth in plants. During root growth, cells originate from the initials surrounding the quiescent center, proliferate in the division zone of the meristem, and then increase in length in the elongation zone, reaching their final size and differentiation stage in the mature zone. Phytohormones, especially auxins and cytokinins, control the dynamic balance between cell division and differentiation and therefore organ size. Plant growth is also regulated by metabolites and nutrients, such as the sugars produced by photosynthesis or nitrate assimilated from the soil. Recent literature has shown that the conserved eukaryotic TOR (target of rapamycin) kinase pathway plays an important role in orchestrating plant growth. We will summarize how the regulation of cell proliferation and cell expansion by phytohormones are at the heart of root growth and then discuss recent data indicating that the TOR pathway integrates hormonal and nutritive signals to orchestrate root growth. PMID:26295391

  13. Enhanced lignin monomer production caused by cinnamic Acid and its hydroxylated derivatives inhibits soybean root growth.

    Directory of Open Access Journals (Sweden)

    Rogério Barbosa Lima

    Full Text Available Cinnamic acid and its hydroxylated derivatives (p-coumaric, caffeic, ferulic and sinapic acids are known allelochemicals that affect the seed germination and root growth of many plant species. Recent studies have indicated that the reduction of root growth by these allelochemicals is associated with premature cell wall lignification. We hypothesized that an influx of these compounds into the phenylpropanoid pathway increases the lignin monomer content and reduces the root growth. To confirm this hypothesis, we evaluated the effects of cinnamic, p-coumaric, caffeic, ferulic and sinapic acids on soybean root growth, lignin and the composition of p-hydroxyphenyl (H, guaiacyl (G and syringyl (S monomers. To this end, three-day-old seedlings were cultivated in nutrient solution with or without allelochemical (or selective enzymatic inhibitors of the phenylpropanoid pathway in a growth chamber for 24 h. In general, the results showed that 1 cinnamic, p-coumaric, caffeic and ferulic acids reduced root growth and increased lignin content; 2 cinnamic and p-coumaric acids increased p-hydroxyphenyl (H monomer content, whereas p-coumaric, caffeic and ferulic acids increased guaiacyl (G content, and sinapic acid increased sinapyl (S content; 3 when applied in conjunction with piperonylic acid (PIP, an inhibitor of the cinnamate 4-hydroxylase, C4H, cinnamic acid reduced H, G and S contents; and 4 when applied in conjunction with 3,4-(methylenedioxycinnamic acid (MDCA, an inhibitor of the 4-coumarate:CoA ligase, 4CL, p-coumaric acid reduced H, G and S contents, whereas caffeic, ferulic and sinapic acids reduced G and S contents. These results confirm our hypothesis that exogenously applied allelochemicals are channeled into the phenylpropanoid pathway causing excessive production of lignin and its main monomers. By consequence, an enhanced stiffening of the cell wall restricts soybean root growth.

  14. Analysis of Puerarin and Chemical Compositions Changes in Kudzu Root during Growth Period

    Directory of Open Access Journals (Sweden)

    Yiguo Zhao

    2014-01-01

    Full Text Available The kudzu root is one of the earliest medicinal plants listed in traditional Chinese medicine. In this paper, chemical compositions changes of kudzu roots from one year old to five years old were analyzed with respect to puerarin, acid-insoluble polysaccharides, acid-soluble polysaccharides, reducing sugar, protein, free amino acids, and lipid. In addition, the puerarin content was determined by high performance liquid chromatography (HPLC method. The results showed that acid-soluble polysaccharides content of kudzu root increased with each growth period. In contrast, the acid-insoluble polysaccharides decreased significantly. The contents of reducing sugar and puerarin in kudzu root decreased significantly during its growth period. Beyond that, the contents of protein, free amino acids, and lipid in kudzu root ranged from 31.8 to 45.8 g/kg, 2.21 to 4.33 g/kg, and 32.2 to 76.9 g/kg, respectively. The trend of protein content coincided with the total content of free amino acids, in contrast to lipid. This paper provides a set of data and the select of kudzu root for the processing and development of new products of kudzu root.

  15. Exaggerated root respiration accounts for growth retardation in a starchless mutant of Arabidopsis thaliana.

    Science.gov (United States)

    Brauner, Katrin; Hörmiller, Imke; Nägele, Thomas; Heyer, Arnd G

    2014-07-01

    The knock-out mutation of plastidial phosphoglucomutase (pgm) causes a starchless phenotype in Arabidopsis thaliana, and results in a severe growth reduction of plants cultivated under diurnal conditions. It has been speculated that high soluble sugar levels accumulating during the light phase in leaf mesophyll might cause a reduction of photosynthetic activity or that shortage of reduced carbon during the night is the reason for the slow biomass gain of pgm. Separate simultaneous measurements of leaf net photosynthesis and root respiration demonstrate that photosynthetic activity per unit fresh weight is not reduced in pgm, whereas root respiration is strongly elevated. Comparison with a mutant defective in the dominating vacuolar invertase (AtβFruct4) revealed that high sucrose concentration in the cytosol, but not in the vacuole, of leaf cells is responsible for elevated assimilate transport to the root. Increased sugar supply to the root, as observed in pgm mutants, forces substantial respiratory losses. Because root respiration accounts for 80% of total plant respiration under long-day conditions, this gives rise to retarded biomass formation. In contrast, reduced vacuolar invertase activity leads to reduced net photosynthesis in the shoot and lowered root respiration, and affords an increased root/shoot ratio. The results demonstrate that roots have very limited capacity for carbon storage but exert rigid control of supply for their maintenance metabolism. © 2014 The Authors The Plant Journal © 2014 John Wiley & Sons Ltd.

  16. [Effects of loess soil stabilization on Lolium perenne L. growth and root activity].

    Science.gov (United States)

    Liu, Yue-mei; Zhang, Xing-chang; Wang, Dan-dan

    2011-10-01

    Taking the loess soils with bulk density 1.2 g cm(-3), 1.3 g cm(-3), and 1.4 g cm(-3) from Ansai, Shaanxi Province as test objects, a pot experiment was conducted to study the effects of different amendment amount of soil stabilizer (EN-1 stabilizer) on the growth and root activity of ryegrass (Lolium perenne L.). Within the range of the bulk densities, the leaf chlorophyll content, root activity, root/shoot ratio, root biomass, and plant biomass of L. perenne all decreased with increasing soil bulk density, and were higher under the amendment of EN-1 stabilizer, as compared with the control. With increasing amendment amount of EN-1 stabilizer, the leaf chlorophyll content, root activity, root/shoot ratio, root biomass, and plant biomass had a trend of increased first and decreased then. Soil bulk density and stabilizer amendment amount had significant interactive effect on the root biomass and plant biomass. Overall, the values of the test indices were the highest under 1.3 g cm(-3) soil bulk density and 0.15% EN-1 stabilizer amendment amount.

  17. Study on Composition, Solubility and Water-holding Capacity of Barley Malt Root Protein%大麦芽根蛋白组成、溶解性及持水性研究

    Institute of Scientific and Technical Information of China (English)

    阮长青; 阚俊鹏; 张平; 钱丽丽; 孙清瑞

    2015-01-01

    为深入研究大麦芽根蛋白的组成及功能特性,以麦芽根蛋白提取物为原料,采用Osborne法对其进行了分级纯化,采用SDS-PAGE电泳分析了蛋白亚基分布及其相对分子质量,考察了蛋白浓度、pH值、温度、NaCl浓度等因素对其溶解性、持水性的影响. 结果表明, 大麦芽根蛋白中清蛋白、 球蛋白、 醇溶蛋白和谷蛋白分别占总蛋白的45.79%、17.46%、5.69%、11.47%;蛋白亚基分子量主要集中在30~40 kDa范围内,另两个谱带的分子量分别为24 kDa、56 kDa;在一定条件下,蛋白提取物具有较好的溶解性、持水性. 研究结果为大麦芽根蛋白在食品中的应用提供了一定的依据.%For further research on composition and functional properties of malt root protein, the barley malt roots protein extract as material were isolated by Osborne method, the relative quantity of major subunits and molecular weight distribution were investigated by SDS-PAGE, and the effects of protein concentration, pH, temperature, NaCl concentration on the solubility and water-holding capacity were researched. The results showed that the contents of albuminin in malt root protein were 45.79%, globulin17.46%, prolamin 5.69% and glutelin 11.47%, respectively. SDS-PAGE analysis showed that the malt root protein subunits were mainly concentrated in the 30-40 kDa, there are also two electrophoretic bands, the molecular weights were 24 kDa, 56 kDa.Under certain conditions, the protein extract had good solubility and water-holding capacity. The results provided the basis for the application of malt root protein in food.

  18. A molecular framework for the inhibition of Arabidopsis root growth in response to boron toxicity.

    Science.gov (United States)

    Aquea, Felipe; Federici, Fernan; Moscoso, Cristian; Vega, Andrea; Jullian, Pastor; Haseloff, Jim; Arce-Johnson, Patricio

    2012-04-01

    Boron is an essential micronutrient for plants and is taken up in the form of boric acid (BA). Despite this, a high BA concentration is toxic for the plants, inhibiting root growth and is thus a significant problem in semi-arid areas in the world. In this work, we report the molecular basis for the inhibition of root growth caused by boron. We show that application of BA reduces the size of root meristems, correlating with the inhibition of root growth. The decrease in meristem size is caused by a reduction of cell division. Mitotic cell number significantly decreases and the expression level of key core cell cycle regulators is modulated. The modulation of the cell cycle does not appear to act through cytokinin and auxin signalling. A global expression analysis reveals that boron toxicity induces the expression of genes related with abscisic acid (ABA) signalling, ABA response and cell wall modifications, and represses genes that code for water transporters. These results suggest that boron toxicity produces a reduction of water and BA uptake, triggering a hydric stress response that produces root growth inhibition. © 2011 Blackwell Publishing Ltd.

  19. Barley seeds coating with humates-phosphatase complexes in order to improve p uptake and plant growth

    International Nuclear Information System (INIS)

    Pilar, M. C.; Busto, M. D.; Ortega, N.; Perez-Mateos, M.

    2009-01-01

    Although plants may uptake some forms of organic phosphorus compounds, most of them must be first mineralized to inorganic forms to become available to plants. this hydrolysis is catalyzed by extracellular phosphatases produced by plant roots and microorganisms when plant P availability is limiting P fertilizers added to soil rapidly become unavailable to plants by forming insoluble P compounds. (Author)

  20. Transgressive segregation for very low and high levels of basal resistance to powdery mildew in barley

    NARCIS (Netherlands)

    Aghnoum, R.; Niks, R.E.

    2011-01-01

    Basal resistance of barley to powdery mildew is a quantitatively inherited trait that limits the growth and sporulation of barley powdery mildew pathogen by a non-hypersensitive mechanism of defense. Two experimental barley lines were developed with a very high (ErBgh) and low (EsBgh) level of basal

  1. Soil contamination with silver nanoparticles reduces Bishop pine growth and ectomycorrhizal diversity on pine roots

    Energy Technology Data Exchange (ETDEWEB)

    Sweet, M. J., E-mail: m.sweet@derby.ac.uk [University of Derby, Environmental Sustainability Research Centre, College of Life and Natural Sciences (United Kingdom); Singleton, I. [Newcastle University, School of Biology (United Kingdom)

    2015-11-15

    Soil contamination by silver nanoparticles (AgNP) is of potential environmental concern but little work has been carried out on the effect of such contamination on ectomycorrhizal fungi (EMF). EMF are essential to forest ecosystem functions as they are known to enhance growth of trees by nutrient transfer. In this study, soil was experimentally contaminated with AgNP (0, 350 and 790 mg Ag/kg) and planted with Bishop pine seedlings. The effect of AgNP was subsequently measured, assessing variation in pine growth and ectomycorrhizal diversity associated with the root system. After only 1 month, the highest AgNP level had significantly reduced the root length of pine seedlings, which in turn had a small effect on above ground plant biomass. However, after 4 months growth, both AgNP levels utilised had significantly reduced both pine root and shoot biomass. For example, even the lower levels of AgNP (350 mg Ag/kg) soil, reduced fresh root biomass by approximately 57 %. The root systems of the plants grown in AgNP-contaminated soils lacked the lateral and fine root development seen in the control plants (no AgNP). Although, only five different genera of EMF were found on roots of the control plants, only one genus Laccaria was found on roots of plants grown in soil containing 350 mg AgNP/kg. At the higher levels of AgNP contamination, no EMF were observed. Furthermore, extractable silver was found in soils containing AgNP, indicating potential dissolution of silver ions (Ag+) from the solid AgNP.

  2. Soil contamination with silver nanoparticles reduces Bishop pine growth and ectomycorrhizal diversity on pine roots

    International Nuclear Information System (INIS)

    Sweet, M. J.; Singleton, I.

    2015-01-01

    Soil contamination by silver nanoparticles (AgNP) is of potential environmental concern but little work has been carried out on the effect of such contamination on ectomycorrhizal fungi (EMF). EMF are essential to forest ecosystem functions as they are known to enhance growth of trees by nutrient transfer. In this study, soil was experimentally contaminated with AgNP (0, 350 and 790 mg Ag/kg) and planted with Bishop pine seedlings. The effect of AgNP was subsequently measured, assessing variation in pine growth and ectomycorrhizal diversity associated with the root system. After only 1 month, the highest AgNP level had significantly reduced the root length of pine seedlings, which in turn had a small effect on above ground plant biomass. However, after 4 months growth, both AgNP levels utilised had significantly reduced both pine root and shoot biomass. For example, even the lower levels of AgNP (350 mg Ag/kg) soil, reduced fresh root biomass by approximately 57 %. The root systems of the plants grown in AgNP-contaminated soils lacked the lateral and fine root development seen in the control plants (no AgNP). Although, only five different genera of EMF were found on roots of the control plants, only one genus Laccaria was found on roots of plants grown in soil containing 350 mg AgNP/kg. At the higher levels of AgNP contamination, no EMF were observed. Furthermore, extractable silver was found in soils containing AgNP, indicating potential dissolution of silver ions (Ag+) from the solid AgNP

  3. Effects of climate change on the length of growth stages and water requirement of wheat and barley (Case Study: Birjand Plain

    Directory of Open Access Journals (Sweden)

    Mitra Rahmani

    2016-03-01

    Full Text Available Introduction The global climate is changing and, despite efforts to reduce greenhouse gas emissions, weather variation is inevitable. Meanwhile, agriculture as a major water consumer will require adaptation to these variations, along with other challenges, to guarantee its persistence and sustainability. Given the arid and semi-arid climate of Iran, water, as a main limiting factor for agricultural production, plays an important role in determining the type of farming activities (Osamu et al., 2005. Crop water requirements and evapotranspiration are the main cause of water consumption in agricultural sector, the both accepted to face a dramatic increase in future under influence of increasing temperatures resulting from climate change (Koocheki et al., 2001. In this regard, the foreknowledge about future changes in climate and its effects on agricultural water use can be helpful for farmers and decision-makers. This study aimed to evaluate the climatic conditions of Birjand plain in the next two decades, and to investigate the effects of climate change on water consumption of wheat and barley as two main crops in this region. Materials and methods In the present survey, the effects of estimated climate change in Birjand plain on water requirement of wheat and barley and wheat yield in the 2010-2039 period were studied. Based on average weather data for the last thirty years from Birjand synoptic stations, climatic parameters of temperature and precipitation for the time period of 2010-2039 were simulated with LARS-WG5 using A1 scenario confirmed by the IPCC. Wind speed and relative humidity also were estimated for the future period. Common planting and harvesting dates were obtained from local farmers and Birjand Agriculture Organization and duration and crop coefficients (Kc for early, developmental, middle and final crop growth stages in the current period were extracted from FAO Irrigation and Drainage Paper No. 56. For the future period

  4. Growth response of Casuarina equisetifolia Forst. rooted stem cuttings to Frankia in nursery and field conditions.

    Science.gov (United States)

    Karthikeyan, A; Chandrasekaran, K; Geetha, M; Kalaiselvi, R

    2013-11-01

    Casuarina equisetifolia Forst. is a tree crop that provides fuel wood, land reclamation, dune stabilization, and scaffolding for construction, shelter belts, and pulp and paper production. C. equisetifolia fixes atmospheric nitrogen through a symbiotic relationship with Frankia, a soil bacterium of the actinobacteria group. The roots of C. equisetifolia produce root nodules where the bacteria fix atmospheric nitrogen, which is an essential nutrient for all plant metabolic activities. However, rooted stem cuttings of elite clones of C. equisetifolia by vegetative propagation is being planted by the farmers of Pondicherry as costeffective method. As the vegetative propagation method uses inert material (vermiculite) for rooting there is no chance for Frankia association. Therefore after planting of these stocks the farmers are applying 150 kg of di-ammonium phosphate (DAP)/acre/year. To overcome this fertilizer usage, the Frankia-inoculated rooted stem cuttings were propagated under nursery conditions and transplanted in the nutrient-deficient soils of Karaikal, Pondicherry (India), in this study. Under nursery experiments the growth and biomass of C. equisetifolia rooted stem cuttings inoculated with Frankia showed 3 times higher growth and biomass than uninoculated control. These stocks were transplanted and monitored for their growth and survival for 1 year in the nutrient-deficient farm land. The results showed that the rooted stem cuttings of C. equisetifolia significantly improved growth in height (8.8 m), stem girth (9.6 cm) and tissue nitrogen content (3.3 mg g-1) than uninoculated controls. The soil nutrient status was also improved due to inoculation of Frankia.

  5. Effect of planting density on root lodging resistance and its relationship to nodal root growth characteristics in maize (Zea mays L.)

    DEFF Research Database (Denmark)

    Liu, Shengqun; Song, Fengbin; Liu, Fulai

    2012-01-01

    Increase of planting density has been widely used to increase grain yield in maize. However, it may lead to higher risk of root lodging hence causing significant yield loss of the crop. The objective of this study was to investigate the effect of planting density on maize nodal root growth...

  6. Development of maternal seed tissue in barley is mediated by regulated cell expansion and cell disintegration and coordinated with endosperm growth.

    Science.gov (United States)

    Radchuk, Volodymyr; Weier, Diana; Radchuk, Ruslana; Weschke, Winfriede; Weber, Hans

    2011-01-01

    After fertilization, filial grain organs are surrounded by the maternal nucellus embedded within the integuments and pericarp. Rapid early endosperm growth must be coordinated with maternal tissue development. Parameters of maternal tissue growth and development were analysed during early endosperm formation. In the pericarp, cell proliferation is accomplished around the time of fertilization, followed by cell elongation predominantly in longitudinal directions. The rapid cell expansion coincides with endosperm cellularization. Distribution of TUNEL (terminal deoxynucleotidyl transferase-mediated dUTP nick end labelling)-positive nuclei reveals distinct patterns starting in the nucellus at anthesis and followed later by the inner cell rows of the pericarp, then spreading to the whole pericarp. The pattern suggests timely and spatially regulated programmed cell death (PCD) processes in maternal seed tissues. When the endosperm is coenocytic, PCD events are only observed within the nucellus. Thereby, remobilization of nucellar storage compounds by PCD could nourish the early developing endosperm when functional interconnections are absent between maternal and filial seed organs. Specific proteases promote PCD events. Characterization of the barley vacuolar processing enzyme (VPE) gene family identified seven gene members specifically expressed in the developing grain. HvVPE2a (known as nucellain) together with closely similar HvVPE2b and HvVPE2d might be involved in nucellar PCD. HvVPE4 is strongly cell specific for pericarp parenchyma. Correlative evidence suggests that HvVPE4 plays a role in PCD events in the pericarp. Possible functions of PCD in the maternal tissues imply a potential nutritive role or the relief of a physical restraint for endosperm growth. PCD could also activate post-phloem transport functions.

  7. Effects of fluoride and 6 benzylaminopurine on growth and respiration of corn and cotton roots

    Energy Technology Data Exchange (ETDEWEB)

    Thompson, C R

    1967-01-01

    Corn and cotton plants exhibit a wide difference in their susceptibility to atmospheric fluoride. Corn shows leaf lesions when 100 ..gamma../gm on a dry weight basis are accumulated but cotton can tolerate 5000 ..gamma../gm without showing leaf necrosis. A comparison of respirational response of potted seedlings of the two species to 10 ..gamma../M/sup 3/ HF caused an increase of about 10%. Addition of 2 x 10/sup 2/M F/sup -/ to solutions for germinating the plants showed that cotton accumulated about twice as much as F/sup -/ in seedling roots. Growth was reduced about one half by 2 x 10/sup -3/M F/sup -/ in both species but respirational rates of root tips from control and fluoride treated tissues were equal. Prolonged treatment of excised root tips with fluoride reduced respiration. Because fluoride causes cellular changes in roots similar to aging and kinetin seems to act to reverse these changes, corn was germinated with 2 x 10/sup -3/M F/sup -/ and increasing levels of 6-benzylaminopurine. Root growth inhibition (63%) was reversed significantly at 0.2 - 0.8..gamma.. ml. Respirational rates of root tips grown in fluoride, fluoride plus 6-benzylaminopurine and controls were equal.

  8. PIV as a method for quantifying root cell growth and particle displacement in confocal images.

    Science.gov (United States)

    Bengough, A Glyn; Hans, Joachim; Bransby, M Fraser; Valentine, Tracy A

    2010-01-01

    Particle image velocimetry (PIV) quantifies displacement of patches of pixels between successive images. We evaluated PIV as a tool for microscopists by measuring displacements of cells and of a surrounding granular medium in confocal laser scanning microscopy images of Arabidopsis thaliana roots labeled with cell-membrane targeted green fluorescent protein. Excellent accuracy (e.g., displacement standard deviation PIV-predicted and actual displacements (r(2) > 0.83). Root mean squared error for these distorted images was 0.4-1.1 pixels, increasing at higher magnification factors. Cell growth and rhizosphere deformation were tracked with good temporal (e.g., 1-min interval) and spatial resolution, with PIV patches located on recognizable cell features being tracked more successfully. Appropriate choice of GFP-label was important to decrease small-scale biological noise due to intracellular motion. PIV of roots grown in stiff 2% versus 0.7% agar showed patterns of cell expansion consistent with physically impeded roots of other species. Roots in glass ballotini underwent rapid changes in growth direction on a timescale of minutes, associated with localized arching of ballotini. By tracking cell vertices, we monitored automatically cell length, width, and area every minute for 0.5 h for cells in different stages of development. In conclusion, PIV measured displacements successfully in images of living root cells and the external granular medium, revealing much potential for use by microscopists. (c) 2009 Wiley-Liss, Inc.

  9. Microbial Growth and Carbon Use Efficiency in the Rhizosphere and Root-Free Soil

    Science.gov (United States)

    Blagodatskaya, Evgenia; Blagodatsky, Sergey; Anderson, Traute-Heidi; Kuzyakov, Yakov

    2014-01-01

    Plant-microbial interactions alter C and N balance in the rhizosphere and affect the microbial carbon use efficiency (CUE)–the fundamental characteristic of microbial metabolism. Estimation of CUE in microbial hotspots with high dynamics of activity and changes of microbial physiological state from dormancy to activity is a challenge in soil microbiology. We analyzed respiratory activity, microbial DNA content and CUE by manipulation the C and nutrients availability in the soil under Beta vulgaris. All measurements were done in root-free and rhizosphere soil under steady-state conditions and during microbial growth induced by addition of glucose. Microorganisms in the rhizosphere and root-free soil differed in their CUE dynamics due to varying time delays between respiration burst and DNA increase. Constant CUE in an exponentially-growing microbial community in rhizosphere demonstrated the balanced growth. In contrast, the CUE in the root-free soil increased more than three times at the end of exponential growth and was 1.5 times higher than in the rhizosphere. Plants alter the dynamics of microbial CUE by balancing the catabolic and anabolic processes, which were decoupled in the root-free soil. The effects of N and C availability on CUE in rhizosphere and root-free soil are discussed. PMID:24722409

  10. Root growth of Lotus corniculatus interacts with P distribution in young sandy soil

    Directory of Open Access Journals (Sweden)

    B. Felderer

    2013-03-01

    Full Text Available Large areas of land are restored with unweathered soil substrates following mining activities in eastern Germany and elsewhere. In the initial stages of colonization of such land by vegetation, plant roots may become key agents in generating soil formation patterns by introducing gradients in chemical and physical soil properties. On the other hand, such patterns may be influenced by root growth responses to pre-existing substrate heterogeneities. In particular, the roots of many plants were found to preferentially proliferate into nutrient-rich patches. Phosphorus (P is of primary interest in this respect because its availability is often low in unweathered soils, limiting especially the growth of leguminous plants. However, leguminous plants occur frequently among the pioneer plant species on such soils, as they only depend on atmospheric nitrogen (N fixation as N source. In this study we investigated the relationship between root growth allocation of the legume Lotus corniculatus and soil P distribution on recently restored land. As test sites, the experimental Chicken Creek Catchment (CCC in eastern Germany and a nearby experimental site (ES with the same soil substrate were used. We established two experiments with constructed heterogeneity, one in the field on the experimental site and the other in a climate chamber. In addition, we conducted high-density samplings on undisturbed soil plots colonized by L. corniculatus on the ES and on the CCC. In the field experiment, we installed cylindrical ingrowth soil cores (4.5 × 10 cm with and without P fertilization around single two-month-old L. corniculatus plants. Roots showed preferential growth into the P-fertilized ingrowth-cores. Preferential root allocation was also found in the climate chamber experiment, where single L. corniculatus plants were grown in containers filled with ES soil and where a lateral portion of the containers was additionally supplied with a range of different P

  11. Growth and root development of four mangrove seedlings under varying salinity

    Science.gov (United States)

    Basyuni, M.; Keliat, D. A.; Lubis, M. U.; Manalu, N. B.; Syuhada, A.; Wati, R.; Yunasfi

    2018-03-01

    This present study describes four mangrove seedlings namely Bruguiera cylindrica, B. sexangula, Ceriops tagal, and Rhizophora apiculata in response to salinity with particular emphasis to root development. The seedlings of four mangroves were grown for 5 months in 0%, 0.5%, 1.5%, 2.0% and 3.0% salt concentration. Salinity significantly decreased the growth (diameter and plant height) of all mangrove seedlings. Root developments were observed from the tap and lateral root. The number, length and diameter of both roots-typed of B. cylindrica, B. sexangula and C. tagal seedlings significantly decreased with increasing salt concentration with optimum development at 0.5% salinity. By contrast, the number, length, and diameter of tap root of R. apiculata seedlings were significantly enhanced by salt with maximal stimulation at 0.5%, and this increase was attenuated by increasing salinity. On the other hand, lateral root development of R. apiculata significantly thrived up to 1.5% salinity then decreasing with the increasing salinity. The different response of root development suggested valuable information for mangrove rehabilitation in North Sumatra and their adaption to withstand salt stress.

  12. Maize Fungal Growth Control with Scopoletin of Cassava Roots Produced in Benin

    Directory of Open Access Journals (Sweden)

    Rafiatou Ba

    2017-01-01

    Full Text Available The chemical contamination of food is among the main public health issues in developing countries. With a view to find new natural bioactive products against fungi responsible for chemical contamination of staple food such as maize, the antifungal activity tests of scopoletin extracted from different components of the cassava root produced in Benin were carried out. The dosage of scopoletin from parts of the root (first skin, second skin, whole root, and flesh was done by High Performance Liquid Chromatography. The scopoletin extract was used to assess the activity of 12 strains (11 strains of maize and a reference strain. The presence of scopoletin was revealed in all components of the cassava root. Scopoletin extracted from the first skin cassava root was the most active both as inhibition of sporulation (52.29 to 87.91% and the mycelial growth (36.51–80.41%. Scopoletin extract from the cassava root skins showed significant inhibitory activity on the tested strains with fungicide concentration (MFC between 0.0125 mg/mL and 0.1 mg/mL. The antifungal scopoletin extracted from the cassava root skins may be well beneficial for the fungal control of the storage of maize.

  13. The effect of ethylene on root growth of Zea mays seedlings

    Science.gov (United States)

    Whalen, M. C.; Feldman, L. J.

    1988-01-01

    The control of primary root growth in Zea mays cv. Merit by ethylene was examined. At applied concentrations of ethylene equal to or greater than 0.1 microliter L-1, root elongation during 24 h was inhibited. The half-maximal response occurred at 0.6 microliter L-1 and the response saturated at 6 microliters L-1. Inhibition of elongation took place within 20 min. However, after ethylene was removed, elongation recovered to control values within 15 min. Root elongation was also inhibited by green light. The inhibition caused by a 24-h exposure to ethylene was restricted to the elongating region just behind the apex, with inhibition of cortical cell elongation being the primary contributor to the effect. Based on use of 2,5-norbornadiene, a gaseous competitive inhibitor of ethylene, it was concluded that endogenous ethylene normally inhibits root elongation.

  14. Root growth of perennials in vertical growing media for use in green walls

    DEFF Research Database (Denmark)

    Jørgensen, Lars; Dresbøll, Dorte Bodin; Thorup-Kristensen, Kristian

    2014-01-01

    The vertical orientation of green walls causes a risk of uneven water distribution within the growing medium, and thereby stress on the plant roots. Therefore it was studied how the root and top growth of different species were affected by the water holding characteristics of the growing media....... Five species of hardy perennials (Campanula poscharskyana ‘Stella’, Fragaria vesca ‘Småland’, Geranium sanguineum ‘Max Frei’, Sesleria heufleriana and Veronica officinalis ‘Allgrün’) were grown in 3 types of growing media (coir and 2 of rockwool) in vertical boxes under greenhouse conditions. Root...... distribution was registered over 52 days and the activity of individual root systems was studied via 15N uptake and plant parameters were measured. The water holding characteristics of the growing media was determined on a sandbox. From day 21 and throughout the experiment, the plants growing in the coir...

  15. High voltage electric field effects on structure and biological characteristics of barley seeds

    Energy Technology Data Exchange (ETDEWEB)

    Khazaei, J. [Tehran Univ., Tehran (Iran, Islamic Republic of). Dept. of Agrotechnology, Univ. College of Abouraihan; Aliabadi, E. [Tehran Univ., Tehran (Iran, Islamic Republic of). Dept. of Crop Production Horticulture, Univ. College of Aburaihan; Shayegani, A.A. [Tehran Univ., Tehran (Iran, Islamic Republic of). Univ. College of Engineering

    2010-07-01

    Electric biostimulation of seeds is a pre-sowing treatment in which an electric field is applied to seeds to increase germination of non standard seeds. This paper reported on a study that examined the effects of AC electric field and exposure time on the structure and biological characteristics of barley seeds. The objective was to determine the potential to accelerate seed germination, plant growth and root development by the electric field strength and exposure time. Makooei cultivar barley seeds were used in this study. The effect of electric field strength (at 2, 4, 9, and 14 kV/m) and exposure time (at 15, 45, 80, and 150 min) on seed germination was studied along with height of seedling, length or root, height of stem, length of leaves, earliness, dry weight and wet weight of seedling. The treated seeds were stored for a month in a refrigerator at 5 degrees C prior to the germination experiments. The initial germination percent of the seed was 81 per cent. The treatment of barley seeds in an AC electric field had a positive effect on all investigated parameters. The germination percent of the treated seed increased to 94.5 per cent . The seeds exposed for long periods of time (45 to 150 min) showed better germination than the seeds exposed to lower exposure times. Dry and wet weights of seedling increased 143.4 per cent and 45.7 per cent, respectively.

  16. Evaluation of barley (hordeum vulgare l.) germplasm for high forage production under salt stress

    International Nuclear Information System (INIS)

    Saleem, A.; Qurainy, F.A.; Akram, N.A.

    2014-01-01

    To explore high biomass producing salt tolerant cultivars of a potential forage crop barley (Hordeum vulgare L.), 30-day old plants of 105 different accessions from different origin were subjected to saline and non-saline (control) conditions for 45 days. Salinity stress (150 mM NaCl) markedly suppressed plant growth (shoot and/or root fresh and dry weights), chlorophyll pigments (a and b), internal CO/sub 2/ concentration, stomatal conductance, rate of transpiration and photosynthesis, while a considerable salt-induced increase was observed in all fluorescence related attributes including efficiency of photosystem-II (Fv/Fm), co-efficient of non-photochemical quenching (QN), photochemical quenching (QP), and non-photochemical quenching (NPQ) in all 105 accessions of barley. The response of all 105 barley accessions to salt stress varied significantly for all the morpho-physiological attributes determined in the present study. Overall, on the basis of shoot and root dry weights, accessions, 4050, 4053, 4056, 4163, 4228, 4229, 4244, 4245, 4290, 4414, 4415, 4427, 4452, Mahali, Jesto, 4165, 4229, 4249, 4405, 4409, 4426, 4456, and Giza 123 were found superior while accessions, 4245, 4158, 4166, 4246, 4406, 4423, 4441, 4442 4447, 4453 and 4458 inferior under saline conditions. (author)

  17. Coordination of growth in root and shoot apices by AIL/PLT transcription factors

    NARCIS (Netherlands)

    Scheres, Ben; Krizek, Beth A.

    2018-01-01

    Growth at the root tip and organ generation at the shoot tip depend on the proper functioning of apical meristems and the transitioning of meristematic cell descendants from a proliferating state to cell elongation and differentiation. Members of the AINTEGUMENTA-LIKE/PLETHORA (AIL/PLT)

  18. Interaction between root growth allocation and mycorrhizal fungi in soil with patchy P distribution

    Czech Academy of Sciences Publication Activity Database

    Felderer, B.; Jansa, Jan; Schulin, R.

    2013-01-01

    Roč. 373, 1-2 (2013), s. 569-582 ISSN 0032-079X Institutional support: RVO:61388971 Keywords : Preferential root growth * Arbuscular mycorrhizal fungi * Lotus japonicus Subject RIV: EE - Microbiology, Virology Impact factor: 3.235, year: 2013

  19. Effects of aluminum on root growth and absorption of nutrients by ...

    African Journals Online (AJOL)

    Aluminum (Al) is a biotoxic which often influences the absorption of nutrients by plants in strongly acidic soils. In this experiment, the effect of Al on root growth, absorption of macronutrients; phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg) and micronutrients; iron (Fe), manganese (Mn), copper (Cu) and zinc ...

  20. Chromosome aberration assays in barley (Hordeum vulgare)

    Energy Technology Data Exchange (ETDEWEB)

    Constantin, M J [Univ. of Tennessee, Knoxville; Nilan, R A

    1982-01-01

    Barley is an exceellent organism for studies of induced chromosome aberrations because of its few (2n = 2x = 14) relatively large chromosomes. Root-tip and shoot-tip cells have been used extensively for the study of ionizing radiation-induced chromosome aberrations. The general procedures are well known, the technology is simple and easy to learn, and the assays are relatively quick and inexpensive. Both root tips and shoot tips can be used for the study of chemical mutagens as well as ionizing radiations. Pollen mother cells are well suited for studying the effects of mutagens on meiotic chromosomes. The literature review for the Gene-Tox Program reported on 61 chemicals tested for their effects on barley chromosomes. Of these, 90% were reported to be either positive or positive dose-related, while 7% were negative and 3% were questionable. Barley assays based on chromosomal aberrations are useful to detect the clastogenic potency of chemicals under laboratory conditions. Indications are that the data from barley can be used to corroborate data obtained from other organisms. Among the classes of chemicals assayed were: alcohols and phenols; alkaloids; epoxides; alkyl sulfates; amides and sulfonamides; aromatic amines; aryl halides; aziridines; alkenes; carbamates; hydroazides; nitroaromatics; nitrosamides; nitrosources; phenothiazines; and polycyclic aromatic hydrocarbons.

  1. Root-associated bacteria promote grapevine growth: from the laboratory to the field

    KAUST Repository

    Rolli, Eleonora

    2016-08-18

    Background and Aims: Laboratory and greenhouse experiments have shown that root-associated bacteria have beneficial effects on grapevine growth; however, these effects have not been tested in the field. Here, we aimed to demonstrate whether bacteria of different geographical origins derived from different crop plants can colonize grapevine to gain a beneficial outcome for the plant leading to promote growth at the field scale. Methods: To link the ecological functions of bacteria to the promotion of plant growth, we sorted fifteen bacterial strains from a larger isolate collection to study in vitro Plant Growth Promoting (PGP) traits. We analysed the ability of these strains to colonise the root tissues of grapevine and Arabidopsis using green-fluorescent-protein-labelled strain derivatives and a cultivation independent approach. We assessed the ability of two subsets randomly chosen from the 15 selected strains to promote grapevine growth in two field-scale experiments in north and central Italy over two years. Parameters of plant vigour were measured during the vegetative season in de novo grafted vine cuttings and adult productive plants inoculated with the bacterial strains. Results: Beneficial bacteria rapidly and intimately colonized the rhizoplane and the root system of grapevine. In the field, plants inoculated with bacteria isolated from grapevine roots out-performed untreated plants. In both the tested vineyards, bacteria-promotion effects largely rely in the formation of an extended epigeal system endowed of longer shoots with larger diameters and more nodes than non-inoculated plants. Conclusions: PGP bacteria isolated in the laboratory can be successfully used to promote growth of grapevines in the field. The resulting larger canopy potentially increased the photosynthetic surface of the grapevine, promoting growth.

  2. The Interaction between Auxin and Nitric Oxide Regulates Root Growth in Response to Iron Deficiency in Rice

    Directory of Open Access Journals (Sweden)

    Huwei Sun

    2017-12-01

    Full Text Available Fe deficiency (-Fe is a common abiotic stress that affects the root development of plants. Auxin and nitric oxide (NO are key regulator of root growth under -Fe. However, the interactions between auxin and NO regulate root growth in response to Fe deficiency are complex and unclear. In this study, the indole-3-acetic acid (IAA and NO levels in roots, and the responses of root growth in rice to different levels of Fe supply were investigated using wild type (WT, ospin1b and osnia2 mutants. -Fe promoted LR formation but inhibited seminal root elongation. IAA levels, [3H] IAA transport, and expression levels of PIN1a-c genes in roots were reduced under -Fe, suggesting that polar auxin transport from shoots to roots was decreased. Application of IAA to -Fe seedlings restored seminal root length, but not LR density, to levels similar to those under normal Fe (+Fe, and the seminal root length was shorter in two ospin1b mutants relative to WT under +Fe, but not under -Fe, confirming that auxin transport participates in -Fe-inhibited seminal root elongation. Moreover, -Fe-induced LR density and -Fe-inhibited seminal root elongation paralleled NO production in roots. Interestingly, similar NO accumulation and responses of LR density and root elongation were observed in osnia2 mutants compared to WT, and the higher expression of NOA gene under -Fe, suggesting that -Fe-induced NO was generated via the NO synthase-like pathway rather than the nitrate reductase pathway. However, IAA could restore the functions of NO in inhibiting seminal root elongation, but did not replace the role of NO-induced LR formation under -Fe. Overall, our findings suggested that NO functions downstream of auxin in regulating LR formation; NO-inhibited seminal root elongation by decreasing meristem activity in root tips under -Fe, with the involvement of auxin.

  3. Evaluation of putative allelochemicals in rice root exudates for their role in the suppression of arrowhead root growth.

    Science.gov (United States)

    Seal, Alexa N; Haig, Terry; Pratley, James E

    2004-08-01

    In previous studies, 15 putative allelopathic compounds detected in rice root exudates were quantified by GC/MS/MS. In this study, multiple regression analysis on these compounds determined that five selected phenolics, namely caffeic, p-hydroxybenzoic, vanillic, syringic, and p-coumaric acids, from rice exudates were best correlated with the observed allelopathic effect on arrowhead (Sagittaria montevidensis) root growth. Despite this positive association, determination of the phenolic acid dose-response curve established that the amount quantified in the exudates was much lower than the required threshold concentration for arrowhead inhibition. A similar dose-response curve resulted from a combination of all 15 quantified compounds. Significant differences between the amounts of trans-ferulic acid, abietic acid, and an indole also existed between allelopathic and non-allelopathic rice cultivars. The potential roles of these three compounds in rice allelopathy were examined by chemoassay. Overall, neither the addition of trans-ferulic acid nor 5-hydroxyindole-3-acetic acid to the phenolic mix significantly contributed to phytotoxicity, although at higher concentrations, trans-ferulic acid appeared to act antagonistically to the phytotoxic effects of the phenolic mix. The addition of abietic acid also decreased the inhibitory effect of the phenolic mix. These studies indicate that the compounds quantified are not directly responsible for the observed allelopathic response. It is possible that the amount of phenolic acids may be indirectly related to the chemicals finally responsible for the observed allelopathic effect.

  4. [Difference of anti-fracture mechanical characteristics between lateral-root branches and adjacent upper straight roots of four plant species in vigorous growth period].

    Science.gov (United States)

    Liu, Peng-fei; Liu, Jing; Zhu, Hong-hui; Zhang, Xin; Zhang, Ge; Li, You-fang; Su, Yu; Wang, Chen-jia

    2016-01-01

    Taking four plant species, Caragana korshinskii, Salix psammophila, Hippophae rhamnides and Artemisia sphaerocephala, which were 3-4 years old and in vigorous growth period, as test materials, the anti-fracture forces of lateral-root branches and adjacent upper straight roots were measured with the self-made fixture and the instrument of TY 8000. The lateral-root branches were vital and the diameters were 1-4 mm. The results showed that the anti-fracture force and anti-fracture strength of lateral-root branches were lesser than those of the adjacent upper straight roots even though the average diameter of lateral-root branches was greater. The ratios of anti-fracture strength of lateral-root branches to the adjacent upper straight roots were 71.5% for C. korshinskii, 62.9% for S. psammophila, 45.4% for H. rhamnides and 35.4% for A. sphaerocephala. For the four plants, the anti-fracture force positively correlated with the diameter in a power function, while the anti-fracture strength negatively correlated with diameter in a power function. The anti-fracture strengths of lateral-root branches and adjacent upper straight roots for the four species followed the sequence of C. korshinskii (33.66 and 47.06 MPa) > S. psammophila (17.31 and 27.54 MPa) > H. rhamnides (3.97 and 8.75 MPa) > A. sphaerphala (2.18 and 6.15 MPa).

  5. The effects of Vexar® seedling protectors on the growth and development of lodgepole pine roots

    Science.gov (United States)

    Engeman, Richard M.; Anthony, R. Michael; Krupa, Heather W.; Evans, James

    1997-01-01

    The effects on the growth and development of lodgepole pine roots from the Vexar® tubes used to protect seedlings from pocket gopher damage were studied in the Targhee National Forest, Idaho and the Deschutes National Forest, Oregon. At each site, Vexar-protected and unprotected seedlings, with and without above-ground gopher damage were examined after six growing seasons for root deformities and growth. Undamaged seedlings exhibited greater growth, reflecting the importance of non-lethal gopher damage as a deterrent to tree growth. Protected seedlings with similar damage history as unprotected seedlings had greater root depth than unprotected seedlings, although unprotected seedlings with no above-ground damage generally had the greatest root weight. In general, the percent of seedlings with root deformities was greater for the unprotected seedlings than for the Vexar-protectd seedlings, although this could be largely due to the greater care required to plant protected seedlings. Acute deformities were more common for unprotected seedlings, whereas root deformities with less severe bending were more common for protected seedlings. The incidence of crossed roots was similar for protected and unprotected seedlings on the Deschutes site, where enough occurrences of this deformity permitted analyses. Protected seedlings were similar in root abundance, root distribution, root size and vigor to the unprotected seedlings, with some indication from the Deshutes study site that root distribution was improved with Vexar protection.

  6. Nitrogen fertilization and root growth dynamics of durum wheat for a sustainable production

    Directory of Open Access Journals (Sweden)

    Donato De Giorgio

    2012-07-01

    Full Text Available In an area of the Apulian Tavoliere (southern Italy, the effects of three levels of nitrogen fertilization (0, 50 and 100 kg N ha–1 on root development, growth analysis and yield parameters of durum wheat were evaluated. The research was conducted over a four-year period (1994-97. The non-destructive mini-rhizotron method was used to study the root system at stem extension and at the beginning of heading and ripening stages. At the end of tillering and at boot and flowering stages, samples of wheat biomass were taken and subjected to growth analysis. Yield data and the main biometric parameters were collected at harvest time. The doses of nitrogen (N fertilizer 50 and 100 kg N ha–1 had a greater effect on root development in the 20-30 cm soil layer and on epigeal biomass than the control test (N0 without nitrogen fertilization. In the test (N0 the growth of root and epigeal biomass was slower during the first vegetative phases, however, afterwards both of them recovered and the root system was mainly developed in the 30-40 cm soil layer. A better development of root system in deeper soil layers, without nitrogen supply, has allowed the plant to overcome more easily the water-deficit and thermal stresses during the ripening stage. The results of this research have shown that the production of grain with 50 kg ha–1 of N is similar to those of 100 kg ha–1 of N doses and higher than the test without nitrogen fertilization. In this kind of environment can be recommended a nitrogen dose of 50 kg ha–1 for obtaining an increase in grain production with low costs and reduced agricultural sources of pollution.

  7. Fe-Chlorophyllin Promotes the Growth of Wheat Roots Associated with Nitric Oxide Generation

    Directory of Open Access Journals (Sweden)

    Hui Jiang

    2010-12-01

    Full Text Available : Effects of Fe-chlorophyllin on the growth of wheat root were investigated in this study. We found that Fe-chlorophyllin can promote root growth. The production of nitric oxide in wheat root was detected using DAF-2DA fluorescent emission. The intensity of fluorescent in the presence of 0.1 mg/L Fe-chlorophyllin was near to that observed with the positive control of sodium nitroprusside (SNP, the nitric oxide donor. IAA oxidase activity decreased with all treatments of Fe-chlorophyllin from 0.01 to 10 mg/L. At the relatively lower Fe-chlorophyllin concentration of 0.1 mg/L, the activity of IAA oxidase displayed a remarkable decrease, being 40.1% lower than the control. Meanwhile, Fe-chlorophyllin treatment could increase the activities of reactive oxygen scavenging enzymes, such as superoxide dismutase (SOD and peroxidase (POD, as determined using non-denaturing polyacrylamide gel electrophoresis. These results indicate that Fe-chlorophyllin contributes to the growth of wheat root associated with nitric oxide generation.

  8. Effects of Growth Environment and Ulking Rate on Cyanogenic Potential of Cassava Tuerous Roots

    International Nuclear Information System (INIS)

    Githunguri, C.M

    2002-01-01

    Various abiotic factors affect the pattern of growth and accumulation of cyanogenic glucosides in cassava plants. Five cassava genotypes were planted in a wet and a dry agro-ecological zone and analyzed at 4, 6, 8, 10 and 12 months after planting for tuberous root bulking rate and cyanogenic potential. Cassava plants at Ibadan (the wetter zone) had higher tuberous roots bulking rate and lower cynogenic potential than those planted at Minjibir (the drier zone). Root bulking rate at Ibadan increased from 4 to 6 months after planting, fell to 10 months, and then levelled off thereafter. At Majorana, bulking rate increased from 4 to 6 months, levelling off u pto 8 months after planting, and then falling slightly u pto to 10 months, and rising gradually u pto 12 months after planting. At Minijibir, the 6-8 months after planting period coincided with drought and the highest root bulking rate but increasing cyanogenic potential. Similarly, at Ibadan the 6-8 months after planting period coincided with drought and the highest root bulking rate but increasing cyanogenic potential. Despite the onset of drought, bulking continued up to 8 months after planting, falling u pto 10 months and levelling off thereafter at both agro-ecological zones. However, whereas cyanogenic potential rose rapidly after 8 months to peak at 10 months, and levelling off up to 12 months at Minjibir, cyanogenic potential levelled of after 8 u pto 12 months at Ibadan. Correlation and regression analysis suggested that root bulking rate and cyanogenic potential were negatively associated, meaning that an increase in root bulking rate would lead to corresponding decrease in it's cyanogenic potential which is highly desirable. This study has demonstrated that whereas the plant age and genotypic effects are not important factors in determining tuberous roots bulking rate and cyanogenic potential of cassava, the agro-ecological zone effect is an important factor in determining them

  9. Mobile phone radiation inhibits Vigna radiata (mung bean) root growth by inducing oxidative stress

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, Ved Parkash [Department of Environment and Vocational Studies, Panjab University, Chandigarh 160014 (India); Department of Zoology, Panjab University, Chandigarh 160014 (India); Singh, Harminder Pal, E-mail: hpsingh_01@yahoo.com [Department of Environment and Vocational Studies, Panjab University, Chandigarh 160014 (India); Kohli, Ravinder Kumar; Batish, Daizy Rani [Department of Botany, Panjab University, Chandigarh 160014 (India)

    2009-10-15

    During the last couple of decades, there has been a tremendous increase in the use of cell phones. It has significantly added to the rapidly increasing EMF smog, an unprecedented type of pollution consisting of radiation in the environment, thereby prompting the scientists to study the effects on humans. However, not many studies have been conducted to explore the effects of cell phone EMFr on growth and biochemical changes in plants. We investigated whether EMFr from cell phones inhibit growth of Vigna radiata (mung bean) through induction of conventional stress responses. Effects of cell phone EMFr (power density: 8.55 {mu}W cm{sup -2}; 900 MHz band width; for 1/2, 1, 2, and 4 h) were determined by measuring the generation of reactive oxygen species (ROS) in terms of malondialdehyde and hydrogen peroxide (H{sub 2}O{sub 2}) content, root oxidizability and changes in levels of antioxidant enzymes. Our results showed that cell phone EMFr significantly inhibited the germination (at {>=}2 h), and radicle and plumule growths ({>=}1 h) in mung bean in a time-dependent manner. Further, cell phone EMFr enhanced MDA content (indicating lipid peroxidation), and increased H{sub 2}O{sub 2} accumulation and root oxidizability in mung bean roots, thereby inducing oxidative stress and cellular damage. In response to EMFr, there was a significant upregulation in the activities of scavenging enzymes, such as superoxide dismutases, ascorbate peroxidases, guaiacol peroxidases, catalases and glutathione reductases, in mung bean roots. The study concluded that cell phone EMFr inhibit root growth of mung bean by inducing ROS-generated oxidative stress despite increased activities of antioxidant enzymes.

  10. Mobile phone radiation inhibits Vigna radiata (mung bean) root growth by inducing oxidative stress

    International Nuclear Information System (INIS)

    Sharma, Ved Parkash; Singh, Harminder Pal; Kohli, Ravinder Kumar; Batish, Daizy Rani

    2009-01-01

    During the last couple of decades, there has been a tremendous increase in the use of cell phones. It has significantly added to the rapidly increasing EMF smog, an unprecedented type of pollution consisting of radiation in the environment, thereby prompting the scientists to study the effects on humans. However, not many studies have been conducted to explore the effects of cell phone EMFr on growth and biochemical changes in plants. We investigated whether EMFr from cell phones inhibit growth of Vigna radiata (mung bean) through induction of conventional stress responses. Effects of cell phone EMFr (power density: 8.55 μW cm -2 ; 900 MHz band width; for 1/2, 1, 2, and 4 h) were determined by measuring the generation of reactive oxygen species (ROS) in terms of malondialdehyde and hydrogen peroxide (H 2 O 2 ) content, root oxidizability and changes in levels of antioxidant enzymes. Our results showed that cell phone EMFr significantly inhibited the germination (at ≥2 h), and radicle and plumule growths (≥1 h) in mung bean in a time-dependent manner. Further, cell phone EMFr enhanced MDA content (indicating lipid peroxidation), and increased H 2 O 2 accumulation and root oxidizability in mung bean roots, thereby inducing oxidative stress and cellular damage. In response to EMFr, there was a significant upregulation in the activities of scavenging enzymes, such as superoxide dismutases, ascorbate peroxidases, guaiacol peroxidases, catalases and glutathione reductases, in mung bean roots. The study concluded that cell phone EMFr inhibit root growth of mung bean by inducing ROS-generated oxidative stress despite increased activities of antioxidant enzymes.

  11. The strategy of carbon utilization in uniculm barley

    International Nuclear Information System (INIS)

    Gordon, A.J.; Ryle, G.J.A.; Powell, C.E.

    1977-01-01

    Following exposure of the youngest mature leaf of uniculm barley to 14 CO 2 , groups of plants were harvested over a 72 h period to determine the fate of 14 C in the photosynthesizing leaf and in growing leaves and roots. Initially, 14 C was mainly present in sucrose with a little in starch and charged compounds; transport out of the fed leaf was rapid and, by 7 and 24 h, 56 and 93% respectively of the 14 C had been translocated about equally to growing leaves and roots. Sucrose entering meristems was quickly metabolized to protein and structural carbohydrate (40 and 60% of the 14 C in these organs at 7 and 24 h respectively), while the remainder was converted to short-term storage products or intermediary metabolites. By the end of the first day c.35% of the 14 C originally assimilated had been lost in respiration. The metabolism of the leaf appeared to be organized on a diurnal basis, for it exported nearly all its carbon within 24 h of assimilation. In contrast, some of the assimilate imported into growing leaves and, to a lesser extent, roots was not immediately used for growth but persisted as temporary metabolites and was subsequently used for growth in the following days. (author)

  12. Putting theory to the test: which regulatory mechanisms can drive realistic growth of a root?

    Science.gov (United States)

    De Vos, Dirk; Vissenberg, Kris; Broeckhove, Jan; Beemster, Gerrit T S

    2014-10-01

    In recent years there has been a strong development of computational approaches to mechanistically understand organ growth regulation in plants. In this study, simulation methods were used to explore which regulatory mechanisms can lead to realistic output at the cell and whole organ scale and which other possibilities must be discarded as they result in cellular patterns and kinematic characteristics that are not consistent with experimental observations for the Arabidopsis thaliana primary root. To aid in this analysis, a 'Uniform Longitudinal Strain Rule' (ULSR) was formulated as a necessary condition for stable, unidirectional, symplastic growth. Our simulations indicate that symplastic structures are robust to differences in longitudinal strain rates along the growth axis only if these differences are small and short-lived. Whereas simple cell-autonomous regulatory rules based on counters and timers can produce stable growth, it was found that steady developmental zones and smooth transitions in cell lengths are not feasible. By introducing spatial cues into growth regulation, those inadequacies could be avoided and experimental data could be faithfully reproduced. Nevertheless, a root growth model based on previous polar auxin-transport mechanisms violates the proposed ULSR due to the presence of lateral gradients. Models with layer-specific regulation or layer-driven growth offer potential solutions. Alternatively, a model representing the known cross-talk between auxin, as the cell proliferation promoting factor, and cytokinin, as the cell differentiation promoting factor, predicts the effect of hormone-perturbations on meristem size. By down-regulating PIN-mediated transport through the transcription factor SHY2, cytokinin effectively flattens the lateral auxin gradient, at the basal boundary of the division zone, (thereby imposing the ULSR) to signal the exit of proliferation and start of elongation. This model exploration underlines the value of

  13. GROWTH AND ROOTING SYSTEM OF ACACIA MANGIUM OBTAINED BY TISSUE CULTURE

    Directory of Open Access Journals (Sweden)

    SUPRIYANTO

    1991-01-01

    Full Text Available Since 1980/1981, the government of Indonesia through the Ministry of Forestry has started to reforest logged-over, alang-alang, unproductive areas and to convert them to Forest Industry Plantation. The target is 300 000 ha per year. It means, 750 million seedlings should be provided per year (planting distance 2 m x 2 m. The tree species to be planted in forest industry plantation should have shorter life cycle (8 - 10 years, good stem-form, good rooting system, and should be fast growing. Acacia mangium has been selected as one of the important tree species for forest industry plantation due to its growth, quality of fiber wood (pulp and paper industry and rooting system (produce a lot of secondary root and nitrogen fixater (Soebardjo 1986. The reforestation of logged-over Dipterocarp forests in Malaysia with A. mangium has also been considered (Appanah and Weinland 1989. Generally, reforestation with A. mangium is done with seedlings obtained by seed germination. A. mangium produce a lot of seeds but its production is still limited by the season, while the conventional method of vegetative propagation through cuttings gave very low percentage of rooted-cuttings (1% (Umboh and Syamsul Yani 1989. The micropropagation of A. mangium through tissue culture is a promising method. The production of A. mangium plantlets through that method has been done at the Forest Genetic Laboratory, Tropical Forest Biology, SEAMEO BIOTROP (Situmorang 1988, Umboh 1988, Umboh et al. 1989, 1990. These rooted-plantlets (plantlings were first put in the green house (acclimatization before planting in the field. Field tests of some agricultural plants have been done but information on forest trees species is still lacking because the production of plantlings through tissue culture is still limited as there are still problems of their rooting. In fact, the progress of reproducing woody plants by tissue culture has been much slower than with herbaceous plants. The major

  14. [Allelopathy autotoxicity effects of aquatic extracts from rhizospheric soil on rooting and growth of stem cuttings in Pogostemon cablin].

    Science.gov (United States)

    Tang, Kun; Li, Ming; Dong, Shan; Li, Yun-qi; Huang, Jie-wen; Li, Long-ming

    2014-06-01

    To study the allelopathy effects of aquatic extracts from rhizospheric soil on the rooting and growth of stem cutting in Pogostemon cablin, and to reveal its mechanism initially. The changes of rhizogenesis characteristics and physic-biochemical during cutting seedlings were observed when using different concentration of aquatic extracts from rhizospheric soil. Aquatic extracts from rhizospheric soil had significant inhibitory effects on rooting rate, root number, root length, root activity, growth rate of cutting with increasing concentrations of tissue extracts; The chlorophyll content of cutting seedlings were decreased, but content of MDA were increased, and activities of POD, PPO and IAAO in cutting seedlings were affected. Aquatic extracts from rhizospheric soil of Pogostemon cablin have varying degrees of inhibitory effects on the normal rooting and growth of stem cuttings.

  15. Effects of Phlomis umbrosa Root on Longitudinal Bone Growth Rate in Adolescent Female Rats

    Directory of Open Access Journals (Sweden)

    Donghun Lee

    2016-04-01

    Full Text Available This study aimed to investigate the effects of Phlomis umbrosa root on bone growth and growth mediators in rats. Female adolescent rats were administered P. umbrosa extract, recombinant human growth hormone or vehicle for 10 days. Tetracycline was injected intraperitoneally to produce a glowing fluorescence band on the newly formed bone on day 8, and 5-bromo-2′-deoxyuridine was injected to label proliferating chondrocytes on days 8–10. To assess possible endocrine or autocrine/paracrine mechanisms, we evaluated insulin-like growth factor-1 (IGF-1, insulin-like growth factor binding protein-3 (IGFBP-3 or bone morphogenetic protein-2 (BMP-2 in response to P. umbrosa administration in either growth plate or serum. Oral administration of P. umbrosa significantly increased longitudinal bone growth rate, height of hypertrophic zone and chondrocyte proliferation of the proximal tibial growth plate. P. umbrosa also increased serum IGFBP-3 levels and upregulated the expressions of IGF-1 and BMP-2 in growth plate. In conclusion, P. umbrosa increases longitudinal bone growth rate by stimulating proliferation and hypertrophy of chondrocyte with the increment of circulating IGFBP-3. Regarding the immunohistochemical study, the effect of P. umbrosa may also be attributable to upregulation of local IGF-1 and BMP-2 expressions in the growth plate, which can be considered as a GH dependent autocrine/paracrine pathway.

  16. Retinue of the beans roots growth by using neutron radiography technique

    International Nuclear Information System (INIS)

    Jesus, Selma Parente de; Crispim, Verginia Reis

    2002-01-01

    Agricultural practices frequently cause the development of a soil compacted layer below the surface. These compacted layers restrict the root penetration into deeper layers of soil, in search for water. It is proposed to monitor, using Non Destructive Test, the roots growth due to the planting of standard seeds in different agricultural soils, in function of their compactness and humidity. It will be used the neutrons beams derived from an irradiation channel called J-9 of the Reactor Argonauta (IEN/CNEN), so that the neutron radiographic images of the soil-plant system can be obtained. Each root can be evaluated for its ability to penetrate into compacted soil layers; this fact would mean an optimization of agricultural harvests. (author)

  17. Growth dynamics of fine roots in a coniferous fern forest site close to Forsmark in the central part of Sweden

    International Nuclear Information System (INIS)

    Persson, Hans; Stadenberg, Ingela

    2007-12-01

    The seasonal growth dynamics of live and dead roots for trees and the field layer species (g/m 2 , varying diameter fractions) and live/dead ratios were analysed at a fresh/moist coniferous fern forest site close to the nuclear power plant at Forsmark in the central eastern parts of Sweden. The changes in depth distribution of fine roots were observed at depth intervals of the top humus horizon down to 40 cm in the mineral soil profile. The bulk of living fine roots of trees ( 2 . The total quantity of fine roots (live + dead) amounted to 543, 434, 314 and 546 g/m 2 . Considerable quantities of fine roots (< 1 mm in diameter) were attributed to field-layer species (about 18% of the total biomass during the whole period of investigation). The turnover rate (the rate of construction of new roots) for tree fine roots < 1 mm in diameter amounted to at least the size of the average fine-root biomass. Our methods of estimating fine-root production and mortality, involved periodic measurements of live and dead dry weight of the fine roots from sequential core samples of the forest soil. The collected data give a proper and instant measure of the spatial and temporal distribution of fine roots in the undisturbed soil-profile. Data from other fine-root investigations suggest turnover rates in agreement with our present findings. Differences between root growth and turnover should be expected between trees of different age, tree species and different forest sites, but also between different years. Substantial variations in fine-root biomass, necromass and live/dead ratios are found in different forest sites. Correct methods for estimating the amount of live and dead fine-roots in the soil at regular time intervals are essential for any calculation of fine-root turnover. Definition of root vitality differs in literature, making it difficult to compare results from different root investigators. Our investigation clarifies the importance of using distinct morphological criteria

  18. Growth of and partitioning between shoot and storage root of carrot in a northern climate

    Directory of Open Access Journals (Sweden)

    T. SUOJALA

    2008-12-01

    Full Text Available Matching the growth pattern of a vegetable cultivar with the seasonal changes in climate is a prerequisite for successful yield production in a northern climate. This paper describes the growth characteristics of two carrot cultivars in relation to climatic conditions in two years, with special reference to the factors associated with high yield. Cv. Fontana produced twice as large a leaf area and shoot weight as cv. Panther. Increased partitioning to shoot in the former cultivar also resulted in a higher root yield. Uniformity in relative growth rates during the period of analysis suggests that intervarietal differences in the shoot to root ratio and in the yield potential appear very early. Nearly half of the root weight at final harvest was gained after mid-August, when temperature and daily irradiance began to decrease. A large leaf area may ensure better utilisation of diminishing growth resources at the end of the growing season. In the more favourable growing season, 1997, plants invested more in leaf production than they did in 1996: shoot fresh and dry weights were considerably higher but leaf area was not much higher.;

  19. Experimental Salix shoot and root growth statistics on the alluvial sediment of a restored river corridor

    Science.gov (United States)

    Pasquale, N.; Perona, P.; Verones, F.; Francis, R.; Burlando, P.

    2009-12-01

    River restoration projects encompass not only the amelioration of flood protection but also the rehabilitation of the riverine ecosystem. However, the interactions and feedbacks between river hydrology, riparian vegetation and aquifer dynamics are still poorly understood. Vegetation interacts with river hydrology on multiple time scales. Hence, there is considerable interest in understanding the morphodynamics of restored river reaches in relation to the characteristics of vegetation that may colonize the bare sediment, and locally stabilize it by root anchoring. In this paper we document results from a number of ongoing experiments within the project RECORD (Restored CORridor Dynamics, sponsored by CCES - www.cces.ch - and Cantons Zurich and Thurgau, CH). In particular, we discuss both the above and below ground biomass growth dynamics of 1188 Salix cuttings (individual and group survival rate, growth of the longest shoots and number of branches and morphological root analysis) in relation to local river hydrodynamics. Cuttings were organized in square plots of different size and planted in spring 2009 on a gravel island of the restored river section of River Thur in Switzerland. By periodical monitoring the plots we obtained a detailed and quite unique set of data, including root statistics of uprooted samples derived from image analysis from a high-resolution scanner. Beyond describing the survival rate dynamics in relation to river hydrology, we show the nature and strength of correlations between island topography and cutting growth statistics. In particular, by root analysis and by comparing empirical histograms of the vertical root distribution vs satured water surface in the sediment, we show that main tropic responses on such environment are oxytropism, hydrotropism and thigmotropism. The main factor influencing the survival rate is naturally found in erosion by floods, of which we also give an interesting example that helps demonstrate the role of river

  20. 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.

  1. [Effects of wheat root exudates on cucumber growth and soil fungal community structure].

    Science.gov (United States)

    Wu, Feng-Zhi; Li, Min; Cao, Peng; Ma, Ya-Fei; Wang, Li-Li

    2014-10-01

    With wheat as the donor plant and cucumber as the receptor plant, this study investigated the effects of root exudates from wheat cultivars with different allelopathic potentials (positive or negative) and companion cropping with wheat on soil fungal community structure by PCR-DGGE method and cucumber growth. Results showed that the wheat root exudates with positive allelopathic potential increased height and stem diameter of cucumber seedlings significantly, compared to the control seedlings (W) after 6 days and 12 days treatment, respectively. Also, wheat root exudates with both positive and negative allelopathic potential increased the seedling height of cucumber significantly after 18 days treatment. The wheat root exudates with different allelopathic potentials decreased the band number, Shannon and evenness indices of soil fungal community significantly in cucumber seedling rhizosphere, and those in the soil with the control seedlings (W) were also significantly higher than that in the control soil without seedlings (Wn) after 6 days treatment. The band number, Shannon and evenness indices in all the treatments were significantly higher than those in the control soil without seedlings (Wn) after 18 days treatment. Companion cropping with negative allelopathic potential wheat decreased the Shannon and evenness indices of soil fungi community significantly in the cucumber seedling rhizosphere, suggesting the wheat root exudates and companion cropping with wheat changed soil fungal community structure in the cucumber seedling rhizosphere. The results of DGGE map and the principal component analysis showed that companion cropping with wheat cultivars with different allelopathic potentials changed soil fungal community structure in cucumber seedling rhizosphere.

  2. Rooting, growth, and color mutation of poinsettias affected by gamma radiation

    International Nuclear Information System (INIS)

    Lee, Eun Kyung; Kim, Won Hee; Kim, Seung Tae; Kang, Si Yong

    2010-01-01

    This experiment was carried out to investigate the effects of gamma-radiation on the rooting, growth, and color mutation in poinsettia. Using 10 poinsettia varieties ('Lollipop', 'Little Peace', 'Happy Day', 'Early Bird', 'Pixy Red', 'Happy Time', 'Heidi', 'Red Bell', 'Clara', and 'Scarlet') bred by National Institute of Horticultural and Herbal Science, 100 Gy of gamma ray was irradiated at the stage of callused cuttings. Four weeks after sticking cuttings in the rooting media, 8 cultivars showed 100% of root formation, but 'Early Bird' rooted 24.4% and even died off during the cutting propagation. After planting rooted cuttings, survival rate until flowering time varied among irradiated cultivars. While 'Pixy Red' and 'Heidi' survived about 98%, 'Clara', 'Happy Day', and 'Early Bird' survived lesser than 30%. All irradiated plants showed remarkably shorter plant height, lesser branch numbers than non-irradiated control plants. Thirty color mutants were obtained among 281 plants survived until flowering time. Nine were complete color mutated branches, whereas 21 mutants were partially color mutated bracts and transitional leaves. Color patterns mutated by 100 Gy of gamma ray were divided into pink, hot pink, light red and spotted (pink spots with red main color). Pink mutants were commonly obtained. Complete color mutants were discovered from 4 plants of 'Pixy Red', 2 plants of 'Red Bell' and 3 plants of Lollipop

  3. Growth of eucalyptus rooted cuttings in toxic organic waste compost of textile industry

    Directory of Open Access Journals (Sweden)

    Priscila F. de Souza

    2015-09-01

    Full Text Available ABSTRACTBiodegradation techniques may help contaminated organic wastes to become useful for plant production. The current study aimed to evaluate the efficiency of composting in the biodegradation of toxic residues from the textile industry and its use as substrate in saplings production. Cotton cloths contaminated with oil and grease, used in loom maintenance, were composted in a mixture with cattle manure. The composted material replaced coconut fiber in the substrate for the production of eucalyptus rooted cuttings: mixture of vermiculite, carbonized rice husk and coconut fiber in the ratio of 2:1:1 (v/v and using it as control. Thus, the amount of rice husks remained unchanged and the amount of vermiculite and compost varied. The compost proportion in the tested substrates were 0, 19, 37, 56 and 75%. The compost produced from textile wastes showed high nutrient levels and low levels of heavy metals. In general, the survival, growth and some growth indices of rooted cuttings produced on substrates with 19 and 37% compost were similar to those of rooted cuttings grown in commercial substrate. Composting is efficient and the material is useful for rooted cuttings production.

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

    Science.gov (United States)

    Tanimoto, Eiichi

    2012-07-01

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

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

    Science.gov (United States)

    Ilieva, Iliana; Ivanova, Tania

    2008-06-01

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

  6. Adaptation of root growth to increased ambient temperature requires auxin and ethylene coordination in Arabidopsis

    DEFF Research Database (Denmark)

    Fei, Qionghui; Wei, Shaodong; Zhou, Zhaoyang

    2017-01-01

    Key message: A fresh look at the roles of auxin, ethylene, and polar auxin transport during the plant root growth response to warmer ambient temperature (AT). Abstract: The ambient temperature (AT) affects plant growth and development. Plants can sense changes in the AT, but how this change......-naphthaleneacetic acid, but not indole-3-acetic acid (IAA). AUX1, PIN1, and PIN2 are involved in the ckrc1-1 root gravity response under increased AT. Furthermore, CKRC1-dependent auxin biosynthesis was critical for maintaining PIN1, PIN2, and AUX1 expression at elevated temperatures. Ethylene was also involved...... in this regulation through the ETR1 pathway. Higher AT can promote CKRC1-dependent auxin biosynthesis by enhancing ETR1-mediated ethylene signaling. Our research suggested that the interaction between auxin and ethylene and that the interaction-mediated polar auxin transport play important roles during the plant...

  7. Round-shape gold nanoparticles: effect of particle size and concentration on Arabidopsis thaliana root growth

    Czech Academy of Sciences Publication Activity Database

    Siegel, J.; Záruba, K.; Švorčík, V.; Kroumanová, Kristýna; Burketová, Lenka; Martinec, Jan

    2018-01-01

    Roč. 13, APR 10 (2018), č. článku 95. ISSN 1556-276X R&D Projects: GA ČR GA17-10907S; GA ČR(CZ) GBP108/12/G108 Institutional support: RVO:61389030 Keywords : Arabidopsis thaliana * Concentration * Gold nanoparticles * Root growth * Size Subject RIV: JJ - Other Materials OBOR OECD: Plant sciences, botany Impact factor: 2.833, year: 2016

  8. Developmental distribution of the plasma membrane-enriched proteome in the maize primary root growth zone

    Directory of Open Access Journals (Sweden)

    Zhe eZhang

    2013-03-01

    Full Text Available Within the growth zone of the maize primary root, there are well-defined patterns of spatial and temporal organization of cell division and elongation. However, the processes underlying this organization remain poorly understood. To gain additional insights into the differences amongst the defined regions, we performed a proteomic analysis focusing on fractions enriched for plasma membrane (PM proteins. The PM is the interface between the plant cell and the apoplast and/or extracellular space. As such, it is a key structure involved in the exchange of nutrients and other molecules as well as in the integration of signals that regulate growth and development. Despite the important functions of PM-localized proteins in mediating these processes, a full understanding of dynamic changes in PM proteomes is often impeded by low relative concentrations relative to total proteins. Using a relatively simple strategy of treating microsomal fractions with Brij-58 detergent to enrich for PM proteins, we compared the developmental distribution of proteins within the root growth zone which revealed a number of previously known as well as novel proteins with interesting patterns of abundance. For instance, the quantitative proteomic analysis detected a gradient of PM aquaporin proteins similar to that previously reported using immunoblot analyses, confirming the veracity of this strategy. Cellulose synthases increased in abundance with increasing distance from the root apex, consistent with expected locations of cell wall deposition. The similar distribution pattern for Brittle-stalk-2-like protein 3 implicate that this protein may also have cell wall related functions. These results show that the simplified PM enrichment method previously demonstrated in Arabidopsis can be successfully applied to completely unrelated plant tissues and provide insights into differences in the PM proteome throughout growth and development zones of the maize primary root.

  9. Developmental distribution of the plasma membrane-enriched proteome in the maize primary root growth zone.

    Science.gov (United States)

    Zhang, Zhe; Voothuluru, Priyamvada; Yamaguchi, Mineo; Sharp, Robert E; Peck, Scott C

    2013-01-01

    Within the growth zone of the maize primary root, there are well-defined patterns of spatial and temporal organization of cell division and elongation. However, the processes underlying this organization remain poorly understood. To gain additional insights into the differences amongst the defined regions, we performed a proteomic analysis focusing on fractions enriched for plasma membrane (PM) proteins. The PM is the interface between the plant cell and the apoplast and/or extracellular space. As such, it is a key structure involved in the exchange of nutrients and other molecules as well as in the integration of signals that regulate growth and development. Despite the important functions of PM-localized proteins in mediating these processes, a full understanding of dynamic changes in PM proteomes is often impeded by low relative concentrations relative to total proteins. Using a relatively simple strategy of treating microsomal fractions with Brij-58 detergent to enrich for PM proteins, we compared the developmental distribution of proteins within the root growth zone which revealed a number of previously known as well as novel proteins with interesting patterns of abundance. For instance, the quantitative proteomic analysis detected a gradient of PM aquaporin proteins similar to that previously reported using immunoblot analyses, confirming the veracity of this strategy. Cellulose synthases increased in abundance with increasing distance from the root apex, consistent with expected locations of cell wall deposition. The similar distribution pattern for Brittle-stalk-2-like protein implicates that this protein may also have cell wall related functions. These results show that the simplified PM enrichment method previously demonstrated in Arabidopsis can be successfully applied to completely unrelated plant tissues and provide insights into differences in the PM proteome throughout growth and development zones of the maize primary root.

  10. Detection of QTLs for seedling characteristics in barley (Hordeum vulgare L.) grown under hydroponic culture condition.

    Science.gov (United States)

    Wang, Qifei; Sun, Genlou; Ren, Xifeng; Wang, Jibin; Du, Binbin; Li, Chengdao; Sun, Dongfa

    2017-11-07

    Seedling characteristics play significant roles in the growth and development of barley (Hordeum vulgare L.), including stable stand establishment, water and nutrients uptake, biotic resistance and abiotic stresses, and can influence yield and quality. However, the genetic mechanisms underlying seedling characteristics in barley are largely unknown and little research has been done. In the present work, 21 seedling-related characteristics are assessed in a barley double haploid (DH) population, grown under hydroponic conditions. Of them, leaf age (LAG), shoot height (SH), maximum root length (MRL), main root number (MRN) and seedling fresh weight (SFW) were investigated at the 13th, 20th, 27th, and 34th day after germination. The objectives were to identify quantitative trait loci (QTLs) underlying these seedling characteristics using a high-density linkage map and to reveal the QTL expression pattern by comparing the QTLs among four different seedling growth stages. A total of 70 QTLs were distributed over all chromosomes except 4H, and, individually, accounted for 5.01%-77.78% of phenotypic variation. Out of the 70 detected QTLs, 23 showed a major effect on 14 seedling-related characteristics. Ten co-localized chromosomal regions on 2H (five regions), 3H (two regions) and 7H (three regions) involved 39 QTLs (55.71%), each simultaneously influenced more than one trait. Meanwhile, 9 co-localized genomic regions involving 22 QTLs for five seedling characteristics (LAG, SH, MRL, MRN and SFW) at the 13th, 20th, 27th and 34th day-old seedling were common for two or more growth stages of seedling. QTL in the vicinity of Vrs1 locus on chromosome 2H with the favorable alleles from Huadamai 6 was found to have the largest main effects on multiple seedling-related traits. Six QTL cluster regions associated with 16 seedling-related characteristics were observed on chromosome 2H, 3H and 7H. The majority of the 29 regions identified for five seedling characteristics were

  11. The ABA receptor PYL8 promotes lateral root growth by enhancing MYB77-dependent transcription of auxin-responsive genes.

    Science.gov (United States)

    Zhao, Yang; Xing, Lu; Wang, Xingang; Hou, Yueh-Ju; Gao, Jinghui; Wang, Pengcheng; Duan, Cheng-Guo; Zhu, Xiaohong; Zhu, Jian-Kang

    2014-06-03

    The phytohormone abscisic acid (ABA) regulates plant growth, development, and abiotic stress responses. ABA signaling is mediated by a group of receptors known as the PYR1/PYL/RCAR family, which includes the pyrabactin resistance 1-like protein PYL8. Under stress conditions, ABA signaling activates SnRK2 protein kinases to inhibit lateral root growth after emergence from the primary root. However, even in the case of persistent stress, lateral root growth eventually recovers from inhibition. We showed that PYL8 is required for the recovery of lateral root growth, following inhibition by ABA. PYL8 directly interacted with the transcription factors MYB77, MYB44, and MYB73. The interaction of PYL8 and MYB77 increased the binding of MYB77 to its target MBSI motif in the promoters of multiple auxin-responsive genes. Compared to wild-type seedlings, the lateral root growth of pyl8 mutant seedlings and myb77 mutant seedlings was more sensitive to inhibition by ABA. The recovery of lateral root growth was delayed in pyl8 mutant seedlings in the presence of ABA, and the defect was rescued by exposing pyl8 mutant seedlings to the auxin IAA (3-indoleacetic acid). Thus, PYL8 promotes lateral root growth independently of the core ABA-SnRK2 signaling pathway by enhancing the activities of MYB77 and its paralogs, MYB44 and MYB73, to augment auxin signaling. Copyright © 2014, American Association for the Advancement of Science.

  12. Effect of inoculation with arbuscular mycorrhizas on rooting, weaning and subsequent growth of micropropagated Malus (L. Moench

    Directory of Open Access Journals (Sweden)

    Marjatta Uosukainen

    1994-05-01

    Full Text Available The importance of different rooting methods and the effects of arbuscular mycorrhizal (AMF inoculation on the rooting rate, weaning survival and subsequent growth of microcuttings of Malus rootstock YP and the Finnish crab apple cultivars Hanna and Marjatta were studied in four experiments conducted at the Laukaa Research and Elite Plant Unit, Finland. Sucrose in the in vitro rooting medium gave the best support to weaning survival in comparision with glucose and fructose. Directly rooted microcuttings had a higher survival rate than in vitro rooted microcuttings. AMF inoculation did not improve the rooting rate in direct rooting. However, the Glomus hoi strain V98 caused severe rotting of microcuttings and thus lowered the rooting rate of cv. Hanna, AMF inoculation increased the mean shoot height of established plants, particularly inoculation with G. hoi V98, G. claroideum V43a or G. fistulosum V128. This effect, however, varied considerably in different host-fungus combinations. Some AMF strains, e.g. G. hoi V1O4, caused strong growth retardation. After the rooting and weaning stage, many uninoculated plants lapsed into arrest of growth. This phenomenon was less frequent in AMF inoculated plants. Optimal timing of AMF inoculation and nutritional level of rooting and weaning substrate are discussed.

  13. Inhibitory Activity of Yokukansankachimpihange against Nerve Growth Factor-Induced Neurite Growth in Cultured Rat Dorsal Root Ganglion Neurons

    Directory of Open Access Journals (Sweden)

    Chiaki Murayama

    2015-08-01

    Full Text Available Chronic pruritus is a major and distressing symptom of many cutaneous diseases, however, the treatment remains a challenge in the clinic. The traditional Chinese-Japanese medicine (Kampo medicine is a conservative and increasingly popular approach to treat chronic pruritus for both patients and medical providers. Yokukansankachimpihange (YKH, a Kampo formula has been demonstrated to be effective in the treatment of itching of atopic dermatitis in Japan although its pharmacological mechanism is unknown clearly. In an attempt to clarify its pharmacological actions, in this study, we focused on the inhibitory activity of YKH against neurite growth induced with nerve growth factor (NGF in cultured rat dorsal root ganglion (DRG neurons because epidermal hyperinnervation is deeply related to itch sensitization. YKH showed approximately 200-fold inhibitory activity against NGF-induced neurite growth than that of neurotropin (positive control, a drug used clinically for treatment of chronic pruritus. Moreover, it also found that Uncaria hook, Bupleurum root and their chemical constituents rhynchophylline, hirsutine, and saikosaponin a, d showed inhibitory activities against NGF-induced neurite growth, suggesting they should mainly contribute to the inhibitory activity of YKH. Further study on the effects of YKH against epidermal nerve density in “itch-scratch” animal models is under investigation.

  14. Poinsettia Growth and Development Response to Container Root Substrate with Biochar

    Directory of Open Access Journals (Sweden)

    Yanjun Guo

    2018-01-01

    Full Text Available A greenhouse study was conducted to evaluate the growth and development of poinsettia ‘Prestige Red’ (Euphorbia pulcherrima grown in a commercial peat-based potting mix (Sunshine Mix #1 amended with biochar at 0%, 20%, 40%, 60%, 80%, or 100% (by volume at four different fertigation regimes: F1: 100 to 200 mg·L−1 nitrogen (N, F2: 200 to 300 mg·L−1 N (control, F3: 300 to 400 mg·L−1 N, or F4: 400 to 500 mg·L−1 N. The experiment was a two-factor factorial design with 10 replications for each combination of biochar by fertigation. As the percentage of biochar increased, root substrate pore space and bulk density increased, while container capacity decreased. Root rot and red bract necrosis only occurred in F4 combined with 100% biochar. Plants grown in 40% biochar had a similar growth and development to those in 0% biochar. Up to 80% biochar, plants exhibited no significant change, except in terms of dry weight, which decreased at higher biochar percentages (60% and 80%. In summary, at a fertigation rate of 100 mg·L−1 N to 400 mg·L−1 N, up to 80% biochar could be used as an amendment to peat-based root substrate with acceptable growth reduction and no changes in quality.

  15. A new species of Burkholderia isolated from sugarcane roots promotes plant growth

    Science.gov (United States)

    Paungfoo-Lonhienne, Chanyarat; Lonhienne, Thierry G A; Yeoh, Yun Kit; Webb, Richard I; Lakshmanan, Prakash; Chan, Cheong Xin; Lim, Phaik-Eem; Ragan, Mark A; Schmidt, Susanne; Hugenholtz, Philip

    2014-01-01

    Sugarcane is a globally important food, biofuel and biomaterials crop. High nitrogen (N) fertilizer rates aimed at increasing yield often result in environmental damage because of excess and inefficient application. Inoculation with diazotrophic bacteria is an attractive option for reducing N fertilizer needs. However, the efficacy of bacterial inoculants is variable, and their effective formulation remains a knowledge frontier. Here, we take a new approach to investigating diazotrophic bacteria associated with roots using culture-independent microbial community profiling of a commercial sugarcane variety (Q208A) in a field setting. We first identified bacteria that were markedly enriched in the rhizosphere to guide isolation and then tested putative diazotrophs for the ability to colonize axenic sugarcane plantlets (Q208A) and promote growth in suboptimal N supply. One isolate readily colonized roots, fixed N2 and stimulated growth of plantlets, and was classified as a new species, Burkholderia australis sp. nov. Draft genome sequencing of the isolate confirmed the presence of nitrogen fixation. We propose that culture-independent identification and isolation of bacteria that are enriched in rhizosphere and roots, followed by systematic testing and confirming their growth-promoting capacity, is a necessary step towards designing effective microbial inoculants. PMID:24350979

  16. Enhanced root and shoot growth of wheat (Triticum aestivum L.) by Trichoderma harzianum from Turkey.

    Science.gov (United States)

    Kucuk, Cigdem

    2014-01-01

    It is well known that Trichoderma species can be used as biocontrol and plant growth promote agent. In this study, Trichoderma harzianum isolates were evaluated for their growth promotion effects on wheat in greenhouse experiments. Two isolates of T. harzianum were used. The experimental design was a randomized complete block with three replications. Seeds were inoculated with conidial suspensions of each isolate. Wheat plants grown in steriled soil in pots. T. harzianum T8 and T15 isolates increased wheat length, root dry weight and shoot dry weight according to untreated control. Turkish isolates T8 and T15 did not produce damage in seeds nor in plants.

  17. Co-ordinated growth between aerial and root systems in young apple plants issued from in vitro culture.

    Science.gov (United States)

    Costes, E; García-Villanueva, E; Jourdan, C; Regnard, J L; Guédon, Y

    2006-01-01

    In several species exhibiting a rhythmic aerial growth, the existence of an alternation between root and shoot growth has been demonstrated. The present study aims to investigate the respective involvement of the emergence of new organs and their elongation in relation to this phenomenon and its possible genotypic variation in young apple plants. Two apple varieties, X6407 (recently named 'Ariane') and X3305 ('Chantecler' x 'Baujade'), were compared. Five plants per variety, issued from in vitro culture, were observed in minirhizotrons over 4 months. For each plant, root emergence and growth were observed twice per week. Growth rates were calculated for all roots with more than two segments and the branching density was calculated on primary roots. On the aerial part, the number of leaves, leaf area and total shoot length were observed weekly. No significant difference was observed between varieties in any of the final characteristics of aerial growth. Increase in leaf area and shoot length exhibited a 3-week rhythm in X3305 while a weaker signal was observed in Ariane. The primary root growth rate was homogeneous between the plants and likewise between the varieties, while their branching density differed significantly. Secondary roots emerged rhythmically, with a 3-week and a 2-week rhythm, respectively, in X3305 and 'Ariane'. Despite a high intra-variety variability, significant differences were observed between varieties in the secondary root life span and mean length. A synchronism between leaf emergence and primary root growth was highlighted in both varieties, while an opposition phase was observed between leaf area increments and secondary root emergence in X3305 only. A biological model of dynamics that summarizes the interactions between processes and includes the assumption of a feedback effect of lateral root emergence on leaf emergence is proposed.

  18. Hydrologic control on the root growth of Salix cuttings at the laboratory scale

    Science.gov (United States)

    Bau', Valentina; Calliari, Baptiste; Perona, Paolo

    2017-04-01

    Riparian plant roots contribute to the ecosystem functioning and, to a certain extent, also directly affect fluvial morphodynamics, e.g. by influencing sediment transport via mechanical stabilization and trapping. There is much both scientific and engineering interest in understanding the complex interactions among riparian vegetation and river processes. For example, to investigate plant resilience to uprooting by flow, one should quantify the probability that riparian plants may be uprooted during specific flooding event. Laboratory flume experiments are of some help to this regard, but are often limited to use grass (e.g., Avena and Medicago sativa) as vegetation replicate with a number of limitations due to fundamental scaling problems. Hence, the use of small-scale real plants grown undisturbed in the actual sediment and within a reasonable time frame would be particularly helpful to obtain more realistic flume experiments. The aim of this work is to develop and tune an experimental technique to control the growth of the root vertical density distribution of small-scale Salix cuttings of different sizes and lengths. This is obtained by controlling the position of the saturated water table in the sedimentary bed according to the sediment size distribution and the cutting length. Measurements in the rhizosphere are performed by scanning and analysing the whole below-ground biomass by means of the root analysis software WinRhizo, from which root morphology statistics and the empirical vertical density distribution are obtained. The model of Tron et al. (2015) for the vertical density distribution of the below-ground biomass is used to show that experimental conditions that allow to develop the desired root density distribution can be fairly well predicted. This augments enormously the flexibility and the applicability of the proposed methodology in view of using such plants for novel flow erosion experiments. Tron, S., Perona, P., Gorla, L., Schwarz, M., Laio, F

  19. Effect of IAA on in vitro growth and colonization of Nostoc in plant roots

    Science.gov (United States)

    Hussain, Anwar; Shah, Syed T.; Rahman, Hazir; Irshad, Muhammad; Iqbal, Amjad

    2015-01-01

    Nostoc is widely known for its ability to fix atmospheric nitrogen and the establishment of symbiotic relationship with a wide range of plants from various taxonomic groups. Several strains of Nostoc produce phytohormones that promote growth of its plant partners. Nostoc OS-1 was therefore selected for study because of the presence of putative ipdC gene that encodes a key enzyme to produce Indole-3-acetic acid (IAA). The results indicated that both cellular and released IAA was found high with increasing incubation time and reached to a peak value (i.e., 21 pmol mg-1ch-a) on the third week as determined by UPLC-ESI-MS/MS. Also the Nostoc OS-1 strain efficiently colonized the roots and promoted the growth of rice as well as wheat under axenic conditions and induced ipdC gene that suggested the possible involvement of IAA in these phenotypes. To confirm the impact of IAA on root colonization efficiency and plant promoting phenotypes of Nostoc OS-1, an ipdC knockout mutant was generated by homologous recombinant method. The amount of releasing IAA, in vitro growth, root colonization, and plant promoting efficiency of the ipdC knockout mutant was observed significantly lower than wild type strain under axenic conditions. Importantly, these phenotypes were restored to wild-type levels when the ipdC knockout mutant was complemented with wild type ipdC gene. These results together suggested that ipdC and/or synthesized IAA of Nostoc OS-1 is required for its efficient root colonization and plant promoting activity. PMID:25699072

  20. Auxin-enhanced root growth for phytoremediation of sewage-sludge amended soil.

    Science.gov (United States)

    Liphadzi, M S; Kirkham, M B; Paulsen, G M

    2006-06-01

    A technology to increase root growth would be advantageous for phytoremediation of trace metal polluted soil, because more roots would be available for metal uptake. The objective of this study was to determine if the auxin, indole-3-acetic acid (IAA), would increase root growth in soil with metals from sewage sludge, when the tetrasodium salt of the chelate EDTA (ethylenediamine-tetraacetic acid) was added to solubilize the metals. Sunflower (Helianthus annuus L.) plants grew in large pots containing either soil from a sludge farm or composted sludge. The EDTA salt was added at a rate of 1 g kg(-1) soil 37 days after planting. IAA at the rate of 3 or 6 mg l(-1) was sprayed on the leaves (500 ml) and added to the soil (500 ml) three times: 41, 50, and 74 days after planting. At harvest 98 days after planting, oven-dry weights were measured, and plant organs were analyzed for Cd, Cu, Fe, Mn, Ni, Pb, and Zn. Metal uptake was determined as the product of metal concentration in an organ and weight. IAA increased root growth of plants grown in the soil with sludge when no EDTA was present. With no EDTA, Mn and Ni in leaves of plants grown in the soil were higher at 3 and 6 mg l(-1) IAA compared to 0 mg l(-1) IAA. With and without EDTA, Cd and Pb in leaves of plants grown in the compost were higher with 3 and 6 mg l(-1) IAA compared to 0 mg l(-1) IAA.

  1. The relationship between growth and development of above ground organs with roots of winter wheat using 32P tracer

    International Nuclear Information System (INIS)

    Wang Zhifen; Chen Xueliu; Yu Meiyan

    1997-01-01

    The relationship of growth and development between above ground organs and roots of winter wheat, Lumai-14, was studied using 32 P tracer. The results showed that before the spike formation, dry matter accumulation in roots, stems and leaves were synchronous, and after that they were asynchronous. The dry matter accumulation in stems and leaves were significantly related to that of roots throughout the whole growing period of winter wheat. After the spike formation, the dry matter accumulation in spikes was not related to that of roots. The 32 P distribution in stems and leaves were related to that of roots significantly, however, the relationship between spikes and roots was not obviously related, which was consistent with the dry matter accumulations in various organs. The metabolic activities of stems, leaves and spike were significantly related to that of roots respectively

  2. Phytotoxicity of water-soluble substances from alfalfa and barley soil extracts on four crop species.

    Science.gov (United States)

    Read, J J; Jensen, E H

    1989-02-01

    Problems associated with continuously planting alfalfa (Medicago saliva L.) or seeding to thicken depleted alfalfa stands may be due to autotoxicity, an intraspecific form of allelopathy. A bioassay approach was utilized to characterize the specificity and chemical nature of phytotoxins in extracts of alfalfa soils as compared to fallow soil or soil where a cereal was the previous crop. In germination chamber experiments, water-soluble substances present in methanol extracts of soil cropped to alfalfa or barley (Hordeum vulgare L.) decreased seedling root length of alfalfa L-720, winter wheat (Triticum aestivum L. Nugaines) and radish (Raphanus sativa L. Crimson Giant). Five days after germination, seedling dry weights of alfalfa and radish in alfalfa soil extracts were lower compared to wheat or red clover (Trifolium pralense L. Kenland). Growth of red clover was not significantly reduced by soil extracts from cropped soil. Extracts of crop residue screened from soil cropped to alfalfa or barley significantly reduced seedling root length; extracts of alfalfa residue caused a greater inhibition of seedling dry weight than extracts of barely residue. A phytotoxic, unidentified substance present in extracts of crop residue screened from alfalfa soil, which inhibited seedling root length of alfalfa, was isolated by thin-layer chromatography (TLC). Residues from a soil cropped continuously to alfalfa for 10 years had the greatest phytotoxic activity.

  3. Barley disease susceptibility factor RACB acts in epidermal cell polarity and positioning of the nucleus.

    Science.gov (United States)

    Scheler, Björn; Schnepf, Vera; Galgenmüller, Carolina; Ranf, Stefanie; Hückelhoven, Ralph

    2016-05-01

    RHO GTPases are regulators of cell polarity and immunity in eukaryotes. In plants, RHO-like RAC/ROP GTPases are regulators of cell shaping, hormone responses, and responses to microbial pathogens. The barley (Hordeum vulgare L.) RAC/ROP protein RACB is required for full susceptibility to penetration by Blumeria graminis f.sp. hordei (Bgh), the barley powdery mildew fungus. Disease susceptibility factors often control host immune responses. Here we show that RACB does not interfere with early microbe-associated molecular pattern-triggered immune responses such as the oxidative burst or activation of mitogen-activated protein kinases. RACB also supports rather than restricts expression of defence-related genes in barley. Instead, silencing of RACB expression by RNAi leads to defects in cell polarity. In particular, initiation and maintenance of root hair growth and development of stomatal subsidiary cells by asymmetric cell division is affected by silencing expression of RACB. Nucleus migration is a common factor of developmental cell polarity and cell-autonomous interaction with Bgh RACB is required for positioning of the nucleus near the site of attack from Bgh We therefore suggest that Bgh profits from RACB's function in cell polarity rather than from immunity-regulating functions of RACB. © The Author 2016. Published by Oxford University Press on behalf of the Society for Experimental Biology.

  4. Trichoderma spp. Improve growth of Arabidopsis seedlings under salt stress through enhanced root development, osmolite production, and Na⁺ elimination through root exudates.

    Science.gov (United States)

    Contreras-Cornejo, Hexon Angel; Macías-Rodríguez, Lourdes; Alfaro-Cuevas, Ruth; López-Bucio, José

    2014-06-01

    Salt stress is an important constraint to world agriculture. Here, we report on the potential of Trichoderma virens and T. atroviride to induce tolerance to salt in Arabidopsis seedlings. We first characterized the effect of several salt concentrations on shoot biomass production and root architecture of Arabidopsis seedlings. We found that salt repressed plant growth and root development in a dose-dependent manner by blocking auxin signaling. Analysis of the wild type and eir1, aux1-7, arf7arf19, and tir1abf2abf19 auxin-related mutants revealed a key role for indole-3-acetic acid (IAA) signaling in mediating salt tolerance. We also found that T. virens (Tv29.8) and T. atroviride (IMI 206040) promoted plant growth in both normal and saline conditions, which was related to the induction of lateral roots and root hairs through auxin signaling. Arabidopsis seedlings grown under saline conditions inoculated with Trichoderma spp. showed increased levels of abscissic acid, L-proline, and ascorbic acid, and enhanced elimination of Na⁺ through root exudates. Our data show the critical role of auxin signaling and root architecture to salt tolerance in Arabidopsis and suggest that these fungi may enhance the plant IAA level as well as the antioxidant and osmoprotective status of plants under salt stress.

  5. Synchronous high-resolution phenotyping of leaf and root growth in Nicotiana tabacum over 24-h periods with GROWMAP-plant

    Directory of Open Access Journals (Sweden)

    Ruts Tom

    2013-01-01

    Full Text Available Abstract Background Root growth is highly responsive to temporal changes in the environment. On the contrary, diel (24 h leaf expansion in dicot plants is governed by endogenous control and therefore its temporal pattern does not strictly follow diel changes in the environment. Nevertheless, root and shoot are connected with each other through resource partitioning and changing environments for one organ could affect growth of the other organ, and hence overall plant growth. Results We developed a new technique, GROWMAP-plant, to monitor growth processes synchronously in leaf and root of the same plant with a high resolution over the diel period. This allowed us to quantify treatment effects on the growth rates of the treated and non-treated organ and the possible interaction between them. We subjected the root system of Nicotiana tabacum seedlings to three different conditions: constant darkness at 22°C (control, constant darkness at 10°C (root cooling, and 12 h/12 h light–dark cycles at 22°C (root illumination. In all treatments the shoot was kept under the same 12 h/12 h light–dark cycles at 22°C. Root growth rates were found to be constant when the root-zone environment was kept constant, although the root cooling treatment significantly reduced root growth. Root velocity was decreased after light-on and light-off events of the root illumination treatment, resulting in diel root growth rhythmicity. Despite these changes in root growth, leaf growth was not affected substantially by the root-zone treatments, persistently showing up to three times higher nocturnal growth than diurnal growth. Conclusion GROWMAP-plant allows detailed synchronous growth phenotyping of leaf and root in the same plant. Root growth was very responsive to the root cooling and root illumination, while these treatments altered neither relative growth rate nor diel growth pattern in the seedling leaf. Our results that were obtained simultaneously in growing

  6. Local and distal effects of arbuscular mycorrhizal colonization on direct pathway Pi uptake and root growth in Medicago truncatula

    DEFF Research Database (Denmark)

    Watts-Williams, Stephanie J.; Jakobsen, Iver; Cavagnaro, Timothy R.

    2015-01-01

    and root growth, at different soil P levels. Medicago truncatula was grown at three soil P levels in split-pots with or without AM fungal inoculation and where one root half grew into soil labelled with 33P. Plant genotypes included the A17 wild type and the mtpt4 mutant. The mtpt4 mutant, colonized by AM...

  7. Potential involvement of drought-induced Ran GTPase CLRan1 in root growth enhancement in a xerophyte wild watermelon.

    Science.gov (United States)

    Akashi, Kinya; Yoshimura, Kazuya; Kajikawa, Masataka; Hanada, Kouhei; Kosaka, Rina; Kato, Atsushi; Katoh, Akira; Nanasato, Yoshihiko; Tsujimoto, Hisashi; Yokota, Akiho

    2016-10-01

    Enhanced root growth is known as the survival strategy of plants under drought. Previous proteome analysis in drought-resistant wild watermelon has shown that Ran GTPase, an essential regulator of cell division and proliferation, was induced in the roots under drought. In this study, two cDNAs were isolated from wild watermelon, CLRan1 and CLRan2, which showed a high degree of structural similarity with those of other plant Ran GTPases. Quantitative RT-PCR and promoter-GUS assays suggested that CLRan1 was expressed mainly in the root apex and lateral root primordia, whereas CLRan2 was more broadly expressed in other part of the roots. Immunoblotting analysis confirmed that the abundance of CLRan proteins was elevated in the root apex region under drought stress. Transgenic Arabidopsis overexpressing CLRan1 showed enhanced primary root growth, and the growth was maintained under osmotic stress, indicating that CLRan1 functions as a positive factor for maintaining root growth under stress conditions.

  8. Fine-root growth in a forested bog is seasonally dynamic, but shallowly distributed in nutrient-poor peat

    Science.gov (United States)

    Colleen M. Iversen; Joanne Childs; Richard J. Norby; Todd A. Ontl; Randall K. Kolka; Deanne J. Brice; Karis J. McFarlane; Paul J. Hanson

    2017-01-01

    Background and aims. Fine roots contribute to ecosystem carbon, water, and nutrient fluxes through resource acquisition, respiration, exudation, and turnover, but are understudied in peatlands. We aimed to determine how the amount and timing of fine-root growth in a forested, ombrotrophic bog varied across gradients of vegetation density, peat...

  9. Effects of simulated root herbivory and fertilizer application on growth and biomass allocation in the clonal perennialSolidago canadensis.

    Science.gov (United States)

    Schmid, B; Miao, S L; Bazzaz, F A

    1990-08-01

    Compensatory growth in response to simulated belowground herbivory was studied in the old-field clonal perennialSolidago canadensis. We grew rootpruned plants and plants with intact root systems in soil with or without fertilizer. For individual current shoots (aerial shoot with rhizome and roots) and for whole clones the following predictions were tested: a) root removal is compensated by increased root growth, b) fertilizer application leads to increased allocation to aboveground plant organs and increased leaf turnover, c) effects of fertilizer application are reduced in rootpruned plants. When most roots (90%) were removed current shoots quickly restored equilibrium between above-and belowground parts by compensatory belowground growth whereas the whole clone responded with reduced aboveground growth. This suggests that parts of a clone which are shared by actively growing shoots act as a buffer that can be used as source of material for compensatory growth in response to herbivory. Current shoots increased aboveground mass and whole clones reduced belowground mass in response to fertilizer application, both leading to increased allocation to aboverground parts. Also with fertilizer application both root-pruned and not root-pruned plants increased leaf and shoot turnover. Unfertilized plants, whether rootpruned or not, showed practically no aboveground growth and very little leaf and shoot turnover. Effects of root removal were as severe or more severe under conditions of high as under conditions of low nutrients, suggesting that negative effects of belowground herbivory are not ameliorated by abundant nutrients. Root removal may negate some effects of fertilizer application on the growth of current shoots and whole clones.

  10. Abscisic acid regulates root growth under osmotic stress conditions via an interacting hormonal network with cytokinin, ethylene and auxin.

    Science.gov (United States)

    Rowe, James H; Topping, Jennifer F; Liu, Junli; Lindsey, Keith

    2016-07-01

    Understanding the mechanisms regulating root development under drought conditions is an important question for plant biology and world agriculture. We examine the effect of osmotic stress on abscisic acid (ABA), cytokinin and ethylene responses and how they mediate auxin transport, distribution and root growth through effects on PIN proteins. We integrate experimental data to construct hormonal crosstalk networks to formulate a systems view of root growth regulation by multiple hormones. Experimental analysis shows: that ABA-dependent and ABA-independent stress responses increase under osmotic stress, but cytokinin responses are only slightly reduced; inhibition of root growth under osmotic stress does not require ethylene signalling, but auxin can rescue root growth and meristem size; osmotic stress modulates auxin transporter levels and localization, reducing root auxin concentrations; PIN1 levels are reduced under stress in an ABA-dependent manner, overriding ethylene effects; and the interplay among ABA, ethylene, cytokinin and auxin is tissue-specific, as evidenced by differential responses of PIN1 and PIN2 to osmotic stress. Combining experimental analysis with network construction reveals that ABA regulates root growth under osmotic stress conditions via an interacting hormonal network with cytokinin, ethylene and auxin. © 2016 The Authors. New Phytologist © 2016 New Phytologist Trust.

  11. Auxin increases the hydrogen peroxide (H2O2) concentration in tomato (Solanum lycopersicum) root tips while inhibiting root growth

    NARCIS (Netherlands)

    Ivanchenko, Maria G.; den Os, Desiree; Monshausen, Gabriele B.; Dubrovsky, Joseph G.; Bednarova, Andrea; Krishnan, Natraj

    2013-01-01

    The hormone auxin and reactive oxygen species (ROS) regulate root elongation, but the interactions between the two pathways are not well understood. The aim of this study was to investigate how auxin interacts with ROS in regulating root elongation in tomato, Solanum lycopersicum. Wild-type and

  12. Winter barley mutants created in the Ukraine

    International Nuclear Information System (INIS)

    Zayats, O.M.

    2001-01-01

    Full text: Increasing fodder and protein production is one of the objectives of the development of agriculture in Ukraine. Higher productivity of fodder crops, due to new highly productive varieties, is the means to meet this aim. Winter barley is an important crop for fodder purposes. The climate of the Ukraine is favourable for growing this crop. The areas used for the growth of winter barley are however, small (500,000-550,000 ha) and there is a shortage of good quality varieties. The main aim of the work was therefore to create new varieties of highly productive winter barley, of good quality. The new varieties and mutation lines of winter barley were created under the influence of water solutions of N-nitroso-N-methylurea (NMH - 0,012, 0,005%), N-nitroso-N-ethylurea (NEH - 0,05; 0.025; 0,012%) ethyleneimine (EI - 0,02; 0,01; 0,005%) on winter barley seeds of the varieties of local and foreign selections. On the basis of many years of investigations (1984-94) the following mutations were described: hard-grained, winter-hardiness, earliness, middle-maturity, late-maturity, wide and large leaves, narrow leaves, multinodal, great number of leaves, great number of flowers, strong stem (lodging resistant), tallness, semi-dwarfness, dwarfness, and high productivity. Particularly valuable are mutants with high productivity of green bulk. Their potential yield is 70 t/ha. As a result of the work two varieties of winter barley 'Shyrokolysty' and 'Kormovy' were released into the State register of plant varieties of the Ukraine. The other valuable mutant genotypes are used in cross breeding programmes. (author)

  13. The effect of tillage intensity on soil structure and winter wheat root/shoot growth

    DEFF Research Database (Denmark)

    Munkholm, Lars Juhl; Hansen, Elly Møller; Olesen, Jørgen E

    2008-01-01

    was followed during the growing seasons using spectral reflectance and mini-rhizotron measurements, respectively. A range of soil physical properties were measured. We found decreased early season shoot and root growth with decreasing tillage intensity. Differences diminished later in the growing season...... of this study was to investigate the effect of tillage intensity on crop growth dynamics and soil structure. A tillage experiment was established in autumn 2002 on two Danish sandy loams (Foulum and Flakkebjerg) in a cereal-based crop rotation. The tillage systems included in this study were direct drilling (D...... with decreasing tillage intensity for the first year winter wheat at Foulum. In general ploughing resulted in the highest grain yields. This study highlights the important interaction between soil structure and crop growth dynamics....

  14. Enhancement of root growth and nitrogen fixation in Trigonella by UV-exclusion from solar radiation.

    Science.gov (United States)

    Sharma, Sonika; Guruprasad, K N

    2012-12-01

    A field experiment was conducted to study the impact of solar UV on root growth and nitrogen fixation in Trigonella foenum-graecum. Plants were grown in iron mesh cages covered with polyester filters that could specifically cut off UV-B (280-315 nm) or UV-A + B (280-400 nm) part of the solar spectrum. The control plants were grown under a polythene filter transmissible to UV. Root biomass, number of nodules and nodule fresh weight were enhanced after exclusion of solar UV. Nitrogenase activity was significantly enhanced by 120% and 80% in the UV-B and UV-A + B excluded plants respectively. Along with nitrogenase there was concomitant increase in leghemoglobin and hemechrome content in the nodules after exclusion of solar UV. These components of sunlight limits nitrogen fixation and their elimination can enhance nitrogen fixation with agricultural advantages like reduction in the use of fertilizers. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

  15. Rotan manau intercropped with rubber: rate of root growth between three and four years after planting

    International Nuclear Information System (INIS)

    Wan Rashidah Kadir; Aminuddin Mohamad; Ahmad Sahali Mardi; Zaharah Abd Rahman

    1997-01-01

    Wan Rashidah, K., Aminuddin, M., Ahmad Sahali, M. & Zaharah, A.R. 1997. Rotan manau intercropped with rubber: rate of root growth between three and four years after planting. Efficient fertiliser management depends partly on understanding the active root distribution. In the present study, the active root distribution of 3- and 4-y-old plantation grown rotan manau (Calamus manan) was assessed using isotope tracer technique. For the 3-y-old rotan manau, three distances from the plant base (0.5, 1.0 and 1.5 m) at 5 and 30 cm depths were examined. For the 4-y-old plants, two distances, viz-a-viz at a centre between two rattan plants and another in the middle between two rattan plants and two rubber trees were studied. The isotope used was 32P, applied as a solution with KH2PO4. The rotan manau plants had been established under mature rubber plantation. High proportions of feeder roots were found at 0.5 and 1.0 m distances at the surface (5 cm depth) for the 3-y-old plants. Uptake of 32P was also observed for the application at 1.5 m distance for both depths but the counts were small. Statistical analysis gave a highly significant difference within the distances and within the different depths. For a better synchronisation between fertiliser application and plant uptake, it seems that application at approximately between 0.5 and 1.0 m distance around the plant is most appropriate at this age. At four years after planting, important uptake was obtained only for the two plants located near the application area. Anyhow, to some extent it reflected that roots had already extended for another 1 m compared to the 3-y-old plants

  16. Rooting, growth, and color mutation of poinsettias affected by gamma radiation

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Eun Kyung; Kim, Won Hee; Kim, Seung Tae [National Institute of Horticultural and Herbal Science, RDA, Suwon (Korea, Republic of); Kang, Si Yong [Korea Atomic Energy Research Institute, Jeongeup (Korea, Republic of)

    2010-09-15

    This experiment was carried out to investigate the effects of gamma-radiation on the rooting, growth, and color mutation in poinsettia. Using 10 poinsettia varieties ('Lollipop', 'Little Peace', 'Happy Day', 'Early Bird', 'Pixy Red', 'Happy Time', 'Heidi', 'Red Bell', 'Clara', and 'Scarlet') bred by National Institute of Horticultural and Herbal Science, 100 Gy of gamma ray was irradiated at the stage of callused cuttings. Four weeks after sticking cuttings in the rooting media, 8 cultivars showed 100% of root formation, but 'Early Bird' rooted 24.4% and even died off during the cutting propagation. After planting rooted cuttings, survival rate until flowering time varied among irradiated cultivars. While 'Pixy Red' and 'Heidi' survived about 98%, 'Clara', 'Happy Day', and 'Early Bird' survived lesser than 30%. All irradiated plants showed remarkably shorter plant height, lesser branch numbers than non-irradiated control plants. Thirty color mutants were obtained among 281 plants survived until flowering time. Nine were complete color mutated branches, whereas 21 mutants were partially color mutated bracts and transitional leaves. Color patterns mutated by 100 Gy of gamma ray were divided into pink, hot pink, light red and spotted (pink spots with red main color). Pink mutants were commonly obtained. Complete color mutants were discovered from 4 plants of 'Pixy Red', 2 plants of 'Red Bell' and 3 plants of Lollipop.

  17. Molecular regulation of aluminum resistance and sulfur nutrition during root growth.

    Science.gov (United States)

    Alarcón-Poblete, Edith; Inostroza-Blancheteau, Claudio; Alberdi, Miren; Rengel, Zed; Reyes-Díaz, Marjorie

    2018-01-01

    Aluminum toxicity and sulfate deprivation both regulate microRNA395 expression, repressing its low-affinity sulfate transporter ( SULTR2;1 ) target. Sulfate deprivation also induces the high-affinity sulfate transporter gene ( SULTR12 ), allowing enhanced sulfate uptake. Few studies about the relationships between sulfate, a plant nutrient, and aluminum, a toxic ion, are available; hence, the molecular and physiological processes underpinning this interaction are poorly understood. The Al-sulfate interaction occurs in acidic soils, whereby relatively high concentrations of trivalent toxic aluminum (Al 3+ ) may hamper root growth, limiting uptake of nutrients, including sulfur (S). On the other side, Al 3+ may be detoxified by complexation with sulfate in the acid soil solution as well as in the root-cell vacuoles. In this review, we focus on recent insights into the mechanisms governing plant responses to Al toxicity and its relationship with sulfur nutrition, emphasizing the role of phytohormones, microRNAs, and ion transporters in higher plants. It is known that Al 3+ disturbs gene expression and enzymes involved in biosynthesis of S-containing cysteine in root cells. On the other hand, Al 3+ may induce ethylene biosynthesis, enhance reactive oxygen species production, alter phytohormone transport, trigger root growth inhibition and promote sulfate uptake under S deficiency. MicroRNA395, regulated by both Al toxicity and sulfate deprivation, represses its low-affinity Sulfate Transporter 2;1 (SULTR2;1) target. In addition, sulfate deprivation induces High Affinity Sulfate Transporters (HAST; SULTR1;2), improving sulfate uptake from low-sulfate soil solutions. Identification of new microRNAs and cloning of their target genes are necessary for a better understanding of the role of molecular regulation of plant resistance to Al stress and sulfate deprivation.

  18. Growth and graviresponsiveness of primary roots of Zea mays seedlings deficient in abscisic acid and gibberellic acid

    Science.gov (United States)

    Moore, R.; Dickey, K.

    1985-01-01

    The objective of this research was to determine if gibberellic acid (GA) and/or abscisic acid (ABA) are necessary for graviresponsiveness by primary roots of Zea mays. To accomplish this objective we measured the growth and graviresponsiveness of primary roots of seedlings in which the synthesis of ABA and GA was inhibited collectively and individually by genetic and chemical means. Roots of seedlings treated with Fluridone (an inhibitor of ABA biosynthesis) and Ancymidol (an inhibitor of GA biosynthesis) were characterized by slower growth rates but not significantly different gravicultures as compared to untreated controls. Gravicurvatures of primary roots of d-5 mutants (having undetectable levels of GA) and vp-9 mutants (having undectable levels of ABA) were not significantly different from those of wild-type seedlings. Roots of seedlings in which the biosynthesis of ABA and GA was collectively inhibited were characterized by gravicurvatures not significantly different for those of controls. These results (1) indicate that drastic reductions in the amount of ABA and GA in Z. mays seedlings do not significantly alter root graviresponsiveness, (2) suggest that neither ABA nor GA is necessary for root gravicurvature, and (3) indicate that root gravicurvature is not necessarily proportional to root elongation.

  19. Tolerance to high soil temperature in foxtail millet (Setaria italica L.) is related to shoot and root growth and metabolism.

    Science.gov (United States)

    Aidoo, Moses Kwame; Bdolach, Eyal; Fait, Aaron; Lazarovitch, Naftali; Rachmilevitch, Shimon

    2016-09-01

    Roots play important roles in regulating whole-plant carbon and water relations in response to extreme soil temperature. Three foxtail millet (Setaria italica L.) lines (448-Ames 21521, 463-P1391643 and 523-P1219619) were subjected to two different soil temperatures (28 and 38 °C). The gas exchange, chlorophyll fluorescence, root morphology and central metabolism of leaves and roots were studied at the grain-filling stage. High soil temperature (38 °C) significantly influenced the shoot transpiration, stomatal conductance, photosynthesis, root growth and metabolism of all lines. The root length and area were significantly reduced in lines 448 and 463 in response to the stress, while only a small non-specific reduction was observed in line 523 in response to the treatment. The shift of root metabolites in response to high soil temperature was also genotype specific. In response to high soil temperature, glutamate, proline and pyroglutamate were reduced in line 448, and alanine, aspartate, glycine, pyroglutamate, serine, threonine and valine were accumulated in line 463. In the roots of line 523, serine, threonine, valine, isomaltose, maltose, raffinose, malate and itaconate were accumulated. Root tolerance to high soil temperature was evident in line 523, in its roots growth potential, lower photosynthesis and stomatal conductance rates, and effective utilization and assimilation of membrane carbon and nitrogen, coupled with the accumulation of protective metabolites. Copyright © 2016. Published by Elsevier Masson SAS.

  20. Boron Toxicity Tolerance in Barley through Reduced Expression of the Multifunctional Aquaporin HvNIP2;11[W

    Science.gov (United States)

    Schnurbusch, Thorsten; Hayes, Julie; Hrmova, Maria; Baumann, Ute; Ramesh, Sunita A.; Tyerman, Stephen D.; Langridge, Peter; Sutton, Tim

    2010-01-01

    Boron (B) toxicity is a significant limitation to cereal crop production in a number of regions worldwide. Here we describe the cloning of a gene from barley (Hordeum vulgare), underlying the chromosome 6H B toxicity tolerance quantitative trait locus. It is the second B toxicity tolerance gene identified in barley. Previously, we identified the gene Bot1 that functions as an efflux transporter in B toxicity-tolerant barley to move B out of the plant. The gene identified in this work encodes HvNIP2;1, an aquaporin from the nodulin-26-like intrinsic protein (NIP) subfamily that was recently described as a silicon influx transporter in barley and rice (Oryza sativa). Here we show that a rice mutant for this gene also shows reduced B accumulation in leaf blades compared to wild type and that the mutant protein alters growth of yeast (Saccharomyces cerevisiae) under high B. HvNIP2;1 facilitates significant transport of B when expressed in Xenopus oocytes compared to controls and to another NIP (NOD26), and also in yeast plasma membranes that appear to have relatively high B permeability. We propose that tolerance to high soil B is mediated by reduced expression of HvNIP2;1 to limit B uptake, as well as by increased expression of Bot1 to remove B from roots and sensitive tissues. Together with Bot1, the multifunctional aquaporin HvNIP2;1 is an important determinant of B toxicity tolerance in barley. PMID:20581256

  1. The Growth of Root Rot Disease on Pepper Seed Applied by Trichoderma Harzianum Inoculum

    Directory of Open Access Journals (Sweden)

    S. Sofian

    2013-06-01

    Full Text Available Normal 0 false false false IN X-NONE X-NONE MicrosoftInternetExplorer4 Root rot disease on pepper caused by Phytophthora capsici is one of the most important diseases on pepper. The using of antagonistic fungus of Trichoderma harzianum as a biological control agent of the pathogen is one of the important alternatives in controlling P. capsici without causing negative effects on the environment. The objectives of the research were to study about the ability of T. harzianum inoculum application in inhibiting the development of root-rot disease, influenced the growth of pepper seed, to studythe effective length time application of T. harzianum inoculum in inhibiting the development of root rot disease, and increased the growth of pepper seedlings. This research was arranged in a completely randomized design, with five treatments of length time application of T. harzianum inoculum i.e. control treatment without applicationtime of T. harzianum inoculum (K, application time of T. harzianum inoculum for 0 week (S0, application time of T. harzianum inoculum for 1 week (S1, application time of T. harzianum inoculum for two weeks (S2, application time of T. harzianum inoculum for three weeks (S3, and application time of T. harzianum inoculum for 4 weeks (S4 before planting. Each treatment was repeated15 times. The observed parameterswere disease percentage, the inhibition of antagonistic fungus, disease infection rate, plant height, number of leaves, wet and dry weight of plant, stem and leaves on pepper seed, and P. capsici population density. The result showed that application time of T. harzianum inoculumfor 4 weeks (S4 before planting is the most effective time in inhibiting the development of root rot disease than the other treatment sand also had significant effect on increasing the growth of pepper seed. The antagonism test showed that T. harzianum could inhibit P. capsiciin vitro. This result proves that application time of T. harzianum inoculums

  2. Does shoot water status limit leaf expansion of nitrogen-deprived barley?

    Science.gov (United States)

    Dodd, I C; Munns, Rana; Passioura, J B

    2002-08-01

    The role of shoot water status in mediating the decline in leaf elongation rate of nitrogen (N)-deprived barley plants was assessed. Plants were grown at two levels of N supply, with or without the application of pneumatic pressure to the roots. Applying enough pressure (balancing pressure) to keep xylem sap continuously bleeding from the cut surface of a leaf allowed the plants to remain at full turgor throughout the experiments. Plants from which N was withheld required a greater balancing pressure during both day and night. This difference in balancing pressure was greater at high (2.0 kPa) than low (1.2 kPa) atmospheric vapour pressure deficit (VPD). Pressurizing the roots did not prevent the decline in leaf elongation rate induced by withholding N at either high or low VPD. Thus low shoot water status did not limit leaf growth of N-deprived plants.

  3. Heat Stress Affects Pi-related Genes Expression and Inorganic Phosphate Deposition/Accumulation in Barley

    DEFF Research Database (Denmark)

    Pacak, Andrzej; Barciszewska-Pacak, Maria; Swida-Barteczka, Aleksandra

    2016-01-01

    Phosphorus (P) in plants is taken from soil as an inorganic phosphate (Pi) and is one of the most important macroelements in growth and development. Plants actively react to Pi starvation by the induced expression of Pi transporters, MIR399, MIR827, and miR399 molecular sponge - IPS1 genes...... and by the decreased expression of the ubiquitin-conjugating enzyme E2 (PHOSPHATE2 - PHO2) and Pi sensing and transport SPX-MFS genes. The PHO2 protein is involved in the degradation of Pi transporters PHT1;1 (from soil to roots) and PHO1 (from roots to shoots). The decreased expression of PHO2 leads to Pi....... In shoots, the PHO2 mRNA level is decreased, leading to an increased Pi level. We concluded that Pi homeostasis in barley during heat stress is maintained by dynamic changes in Pi-related genes expression....

  4. Inhibition of Human Cervical Cancer Cell Growth by Ethanolic Extract of Boerhaavia diffusa Linn. (Punarnava Root

    Directory of Open Access Journals (Sweden)

    Rakhi Srivastava

    2011-01-01

    Full Text Available In Indian traditional medicine, Boerhaavia diffusa (punarnava roots have been widely used for the treatment of dyspepsia, jaundice, enlargement of spleen, abdominal pain and as an anti-stress agent. Pharmacological evaluation of the crude ethanolic extract of B. diffusa roots has been shown to possess antiproliferative and immunomodulatory properties. The extract of B. diffusa was studied for anti-proliferative effects on the growth of HeLa cells and for its effect on cell cycle. Bio-assays of extracts from B. diffusa root showed that a methanol : chloroform fraction (BDF 5 had an antiproliferative effect on HeLa cells. After 48 h of exposure, this fraction at a concentration of 200 μg mL−1 significantly reduced cell proliferation with visible morphological changes in HeLa cells. Cell cycle analysis suggests that antiproliferative effect of BDF 5 could be due to inhibition of DNA synthesis in S-phase of cell cycle in HeLa cells, whereas no significant change in cell cycle was detected in control cells. The fraction BDF 5 caused cell death via apoptosis as evident from DNA fragmentation and caspase-9 activation. Thus the extract has potential to be evaluated in detail to assess the molecular mechanism-mediated anticancer activities of this plant.

  5. Root growth conditions in the topsoil as affected by tillage intensity

    DEFF Research Database (Denmark)

    Kadziene, Grazina; Munkholm, Lars Juhl; Mutegi, James

    2011-01-01

    in the topsoil. Samples were taken from a 7-year tillage experiment on a Danish sandy loam at Foulum, Denmark (56°30′ N, 9°35′ E) in 2008. The main crop was spring barley followed by either dyer's woad (Isatis tinctoria L.) or fodder radish (Raphanus sativus L.) cover crops as subtreatment. The tillage...

  6. Growth and proteomic analysis of tomato fruit under partial root-zone drying.

    Science.gov (United States)

    Marjanović, Milena; Stikić, Radmila; Vucelić-Radović, Biljana; Savić, Sladjana; Jovanović, Zorica; Bertin, Nadia; Faurobert, Mireille

    2012-06-01

    The effects of partial root-zone drying (PRD) on tomato fruit growth and proteome in the pericarp of cultivar Ailsa Craig were investigated. The PRD treatment was 70% of water applied to fully irrigated (FI) plants. PRD reduced the fruit number and slightly increased the fruit diameter, whereas the total fruit fresh weight (FW) and dry weight (DW) per plant did not change. Although the growth rate was higher in FI than in PRD fruits, the longer period of cell expansion resulted in bigger PRD fruits. Proteins were extracted from pericarp tissue at two fruit growth stages (15 and 30 days post-anthesis [dpa]), and submitted to proteomic analysis including two-dimensional gel electrophoresis and mass spectrometry for identification. Proteins related to carbon and amino acid metabolism indicated that slower metabolic flux in PRD fruits may be the cause of a slower growth rate compared to FI fruits. The increase in expression of the proteins related to cell wall, energy, and stress defense could allow PRD fruits to increase the duration of fruit growth compared to FI fruits. Upregulation of some of the antioxidative enzymes during the cell expansion phase of PRD fruits appears to be related to their role in protecting fruits against the mild stress induced by PRD.

  7. Observations of the severity of notch-root radius in initiation of subcritical crack growth

    International Nuclear Information System (INIS)

    Reuter, W.G.; Eiholzer, C.R.; Tupper, M.A.

    1981-01-01

    Slow bend tests were conducted on Charpy specimens containing precracks or machined notches of 0.10 or 0.25 mm radius. The test specimens were fabricated from three heats of annealed Type 304 stainless steel. The purpose of these tests was to examine the effects of notch root radius, in very ductile materials, on initiation of subcritical crack growth. In addition, it was intended to establish the critical values of J, COD, etc. for the single-edge notch specimen for comparison with results obtained from specimens containing surface flaws. This paper will briefly describe only those results of the calculation for J. The tests were monitored by acoustic emission to identify the load corresponding to initiation of subcritical crack growth, by a crack-opening displacement gage (COD), by cross-head displacement, and by stop-action photography

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

    Science.gov (United States)

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

    2018-05-15

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

  9. The garlic allelochemical diallyl disulfide affects tomato root growth by influencing cell division, phytohormone balance and expansin gene expression

    Directory of Open Access Journals (Sweden)

    Fang Cheng

    2016-08-01

    Full Text Available Diallyl disulfide (DADS is a volatile organosulfur compound derived from garlic (Allium sativum L., and it is known as an allelochemical responsible for the strong allelopathic potential of garlic. The anticancer properties of DADS have been studied in experimental animals and various types of cancer cells, but to date, little is known about its mode of action as an allelochemical at the cytological level. The current research presents further studies on the effects of DADS on tomato (Solanum lycopersicum L. seed germination, root growth, mitotic index and cell size in root meristem, as well as the phytohormone levels and expression profile of auxin biosynthesis genes (FZYs, auxin transport genes (SlPINs and expansin genes (EXPs in tomato root. The results showed a biphasic, dose-dependent effect on tomato seed germination and root growth under different DADS concentrations. Lower concentrations (0.01-0.62 mM of DADS significantly promoted root growth, whereas higher levels (6.20-20.67 mM showed inhibitory effects. Cytological observations showed that the cell length of root meristem was increased and that the mitotic activity of meristematic cells in seedling root tips was enhanced at lower concentrations of DADS. In contrast, DADS at higher concentrations inhibited root growth by affecting both the length and division activity of meristematic cells. However, the cell width of the root meristem was not affected. Additionally, DADS increased the IAA and ZR contents of seedling roots in a dose-dependent manner. The influence on IAA content may be mediated by the up-regulation of FZYs and PINs. Further investigation into the underlying mechanism revealed that the expression levels of tomato EXPs were significantly affected by DADS. The expression levels of EXPB2 and beta-expansin precursor were increased after 3 d, and those of EXP1, EXPB3 and EXLB1 were increased after 5 d of DADS treatment (0.41 mM. This result suggests that tomato root growth

  10. Effect of irradiation, pruning and removal of in vitro formed roots on ex vitro growth in micro propagated grape

    International Nuclear Information System (INIS)

    Charbaji, T.; Ayyoubi, Z.

    2003-01-01

    In vitro rootstock (Ru 140) and Helwani variety were cultured on DSD1 media, were irradiated at low doses of gamma irradiation before acclimatization. Ru 140 were exposed to 0-5 Gy, while Helwani was exposed to 0-7 Gy. Then, the plants were divided into three different groups: in the first group the plant roots were pruned, in the second the plant roots were completely removed and in the third group the plant roots were kept intact (control). The ex vitro plants were observed after 45 days of planting. Shoots growth, leaf number and dry weight of Ru 140 were significantly higher than those of the control when roots were pruned and 5 Gy was applied. Those parameters were negatively affected by root removal. Gamma irradiation had a positive effect on the control comparing to unirradiated plants. Root pruning had positive effects on shoot growth, leaf number and dry weight of Helwani variety, while root removal had a contrary effect on this variety. Gamma irradiation positively affected shoot growth and dry weight of control comparing to unirradiated plants, similar effect was observed on leaf number of control and pruned plant of Helwani. (author)

  11. Effect of Irradiation, Pruning and Removal of In Vitro Formed Roots on Ex Vitro Growth in Micropropagated Grape

    International Nuclear Information System (INIS)

    Charabaji, T.; Ayyoubi, Z.; Karajoly, I

    2007-01-01

    In vitro rootstock (Ru 140) and Helwani variety were cultured on DSD1 media, were irradiated at low doses of gamma irradiation before acclimatization. Ru 140 was exposed to 0-5 Gy, while Helwani was exposed to 0-7 Gy. Then, the plants were divided into three different procedures, 1)- the plant roots were pruned, 2)- the plant roots were completely removed, 3)- the plant roots were kept intact (control). The ex vitro plants were observed after 45 days of planting. Shoots growth, leaf number and dry weight of Ru 140 were significantly higher than those of the control when roots were pruned and 5 Gy was applied. Those parameters were negatively affected by root removal. Gamma irradiation had a positive effect on the control comparing to unirradiated plants. Root pruning had positive effects on shoot growth, leaf number and dry weight of Helwani variety, while root removal had a contrary effect on this variety. Gamma irradiation positively affected shoot growth and dry weight of control comparing to unirradiated plants, similar effect was observed on leaf number of control and pruned plant of Helwani.

  12. Effect of applied synthetic auxin on root growth in plantlet propagation by cuttage and tissue culture; Sashiki to soshiki baiyo ni okeru gosei auxin rui no shiyo koka

    Energy Technology Data Exchange (ETDEWEB)

    Shoji, K; Yoshihara, T [Central Research Institute of Electric Power Industry, Tokyo (Japan)

    1996-12-01

    The effect of synthetic plant hormone 4-C1-IAA and TFIBA on root growth in plantlet propagation was clarified by the cuttage and the issue culture of strawberry seedling production. A periwinkle, vine, and azalea are the effect of 4-C1-IAA on root growth, and a promotion effect was recognized for rooting and root elongation. The concentration of 4-C1-IAA in which the growth promotion effect of a root most appears varies depending on the species of a plant. The concentration of a periwinkle was 20 ppm, and that of an azalea was 2000 ppm. The growth promotion effect of a root in 4-C1-IAA and TFIBA was compared with IBA for an azalea. The result showed that 4-C1-IAA is the same in the effect as IBA and that TFIBA is higher than for IBA. The growth of a vine`s terminal bud was promoted by the effect of TFIBA on root growth, and the callus occurring when IBA was treated was not formed. The rooting of a strawberry was promoted by the effect of TFIBA on root growth. The combined use of TFIBA and BA promotes the growth of a side bud and forms a multi-bud plant. However, rooting was inhibited. The callus caused by the effect of BA on root growth could be suppressed through the combined use with TFIBA. 6 refs., 7 figs., 2 tabs.

  13. Construction of barley consensus map showing chromosomal ...

    African Journals Online (AJOL)

    In the past, it has been difficult to accurately determine the location of many types of barley molecular markers due to the lack of commonality between international barley linkage maps. In this study, a consensus map of barley was constructed from five different maps (OWB, VxHs, KxM, barley consensus 2 and barley ...

  14. Local and distal effects of arbuscular mycorrhizal colonization on direct pathway Pi uptake and root growth in Medicago truncatula

    Science.gov (United States)

    Watts-Williams, Stephanie J.; Jakobsen, Iver; Cavagnaro, Timothy R.; Grønlund, Mette

    2015-01-01

    Two pathways exist for plant Pi uptake from soil: via root epidermal cells (direct pathway) or via associations with arbuscular mycorrhizal (AM) fungi, and the two pathways interact in a complex manner. This study investigated distal and local effects of AM colonization on direct root Pi uptake and root growth, at different soil P levels. Medicago truncatula was grown at three soil P levels in split-pots with or without AM fungal inoculation and where one root half grew into soil labelled with 33P. Plant genotypes included the A17 wild type and the mtpt4 mutant. The mtpt4 mutant, colonized by AM fungi, but with no functional mycorrhizal pathway for Pi uptake, was included to better understand effects of AM colonization per se. Colonization by AM fungi decreased expression of direct Pi transporter genes locally, but not distally in the wild type. In mtpt4 mutant plants, direct Pi transporter genes and the Pi starvation-induced gene Mt4 were more highly expressed than in wild-type roots. In wild-type plants, less Pi was taken up via the direct pathway by non-colonized roots when the other root half was colonized by AM fungi, compared with non-mycorrhizal plants. Colonization by AM fungi strongly influenced root growth locally and distally, and direct root Pi uptake activity locally, but had only a weak influence on distal direct pathway activity. The responses to AM colonization in the mtpt4 mutant suggested that in the wild type, the increased P concentration of colonized roots was a major factor driving the effects of AM colonization on direct root Pi uptake. PMID:25944927

  15. Brassinolide Increases Potato Root Growth In Vitro in a Dose-Dependent Way and Alleviates Salinity Stress

    Directory of Open Access Journals (Sweden)

    Yueqing Hu

    2016-01-01

    Full Text Available Brassinosteroids (BRs are steroidal phytohormones that regulate various physiological processes, such as root development and stress tolerance. In the present study, we showed that brassinolide (BL affects potato root in vitro growth in a dose-dependent manner. Low BL concentrations (0.1 and 0.01 μg/L promoted root elongation and lateral root development, whereas high BL concentrations (1–100 μg/L inhibited root elongation. There was a significant (P<0.05 positive correlation between root activity and BL concentrations within a range from 0.01 to 100 μg/L, with the peak activity of 8.238 mg TTC·g−1 FW·h−1 at a BL concentration of 100 μg/L. Furthermore, plants treated with 50 μg/L BL showed enhanced salt stress tolerance through in vitro growth. Under this scenario, BL treatment enhanced the proline content and antioxidant enzymes’ (superoxide dismutase, peroxidase, and catalase activity and reduced malondialdehyde content in potato shoots. Application of BL maintain K+ and Na+ homeostasis by improving tissue K+/Na+ ratio. Therefore, we suggested that the effects of BL on root development from stem fragments explants as well as on primary root development are dose-dependent and that BL application alleviates salt stress on potato by improving root activity, root/shoot ratio, and antioxidative capacity in shoots and maintaining K+/Na+ homeostasis in potato shoots and roots.

  16. Effect of (/sup 60/cobalt) gamma rays on growth and root rot diseases in mungbean (vigna radiata L.)

    International Nuclear Information System (INIS)

    Ikram, N.; Dawar, S.; Zaki, M.J.; Abass, Z.

    2010-01-01

    Present investigation showed that gamma rays influences suppressive effect on root rot fungi such as Macrophomina phaseolina (Tassi) Goid, Rhizoctonia solani Kuhn and Fusarium spp., and inducive effect on growth parameters of mung bean (Vigna radiata L.). Seeds of mung bean were treated with gamma rays (/sup 60/Cobalt) at time periods of 0 and 4 minutes and stored for 90 days at room temperature to determine its effect on growth parameters and infection of root infecting fungi. All treatments of gamma rays enhanced the growth parameters as compared to untreated plants. Infection of M. phaseolina, R. solani and Fusarium spp., were significantly decreased on mung bean seeds treated with gamma rays. Gamma rays significantly increased the growth parameters and controlled the root rot fungi up to 90 days of storage of seeds. (author)

  17. Malting barley BRS Borema

    Directory of Open Access Journals (Sweden)

    Euclydes Minella

    2006-01-01

    Full Text Available BRS Borema is an early maturing, two-rowed spring barley registered in 2003 for commercial production inSouthern Brazil, bred by Embrapa Trigo. It combines good yield potential with superior malting quality and a reasonable levelof disease (net blotch, powdery mildew, leaf rust resistance. It is well-adapted to all major production regions of maltingbarley in Brazil.

  18. Growth performance, behaviour, forestomach development and meat quality of veal calves provided with barley grain or ground wheat straw for welfare purpose

    Directory of Open Access Journals (Sweden)

    Igino Andrighetto

    2010-01-01

    Full Text Available Two different feeding plans for veal calves were compared in the study: a traditional liquid diet supplemented with 250  g/calf/d of barley grain or with 250 g/calf/d of ground wheat straw. The two solid feeds had different chemical composi-  tion but a similar particle size obtained by grinding the straw in a mill with an 8-mm mesh screen. Twenty-four Polish  Friesian male calves were used in the study and they were housed in individual wooden stalls (0.83 x 1.80 m. The health  status of all the calves was satisfactory for the entire fattening period and no specific medical treatment was required  during the trial. Calves fed wheat straw showed a greater intake of solid feed (196 vs. 139 g/d; P  average daily gain (1288 vs. 1203 g/d; P  not affected by the type of solid feed and no milk refusal episodes were detected. The haemoglobin concentration was  similar in calves receiving the two feeding treatments despite the higher iron intake provided by the wheat straw through-  out the fattening period (2.12 vs. 1.15 g; P  calves’ metabolism. Feeding behaviour was affected by the provision of solid feeds. Eating and chewing were prolonged  in calves receiving ground wheat straw and the same solid feed reduced the frequency of oral stereotypies at the end of  the fattening period. At the slaughterhouse, no differences were observed between the feeding treatments as regards  carcass weight and dressing percentage. The calves fed ground wheat straw had a heavier weight of the empty omasum  (518 vs. 341 g; P  fed barley grain. The incidence of abomasal erosions, ulcers and scars was similar in both treatments; however the index  of abomasal damage, which considers the number and the seriousness of different type of lesions, was higher in calves  receiving barley grain. Therefore, the grinding of straw particles, as opposed to barley grain, can reduce the abrasive-  ness of roughage at the abomasum level. Visual evaluation of the

  19. [Effects of elicitors on growth of adventitious roots and contents of secondary metabolites in Tripterygium wilfordii Hook. f].

    Science.gov (United States)

    Li, Yan; Zhao, Lei; Cui, Lei; Lei, Jiamin; Zhang, Xing

    2015-05-01

    To study the effects of the extract of fungal elicitor, AgNO3, MeJA and yeast on the growth and content of secondary metabolites of adventitious roots in Tripterygium wilfordii. The above elicitors were supplemented to the medium, the growth and the content of secondary metabolites were measured. When the medium was supplemented with the elicitor Glomerella cingulata or Collectotrichum gloeosporioides, the content of triptolide was increased by 2.24 and 1.93-fold, the alkaloids content was increased by 2.02 and 2.07-fold, respectively. The optimal concentration of G. cingulata was 50 μg/mL for accumulation of triptolide, alkaloids and for the growth of adventitious roots. AgNO3 inhibited the growth of adventitious roots and the accumulation of the alkaloids, whereas it (at 25 μmol/L) increased the accumulation of triptolide by 1.71-fold compared to the control. The growth of adventitious roots, the contents of triptolide and alkaloids were increased 1.04, 1.64 and 2.12-folds, respectively when MeJA was at 50 μmol/L. When the concentration of yeast reached 2 g/L, the content of triptolide increased 1.48-folds. This research demonstrated that supplementation of AgNO3 and yeast enhanced the biosynthesis of triptolide in adventitious roots and the synergism of G. cingulata and MeJA could promote the biosynthesis of both triptolide and alkaloids.

  20. Effects of chicory root powder on growth performance and histomorphometry of jejunum in broiler chicks

    Directory of Open Access Journals (Sweden)

    Homan Izadi

    2013-09-01

    Full Text Available In the present study, chicory root powder (CRP as growth promoter at 1% and 3% levels was supplemented in broilers’ diet to investigate the growth performance and histo- morphometry of jejunum. One hundred twenty, one-day-old male broilers were used in a completely randomized design (CRD with 3 treatments and 4 replicates (10 chicks per replicate. At the end of each period (0-10, 11-24 and 0-24 days, feed intake (FI, weight gain (WG, and feed conversion ratio (FCR were measured. At the end of experiment (day 24, one bird per replicate was sacrificed for breast weight (BW, drumstick weight (DW, and jejunum length (JL as a percentage of body weight, and histomorphometry of villus. The FI increased by 3% CRP in the 1st period (p < 0.01. The percentage of WG significantly increased at 1% during the 1st period and, in the 2nd and total periods, it increased only at 3% CRP (p < 0.05. The FCR decreased at 1% in the 1st (p < 0.04 and, at 3% in the 2nd (p < 0.01 and total periods (p < 0.05. The percentage of DW increased at 3% CRP (p < 0.05. The treatments increased the percentage of BW (p < 0.059 and, percentage of JL (p < 0.079 as well. The villus width and, crypt depth (CD at 1% and 3% CRP and, villus surface at 3% reduced. The 3% CRP increased the villus length (VL and villi number (p < 0.05 and, VL/CD (p < 0.01 and, villus surface area (p < 0.02. The percentage of leaf-like villi decreased in CRP treatments (p < 0.05. The number of goblet cells increased in CRP treatments (p < 0.01. In conclusion, chicory root powder can improve growth performance in broilers by enhancing food digestion and absorption through modification of jejunum histomorphometry.

  1. Effects of root pruning on the growth and rhizosphere soil characteristics of short-rotation closed-canopy poplar

    Energy Technology Data Exchange (ETDEWEB)

    Du, Z. Y.; Xing, S. J.; Ma, B. Y.; Liu, F. C.; Ma, H. L.; Wang, Q. H.

    2012-11-01

    When poplar trees planted at a high density are canopy-closed in plantation after 4-5 years of growth, the roots of adjacent trees will inevitably intermingle together, which possibly restricts the nutrient uptake by root system. Root pruning might stimulate the emergence of fine roots and benefit the tree growth of short-rotation poplar at the stage of canopy closing. The aim of this study is to evaluate the effects of root pruning on DBH (diameter at breast height, 1.3 m), tree height, nutrients (N, P and K) and hormones (indoleacetic acid and cytokinin) in poplar leaves, gas exchange variables (photosynthetic rate and stomatal conductance), and rhizosphere soil characteristics. Field experiment was carried out with four-yearold poplar (Populus × euramericana cv. ‘Neva’) planted in a fluvo-aquic loam soil in Shandong province, China in early April, 2008. Three root pruning treatments (severe, moderate and light degree) were conducted at the distances of 6, 8 and 10 times DBH on both inter-row sides of the trees to the depth of 30 cm, respectively. The results showed that the growth performance was obtained in the following order of treatments: moderate > light = control > severe. In the rhizophere soil, moderate and light pruning increased the microbial populations, enzymatic activities, and the concentrations of available N, P, K and organic matter. Generally, root pruning to improve tree growth and rhizosphere soil fertility can be recommended in canopy-closed poplar plantation. The appropriate selection of root pruning intensity is a pivotal factor for the effectiveness of this technique. (Author) 35 refs.

  2. Levisticum officinale hairy root cultures: influence of light and light type on growth and essential oil production

    OpenAIRE

    Lima, A. Sofia; Sousa, Maria João; Pedro, Luís G.; Figueiredo, A. Cristina; Barroso, J.G.; Deans, S.G.; Scheffer, J.J.C.

    2005-01-01

    The essential oils of Levisticum officinale W.D.J. Koch (Apiaceae), including those isolated from the roots, are used in the cosmetic, pharmaceutical and food industries [1]. This perennial and herbaceous plant, commonly known as lovage, is widely known by its aromatic, ornamental and medicinal properties. The effect of light and light type on growth and essential oil production of lovage hairy root cultures was studied by comparison of cultures maintained under “blue-basic” (400-550nm) and “...

  3. Effect of irradiation, pruning and removal of in vitro formed roots on ex vitro growth in micropropagated grape

    International Nuclear Information System (INIS)

    Charbaji, T.; Ayyoubi, Z.

    2002-06-01

    In vitro rootstock (Ru 140) and Helwani variety were cultured on DSD1 media, were irradiated at low doses of gamma irradiation before acclimatization. Ru 140 were exposed to 0-5 Gy, while Helwani was exposed to 0-7 Gy. Then, the plants were divided into three different groups: in the first group the plant roots were pruned, in the second the plant roots were completely removed and in the third group the plant roots were kept intact (control). The ex vitro plants were observed after 45 days of planting. Shoots groeth, leaf number and dry weight of Ru 140 were significantly higher than those of the control when roots were pruned and 5 Gy was applied. Those parameters were negatively affected by root removal. Gamma irradiation had a positive effect on the control comparing to unirradiated plants. Root pruning had positive effects on shoot growth, leaf number and dry weight of helwani veriety, while root removal had a contrary effect on this variety. Gamma irradiation positively affected shoot growth and dry weight of control comparing to unirradiated plants, similar effect was observed on leaf number of control and pruned plant of Helwani. (author)

  4. Naringenin inhibits the growth and stimulates the lignification of soybean root

    Directory of Open Access Journals (Sweden)

    Graciene de Souza Bido

    2010-06-01

    Full Text Available The flavanone naringenin, an intermediate in flavonoid biosynthesis, was tested for its effect on root growth, phenylalanine ammonia-lyase (PAL and peroxidase (POD activities, as well as phenolic compounds and lignin contents in soybean (Glycine max L. Merrill seedlings. Three-day-old seedlings were cultivated in half-strength Hoagland nutrient solution (pH 6.0, with or without 0.1 to 0.4 mM naringenin in a growth chamber (25°C, 12-h photoperiod, irradiance of 280 µmol m-2 s-1 for 24 h. Inhibitory effects on root growth (length, weight, cell viability, PAL and soluble POD activities were detected after naringenin treatments. These effects were associated with stimulatory activity of the cell wall-bound POD followed by an increase in the lignin contents, suggesting that naringenin-induced inhibition in soybean roots could be due to the lignification process.Os efeitos de naringenina, um intermediário da biossíntese de flavonóides, foram avaliados sobre o crescimento das raízes, as atividades da fenilalanina amônia liase (PAL e peroxidases, bem como sobre os teores de compostos fenólicos e de lignina em plântulas de soja (Glycine max L. Merrill. Plântulas de três dias foram cultivadas em solução nutritiva de Hoagland, meia-força (pH 6,0, contendo ou não, naringenina 0,1 a 0,4 mM, em uma câmara de germinação (25°C, fotoperíodo de 12 h, 280 µmol m-2 s-1 durante 24 h. Efeitos inibitórios no crescimento das raízes (comprimento, massa e viabilidade celular e nas atividades da PAL e POD solúvel foram constatados após os tratamentos com naringenina. Estes efeitos foram associados com atividade estimulatória da POD ligada à parede celular, seguido por aumento nos teores de lignina, sugerindo que a inibição do crescimento das raízes pode ser devido ao processo de lignificação.

  5. Root Zone Cooling and Exogenous Spermidine Root-Pretreatment Promoting Lactuca sativa L. Growth and Photosynthesis in the High-Temperature Season

    Directory of Open Access Journals (Sweden)

    Jin eSun

    2016-03-01

    Full Text Available Root zone high-temperature stress is a major factor limiting hydroponic plant growth during the high-temperature season. The effects of root zone cooling (RZC; at 25°C and exogenous spermidine (Spd root-pretreatment (SRP, 0.1 mM on growth, leaf photosynthetic traits, and chlorophyll fluorescence characteristics of hydroponic Lactuca sativa L. grown in a high-temperature season (average temperature > 30°C were examined. Both treatments significantly promoted plant growth and photosynthesis in the high-temperature season, but the mechanisms of photosynthesis improvement in the hydroponic grown lettuce plants were different between the RZC and SRP treatments. The former improved plant photosynthesis by increasing stoma conductance (Gs to enhance CO2 supply, thus promoting photosynthetic electron transport activity and phosphorylation, which improved the level of the photochemical efficiency of photosystem II (PSII, rather than enhancing CO2 assimilation efficiency. The latter improved plant photosynthesis by enhancing CO2 assimilation efficiency, rather than stomatal regulation. Combination of RZC and SRP significantly improved PN of lettuce plants in a high-temperature season by both improvement of Gs to enhance CO2 supply and enhancement of CO2 assimilation. The enhancement of photosynthetic efficiency in both treatments was independent of altering light-harvesting or excessive energy dissipation.

  6. Root Zone Cooling and Exogenous Spermidine Root-Pretreatment Promoting Lactuca sativa L. Growth and Photosynthesis in the High-temperature Season.

    Science.gov (United States)

    Sun, Jin; Lu, Na; Xu, Hongjia; Maruo, Toru; Guo, Shirong

    2016-01-01

    Root zone high-temperature stress is a major factor limiting hydroponic plant growth during the high-temperature season. The effects of root zone cooling (RZC; at 25°C) and exogenous spermidine (Spd) root-pretreatment (SRP, 0.1 mM) on growth, leaf photosynthetic traits, and chlorophyll fluorescence characteristics of hydroponic Lactuca sativa L. grown in a high-temperature season (average temperature > 30°C) were examined. Both treatments significantly promoted plant growth and photosynthesis in the high-temperature season, but the mechanisms of photosynthesis improvement in the hydroponic grown lettuce plants were different between the RZC and SRP treatments. The former improved plant photosynthesis by increasing stoma conductance (G s) to enhance CO2 supply, thus promoting photosynthetic electron transport activity and phosphorylation, which improved the level of the photochemical efficiency of photosystem II (PSII), rather than enhancing CO2 assimilation efficiency. The latter improved plant photosynthesis by enhancing CO2 assimilation efficiency, rather than stomatal regulation. Combination of RZC and SRP significantly improved P N of lettuce plants in a high-temperature season by both improvement of G s to enhance CO2 supply and enhancement of CO2 assimilation. The enhancement of photosynthetic efficiency in both treatments was independent of altering light-harvesting or excessive energy dissipation.

  7. Determinate primary root growth as an adaptation to aridity in Cactaceae: towards an understanding of the evolution and genetic control of the trait.

    Science.gov (United States)

    Shishkova, Svetlana; Las Peñas, María Laura; Napsucialy-Mendivil, Selene; Matvienko, Marta; Kozik, Alex; Montiel, Jesús; Patiño, Anallely; Dubrovsky, Joseph G

    2013-07-01

    Species of Cactaceae are well adapted to arid habitats. Determinate growth of the primary root, which involves early and complete root apical meristem (RAM) exhaustion and differentiation of cells at the root tip, has been reported for some Cactoideae species as a root adaptation to aridity. In this study, the primary root growth patterns of Cactaceae taxa from diverse habitats are classified as being determinate or indeterminate, and the molecular mechanisms underlying RAM maintenance in Cactaceae are explored. Genes that were induced in the primary root of Stenocereus gummosus before RAM exhaustion are identified. Primary root growth was analysed in Cactaceae seedlings cultivated in vertically oriented Petri dishes. Differentially expressed transcripts were identified after reverse northern blots of clones from a suppression subtractive hybridization cDNA library. All species analysed from six tribes of the Cactoideae subfamily that inhabit arid and semi-arid regions exhibited determinate primary root growth. However, species from the Hylocereeae tribe, which inhabit mesic regions, exhibited mostly indeterminate primary root growth. Preliminary results suggest that seedlings of members of the Opuntioideae subfamily have mostly determinate primary root growth, whereas those of the Maihuenioideae and Pereskioideae subfamilies have mostly indeterminate primary root growth. Seven selected transcripts encoding homologues of heat stress transcription factor B4, histone deacetylase, fibrillarin, phosphoethanolamine methyltransferase, cytochrome P450 and gibberellin-regulated protein were upregulated in S. gummosus root tips during the initial growth phase. Primary root growth in Cactoideae species matches their environment. The data imply that determinate growth of the primary root became fixed after separation of the Cactiodeae/Opuntioideae and Maihuenioideae/Pereskioideae lineages, and that the genetic regulation of RAM maintenance and its loss in Cactaceae is

  8. Dynamic Allocation of Sugars in Barley

    Science.gov (United States)

    Cumberbatch, L. C.; Crowell, A. S.; Fallin, B. A.; Howell, C. R.; Reid, C. D.; Weisenberger, A. G.; Lee, S. J.; McKisson, J. E.

    2014-03-01

    Allocation of carbon and nitrogen is a key factor for plant productivity. Measurements are carried out by tracing 11C-tagged sugars using positron emission tomography and coincidence counting. We study the mechanisms of carbon allocation and transport from carbohydrate sources (leaves) to sinks (stem, shoot, roots) under various environmental conditions such as soil nutrient levels and atmospheric CO2 concentration. The data are analyzed using a transfer function analysis technique to model transport and allocation in barley plants. The experimental technique will be described and preliminary results presented. This work was supported in part by USDOE Grant No. DE-FG02-97-ER41033 and DE-SC0005057.

  9. Drought effect on growth, gas exchange and yield, in two strains of local barley Ardhaoui, under water deficit conditions in southern Tunisia.

    Science.gov (United States)

    Thameur, Afwa; Lachiheb, Belgacem; Ferchichi, Ali

    2012-12-30

    Two local barley strains cv. Ardhaoui originated from Tlalit and Switir, sourthern Tunisia were grown in pots in a glasshouse assay, under well-watered conditions for a month. Plants were then either subjected to water deficit (treatment) or continually well-watered (control). Control pots were irrigated several times each week to maintain soil moisture near field capacity (FC), while stress pots experienced soil drying by withholding irrigation until they reached 50% of FC. Variation in relative water content, leaf area, leaf appearance rate and leaf gas exchange (i.e. net CO(2) assimilation rate (A), transpiration (E), and stomatal conductance (gs)) in response to water deficit was investigated. High leaf relative water content (RWC) was maintained in Tlalit by stomatal closure and a reduction of leaf area. Reduction in leaf area was due to decline in leaf gas exchange during water deficit. Tlalit was found to be drought tolerant and able to maintain higher leaf RWC under drought conditions. Water deficit treatment reduced stomatal conductance by 43% at anthesis. High net CO(2) assimilation rate under water deficit was associated with high RWC (r = 0.998; P gas exchange parameters were found, which can give some indications on the degree of drought tolerance. Thus, the ability of the low leaf area plants to maintain higher RWC could explain the differences in drought tolerance in studied barley strains. Results showed that Tlalit showed to be more efficient and more productive than Switir. Copyright © 2012 Elsevier Ltd. All rights reserved.

  10. Characterization of molecular signature of the roots of Paeonia lactiflora during growth

    Institute of Scientific and Technical Information of China (English)

    LIU Pei; XU Yuan; YAN Hui; CHEN Jing; SHANG Er-Xin; QIAN Da-Wei; JIANG Shu; DUAN Jin-Ao

    2017-01-01

    The roots ofPaeoniae lactiflora Pall.are widely consumed as crude drugs in Asian countries due to their remarkable beneficial health effects.The present research was undertaken to illuminate the dynamic changes in metabolites and enzymes and facilitate selection of the harvesting time when the herb can provide optimum health benefits.P.lactiflora roots were analyzed at 12 stages of growth for monoterpenoid glycosides,phenols,nucleosides,nucleobases,amino acids,and polysaccharides by high-performance liquid chromatography with photodiode array detector,ultra-high pressure liquid chromatography coupled with tandem mass spectrometry,and UV spectrophotometry.The enzyme activities of plant β-glucosidases and esterases were determined by UV methods.The total content of monoterpenoid glycosides and phenols peaked in December.For nucleosides and nucleobases,the highest content appeared in April.The maximum phasic accumulation of the total amino acids took place in March,and the content of total polysaccharides reached a peak value in September.December,April,and March were selected as the appropriate harvesting times for producing natural medicinal or health food products.Plant β-glucosidases and esterases showed the highest activity in December and May,respectively.When the activity of β-glucosidase increased,esterase activity decreased,while the contents of oxypaeoniflora and paeoniflorin increased.When esterase activity increased,the contents of benzoylpaeoniflorin,paeoniflorin,and gallic acid decreased.In conclusion,the results from the present study would be useful in determination of the suitable time for harvesting P.lactiflora roots for medicinal purposes.

  11. Desmodium gangeticum root extract attenuates isoproterenol-induced cardiac hypertrophic growth in rats.

    Directory of Open Access Journals (Sweden)

    Divya Hitler

    2014-10-01

    Full Text Available Context: Desmodium gangeticum (L DC (Fabaceae; DG, a medicinal plant that grows in tropical habitats, is widely used to treat various ailments including digestive and inflammatory disorders. Aims: To investigate the possible cardioprotective activity of a DG root extract against isoproterenol (ISO-induced left ventricular cardiac hypertrophy (LVH in adult Wistar rats. Methods: Daily intraperitoneal administration of ISO (10 mg/kg body weight, single injection for 7 days induced LVH in rats. The LVH rats were post-treated orally with DG (100 mg/kg body weight for a period of 30 days. Thereafter, changes in heart weight (HW and body weight (BW, HW/BW ratio, percent of hypertrophy, collagen accumulation, activities of matrix metalloproteinase (MMP -2 and -9, superoxide dismutase (SOD and catalase (CAT enzymes, and the level of an oxidative stress marker, lipid peroxide (LPO, were determined. Results: HW/BW ratio, an indicator of hypertrophic growth, was significantly reduced in DG root post-treated LVH rats as compared with that for the non-treated LVH rats. The altered levels of ventricular LPO, collagen, MMPs-2 and -9, and antioxidant enzymes in the ISO-treated animals reverted back to near normal upon DG treatment. Further, the anti-hypertrophic activity of DG was comparable to that of the standard drug losartan (10 mg/kg. Conclusions: The results of the present study suggest that the aqueous root extract of DG exhibited anti-hypertrophic activity in-vivo by inhibiting ISO-induced ROS generation and MMP activities.

  12. Growth and yield of grafted cucumbers in soil infested with root-knot nematodes

    Directory of Open Access Journals (Sweden)

    Smiljana Goreta Ban

    2014-03-01

    Full Text Available The aim of this study was to determine the effect of rootstocks on the growth and yield of cucumber (Cucumis sativus L. plants in soils infested with root-knot nematodes (Meloidogyne spp. Cucumber 'Adrian' was grown with its own roots or was grafted onto three rootstocks of Lagenariasiceraria (Molina Standi. ('Emphasis', 'S-1', and 'Gourd', two interspecific hybrid rootstocks of Cucurbita maxima Duchesne x C. moschata Duchesne ('Strong Tosa' and 'RS 841 Improved' and zucchini Cucurbita pepo L. ('Romanesco Zucchini'. The experiments were conducted in commercial greenhouse, with cucumber grafted onto three rootstocks in the first season and onto six rootstocks in the second spring-summer season. The number of leaves was considerably affected by the rootstock in both seasons, and was the highest for the plants grafted onto interspecific rootstocks (28.0 in the first and 44.9 in the second season. The plants grafted onto 'Strong Tosa' had higher total number of fruits (19.9 and yield (5.38 kg compared to other rootstocks or non-grafted plants in first season, and the same result was found for two interspecific rootstocks in the second season (6.96 kg and more than 28.9 fruits per plant. The total soluble solids, pH and electrical conductivity of the fruit were not affected by rootstock, while titratable acidity changed with the rootstock type. The grafting of cucumber plants onto different rootstocks was confirmed as an acceptable non-chemical method to compete with the limitations of soils infected with root-knot nematodes, but the effect was highly dependent on the choice of the rootstock.

  13. Effects of root radius, stress, crack growth and rate on fracture instability

    Energy Technology Data Exchange (ETDEWEB)

    McClintock, F A

    1965-01-01

    Of various criteria for fracture at the root of a notch, the energy, local stress, and displacement criteria have limited validity. More appropriate is the history of both stress and strain over a small region ahead of the crack, as required for fracture by the coalescence of holes. Expressions are given for crack initiation, growth, and subsequent instability in anti-plane strain of a nonhardening material. Instability is shown to depend primarily on those strain increments arising from crack growth at constant load rather than on those from increasing load at constant crack length. Thus final instability conditions are similar for single and double- ended cracks, round notches, and cracks cut under constant load. Round notches may give instability, restabilization and final instability. The growth and coalescence of holes in front of a crack in a linearly viscous material is studied for both tensile and anti-plant-strain cracks. The absence of residual strain eliminates instability, but the crack continually accelerates. (26 refs.)

  14. Growth and Flowering Responses of Cut Chrysanthemum Grown under Restricted Root Volume to Irrigation Frequency

    Directory of Open Access Journals (Sweden)

    Viyachai Taweesak

    2014-01-01

    Full Text Available Influences of irrigation frequency on the growth and flowering of chrysanthemum grown under restricted root volume were tested. Chrysanthemum cuttings (Chrysanthemum morifolium “Reagan White” were grown in seedling tray which contained coconut peat in volumes of 73 and 140 cm3. Plants were irrigated with drip irrigation at irrigation frequencies of 4 (266 mL, 6 (400 mL, and 8 (533 mL times/day to observe their growth and flowering performances. There was interaction between irrigation frequency and substrate volume on plant height of chrysanthemum. Plants grown in 140 cm3 substrates and irrigated 6 times/day produced the tallest plant of 109.25 cm. Plants irrigated 6 and 8 times/day had significantly higher level of phosphorus content in their leaves than those plants irrigated 4 times/day. The total leaf area, number of internodes, leaf length, and leaf width of chrysanthemums grown in 140 cm3 substrate were significantly higher than those grown in 73 cm3 substrate. The numbers of flowers were affected by both irrigation frequencies and substrate volumes. Chrysanthemums irrigated 8 times/day had an average of 19.56 flowers while those irrigated 4 times/day had an average of 16.63 flowers. Increasing irrigation frequency can improve the growth and flowering of chrysanthemums in small substrate volumes.

  15. Association of plant growth-promoting Serratia spp. with the root nodules of chickpea.

    Science.gov (United States)

    Zaheer, Ahmad; Mirza, Babur S; Mclean, Joan E; Yasmin, Sumera; Shah, Tariq Mahmud; Malik, Kauser A; Mirza, M Sajjad

    2016-01-01

    Serratia species-affiliated DNA sequences have recently been discovered in the root nodules of two chickpea cultivars; however, little is known about their potential influence on chickpea plant growth. All Serratia-affiliated sequences (1136) could be grouped into two clusters at 98% DNA similarity. The major cluster, represented by 96% of sequences, was closely associated with Serratia marcescens sequences from GenBank. In the current study, we isolated two Serratia strains, 5D and RTL100, from root nodules of a field-grown Desi cultivar from Faisalabad and Thal areas, respectively. In vitro, strain 5D showed significantly higher phosphate (P) solubilization and lactic acid production than RTL100, whereas a comparable concentration of phytohormone was produced by both isolates. The application of Serratia strain 5D as an inoculum resulted in 25.55% and 30.85% increases in the grain yield of crops grown on fertile soil in irrigated areas and nutrient-deficient soil in rainfed areas, respectively, compared to the non-inoculated control. Results of plant inoculations indicated that Serratia sp. 5D and RTL100 can serve as effective microbial inoculants, particularly in nutrient-deficient soils in rainfed areas, where chickpea is the only major crop grown during the entire year. Copyright © 2016 Institut Pasteur. All rights reserved.

  16. Root growth of Cynodon dactylon and Eleusine indica collected from motorways at different concentrations of lead.

    Science.gov (United States)

    Wong, M H; Lau, W M

    1985-04-01

    An ecological survey was conducted on the roadside vegetation at three different sites: Tai Po, a commercial and residential area (average annual daily traffic (AADT) = 23730; and Shek O and Wu Kai Sha, recreational areas (AADT = 1590 and 20, respectively). Cynodon dactylon and Eleusine indica were the two most dominant species recorded. The Tai Po site had higher Pb contents in both soil and plant, followed by Shek O, and then Wu Kai Sha. Tillers of C. dactylon and E. indica from the three sites were subjected to a series concentrations of Pb(NO3)2. By comparing their indexes of tolerance and values of 14-day EC50 (effective concentration reducing the normal root growth by 50%), roadside populations of the two grasses collected from Tai Po and Shek O, especially the former one, were more tolerant to elevated levels of Pb compared with those collected from Wu Kai Sha.

  17. Water Deficit and Abscisic Acid Cause Differential Inhibition of Shoot versus Root Growth in Soybean Seedlings 1

    Science.gov (United States)

    Creelman, Robert A.; Mason, Hugh S.; Bensen, Robert J.; Boyer, John S.; Mullet, John E.

    1990-01-01

    Roots often continue to elongate while shoot growth is inhibited in plants subjected to low-water potentials. The cause of this differential response to water deficit was investigated. We examined hypocotyl and root growth, polysome status and mRNA populations, and abscisic acid (ABA) content in etiolated soybean (Glycine max [L.] Merr. cv Williams) seedlings whose growth was inhibited by transfer to low-water potential vermiculite or exogenous ABA. Both treatments affected growth and dry weight in a similar fashion. Maximum inhibition of hypocotyl growth occurred when internal ABA levels (modulated by ABA application) reached the endogenous level found in the elongating zone of seedlings grown in water-deficient vermiculite. Conversely, root growth was affected to only a slight extent in low-water potential seedlings and by most ABA treatments (in some, growth was promoted). In every seedling section examined, transfer of seedlings into low-water potential vermiculite caused ABA levels to increase approximately 5- to 10-fold over that found in well-watered seedlings. Changes in soluble sugar content, polysome status, and polysome mRNA translation products seen in low-water potential seedlings did not occur with ABA treatments sufficient to cause significant inhibition of hypocotyl elongation. These data suggest that both variation in endogenous ABA levels, and differing sensitivity to ABA in hypocotyls and roots can modulate root/shoot growth ratios. However, exogenous ABA did not induce changes in sugar accumulation, polysome status, and mRNA populations seen after transfer into low-water potential vermiculite. Images Figure 6 Figure 7 PMID:16667248

  18. Epicoccum nigrum P16, a Sugarcane Endophyte, Produces Antifungal Compounds and Induces Root Growth

    Science.gov (United States)

    Fávaro, Léia Cecilia de Lima; Sebastianes, Fernanda Luiza de Souza; Araújo, Welington Luiz

    2012-01-01

    Background Sugarcane is one of the most important crops in Brazil, mainly because of its use in biofuel production. Recent studies have sought to determine the role of sugarcane endophytic microbial diversity in microorganism-plant interactions, and their biotechnological potential. Epicoccum nigrum is an important sugarcane endophytic fungus that has been associated with the biological control of phytopathogens, and the production of secondary metabolites. In spite of several studies carried out to define the better conditions to use E. nigrum in different crops, little is known about the establishment of an endophytic interaction, and its potential effects on plant physiology. Methodology/Principal Findings We report an approach based on inoculation followed by re-isolation, molecular monitoring, microscopic analysis, plant growth responses to fungal colonization, and antimicrobial activity tests to study the basic aspects of the E. nigrum endophytic interaction with sugarcane, and the effects of colonization on plant physiology. The results indicate that E. nigrum was capable of increasing the root system biomass and producing compounds that inhibit the in vitro growth of sugarcane pathogens Fusarium verticillioides, Colletotrichum falcatum, Ceratocystis paradoxa, and Xanthomomas albilineans. In addition, E. nigrum preferentially colonizes the sugarcane surface and, occasionally, the endophytic environment. Conclusions/Significance Our work demonstrates that E. nigrum has great potential for sugarcane crop application because it is capable of increasing the root system biomass and controlling pathogens. The study of the basic aspects of the interaction of E. nigrum with sugarcane demonstrated the facultative endophytism of E. nigrum and its preference for the phylloplane environment, which should be considered in future studies of biocontrol using this species. In addition, this work contributes to the knowledge of the interaction of this ubiquitous endophyte

  19. Root growth, soil water variation, and grain yield response of winter wheat to supplemental irrigation

    Directory of Open Access Journals (Sweden)

    Jianguo Man

    2016-04-01

    Full Text Available Water shortage threatens agricultural sustainability in the Huang-Huai-Hai Plain of China. Thus, we investigated the effect of supplemental irrigation (SI on the root growth, soil water variation, and grain yield of winter wheat in this region by measuring the moisture content in different soil layers. Prior to SI, the soil water content (SWC at given soil depths was monitored to calculate amount of irritation water that can rehydrate the soil to target SWC. The SWC before SI was monitored to depths of 20, 40, and 60 cm in treatments of W20, W40, and W60, respectively. Rainfed treatment with no irrigation as the control (W0. The mean root weight density (RWD, triphenyl tetrazolium chloride reduction activity (TTC reduction activity, soluble protein (SP concentrations as well as catalase (CAT, and superoxide dismutase (SOD activities in W40 and W60 treatments were significantly higher than those in W20. The RWD in 60–100 cm soil layers and the root activity, SP concentrations, CAT and SOD activities in 40–60 cm soil layers in W40 treatment were significantly higher than those in W20 and W60. W40 treatment is characterized by higher SWC in the upper soil layers but lower SWC in the 60–100-cm soil layers during grain filling. The soil water consumption (SWU in the 60–100 cm soil layers from anthesis after SI to maturity was the highest in W40. The grain yield, water use efficiency (WUE, and irrigation water productivity were the highest in W40, with corresponding mean values of 9169 kg ha−1, 20.8 kg ha−1 mm−1, and 35.5 kg ha−1 mm−1. The RWD, root activities, SP concentrations, CAT and SOD activities, and SWU were strongly positively correlated with grain yield and WUE. Therefore, the optimum soil layer for SI of winter wheat after jointing is 0–40 cm.

  20. Water Deficit and Abscisic Acid Cause Differential Inhibition of Shoot versus Root Growth in Soybean Seedlings : Analysis of Growth, Sugar Accumulation, and Gene Expression.

    Science.gov (United States)

    Creelman, R A; Mason, H S; Bensen, R J; Boyer, J S; Mullet, J E

    1990-01-01

    Roots often continue to elongate while shoot growth is inhibited in plants subjected to low-water potentials. The cause of this differential response to water deficit was investigated. We examined hypocotyl and root growth, polysome status and mRNA populations, and abscisic acid (ABA) content in etiolated soybean (Glycine max [L.] Merr. cv Williams) seedlings whose growth was inhibited by transfer to low-water potential vermiculite or exogenous ABA. Both treatments affected growth and dry weight in a similar fashion. Maximum inhibition of hypocotyl growth occurred when internal ABA levels (modulated by ABA application) reached the endogenous level found in the elongating zone of seedlings grown in water-deficient vermiculite. Conversely, root growth was affected to only a slight extent in low-water potential seedlings and by most ABA treatments (in some, growth was promoted). In every seedling section examined, transfer of seedlings into low-water potential vermiculite caused ABA levels to increase approximately 5- to 10-fold over that found in well-watered seedlings. Changes in soluble sugar content, polysome status, and polysome mRNA translation products seen in low-water potential seedlings did not occur with ABA treatments sufficient to cause significant inhibition of hypocotyl elongation. These data suggest that both variation in endogenous ABA levels, and differing sensitivity to ABA in hypocotyls and roots can modulate root/shoot growth ratios. However, exogenous ABA did not induce changes in sugar accumulation, polysome status, and mRNA populations seen after transfer into low-water potential vermiculite.

  1. Effects of an ultraviolet-visible rays translation film on growth of leaf or root vegetables

    International Nuclear Information System (INIS)

    Hamamoto, H.; Ueno, K.; Yamazaki, K.

    2008-01-01

    A new film that absorbs ultraviolet radiation (UV) and fluoresces red light was tested as a rain shelter for the cultivation of turnip (Brassica rapa L.), spinach (Spinacia oleracea L.), and Welsh onion (Allium fistulosum L.). The effect of this UV-visible ray translation film on various growth parameters (height, fresh and dry weight, leaf area and leaf sheath diameter) was compared with those under normal clear film, new UV-cut film, and used UV-cut film respectively. The transmissivity of UV was about 70% for the normal clear film, about 20% for the UV-visible ray translation film and used UV-cut film, and about 10% for the new UV-cut film. The transmissivity of photosynthetically active radiation (PAR) was about 90% for the normal clear film and the new UV-cut film, and about 80% for the used UV-cut film, while the mean transmissivity of PAR was about 80% for the UV-visible ray translation film, with about 60% transmissivity of blue radiation and over 90% of red radiation. The UV-visible ray translation film did not promote the growth of turnip roots but did significantly promote the growth of spinaches and Welsh onions compared with the normal clear film. The UV-visible ray translation film cover promoted the growth of spinaches and Welsh onions to a similar or greater extent compared to the new UV-cut film and also to a greater extent compared to the used UV-cut film

  2. Growth dynamics of fine roots in a coniferous fern forest site close to Forsmark in the central part of Sweden

    Energy Technology Data Exchange (ETDEWEB)

    Persson, Hans; Stadenberg, Ingela (SLU, Dept. of Ecology and Environmental Research, Uppsala (Sweden))

    2007-12-15

    The seasonal growth dynamics of live and dead roots for trees and the field layer species (g/m2, varying diameter fractions) and live/dead ratios were analysed at a fresh/moist coniferous fern forest site close to the nuclear power plant at Forsmark in the central eastern parts of Sweden. The changes in depth distribution of fine roots were observed at depth intervals of the top humus horizon down to 40 cm in the mineral soil profile. The bulk of living fine roots of trees (< 1 mm in diameter) were found in the mineral soil horizon the total profile down to 40 cm of the mineral soil, where 89, 82, 83 and 89% of the total amount in the whole profile were found. The upper 2.5 cm part of the humus layer contained 83, 81, 100 and 100% of all roots of the humus layer on the four different sampling occasions. High amounts of living fine roots were found in the upper 10 cm of the mineral soil horizon viz. 84, 76, 91 and 69% of the total mineral soil layer. Consequently, both the top soil horizons of the humus and the mineral soil layers were heavily penetrated by living fine roots. The highest proportion of living fine roots was found in the top 2.5 cm of the humus layer. Accordingly, the live/dead ratio of fine roots (< 1 mm in diameter) decreased from the top of the humus layer to the lower part of mineral soil horizon from 8.0-0.3, 0.8-0.2, 4.4-0.4 and 3.3-0.7 (g g-1) for the four sampling occasions, respectively. We concluded that the decrease in the live/ dead ratio was related to decreased vitality with depth of the fine roots in the soil profile. The highest live/dead ratio was found in the upper 2.5 cm of the humus layer for both the tree and field-layer species. This distribution pattern was most evident for tree fine roots < 1 mm in diameter. The mean fine-root biomass (live tissue < 1 mm in diameter) of tree species for the total profile varied on the four sampling occasions between 317, 113, 139 and 248 g m-2. The related fine root necromass (dead tissue

  3. Gibberellin Is Involved in Inhibition of Cucumber Growth and Nitrogen Uptake at Suboptimal Root-Zone Temperatures.

    Directory of Open Access Journals (Sweden)

    Longqiang Bai

    Full Text Available Suboptimal temperature stress often causes heavy yield losses of vegetables by suppressing plant growth during winter and early spring. Gibberellin acid (GA has been reported to be involved in plant growth and acquisition of mineral nutrients. However, no studies have evaluated the role of GA in the regulation of growth and nutrient acquisition by vegetables under conditions of suboptimal temperatures in greenhouse. Here, we investigated the roles of GA in the regulation of growth and nitrate acquisition of cucumber (Cucumis sativus L. plants under conditions of short-term suboptimal root-zone temperatures (Tr. Exposure of cucumber seedlings to a Tr of 16°C led to a significant reduction in root growth, and this inhibitory effect was reversed by exogenous application of GA. Expression patterns of several genes encoding key enzymes in GA metabolism were altered by suboptimal Tr treatment, and endogenous GA concentrations in cucumber roots were significantly reduced by exposure of cucumber plants to 16°C Tr, suggesting that inhibition of root growth by suboptimal Tr may result from disruption of endogenous GA homeostasis. To further explore the mechanism underlying the GA-dependent cucumber growth under suboptimal Tr, we studied the effect of suboptimal Tr and GA on nitrate uptake, and found that exposure of cucumber seedlings to 16°C Tr led to a significant reduction in nitrate uptake rate, and exogenous application GA can alleviate the down-regulation by up regulating the expression of genes associated with nitrate uptake. Finally, we demonstrated that N accumulation in cucumber seedlings under suboptimal Tr conditions was improved by exogenous application of GA due probably to both enhanced root growth and nitrate absorption activity. These results indicate that a reduction in endogenous GA concentrations in roots due to down-regulation of GA biosynthesis at transcriptional level may be a key event to underpin the suboptimal Tr

  4. Soybean root growth and crop yield in reponse to liming at the beginning of a no-tillage system

    Directory of Open Access Journals (Sweden)

    Edson Campanhola Bortoluzzi

    2014-02-01

    Full Text Available Analyzing the soil near crop roots may reveal limitations to growth and yield even in a no-tillage system. The purpose of the present study was to relate the chemical and physical properties of soil under a no-tillage system to soybean root growth and plant yield after five years of use of different types of limestone and forms of application. A clayey Oxisol received application of dolomitic and calcitic limestones and their 1:1 combination in two forms: surface application, maintained on the soil surface; and incorporated, applied on the surface and incorporated mechanically. Soil physical properties (resistance to mechanical penetration, soil bulk density and soil aggregation, soil chemical properties (pH, exchangeable cations, H+Al, and cation exchange capacity and plant parameters (root growth system, soybean grain yield, and oat dry matter production were evaluated five years after setting up the experiment. Incorporation of lime neutralized exchangeable Al up to a depth of 20 cm without affecting the soil physical properties. The soybean root system reached depths of 40 cm or more with incorporated limestone, increasing grain yield an average of 31 % in relation to surface application, which limited the effect of lime up to a depth of 5 cm and root growth up to 20 cm. It was concluded that incorporation of limestone at the beginning of a no-tillage system ensures a favorable environment for root growth and soybean yield, while this intervention does not show long-term effects on soil physical properties under no-tillage. This suggests that there is resilience in the physical properties evaluated.

  5. Water stress drastically reduces root growth and inulin yield in Cichorium intybus (var. sativum) independently of photosynthesis

    Science.gov (United States)

    Vandoorne, B.; Mathieu, A.-S.; Van den Ende, W.; Vergauwen, R.; Périlleux, C.; Javaux, M.; Lutts, S.

    2012-01-01

    Root chicory (Cichorium intybus var. sativum) is a cash crop cultivated for inulin production in Western Europe. This plant can be exposed to severe water stress during the last 3 months of its 6-month growing period. The aim of this study was to quantify the effect of a progressive decline in water availability on plant growth, photosynthesis, and sugar metabolism and to determine its impact on inulin production. Water stress drastically decreased fresh and dry root weight, leaf number, total leaf area, and stomatal conductance. Stressed plants, however, increased their water-use efficiency and leaf soluble sugar concentration, decreased the shoot-to-root ratio and lowered their osmotic potential. Despite a decrease in photosynthetic pigments, the photosynthesis light phase remained unaffected under water stress. Water stress increased sucrose phosphate synthase activity in the leaves but not in the roots. Water stress inhibited sucrose:sucrose 1-fructosyltransferase and fructan:fructan 1 fructosyltransferase after 19 weeks of culture and slightly increased fructan 1-exohydrolase activity. The root inulin concentration, expressed on a dry-weight basis, and the mean degree of polymerization of the inulin chain remained unaffected by water stress. Root chicory displayed resistance to water stress, but that resistance was obtained at the expense of growth, which in turn led to a significant decrease in inulin production. PMID:22577185

  6. Genetic Variation in Deep Root Growth of North-European Winter Wheat

    DEFF Research Database (Denmark)

    Ytting, Nanna Karkov

    no correlation between root length density in the subsoil and shoot N content was found at higher subsoil N levels (> 12.5 mg N kg-1 soil). Shoot size and especially average tiller size was highly correlated to subsoil root density (R2 = 0.26 – 0.37, p ≤ 0.001). Low N levels (... and environments, as the interaction between genotypes and environment is substantial for most root traits. Root quantification with the line intersect method can be optimized by choosing the right strategy when scoring the root traits. For example, by adapting counting grids to match specific root densities, data...

  7. Effectiveness of rabbit manure biofertilizer in barley crop yield.

    Science.gov (United States)

    Islas-Valdez, Samira; Lucho-Constantino, Carlos A; Beltrán-Hernández, Rosa I; Gómez-Mercado, René; Vázquez-Rodríguez, Gabriela A; Herrera, Juan M; Jiménez-González, Angélica

    2017-11-01

    The quality of biofertilizers is usually assessed only in terms of the amount of nutrients that they supply to the crops and their lack of viable pathogens and phytotoxicity. The goal of this study was to determine the effectiveness of a liquid biofertilizer obtained from rabbit manure in terms of presence of pathogens, phytotoxicity, and its effect on the grain yield and other agronomic traits of barley (Hordeum vulgare L.). Environmental effects of the biofertilizer were also evaluated by following its influence on selected soil parameters. We applied the biofertilizer at five combinations of doses and timings each and in two application modes (foliar or direct soil application) within a randomized complete block design with three replicates and using a chemical fertilizer as control. The agronomic traits evaluated were plant height, root length, dry weight, and number of leaves and stems at three growth stages: tillering, jointing, and flowering. The effectiveness of the biofertilizer was significantly modified by the mode of application, the growth stage of the crop, and the dose of biofertilizer applied. The results showed that the foliar application of the biofertilizer at the tillering stage produced the highest increase in grain yield (59.7 %, p biofertilizer caused significant changes in soil, particularly concerning pH, EC, Ca, Zn, Mg, and Mn. It is our view that the production and use of biofertilizers are a reliable alternative to deal with a solid waste problem while food security is increased.

  8. The effect of gamma irradiation of seeds on germination - growth - mineral content and yield of two barley varieties grown under saline conditions

    International Nuclear Information System (INIS)

    Charbaji, T.; Khalifa, Kh.; Al-Ain, F.

    2003-01-01

    Seeds of two barley varieties [Arabi Abiad (AA) and Pakistani PK 30163 (PK)] were irradiated with 0 and 15 Gy doses of gamma irradiation. Then, they were sown on salty soil (16.8-18 dS/m) and irrigated with salty water (7-8 dS/m). Gamma irradiation significantly increased the % of seedling emergence of PK only. At the heading stage, gamma irradiation decreased the % of total N of PK and increased shoot dry weight, Mg++ and P content and the % of total N of AA. K+ content of PK was lower than that of AA. At harvest stage, gamma irradiation increased total and grain yields and harvest index of PK; however, straw yield and 1,000 grain weight of AA were higher than those of PK [it

  9. Growth and rooting of Solanecio mannii: comparison of seedlings and air layers on a 24-month trial in East Africa

    Directory of Open Access Journals (Sweden)

    Quentin Meunier

    2016-06-01

    Full Text Available Vegetative propagation of trees remains understudied in Africa. Such methods however provide potential for producing trees and shrubs with high social and economic value. Air layering is one of these techniques and can be used in Uganda for the domestication of underutilized multipurpose trees. The main purposes of this trial were to compare the growth rates of 30 Solanecio mannii plants grown from seed and 30 plants grown from air layering, and to observe the main morphological differences that affected the growth and root system of those 60 plants. This 24-month preliminary and prospective trial was conducted to compare the growth characteristics of seedlings and air layers, by measuring their height, diameter, precocity to flower and fruit, and their root system quality. Air layers were stronger, quickly reaching maturity but showing weakness in their root systems, while seedlings seemingly smaller and slower showed more stability with a well-structured root system. Air layering could be used to reproduce desirable genotypes. Due to their unbalanced root system observed in the field after two years, the air layers, once transplanted into a nursery, should be propagated by cuttings or grafting only.

  10. Ethylene-Induced Inhibition of Root Growth Requires Abscisic Acid Function in Rice (Oryza sativa L.) Seedlings

    Science.gov (United States)

    He, Si-Jie; Lu, Xiang; Zhang, Wan-Ke; Lu, Tie-Gang; Chen, Shou-Yi; Zhang, Jin-Song

    2014-01-01

    Ethylene and abscisic acid (ABA) have a complicated interplay in many developmental processes. Their interaction in rice is largely unclear. Here, we characterized a rice ethylene-response mutant mhz4, which exhibited reduced ethylene-response in roots but enhanced ethylene-response in coleoptiles of etiolated seedlings. MHZ4 was identified through map-based cloning and encoded a chloroplast-localized membrane protein homologous to Arabidopsis thaliana (Arabidopsis) ABA4, which is responsible for a branch of ABA biosynthesis. MHZ4 mutation reduced ABA level, but promoted ethylene production. Ethylene induced MHZ4 expression and promoted ABA accumulation in roots. MHZ4 overexpression resulted in enhanced and reduced ethylene response in roots and coleoptiles, respectively. In root, MHZ4-dependent ABA pathway acts at or downstream of ethylene receptors and positively regulates root ethylene response. This ethylene-ABA interaction mode is different from that reported in Arabidopsis, where ethylene-mediated root inhibition is independent of ABA function. In coleoptile, MHZ4-dependent ABA pathway acts at or upstream of OsEIN2 to negatively regulate coleoptile ethylene response, possibly by affecting OsEIN2 expression. At mature stage, mhz4 mutation affects branching and adventitious root formation on stem nodes of higher positions, as well as yield-related traits. Together, our findings reveal a novel mode of interplay between ethylene and ABA in control of rice growth and development. PMID:25330236

  11. Congruence between PM H+-ATPase and NADPH oxidase during root growth: a necessary probability.

    Science.gov (United States)

    Majumdar, Arkajo; Kar, Rup Kumar

    2018-07-01

    Plasma membrane (PM) H + -ATPase and NADPH oxidase (NOX) are two key enzymes responsible for cell wall relaxation during elongation growth through apoplastic acidification and production of ˙OH radical via O 2 ˙ - , respectively. Our experiments revealed a putative feed-forward loop between these enzymes in growing roots of Vigna radiata (L.) Wilczek seedlings. Thus, NOX activity was found to be dependent on proton gradient generated across PM by H + -ATPase as evident from pharmacological experiments using carbonyl cyanide m-chlorophenylhydrazone (CCCP; protonophore) and sodium ortho-vanadate (PM H + -ATPase inhibitor). Conversely, H + -ATPase activity retarded in response to different ROS scavengers [CuCl 2 , N, N' -dimethylthiourea (DMTU) and catalase] and NOX inhibitors [ZnCl 2 and diphenyleneiodonium (DPI)], while H 2 O 2 promoted PM H + -ATPase activity at lower concentrations. Repressing effects of Ca +2 antagonists (La +3 and EGTA) on the activity of both the enzymes indicate its possible mediation. Since, unlike animal NOX, the plant versions do not possess proton channel activity, harmonized functioning of PM H + -ATPase and NOX appears to be justified. Plasma membrane NADPH oxidase and H + -ATPase are functionally synchronized and they work cooperatively to maintain the membrane electrical balance while mediating plant cell growth through wall relaxation.

  12. Total Saponin from Root of Actinidia valvata Dunn Inhibits Hepatoma 22 Growth and Metastasis In Vivo by Suppression Angiogenesis

    Directory of Open Access Journals (Sweden)

    Guo-Yin Zheng

    2012-01-01

    Full Text Available The root of Actinidia valvata dunn has been widely used in the treatment of hepatocellular carcinoma (HCC, proved to be beneficial for a longer and better life in China. In present work, total saponin from root of Actinidia valvata Dunn (TSAVD was extracted, and its effects on hepatoma H22-based mouse in vivo were observed. Primarily transplanted hypodermal hepatoma H22-based mice were used to observe TSAVD effect on tumor growth. The microvessel density (MVD, vascular endothelial growth factor (VEGF, basic fibroblast growth factor (bFGF are characterized factors of angiogenesis, which were compared between TSAVD-treated and control groups. Antimetastasis effect on experimental pulmonary metastasis hepatoma mice was also observed in the study. The results demonstrated that TSAVD can effectively inhibit HCC growth and metastasis in vivo, inhibit the formation of microvessel, downregulate expressions of VEGF and bFGF, and retrain angiogenesis of hepatoma 22 which could be one of the reasons.

  13. Root-zone temperatures affect phenology of bud break, flower cluster development, shoot extension growth and gas exchange of 'Braeburn' (Malus domestica) apple trees.

    Science.gov (United States)

    Greer, Dennis H; Wünsche, Jens N; Norling, Cara L; Wiggins, Harry N

    2006-01-01

    We investigated the effects of root-zone temperature on bud break, flowering, shoot growth and gas exchange of potted mature apple (Malus domestica (Borkh.)) trees with undisturbed roots. Soil respiration was also determined. Potted 'Braeburn' apple trees on M.9 rootstock were grown for 70 days in a constant day/night temperature regime (25/18 degrees C) and one of three constant root-zone temperatures (7, 15 and 25 degrees C). Both the proportion and timing of bud break were significantly enhanced as root-zone temperature increased. Rate of floral cluster opening was also markedly increased with increasing root-zone temperature. Shoot length increased but shoot girth growth declined as root-zone temperatures increased. Soil respiration and leaf photosynthesis generally increased as root-zone temperatures increased. Results indicate that apple trees growing in regions where root zone temperatures are or = 15 degrees C. The effect of root-zone temperature on shoot performance may be mediated through the mobilization of root reserves, although the role of phytohormones cannot be discounted. Variation in leaf photosynthesis across the temperature treatments was inadequately explained by stomatal conductance. Given that root growth increases with increasing temperature, changes in sink activity induced by the root-zone temperature treatments provide a possible explanation for the non-stomatal effect on photosynthesis. Irrespective of underlying mechanisms, root-zone temperatures influence bud break and flowering in apple trees.

  14. The bean rhizosphere Pseudomonas aeruginosa strain RZ9 strongly reduces Fusarium culmorum growth and infectiveness of plant roots

    Energy Technology Data Exchange (ETDEWEB)

    Haddoudi, I.; Sendi, Y.; Batnini, M.; Romdhane, S.B.; Mhadhbi, H.; Mrabet, M.

    2017-07-01

    A faba bean rhizospheric Pseudomonas aeruginosa isolate RZ9 was used for studying its antifungal activity and protecting effects of faba bean and common bean against the root pathogen Fusarium culmorum strain MZB47. The dual culture tests showed that RZ9 inhibits MZB47 in vitro growth by 56%. When mixing RZ9 cell suspension with MZB47 macroconidia at equal proportion, the macroconidia viability was reduced with 70%. Pathogenicity tests conducted in sterile conditions showed that MZB47 caused an intense root rotting in faba bean ‘Aquadulce’ plantlets and a slight level in common bean ‘Coco blanc’. This was associated to significant decreases in plant growth only in ‘Aquadulce’, reducing shoot dry weight (DW) by 82% and root DW by 70%. In soil samples, MZB47 caused severe root rotting and induced significant decreases in shoot DW (up to 51%) and root DW (up to 60%) for both beans. It was associated to a decrease in nodule number by 73% and 52% for faba bean and common bean, respectively. Biocontrol assays revealed that the inoculation of RZ9 to MZB47-treated plantlets enhanced shoot DWs (25% and 110%) and root DWs (29% and 67%), in faba bean and common bean, respectively. Moreover, root rotting levels decreased and nodule number increased in treated compared to untreated plantlets. Collected data highlighted the disease severity of F. culmorum and demonstrated the potential of using RZ9 in controlling Fusaria root diseases in beans. Thereby, the current study represents the first report on the biocontrol effectiveness of P. aeruginosa against F. culmorum in beans.

  15. The bean rhizosphere Pseudomonas aeruginosa strain RZ9 strongly reduces Fusarium culmorum growth and infectiveness of plant roots

    Directory of Open Access Journals (Sweden)

    Imen Haddoudi

    2017-07-01

    Full Text Available A faba bean rhizospheric Pseudomonas aeruginosa isolate RZ9 was used for studying its antifungal activity and protecting effects of faba bean and common bean against the root pathogen Fusarium culmorum strain MZB47. The dual culture tests showed that RZ9 inhibits MZB47 in vitro growth by 56%. When mixing RZ9 cell suspension with MZB47 macroconidia at equal proportion, the macroconidia viability was reduced with 70%. Pathogenicity tests conducted in sterile conditions showed that MZB47 caused an intense root rotting in faba bean ‘Aquadulce’ plantlets and a slight level in common bean ‘Coco blanc’. This was associated to significant decreases in plant growth only in ‘Aquadulce’, reducing shoot dry weight (DW by 82% and root DW by 70%. In soil samples, MZB47 caused severe root rotting and induced significant decreases in shoot DW (up to 51% and root DW (up to 60% for both beans. It was associated to a decrease in nodule number by 73% and 52% for faba bean and common bean, respectively. Biocontrol assays revealed that the inoculation of RZ9 to MZB47-treated plantlets enhanced shoot DWs (25% and 110% and root DWs (29% and 67%, in faba bean and common bean, respectively. Moreover, root rotting levels decreased and nodule number increased in treated compared to untreated plantlets. Collected data highlighted the disease severity of F. culmorum and demonstrated the potential of using RZ9 in controlling Fusaria root diseases in beans. Thereby, the current study represents the first report on the biocontrol effectiveness of P. aeruginosa against F. culmorum in beans.

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

    International Nuclear Information System (INIS)

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

    1984-01-01

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

  17. Shoot position affects root initiation and growth of dormant unrooted cuttings of Populus

    Science.gov (United States)

    R.S., Jr. Zalesny; R.B. Hall; E.O. Bauer; D.E. Riemenschneider

    2003-01-01

    Rooting of dormant unrooted cuttings is crucial to the commercial deployment of intensively cultured poplar (Populus spp.) plantations because it is the first biological prerequisite to stand establishment. Rooting can be genetically controlled and subject to selection. Thus, our objective was to test for differences in rooting ability among cuttings...

  18. Different parts, different stories: climate sensitivity of growth is stronger in root collars vs. stems in tundra shrubs.

    Science.gov (United States)

    Ropars, Pascale; Angers-Blondin, Sandra; Gagnon, Marianne; Myers-Smith, Isla H; Lévesque, Esther; Boudreau, Stéphane

    2017-08-01

    Shrub densification has been widely reported across the circumpolar arctic and subarctic biomes in recent years. Long-term analyses based on dendrochronological techniques applied to shrubs have linked this phenomenon to climate change. However, the multi-stemmed structure of shrubs makes them difficult to sample and therefore leads to non-uniform sampling protocols among shrub ecologists, who will favor either root collars or stems to conduct dendrochronological analyses. Through a comparative study of the use of root collars and stems of Betula glandulosa, a common North American shrub species, we evaluated the relative sensitivity of each plant part to climate variables and assessed whether this sensitivity is consistent across three different types of environments in northwestern Québec, Canada (terrace, hilltop and snowbed). We found that root collars had greater sensitivity to climate than stems and that these differences were maintained across the three types of environments. Growth at the root collar was best explained by spring precipitation and summer temperature, whereas stem growth showed weak and inconsistent responses to climate variables. Moreover, sensitivity to climate was not consistent among plant parts, as individuals having climate-sensitive root collars did not tend to have climate-sensitive stems. These differences in sensitivity of shrub parts to climate highlight the complexity of resource allocation in multi-stemmed plants. Whereas stem initiation and growth are driven by microenvironmental variables such as light availability and competition, root collars integrate the growth of all plant parts instead, rendering them less affected by mechanisms such as competition and more responsive to signals of global change. Although further investigations are required to determine the degree to which these findings are generalizable across the tundra biome, our results indicate that consistency and caution in the choice of plant parts are a key

  19. Root colonization and growth promotion of sunflower (Helianthus annuus L.) by phosphate solubilizing Enterobacter sp. Fs-11

    NARCIS (Netherlands)

    Shahid, Muhammad; Hameed, Sohail; Imran, Asma; Ali, Saira; van Elsas, Jan Dirk

    An Enterobacter sp. Fs-11 was isolated from sunflower rhizosphere, identified on the basis of 16S rRNA gene sequence analysis (GeneBank accession no. GQ179978) and studied for its root colonization and growth promotion ability in sunflower. Morphologically, it was rod shaped Gram-negative, motile

  20. Dark septate root endophytic fungi increase growth of Scots pine seedlings under elevated CO2 through enhanced nitrogen use efficiency.

    NARCIS (Netherlands)

    Alberton, O.; Kuyper, T.W.; Summerbell, R.C.

    2010-01-01

    Although increasing concentrations of atmospheric CO2 are predicted to have substantial impacts on plant growth and functioning of ecosystems, there is insufficient understanding of the responses of belowground processes to such increases. We investigated the effects of different dark septate root

  1. EFFECTS OF ELEVATED CO-2 AND N FERTILIZATION ON FINE ROOT DYNAMICS AND FUNGAL GROWTH IN SEEDLING PINUS PONDEROSA

    Science.gov (United States)

    The effects of elevated CO-2 and N fertilization on fine root growth of Pinus ponderosa Dougl. ex P. Laws. C. Laws., grown in native soil in open-top field-exposure chambers at Placerville, CA, were monitored for a 2-year period using minirhizotrons. The experimental design was a...

  2. N-P Fertilization Inhibits Growth of Root Hemiparasite Pedicularis kansuensis in Natural Grassland

    Science.gov (United States)

    Liu, Yanyan; Taxipulati, Teyibai; Gong, Yanming; Sui, Xiaolin; Wang, Xuezhao; Parent, Serge-Étienne; Hu, Yukun; Guan, Kaiyun; Li, Airong

    2017-01-01

    Fertilization has been shown to affect interactions between root hemiparasitic plants and their host plants, alleviating damage to the hosts by parasitism. However, as a majority of studies were conducted in pot cultivation, the influence of fertilizer application on root hemiparasites and the surrounding plant community in field conditions as well as relevant mechanisms remain unclear. We manipulated soil nutrient resources in a semi-arid subalpine grassland in the Tianshan Mountains, northwestern China, to explore the links between fertilization and plant community composition, productivity, survival, and growth of a weedy root hemiparasite (Pedicularis kansuensis). Nitrogen (at a low rate, LN, 30 kg N ha-1 year-1 as urea; or at a high rate, HN, 90 kg N ha-1 year-1 as urea) and phosphorus [100 kg ha-1 year-1 as Ca(H2PO4)2⋅H2O] were added during two growing seasons. Patterns of foliar nutrient balances were described with isometric log ratios for the different plant functional groups receiving these fertilization regimes. Fertilization with LN, HN, and P reduced above-ground biomass of P. kansuensis, with above-ground biomass in the fertilization treatments, respectively, 12, 1, and 39% of the value found in the unfertilized control. Up to three times more above-ground biomass was produced in graminoids receiving fertilizers, whereas forb above-ground biomass was virtually unchanged by the fertilization regimes and forb species richness was reduced by 52% in the HN treatment. Fertilization altered foliar nutrient balances, and distinct patterns emerged for each plant functional group. Foliar [C | P,N] balance in the plant community was negatively correlated with above-ground biomass (P = 0.03). The inhibited competitiveness of P. kansuensis, which showed a much higher [C | P,N] balance, could be attributed to reduced C assimilation rather than mineral nutrient acquisition, as shown by significant increase in foliar N and P concentrations but little increase in C

  3. Root growth and N dynamics in response to multi-year experimental warming, summer drought and elevated CO2 in a mixed heathland-grass ecosystem

    DEFF Research Database (Denmark)

    Arndal, M. F.; Schmidt, I. K.; Kongstad, J.

    2013-01-01

    growth would be matched by an increase in root nutrient uptake of NH4+-N and NO3- -N. Root growth was significantly increased by elevated CO2. The roots, however, did not fully compensate for the higher growth with a similar increase in nitrogen uptake per unit of root mass. Hence the nitrogen...... concentration in roots was decreased in elevated CO2, whereas the biomass N pool was unchanged or even increased. The higher net root production in elevated CO2 might be a strategy for the plants to cope with increased nutrient demand leading to a long-term increase in N uptake on a whole-plant basis. Drought...... reduced grass root biomass and N uptake, especially when combined with warming, but CO2 was the most pronounced main factor effect. Several significant interactions of the treatments were found, which indicates that the responses were nonadditive and that changes to multiple environmental changes cannot...

  4. Association mapping of partitioning loci in barley

    Directory of Open Access Journals (Sweden)

    Mackay Ian J

    2008-02-01

    Full Text Available Abstract Background Association mapping, initially developed in human disease genetics, is now being applied to plant species. The model species Arabidopsis provided some of the first examples of association mapping in plants, identifying previously cloned flowering time genes, despite high population sub-structure. More recently, association genetics has been applied to barley, where breeding activity has resulted in a high degree of population sub-structure. A major genotypic division within barley is that between winter- and spring-sown varieties, which differ in their requirement for vernalization to promote subsequent flowering. To date, all attempts to validate association genetics in barley by identifying major flowering time loci that control vernalization requirement (VRN-H1 and VRN-H2 have failed. Here, we validate the use of association genetics in barley by identifying VRN-H1 and VRN-H2, despite their prominent role in determining population sub-structure. Results By taking barley as a typical inbreeding crop, and seasonal growth habit as a major partitioning phenotype, we develop an association mapping approach which successfully identifies VRN-H1 and VRN-H2, the underlying loci largely responsible for this agronomic division. We find a combination of Structured Association followed by Genomic Control to correct for population structure and inflation of the test statistic, resolved significant associations only with VRN-H1 and the VRN-H2 candidate genes, as well as two genes closely linked to VRN-H1 (HvCSFs1 and HvPHYC. Conclusion We show that, after employing appropriate statistical methods to correct for population sub-structure, the genome-wide partitioning effect of allelic status at VRN-H1 and VRN-H2 does not result in the high levels of spurious association expected to occur in highly structured samples. Furthermore, we demonstrate that both VRN-H1 and the candidate VRN-H2 genes can be identified using association mapping

  5. Relationships between Nutrient Heterogeneity, Root Growth, and Hormones: Evidence for Interspecific Variation.

    Science.gov (United States)

    Dong, Jia; Jones, Robert H; Mou, Pu

    2018-02-28

    (1) Background: Plant roots respond to nutrients through root architecture that is regulated by hormones. Strong inter-specific variation in root architecture has been well documented, but physiological mechanisms that may control the variation have not. (2) Methods: We examined correlations between root architecture and hormones to seek clues on mechanisms behind root foraging behavior. In the green house at Beijing Normal University, hydroponic culture experiments were used to examine the root responses of four species- Callistephus chinensis , Solidago canadensis , Ailanthus altissima , Oryza sativa- to two nitrogen types (NO₃ - or NH₄⁺), three nitrogen concentrations (low, medium, and high concentrations of 0.2, 1, and 18 mM, respectively) and two ways of nitrogen application (stable vs. variable). The plants were harvested after 36 days to measure root mass, 1st order root length, seminal root length for O. sativa , density of the 1st order laterals, seminal root number for O. sativa , the inter-node length of the 1st order laterals, and root hormone contents of indole-3-acetic acid, abscisic acid, and cytokinins (zeatin + zeatinriboside). (3) Results: Species differed significantly in their root architecture responses to nitrogen treatments. They also differed significantly in hormone responses to the nitrogen treatments. Additionally, the correlations between root architecture and hormone responses were quite variable across the species. Each hormone had highly species-specific relationships with root responses. (4) Conclusions: Our finding implies that a particular root foraging behavior is probably not controlled by the same biochemical pathway in all species.

  6. Relationships between Nutrient Heterogeneity, Root Growth, and Hormones: Evidence for Interspecific Variation

    Directory of Open Access Journals (Sweden)

    Jia Dong

    2018-02-01

    Full Text Available (1 Background: Plant roots respond to nutrients through root architecture that is regulated by hormones. Strong inter-specific variation in root architecture has been well documented, but physiological mechanisms that may control the variation have not. (2 Methods: We examined correlations between root architecture and hormones to seek clues on mechanisms behind root foraging behavior. In the green house at Beijing Normal University, hydroponic culture experiments were used to examine the root responses of four species—Callistephus chinensis, Solidago canadensis, Ailanthus altissima, Oryza sativa—to two nitrogen types (NO3− or NH4+, three nitrogen concentrations (low, medium, and high concentrations of 0.2, 1, and 18 mM, respectively and two ways of nitrogen application (stable vs. variable. The plants were harvested after 36 days to measure root mass, 1st order root length, seminal root length for O. sativa, density of the 1st order laterals, seminal root number for O. sativa, the inter-node length of the 1st order laterals, and root hormone contents of indole-3-acetic acid, abscisic acid, and cytokinins (zeatin + zeatinriboside. (3 Results: Species differed significantly in their root architecture responses to nitrogen treatments. They also differed significantly in hormone responses to the nitrogen treatments. Additionally, the correlations between root architecture and hormone responses were quite variable across the species. Each hormone had highly species-specific relationships with root responses. (4 Conclusions: Our finding implies that a particular root foraging behavior is probably not controlled by the same biochemical pathway in all species.

  7. PLATINUM SENSITIVE 2 LIKE impacts growth, root morphology, seed set, and stress responses.

    Directory of Open Access Journals (Sweden)

    Amr R A Kataya

    Full Text Available Eukaryotic protein phosphatase 4 (PP4 is a PP2A-type protein phosphatase that is part of a conserved complex with regulatory factors PSY2 and PP4R2. Various lines of Arabidopsis thaliana with mutated PP4 subunit genes were constructed to study the so far completely unknown functions of PP4 in plants. Mutants with knocked out putative functional homolog of the PSY2 LIKE (PSY2L gene were dwarf and bushy, while plants with knocked out PP4R2 LIKE (PP4R2L looked very similar to WT. The psy2l seedlings had short roots with disorganized morphology and impaired meristem. Seedling growth was sensitive to the genotoxin cisplatin. Global transcript analysis (RNA-seq of seedlings and rosette leaves revealed several groups of genes, shared between both types of tissues, strongly influenced by knocked out PSY2L. Receptor kinases, CRINKLY3 and WAG1, important for growth and development, were down-regulated 3-7 times. EUKARYOTIC ELONGATION FACTOR5A1 was down-regulated 4-6 fold. Analysis of hormone sensitive genes indicated that abscisic acid levels were high, while auxin, cytokinin and gibberellic acid levels were low in psy2l. Expression of specific transcription factors involved in regulation of anthocyanin synthesis were strongly elevated, e.g. the master regulator PAP1, and intriguingly TT8, which is otherwise mainly expressed in seeds. The psy2l mutants accumulated anthocyanins under conditions where WT did not, pointing to PSY2L as a possible upstream negative regulator of PAP1 and TT8. Expression of the sugar-phosphate transporter GPT2, important for cellular sugar and phosphate homeostasis, was enhanced 7-8 times. Several DNA damage response genes, including the cell cycle inhibitor gene WEE1, were up-regulated in psy2l. The activation of DNA repair signaling genes, in combination with phenotypic traits showing aberrant root meristem and sensitivity to the genotoxic cisplatin, substantiate the involvement of Arabidopsis PSY2L in maintenance of genome

  8. Element distribution of the barley plant grown in an agar slice suspended culture

    International Nuclear Information System (INIS)

    Makino-Nakanishi, Tomoko; Matsumoto, Satoshi

    1991-01-01

    An agar slice suspended culture was devised for the further study of the barley root. The roots were placed into an agar covered with a nylon cloth and suspended in a water culture vessel. Barley roots grown in the agar developed hardly any root hair. The element contents of the root grown in the agar culture and that in the water culture were measured by neutron activation analysis. The concentrations of K, Mg and Cl in the root grown in the agar were about half of these grown in the water. Na and Mn concentrations were the same and Ca concentration was slightly higher when grown in the agar. The agar system is expected to provide more information to study the root hair. (author)

  9. QTL meta-analysis of root traits in Brassica napus under contrasting phosphorus supply in two growth systems.

    Science.gov (United States)

    Zhang, Ying; Thomas, Catherine L; Xiang, Jinxia; Long, Yan; Wang, Xiaohua; Zou, Jun; Luo, Ziliang; Ding, Guangda; Cai, Hongmei; Graham, Neil S; Hammond, John P; King, Graham J; White, Philip J; Xu, Fangsen; Broadley, Martin R; Shi, Lei; Meng, Jinling

    2016-09-14

    A high-density SNP-based genetic linkage map was constructed and integrated with a previous map in the Tapidor x Ningyou7 (TNDH) Brassica napus population, giving a new map with a total of 2041 molecular markers and an average marker density which increased from 0.39 to 0.97 (0.82 SNP bin) per cM. Root and shoot traits were screened under low and 'normal' phosphate (Pi) supply using a 'pouch and wick' system, and had been screened previously in an agar based system. The P-efficient parent Ningyou7 had a shorter primary root length (PRL), greater lateral root density (LRD) and a greater shoot biomass than the P-inefficient parent Tapidor under both treatments and growth systems. Quantitative trait loci (QTL) analysis identified a total of 131 QTL, and QTL meta-analysis found four integrated QTL across the growth systems. Integration reduced the confidence interval by ~41%. QTL for root and shoot biomass were co-located on chromosome A3 and for lateral root emergence were co-located on chromosomes A4/C4 and C8/C9. There was a major QTL for LRD on chromosome C9 explaining ~18% of the phenotypic variation. QTL underlying an increased LRD may be a useful breeding target for P uptake efficiency in Brassica.

  10. 11C-methionine translocation in barley

    International Nuclear Information System (INIS)

    Nakanishi, Hiromi; Bughio, Naimatullah; Shigeta Ishioka, Noriko

    2000-01-01

    11 C-methionine was supplied to barley plants through a single leaf or via the roots and real time 11 C movement was monitored using a PETIS (positron emitting tracer imaging system). In Fe-deficient plants, 11 C-methionine was translocated from the tip of the absorbing leaf to the discrimination center' at the basal part of the shoot and then retranslocated to all the chlorotic leaves, while a negligible amount was retranslocated to the roots. In Fe-sufficient plants, methionine was translocated from the absorbing leaf to the discrimination center and then only to the newest leaf on the main shoot. A negligible amount was also retranslocated to the roots. Although, in Fe-sufficient plants, methionine translocation was observed from absorbing roots to shoots, in Fe-deficient plants, only a little amount was translocated from roots to shoots. In conclusion, methionine from the upper portion of a plant is not used as a precursor of mugineic acid under Fe-deficiency conditions. (author)

  11. Abscisic Acid Regulation of Root Hydraulic Conductivity and Aquaporin Gene Expression Is Crucial to the Plant Shoot Growth Enhancement Caused by Rhizosphere Humic Acids.

    Science.gov (United States)

    Olaetxea, Maite; Mora, Verónica; Bacaicoa, Eva; Garnica, María; Fuentes, Marta; Casanova, Esther; Zamarreño, Angel M; Iriarte, Juan C; Etayo, David; Ederra, Iñigo; Gonzalo, Ramón; Baigorri, Roberto; García-Mina, Jose M

    2015-12-01

    The physiological and metabolic mechanisms behind the humic acid-mediated plant growth enhancement are discussed in detail. Experiments using cucumber (Cucumis sativus) plants show that the shoot growth enhancement caused by a structurally well-characterized humic acid with sedimentary origin is functionally associated with significant increases in abscisic acid (ABA) root concentration and root hydraulic conductivity. Complementary experiments involving a blocking agent of cell wall pores and water root transport (polyethylenglycol) show that increases in root hydraulic conductivity are essential in the shoot growth-promoting action of the model humic acid. Further experiments involving an inhibitor of ABA biosynthesis in root and shoot (fluridone) show that the humic acid-mediated enhancement of both root hydraulic conductivity and shoot growth depended on ABA signaling pathways. These experiments also show that a significant increase in the gene expression of the main root plasma membrane aquaporins is associated with the increase of root hydraulic conductivity caused by the model humic acid. Finally, experimental data suggest that all of these actions of model humic acid on root functionality, which are linked to its beneficial action on plant shoot growth, are likely related to the conformational structure of humic acid in solution and its interaction with the cell wall at the root surface. © 2015 American Society of Plant Biologists. All Rights Reserved.

  12. Morphological plasticity of root growth under mild water stress increases water use efficiency without reducing yield in maize

    Science.gov (United States)

    Cai, Qian; Zhang, Yulong; Sun, Zhanxiang; Zheng, Jiaming; Bai, Wei; Zhang, Yue; Liu, Yang; Feng, Liangshan; Feng, Chen; Zhang, Zhe; Yang, Ning; Evers, Jochem B.; Zhang, Lizhen

    2017-08-01

    A large yield gap exists in rain-fed maize (Zea mays L.) production in semi-arid regions, mainly caused by frequent droughts halfway through the crop-growing period due to uneven distribution of rainfall. It is questionable whether irrigation systems are economically required in such a region since the total amount of rainfall does generally meet crop requirements. This study aimed to quantitatively determine the effects of water stress from jointing to grain filling on root and shoot growth and the consequences for maize grain yield, above- and below-ground dry matter, water uptake (WU) and water use efficiency (WUE). Pot experiments were conducted in 2014 and 2015 with a mobile rain shelter to achieve conditions of no, mild or severe water stress. Maize yield was not affected by mild water stress over 2 years, while severe stress reduced yield by 56 %. Both water stress levels decreased root biomass slightly but shoot biomass substantially. Mild water stress decreased root length but increased root diameter, resulting in no effect on root surface area. Due to the morphological plasticity in root growth and the increase in root / shoot ratio, WU under water stress was decreased, and overall WUE for both above-ground dry matter and grain yield increased. Our results demonstrate that an irrigation system might be not economically and ecologically necessary because the frequently occurring mild water stress did not reduce crop yield much. The study helps us to understand crop responses to water stress during a critical water-sensitive period (middle of the crop-growing season) and to mitigate drought risk in dry-land agriculture.

  13. The MicroRNA390/TAS3 Pathway Mediates Symbiotic Nodulation and Lateral Root Growth1[OPEN

    Science.gov (United States)

    Bustos-Sanmamed, Pilar; Mysore, Kirankumar S.

    2017-01-01

    Legume roots form two types of postembryonic organs, lateral roots and symbiotic nodules. Nodule formation is the result of the interaction of legumes with rhizobia and requires the mitotic activation and differentiation of root cells as well as an independent, but coordinated, program that allows infection by rhizobia. MicroRNA390 (miR390) is an evolutionarily conserved microRNA that targets the Trans-Acting Short Interference RNA3 (TAS3) transcript. Cleavage of TAS3 by ARGONAUTE7 results in the production of trans-acting small interference RNAs, which target mRNAs encoding AUXIN RESPONSE FACTOR2 (ARF2), ARF3, and ARF4. Here, we show that activation of the miR390/TAS3 regulatory module by overexpression of miR390 in Medicago truncatula promotes lateral root growth but prevents nodule organogenesis, rhizobial infection, and the induction of two key nodulation genes, Nodulation Signaling Pathway1 (NSP1) and NSP2. Accordingly, inactivation of the miR390/TAS3 module, either by expression of a miR390 target mimicry construct or mutations in ARGONAUTE7, enhances nodulation and rhizobial infection, alters the spatial distribution of the nodules, and increases the percentage of nodules with multiple meristems. Our results revealed a key role of the miR390/TAS3 pathway in legumes as a modulator of lateral root organs, playing opposite roles in lateral root and nodule development. PMID:28663332

  14. Genomic Prediction in Barley

    DEFF Research Database (Denmark)

    Edriss, Vahid; Cericola, Fabio; Jensen, Jens D

    2015-01-01

    to next generation. The main goal of this study was to see the potential of using genomic prediction in a commercial Barley breeding program. The data used in this study was from Nordic Seed company which is located in Denmark. Around 350 advanced lines were genotyped with 9K Barely chip from Illumina....... Traits used in this study were grain yield, plant height and heading date. Heading date is number days it takes after 1st June for plant to head. Heritabilities were 0.33, 0.44 and 0.48 for yield, height and heading, respectively for the average of nine plots. The GBLUP model was used for genomic...

  15. Advanced nutrient root feeding system for conveyer-type cylindrical plant growth facilities developed for microgravity

    Science.gov (United States)

    Berkovich, Yuliy A.; Smolyanina, Svetlana O.; Krivobok, Anna; Krivobok, Nikolay

    A new brand of cylindrical conveyer-type space plant growth facilities (PGF) has been created to improve of cosmonauts’ diet in the microgravity conditions. Up to date several ground prototypes of the space PGF have been made and tested: “Phytocycle”, “Vitacycle”, “Phytocycle-LED”, “Phytoconveyer”; now the space PGF “Vitacycle-T” for the Russian segment of the ISS is under developing. In the PGFs the ion-exchange salt-saturated fibrous artificial soil (AS) is used as a root medium. We have proposed the system for enrichment of irrigation water by nutrients to decrease of the AS store required for PGF working during the long space mission. The system includes root modules filled in fibrous ion-exchange AS, the enrichment column with crumble salt-saturation ion-exchange resin and the cassette with slow releasing fertilizer (SRF). Both substrates (ion-exchange resin and SRF) are necessary because of the SRF contains mostly N, P and K but another three essential elements S, Ca, Mg are provided by the ion-exchange resin. In the system water goes throw the enrichment column with ion-exchange resin fertilizing by the nutrients and comes into the mixer cell fertilize equipped with the electrical conductivity sensor. When the signal of the conductivity sensor is coming to the controller it turns on the pump directed the water flow throw the cassette with SRF until the electric conductivity of the solution in the mixer cell will reach the setpoint. The nutrient root feeding system was tested during 88 days when Chinese cabbage grew in PGF “Phytocycle-LED”. The crop has been continuously illuminated by red and blue LEDs in the PPF ratio 7 to 1; an integral PPF level has been (240 ± 10) µmol/(m2×s). There was no renewal of the used fibrous AS during the experiment. The PGF total electric power consumption was of 0,45 kW. The average fresh biomass productivity of the PGF during steady state working mode was equal 135×g/day per m2 of the illuminated

  16. The function of stilt roots in the growth strategy of Socratea exorrhiza (Arecaceae at two neotropical sites

    Directory of Open Access Journals (Sweden)

    Gregory R Goldsmith

    2007-12-01

    Full Text Available Arboreal palms have developed a variety of structural root modifications and systems to adapt to the harsh abiotic conditions of tropical rain forests. Stilt roots have been proposed to serve a number of functions including the facilitation of rapid vertical growth to the canopy and enhanced mechanical stability. To examine whether stilt roots provide these functions, we compared stilt root characteristics of the neotropical palm tree Socratea exorrhiza on sloped (>20º and flat locations at two lowland neotropical sites. S. exorrhiza (n=80 trees did not demonstrate differences in number of roots, vertical stilt root height, root cone circumference, root cone volume, or location of roots as related to slope. However, we found positive relationships between allocation to vertical growth and stilt root architecture including root cone circumference, number of roots, and root cone volume. Accordingly, stilt roots may allow S. exorrhiza to increase height and maintain mechanical stability without having to concurrently invest in increased stem diameter and underground root structure. This strategy likely increases the species ability to rapidly exploit light gaps as compared to non-stilt root palms and may also enhance survival as mature trees approach the theoretical limits of their mechanical stability. Rev. Biol. Trop. 55 (3-4: 787-793. Epub 2007 December, 28.Comparamos características físicas de raíces aéreas de la palmera Socratea exorrhiza en sitios inclinados (pendiente>20º y sitios planos, en dos lugares neotropicales. S. exorrhiza (n=80 árboles no muestra diferencias en el número de raíces, la altura vertical de las raíces, la circunferencia y la masa del cono de las raíces, o la posición de las raíces en los sitios con pendiente. Encontramos relaciones positivas entre el crecimiento vertical y la arquitectura de las raíces aéreas, incluso entre el número de raíces, la circunferencia del cono de las raíces, y la masa del

  17. Impact of soil salinity on the plant-growth – promoting and biological control abilities of root associated bacteria

    Directory of Open Access Journals (Sweden)

    Dilfuza Egamberdieva

    2017-11-01

    Full Text Available The effectiveness of plant growth – promoting bacteria is variable under different biotic and abiotic conditions. Abiotic factors may negatively affect the beneficial properties and efficiency of the introduced PGPR inoculants. The aim of this study was to evaluate the effect of plant growth – promoting rhizobacteria on plant growth and on the control of foot and root rot of tomatoes caused by Fusarium solani under different soil salinity conditions. Among the five tested strains, only Pseudomonas chlororaphis TSAU13, and Pseudomonas extremorientalis TSAU20 were able to stimulate plant growth and act as biological controls of foot and root rot disease of tomato. The soil salinity did not negatively affect the beneficial impacts of these strains, as they were able to colonize and survive on the roots of tomato plants under both saline and non-saline soil conditions. The improved plant height and fruit yield of tomato was also observed for plants inoculated with P. extremorientalis TSAU20. Our results indicated that, saline condition is not crucial factor in obtaining good performance with respect to the plant growth stimulating and biocontrol abilities of PGPR strains. The bacterial inoculant also enhanced antioxidant enzymes activities thereby preventing ROS induced oxidative damage in plants, and the proline concentrations in plant tissue that play an important role in plant stress tolerance.

  18. Effect of different irrigation systems on root growth of maize and cowpea plants in sandy soil

    Directory of Open Access Journals (Sweden)

    Noha A. Mahgoub

    2017-10-01

    Full Text Available A field experiment was conducted at the Experimental Farm, Faculty of Agriculture, Suez Canal University to study the influence of different irrigation systems on root length density and specific root length of maize and cowpea plants cultivated in sandy soil. Three irrigation systems (Surface, drip and sprinkler irrigation were used in this study. The NPK fertilizers were applied as recommended doses for maize and cowpea. Root samples were collected from the soil profile below one plant (maize and cowpea which was irrigated by the three irrigation systems by using an iron box (30 cm× 20 cm which is divided into 24 small boxes each box is (5× 5 × 5 cm. At surface irrigation, root length density of cowpea reached to soil depth 30-40cm with lateral distances 5-10 cm and 15-20 cm. Vertical distribution of root length density of maize was increased with soil depth till 20-25 cm, and then it decreased till soil depth 35-40cm. Under drip irrigation, root length density of cowpea increased horizontally from 0-5cm to 10-15cm then it decreased till soil depth 25-30 cm and below this depth root length density disappeared. For the root length density and specific root length of maize under drip irrigation, the data showed that root length density and specific root length decreased with increasing in soil depth. The root length density of cowpea under sprinkler irrigation at 0-5cm disappeared from horizontal distance at 25-30 cm. The data showed that root length density of maize under sprinkler irrigation was higher at the soil top layers 0-5 cm and 5-10 cm than other layers from 10-40 cm.

  19. Effects of silver nanoparticles on radish sprouts: Root growth reduction and modifications in the nutritional value

    Directory of Open Access Journals (Sweden)

    Nubia eZuverza-Mena

    2016-02-01

    Full Text Available Reports indicate that silver nanoparticles (nAg are toxic to vegetation, but little is known about their effects in crop plants. This study examines the impacts of nAg on the physiology and nutritional quality of radish (Raphanus sativus sprouts. Seeds were germinated and grown for five days in nAg suspensions at 0, 125, 250, and 500 mg/L. Seed germination and seedling growth were evaluated with traditional methodologies; the uptake of Ag and nutrients was quantified by inductively coupled plasma-optical emission spectroscopy (ICP-OES and changes in macromolecules were analyzed by infrared (IR spectroscopy. None of the nAg concentrations reduced seed germination. However, the water content (% of the total weight was reduced by 1.62%, 1.65%, and 2.54% with exposure to 125, 250 and 500 mg/L, respectively, compared with the control. At 500 mg/L, the root and shoot lengths were reduced by 47.7% and 40%, with respect to the control. The seedlings exposed to 500 mg/L had 901±150 mg Ag/kg dry wt and significantly less Ca, Mg, B, Cu, Mn, and Zn, compared with the control. The infrared spectroscopy analysis showed changes in the bands corresponding to lipids (3000 – 2800 cm-1, proteins (1550 - 1530, and structural components of plant cells such as lignin, pectin and cellulose. These results suggest that nAg could significantly affect the growth, nutrient content and macromolecule conformation in radish sprouts, with unknown consequences for human health.

  20. Growth promotion-related miRNAs in Oncidium orchid roots colonized by the endophytic fungus Piriformospora indica.

    Directory of Open Access Journals (Sweden)

    Wei Ye

    Full Text Available Piriformospora indica, an endophytic fungus of Sebacinales, colonizes the roots of a wide range of host plants and establishes various benefits for the plants. In this work, we describe miRNAs which are upregulated in Oncidium orchid roots after colonization by the fungus. Growth promotion and vigorous root development were observed in Oncidium hybrid orchid, while seedlings were colonized by P. indica. We performed a genome-wide expression profiling of small RNAs in Oncidium orchid roots either colonized or not-colonized by P. indica. After sequencing, 24,570,250 and 24744,141 clean reads were obtained from two libraries. 13,736 from 17,036,953 unique sequences showed homology to either 86 miRNA families described in 41 plant species, or to 46 potential novel miRNAs, or to 51 corresponding miRNA precursors. The predicted target genes of these miRNAs are mainly involved in auxin signal perception and transduction, transcription, development and plant defense. The expression analysis of miRNAs and target genes demonstrated the regulatory functions they may participate in. This study revealed that growth stimulation of the Oncidium orchid after colonization by P. indica includes an intricate network of miRNAs and their targets. The symbiotic function of P. indica on Oncidium orchid resembles previous findings on Chinese cabbage. This is the first study on growth regulation and development of Oncidium orchid by miRNAs induced by the symbiotic fungus P. indica.

  1. The Arabidopsis SKU5 gene encodes an extracellular glycosyl phosphatidylinositol-anchored glycoprotein involved in directional root growth

    Science.gov (United States)

    Sedbrook, John C.; Carroll, Kathleen L.; Hung, Kai F.; Masson, Patrick H.; Somerville, Chris R.

    2002-01-01

    To investigate how roots respond to directional cues, we characterized a T-DNA-tagged Arabidopsis mutant named sku5 in which the roots skewed and looped away from the normal downward direction of growth on inclined agar surfaces. sku5 roots and etiolated hypocotyls were slightly shorter than normal and exhibited a counterclockwise (left-handed) axial rotation bias. The surface-dependent skewing phenotype disappeared when the roots penetrated the agar surface, but the axial rotation defect persisted, revealing that these two directional growth processes are separable. The SKU5 gene belongs to a 19-member gene family designated SKS (SKU5 Similar) that is related structurally to the multiple-copper oxidases ascorbate oxidase and laccase. However, the SKS proteins lack several of the conserved copper binding motifs characteristic of copper oxidases, and no enzymatic function could be assigned to the SKU5 protein. Analysis of plants expressing SKU5 reporter constructs and protein gel blot analysis showed that SKU5 was expressed most strongly in expanding tissues. SKU5 was glycosylated and modified by glycosyl phosphatidylinositol and localized to both the plasma membrane and the cell wall. Our observations suggest that SKU5 affects two directional growth processes, possibly by participating in cell wall expansion.

  2. Isolation, selection and characterization of root-associated growth promoting bacteria in Brazil Pine (Araucaria angustifolia).

    Science.gov (United States)

    Ribeiro, Carlos Marcelo; Cardoso, Elke Jurandy Bran Nogueira

    2012-01-20

    Araucaria angustifolia, a unique species of this genus that occurs naturally in Brazil, has a high socio-economic and environmental value and is critically endangered of extinction, since it has been submitted to intense predatory exploitation during the last century. Root-associated bacteria from A. angustifolia were isolated, selected and characterized for their biotechnological potential of growth promotion and biocontrol of plant pathogenic fungi. Ninety-seven strains were isolated and subjected to chemical tests. All isolates presented at least one positive feature, characterizing them as potential PGPR. Eighteen isolates produced indole-3-acetic acid (IAA), 27 were able to solubilize inorganic phosphate, 21 isolates were presumable diazotrophs, with pellicle formation in nitrogen-free culture medium, 83 were phosphatases producers, 37 were positive for siderophores and 45 endospore-forming isolates were antagonistic to Fusarium oxysporum, a pathogen of conifers. We also observed the presence of bacterial strains with multiple beneficial mechanisms of action. Analyzing the fatty acid methyl ester (FAME) and partial sequencing of the 16S rRNA gene of these isolates, it was possible to characterize the most effective isolates as belonging to Bacillaceae (9 isolates), Enterobacteriaceae (11) and Pseudomonadaceae (1). As far as we know, this is the first study to include the species Ewingella americana as a PGPR. Copyright © 2011 Elsevier GmbH. All rights reserved.

  3. Inhibition of tomato (Solanum lycopersicum L.) root growth by cyanamide is not always accompanied with enhancement of ROS production.

    Science.gov (United States)

    Soltys, Dorota; Gniazdowska, Agnieszka; Bogatek, Renata

    2013-05-01

    Mode of action of allelochemicals in target plants is currently widely studied. Cyanamide is one of the newly discovered allelochemical, biosynthesized in hairy vetch. Recently, it has been recognized that cyanamide is plant growth inhibitor, which affects mitosis in root tip cells and causes,e.g., disorder in phytohormonal balance. We also demonstrated that CA may act as oxidative stress agent but it strictly depends on plant species, exposure time and doses. Roots of tomato seedling treated with water solution of 1.2 mM cyanamide did not exhibit elevated reactive oxygen species concentration during the whole culture period.

  4. A Vegetal Biopolymer-Based Biostimulant Promoted Root Growth in Melon While Triggering Brassinosteroids and Stress-Related Compounds

    Directory of Open Access Journals (Sweden)

    Luigi Lucini

    2018-04-01

    Full Text Available Plant biostimulants are receiving great interest for boosting root growth during the first phenological stages of vegetable crops. The present study aimed at elucidating the morphological, physiological, and metabolomic changes occurring in greenhouse melon treated with the biopolymer-based biostimulant Quik-link, containing lateral root promoting peptides, and lignosulphonates. The vegetal-based biopolymer was applied at five rates (0, 0.06, 0.12, 0.24, or 0.48 mL plant-1 as substrate drench. The application of biopolymer-based biostimulant at 0.12 and 0.24 mL plant-1 enhanced dry weight of melon leaves and total biomass by 30.5 and 27.7%, respectively, compared to biopolymer applications at 0.06 mL plant-1 and untreated plants. The root dry biomass, total root length, and surface in biostimulant-treated plants were significantly higher at 0.24 mL plant-1 and to a lesser extent at 0.12 and 0.48 mL plant-1, in comparison to 0.06 mL plant-1 and untreated melon plants. A convoluted biochemical response to the biostimulant treatment was highlighted through UHPLC/QTOF-MS metabolomics, in which brassinosteroids and their interaction with other hormones appeared to play a pivotal role. Root metabolic profile was more markedly altered than leaves, following application of the biopolymer-based biostimulant. Brassinosteroids triggered in roots could have been involved in changes of root development observed after biostimulant application. These hormones, once transported to shoots, could have caused an hormonal imbalance. Indeed, the involvement of abscisic acid, cytokinins, and gibberellin related compounds was observed in leaves following root application of the biopolymer-based biostimulant. Nonetheless, the treatment triggered an accumulation of several metabolites involved in defense mechanisms against biotic and abiotic stresses, such as flavonoids, carotenoids, and glucosinolates, thus potentially improving resistance toward plant stresses.

  5. Wheat shovelomics II: Revealing relationships between root crown traits and crop growth

    OpenAIRE

    Foulkes, John; York, Larry; Roghazai, Yadgar; Slack, Shaunagh; Bennett, Malcolm; Lynch, Jonathan

    2018-01-01

    Optimization of root system architecture represents an important goal in wheat breeding. Adopting new field methods for root phenotyping is key to delivering this goal. A novel 'shovelomics' method was applied for phenotyping root crown traits to characterize the Savannah x Rialto doubled-haploid (DH) population in two field experiments under irrigated and rain-fed conditions. Trait validation was carried out through soil coring on a subset of 14 DH lines and the two parents. We observed that...

  6. Water-soluble carbohydrates of root components and activity rhythms at vegetative growth stage of Artemisia scoparia in northeastern grassland of China.

    Science.gov (United States)

    Wang, Shiyu; Yang, Yunfei; Zhi, Heng

    2017-01-01

    The root system of perennials is composed of the roots of different growth years. The nutrient storage capacities and activities of roots are an important basis for judging root components and plant senescence. In this research, changes in the contents of water-soluble carbohydrate (WSC) were used as indicators of the nutrient storage and activity of roots of different life years. From the early resprouting stage to the rapid growth stage, Artemisia scoparia L. plants of 1-3 age classes were sampled and measured once every 18 days. The nutrient storage capacities and activity rhythms of plant root components of the three age classes were analysed quantitatively. Among the A. scoparia population in northeast China, the nutrient storage capacities of 1a/2a plant root collars and 2-year old roots were generally large, whereas those of 3a plant root collars and 3-year old roots were significantly reduced. As for changes in the WSC content in the root system at the 18 day resprouting stage, the decline rates in the root collars of the 1a and 2a plants were 102 and 109 times those of the 3a plants, respectively. The decline rate in the 2-year old roots of the 1a plants was 1.8 times that of the 2a plants and 29.6 times that of the 3a plants. When nutrients were most active, all root components of the 1a plants entered into the resprouting stage, but the 2/3-year old roots of the 2a plants lagged behind. All the root components of the 3a plants generally lagged. At the vegetative growth stage, the WSC contents in all root components of the 1a plants declined logarithmically. For the 3a plants, the content in the root collars decreased linearly with that in the 3-year old roots. The older root components (3-year old roots) of the 2a plants and all root components of the 3a plants exhibited signs of aging.

  7. Rhizoslides: paper-based growth system for non-destructive, high throughput phenotyping of root development by means of image analysis.

    Science.gov (United States)

    Le Marié, Chantal; Kirchgessner, Norbert; Marschall, Daniela; Walter, Achim; Hund, Andreas

    2014-01-01

    A quantitative characterization of root system architecture is currently being attempted for various reasons. Non-destructive, rapid analyses of root system architecture are difficult to perform due to the hidden nature of the root. Hence, improved methods to measure root architecture are necessary to support knowledge-based plant breeding and to analyse root growth responses to environmental changes. Here, we report on the development of a novel method to reveal growth and architecture of maize root systems. The method is based on the cultivation of different root types within several layers of two-dimensional, large (50 × 60 cm) plates (rhizoslides). A central plexiglass screen stabilizes the system and is covered on both sides with germination paper providing water and nutrients for the developing root, followed by a transparent cover foil to prevent the roots from falling dry and to stabilize the system. The embryonic roots grow hidden between a Plexiglas surface and paper, whereas crown roots grow visible between paper and the transparent cover. Long cultivation with good image quality up to 20 days (four fully developed leaves) was enhanced by suppressing fungi with a fungicide. Based on hyperspectral microscopy imaging, the quality of different germination papers was tested and three provided sufficient contrast to distinguish between roots and background (segmentation). Illumination, image acquisition and segmentation were optimised to facilitate efficient root image analysis. Several software packages were evaluated with regard to their precision and the time investment needed to measure root system architecture. The software 'Smart Root' allowed precise evaluation of root development but needed substantial user interference. 'GiaRoots' provided the best segmentation method for batch processing in combination with a good analysis of global root characteristics but overestimated root length due to thinning artefacts. 'WhinRhizo' offered the most rapid

  8. Morphological plasticity of root growth under mild water stress increases water use efficiency without reducing yield in maize

    Directory of Open Access Journals (Sweden)

    Q. Cai

    2017-08-01

    Full Text Available A large yield gap exists in rain-fed maize (Zea mays L. production in semi-arid regions, mainly caused by frequent droughts halfway through the crop-growing period due to uneven distribution of rainfall. It is questionable whether irrigation systems are economically required in such a region since the total amount of rainfall does generally meet crop requirements. This study aimed to quantitatively determine the effects of water stress from jointing to grain filling on root and shoot growth and the consequences for maize grain yield, above- and below-ground dry matter, water uptake (WU and water use efficiency (WUE. Pot experiments were conducted in 2014 and 2015 with a mobile rain shelter to achieve conditions of no, mild or severe water stress. Maize yield was not affected by mild water stress over 2 years, while severe stress reduced yield by 56 %. Both water stress levels decreased root biomass slightly but shoot biomass substantially. Mild water stress decreased root length but increased root diameter, resulting in no effect on root surface area. Due to the morphological plasticity in root growth and the increase in root ∕ shoot ratio, WU under water stress was decreased, and overall WUE for both above-ground dry matter and grain yield increased. Our results demonstrate that an irrigation system might be not economically and ecologically necessary because the frequently occurring mild water stress did not reduce crop yield much. The study helps us to understand crop responses to water stress during a critical water-sensitive period (middle of the crop-growing season and to mitigate drought risk in dry-land agriculture.

  9. Effect of crop density on competition by wheat and barley with Agrostemma githago and other weeds

    DEFF Research Database (Denmark)

    Doll, H.; Holm, U.; Søgaard, B.

    1995-01-01

    The effect of Agrostemma githago L. and other naturally occurring weeds on biomass production and grain yield was studied in winter wheat and winter barley. Naturally occurring weeds had only a negligible effect on barley, but reduced wheat grain yield by 10% at a quarter of normal crop density....... The interaction between the cereals and A. githago was studied in additive series employing different crop densities. Growth of this weed species was strongly dependent on crop density, which was more important for controlling weed growth than it was for obtaining a normal grain yield. Wheat and especially barley...

  10. Salinity tolerance in barley (hordeum vulgare l.): effects of varying NaCl, K/sup +/ Na/sup +/ and NaHCO/sub 3/ levels on cultivars differing in tolerance

    International Nuclear Information System (INIS)

    Mahmood, K.

    2011-01-01

    Although barley (Hordeum vulgare L.) is regarded as salt tolerant among crop plants, its growth and plant development is severely affected by ionic and osmotic stresses in salt-affected soils. To elucidate the tolerance mechanism, growth and ion uptake of three barley cultivars, differing in salt tolerance, were examined under different levels of NaCl, K/sup +/ Na/sup +/ and NaHCO/sub 3/ in the root medium. The cultivars differed greatly in their responses to varying root medium conditions. Plant growth was more adversely affected by NaHCO/sub 3/ than NaCl. In general, biomass yields were comparable under control and 100 mM NaCl. However, growth of all three cultivars was significantly inhibited by NaHCO/sub 3/ even at low concentration (10 mM). Improved K/sup +/ supply in saline medium increased K/sup +/ uptake and growth of less tolerant cultivars. K/sup +/ uptake was more adversely affected by NaHCO/sub 3/ than NaCl salinity. Selective K/sup +/ uptake and lower Cl/sup -/ in shoots seemed to be associated with the growth responses. K application would help better growth of these cultivars on K-deficient saline-sodic soils and under irrigation with poor quality water having high Residual Sodium Carbonate (RSC) and/or Sodium Adsorption Ratio (SAR). (author)

  11. Competition for and utilisation of sulfur in sole and intercrops of pea and barley

    DEFF Research Database (Denmark)

    Andersen, Mette Klindt; Hauggaard-Nielsen, Henrik; Jensen, Henning Høgh

    2007-01-01

    gave barley a growth and nutrient use advantage compared to pea (REIc values importance of initial size differences decreased relative to the effect of species identity in determining the competitive strength of the two species and by the end...

  12. ROOT GROWTH AND TURNOVER IN DIFFERENT AGED PONDEROSA PINE STANDS IN OREGON, USA

    Science.gov (United States)

    The impacts of pollution and climate change on soil carbon dynamics are poorly understood, in part due to a lack of information regarding root production and turnover in natural ecosystems. In order to examine how root dynamics change with stand age in ponderosa pine forests (...

  13. PATTERNS OF ROOT GROWTH, TURNOVER, AND DISTRIBUTION IN DIFFERENT AGED PONDEROSA PINE STANDS

    Science.gov (United States)

    The objectives of this study are to examine the spatial distribution of roots in relation to canopy size and tree distribution, and to determine if rates of fine root production and turnover are similar in the different aged stands. During the fall of 1998, 54 clear plexiglass t...

  14. Soil acidification effects on fine root growth of Douglas-fir on sandy soils

    NARCIS (Netherlands)

    Olsthoorn, A.F.M.

    1998-01-01

    The ammonium sulphate deposited in forest ecosystems in the Netherlands as a result of air pollution currently exceeds 80 kg N ha -1yr -1locally. To study the influence of this air pollution on fine root density and its dynamics, fine root

  15. Soil and Root Respiration Under Elevated CO2 Concentrations During Seedling Growth of Pinus sylvestris var. sylvestriformis

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The objectives of this study were to investigate the effect of higher CO2 concentrations (500 and 700 μmol mol-1) in atmosphere on total soil respiration and the contribution of root respiration to total soil respiration during seedling growth of Pinus sylvestris var. sylvestriformis. During the four growing seasons (May-October) from 1999 to 2003, the seedlings were exposed to elevated concentrations of CO2 in open-top chambers. The total soil respiration and contribution of root respiration were measured using an LI-6400-09 soil CO2 flux chamber on June 15 and October 8, 2003. To separate root respiration from total soil respiration, three PVC cylinders were inserted approximately 30 cm deep into the soil in each chamber. There were marked diurnal changes in air and soil temperatures on June 15. Both the total soil respiration and the soil respiration without roots showed a strong diurnal pattern, increasing from before sunrise to about 14:00in the afternoon and then decreasing before the next sunrise. No increase in the mean total soil respiration and mean soil respiration with roots severed was observed under the elevated CO2 treatments on June 15, 2003, as compared to the open field and control chamber with ambient CO2. However, on October 8, 2003, the total soil respiration and soil respiration with roots severed in the open field were lower than those in the control and elevated CO2 chambers. The mean contribution of root respiration measured on June 15, 2003, ranged from 8.3% to 30.5% and on October 8, 2003,from 20.6% to 48.6%.

  16. A weed suppressive index for spring barley (Hordeum vulgare) varieties

    DEFF Research Database (Denmark)

    Hansen, P K; Kristensen, K; Willas, J

    2008-01-01

    A screening programme for crop variety competitiveness would ideally be based on only a few, non-destructive measurements of key growth traits. In this study we measured the weed suppressive ability of 79 varieties of spring barley in two ways: (i) directly, by weed coverage assessments under wee...

  17. Effects of rooting and tree growth of selected woodland species on cap integrity in a mineral capped landfill site.

    Science.gov (United States)

    Hutchings, T R; Moffat, A J; Kemp, R A

    2001-06-01

    The above and below ground growth of three tree species (Alnus glutinosa, Pinus nigra var. maritima and Acer pseudoplatanus) was studied on a containment landfill site at Waterford, Hertfordshire, UK. Tree root architecture was studied using soil inspection pits excavated next to 12 trees of each species and mapped in detail. Tree height was related to soil thickness over the compacted mineral cap. No roots entered the cap where soil thickness was 1.3 m, but a few roots, especially of alder, were observed within it when the soil cover was 1.0 m or less. Micromorphological analysis of undisturbed samples of the mineral cap suggested that roots exploited weaknesses in the cap rather than actively causing penetration into it. Alder roots were more tolerant of anaerobic conditions within the cap than the other species examined. The results confirm that mineral caps should be covered by 1.5 m of soil or soil-forming material if tree establishment is intended over a restored landfill site, unless protected by other parts of a composite capping system.

  18. Trickle-bed root culture bioreactor design and scale-up: growth, fluid-dynamics, and oxygen mass transfer.

    Science.gov (United States)

    Ramakrishnan, Divakar; Curtis, Wayne R

    2004-10-20

    Trickle-bed root culture reactors are shown to achieve tissue concentrations as high as 36 g DW/L (752 g FW/L) at a scale of 14 L. Root growth rate in a 1.6-L reactor configuration with improved operational conditions is shown to be indistinguishable from the laboratory-scale benchmark, the shaker flask (mu=0.33 day(-1)). These results demonstrate that trickle-bed reactor systems can sustain tissue concentrations, growth rates and volumetric biomass productivities substantially higher than other reported bioreactor configurations. Mass transfer and fluid dynamics are characterized in trickle-bed root reactors to identify appropriate operating conditions and scale-up criteria. Root tissue respiration goes through a minimum with increasing liquid flow, which is qualitatively consistent with traditional trickle-bed performance. However, liquid hold-up is much higher than traditional trickle-beds and alternative correlations based on liquid hold-up per unit tissue mass are required to account for large changes in biomass volume fraction. Bioreactor characterization is sufficient to carry out preliminary design calculations that indicate scale-up feasibility to at least 10,000 liters.

  19. Over-expression of mango (Mangifera indica L.) MiARF2 inhibits root and hypocotyl growth of Arabidopsis.

    Science.gov (United States)

    Wu, Bei; Li, Yun-He; Wu, Jian-Yong; Chen, Qi-Zhu; Huang, Xia; Chen, Yun-Feng; Huang, Xue-Lin

    2011-06-01

    An auxin response factor 2 gene, MiARF2, was cloned in our previous study [1] from the cotyledon section of mango (Mangifera indica L. cv. Zihua) during adventitious root formation, which shares an 84% amino acid sequence similarity to Arabidopsis ARF2. This study was to examine the effects of over-expression of the full-length MiARF2 open reading frame on the root and hypocotyl growth in Arabidopsis. Phenotype analysis showed that the T(3) transgenic lines had about 20-30% reduction in the length of hypocotyls and roots of the seedlings in comparison with the wild-type. The transcription levels of ANT and ARGOS genes which play a role in controlling organ size and cell proliferation in the transgenic seedlings also decreased. Therefore, the inhibited root and hypocotyl growth in the transgenic seedlings may be associated with the down-regulated transcription of ANT and ARGOS by the over-expression of MiARF2. This study also suggests that although MiARF2 only has a single DNA-binding domain (DBD), it can function as other ARF-like proteins containing complete DBD, middle region (MR) and carboxy-terminal dimerization domain (CTD).

  20. A dynamic growth model of vegetative soya bean plants: model structure and behaviour under varying root temperature and nitrogen concentration

    Science.gov (United States)

    Lim, J. T.; Wilkerson, G. G.; Raper, C. D. Jr; Gold, H. J.

    1990-01-01

    A differential equation model of vegetative growth of the soya bean plant (Glycine max (L.) Merrill cv. Ransom') was developed to account for plant growth in a phytotron system under variation of root temperature and nitrogen concentration in nutrient solution. The model was tested by comparing model outputs with data from four different experiments. Model predictions agreed fairly well with measured plant performance over a wide range of root temperatures and over a range of nitrogen concentrations in nutrient solution between 0.5 and 10.0 mmol NO3- in the phytotron environment. Sensitivity analyses revealed that the model was most sensitive to changes in parameters relating to carbohydrate concentration in the plant and nitrogen uptake rate.

  1. Enumeration of fungi in barley

    CSIR Research Space (South Africa)

    Rabie, CJ

    1997-04-01

    Full Text Available Estimation of fungal contamination of barley grain is important as certain fungi can proliferate during the malting process. The following factors which may affect the enumeration of fungi were evaluated: dilution versus direct plating, pre...

  2. Towards systems biology of the gravity response of higher plants -multiscale analysis of Arabidopsis thaliana root growth

    Science.gov (United States)

    Palme, Klaus; Aubry, D.; Bensch, M.; Schmidt, T.; Ronneberger, O.; Neu, C.; Li, X.; Wang, H.; Santos, F.; Wang, B.; Paponov, I.; Ditengou, F. A.; Teale, W. T.; Volkmann, D.; Baluska, F.; Nonis, A.; Trevisan, S.; Ruperti, B.; Dovzhenko, A.

    Gravity plays a fundamental role in plant growth and development. Up to now, little is known about the molecular organisation of the signal transduction cascades and networks which co-ordinate gravity perception and response. By using an integrated systems biological approach, a systems analysis of gravity perception and the subsequent tightly-regulated growth response is planned in the model plant Arabidopsis thaliana. This approach will address questions such as: (i) what are the components of gravity signal transduction pathways? (ii) what are the dynamics of these components? (iii) what is their spatio-temporal regulation in different tis-sues? Using Arabidopsis thaliana as a model-we use root growth to obtain insights in the gravity response. New techniques enable identification of the individual genes affected by grav-ity and further integration of transcriptomics and proteomics data into interaction networks and cell communication events that operate during gravitropic curvature. Using systematic multiscale analysis we have identified regulatory networks consisting of transcription factors, the protein degradation machinery, vesicle trafficking and cellular signalling during the gravire-sponse. We developed approach allowing to incorporate key features of the root system across all relevant spatial and temporal scales to describe gene-expression patterns and correlate them with individual gene and protein functions. Combination of high-resolution microscopy and novel computational tools resulted in development of the root 3D model in which quantitative descriptions of cellular network properties and of multicellular interactions important in root growth and gravitropism can be integrated for the first time.

  3. Environmental Response and Genomic Regions Correlated with Rice Root Growth and Yield under Drought in the OryzaSNP Panel across Multiple Study Systems.

    Directory of Open Access Journals (Sweden)

    Len J Wade

    Full Text Available The rapid progress in rice genotyping must be matched by advances in phenotyping. A better understanding of genetic variation in rice for drought response, root traits, and practical methods for studying them are needed. In this study, the OryzaSNP set (20 diverse genotypes that have been genotyped for SNP markers was phenotyped in a range of field and container studies to study the diversity of rice root growth and response to drought. Of the root traits measured across more than 20 root experiments, root dry weight showed the most stable genotypic performance across studies. The environment (E component had the strongest effect on yield and root traits. We identified genomic regions correlated with root dry weight, percent deep roots, maximum root depth, and grain yield based on a correlation analysis with the phenotypes and aus, indica, or japonica introgression regions using the SNP data. Two genomic regions were identified as hot spots in which root traits and grain yield were co-located; on chromosome 1 (39.7-40.7 Mb and on chromosome 8 (20.3-21.9 Mb. Across experiments, the soil type/ growth medium showed more correlations with plant growth than the container dimensions. Although the correlations among studies and genetic co-location of root traits from a range of study systems points to their potential utility to represent responses in field studies, the best correlations were observed when the two setups had some similar properties. Due to the co-location of the identified genomic regions (from introgression block analysis with QTL for a number of previously reported root and drought traits, these regions are good candidates for detailed characterization to contribute to understanding rice improvement for response to drought. This study also highlights the utility of characterizing a small set of 20 genotypes for root growth, drought response, and related genomic regions.

  4. Aluminium-induced reduction of plant growth in alfalfa (Medicago sativa) is mediated by interrupting auxin transport and accumulation in roots

    Science.gov (United States)

    Wang, Shengyin; Ren, Xiaoyan; Huang, Bingru; Wang, Ge; Zhou, Peng; An, Yuan

    2016-01-01

    The objective of this study was to investigate Al3+-induced IAA transport, distribution, and the relation of these two processes to Al3+-inhibition of root growth in alfalfa. Alfalfa seedlings with or without apical buds were exposed to 0 or 100 μM AlCl3 and were foliar sprayed with water or 6 mg L−1 IAA. Aluminium stress resulted in disordered arrangement of cells, deformed cell shapes, altered cell structure, and a shorter length of the meristematic zone in root tips. Aluminium stress significantly decreased the IAA concentration in apical buds and root tips. The distribution of IAA fluorescence signals in root tips was disturbed, and the IAA transportation from shoot base to root tip was inhibited. The highest intensity of fluorescence signals was detected in the apical meristematic zone. Exogenous application of IAA markedly alleviated the Al3+-induced inhibition of root growth by increasing IAA accumulation and recovering the damaged cell structure in root tips. In addition, Al3+ stress up-regulated expression of AUX1 and PIN2 genes. These results indicate that Al3+-induced reduction of root growth could be associated with the inhibitions of IAA synthesis in apical buds and IAA transportation in roots, as well as the imbalance of IAA distribution in root tips. PMID:27435109

  5. GROWTH PROCESS OF ORGANIC VETIVER ROOT WITH POTATO AS INTERCROPPING PLANT

    Directory of Open Access Journals (Sweden)

    Asep Kadarohman

    2012-02-01

    Full Text Available Vetiver oil (Vetiveria zizanoides is one of Indonesia main export commodities. Vetiver root is perennial plant and generally planted with vegetables as intercropping plant. Increasing the selling price of vetiver oil can be done by transferring the production of conventional vetiver oil (non-organic to organic vetiver oil. Demonstration of land used was one hectare, which 2,000 m2 for planting vetiver root with potato (Solanum tuberosum as inter-cropping plant and 8,000 m2 for vetiver root without intercropping, in Sukakarya-Samarang, Garut. The planting used goat and cow dung as manure, distillate water of vetiver oil and liquid bio-pesticide as pesticide. Variables studied included plant height, number of leaf and crotch. In the first quarter of the years, the number of leaf and crotch of vetiver root with intercropping was better than vetiver root without inter-cropping. However, there was not significant difference for plant height of vetiver root, both with and without intercropping. Products of organic potato as intercropping plant of vetiver root were less than those of non-organic potato, but the latter had a better texture and durability.

  6. Digestible energy of unpeeled cassava root meal and its effect on growth performance and carcass traits in rabbits

    Directory of Open Access Journals (Sweden)

    L.M. Mora

    2014-06-01

    Full Text Available Two experiments were conducted to evaluate the use of cassava root meal (891 g dry matter [DM]/kg, 639 g starch/kg, 74.1 g neutral detergent fibre [NDF]/kg, and 26.6 g crude protein [CP]/kg in diets for growing rabbits. In the first experiment, a basal diet (419 g NDF/kg and 181 g CP/kg and a test diet, in which cassava replaced 25% of the DM of the reference diet, were used. Twenty 50-d-old New Zealand White rabbits weighing 1474±10 g were randomly assigned to the 2 treatments, and digestibility of DM and gross energy (GE were determined. The inclusion of cassava root meal in the diet increased DM digestibility (67.0±0.80 vs. 58.0±1.12%, P<0.01 and digestible energy (DE content (11.86±0.16 vs. 10.45±0.22 MJ/kg, P<0.01. Digestible DM and DE contents of the unpeeled cassava root meal, obtained by the substitution method, were 943.3±15.8 g/kg and 15.28±0.32 MJ/kg. In the second experiment, 5 experimental diets were formulated to contain 150 g CP/kg, 184 g acid detergent fibre/kg and 10.9 MJ DE/kg, and increasing levels (0, 7, 14, 21 and 28% of unpeeled cassava root meal, mainly in substitution of corn. A growth trial was carried out using 90 rabbits from the Botucatu genetic group from weaning (35 d, weighing 951±13 g up to 71 d of age. The rabbits were housed in pairs, and randomly assigned to the 5 treatments (9 replicates/ treatment. No effect of the substitution of corn with cassava root meal was detected on growth performance (growth rate, feed intake and feed conversion ratio, on av. 44.6±0.50 g/d, 132±1.4 g/d and 2.97±0.028 g/g, respectively. The level of inclusion of cassava root meal had a quadratic effect (P=0.005 on the dressing out percentage, showing a minimal value (51.2% for inclusion of 139 g/kg. No other effect was observed on slaughter and reference carcass weights (2383±19 and 1238±11 g, respectively. Unpeeled cassava root meal may be used to completely replace corn in the diet, supporting high performance in

  7. Root proteome response to growth on tannery waste in three different poplar species with various adaptation abilities

    Directory of Open Access Journals (Sweden)

    Zemleduch-Barylska A.

    2013-04-01

    Full Text Available In our study we compared growth of three poplar clones (Populus tremula ×alba, P. alba ‘Villafranca” and P. nigra on chromium-containing solid tannery waste. Tolerance index of saplings ranged from only 25% for P. nigra up to 80% for P. tremula x alba. Standard morphological, chemical and biochemical analyses also confirmed significant differences in reaction of all tested clones to such growth conditions. Preliminary proteomic study showed an unequal level of changes in protein profiles from roots in different poplars.

  8. Spring Barley Yield Parameters after Lignite, Sodium Humate and Nitrogen Utilization

    Directory of Open Access Journals (Sweden)

    Kováčik Peter

    2016-10-01

    Full Text Available The existence of a small number of publications dealing with the impact of solid sodium humate and lignite on the quantity and quality of grown crops was the reason for establishing the field experiment. The objective of this experiment was to detect the impact of solid lignite and solid sodium humate on the quantity and quality of spring barley yield. These substances were applied into the soil either independently or along with nitrogen fertiliser. The next objective was to determine the impact of foliar application of sodium humate water solution applied either independently or along with nitrogen fertiliser on the quality and quantity of spring barley yield. The achieved results showed that the autumn application of solid lignite and the presowing application of solid sodium humate into the soil tended to decrease the yield of both grain and straw of spring barley, crude protein content in grain, proportion of the first-class grains and volume weight of grain, whereas the impact of humate was more negative. Lignite and sodium humate in the solid form should be used along with nitrogen fertiliser. The application of sodium humate in liquid form during the growth season of barley tended to increase the yield of both grain and straw. The joint application of nitrogen and liquid sodium humate during the growth season of barley increased the grain yield of barley significantly. A lower dose of nitrogen, applied during the growth season of barley (growth season BBCH 23, increased the grain yield of barley considerably more than a higher N dose, applied into the soil before barley sowing.

  9. Primary root growth in Arabidopsis thaliana is inhibited by the miR159 mediated repression of MYB33, MYB65 and MYB101.

    Science.gov (United States)

    Xue, Tao; Liu, Zhenhua; Dai, Xuehuan; Xiang, Fengning

    2017-09-01

    Organ growth is a fundamental developmental process basing on cell proliferation and differentiation. The growth of the plant root is sustained by the activity of the root meristem, a process controlled in part by various transcription factors. Here, the miR159 has been identified as a post transcriptional repressor of root growth, on the basis that the mir159ab double mutant developed a larger meristem than did the wild type, and that it formed longer roots. In the mutant, the abundance of MYB33, MYB65 and MYB101 transcript was substantially increased. When MYB33, MYB65 and MYB101 were replaced by the miR159-resistant forms mMYB33, mMYB65 and mMYB101 respectively, the root meristem was similarly enlarged and the growth of the primary root enhanced. MYB65 activity promoted cell division in the root meristem by accelerating the cell cycle. The data suggest that miR159 acts as a key repressor of the primary root's growth, acting through its repression of MYB65 and consequent blocking of the cell cycle. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. Biocontrol of Fusarium Crown and Root Rot and Promotion of Growth of Tomato by Paenibacillus Strains Isolated from Soil

    Science.gov (United States)

    Xu, Sheng Jun

    2014-01-01

    In this study, bacterial strains were isolated from soils from 30 locations of Samcheok, Gangwon province. Of the isolated strains, seven showed potential plant growth promoting and antagonistic activities. Based on cultural and morphological characterization, and 16S rRNA gene sequencing, these strains were identified as Paenibacillus species. All seven strains produced ammonia, cellulase, hydrocyanic acid, indole-3-acetic acid, protease, phosphatase, and siderophores. They also inhibited the mycelial growth of Fusarium oxysporum f. sp. radicis-lycopersici in vitro. The seven Paenibacillus strains enhanced a range of growth parameters in tomato plants under greenhouse conditions, in comparison with non-inoculated control plants. Notably, treatment of tomato plants with one identified strain, P. polymyxa SC09-21, resulted in 80.0% suppression of fusarium crown and root rot under greenhouse conditions. The plant growth promoting and antifungal activity of P. polymyxa SC09-21 identified in this study highlight its potential suitability as a bioinoculant. PMID:25071385

  11. Altered growth and fine root chemistry of Betula papyrifera and Acer saccharum under elevated CO2

    International Nuclear Information System (INIS)

    Parsons, W. F. J.; Kopper, B. J.; Lindroth, R. L.

    2003-01-01

    The effects of carbon dioxide enrichment on fine root chemical composition of two tree species common to northern hardwood forests was investigated. Results showed no change in the root/shoot ratios and fine root percentages in either birch or maple samples as a result of enriched carbon dioxide. Tissue nitrogen concentrations decreased in the fine roots, and consequently, carbon/nitrogen ratios increased with elevated carbon dioxide. In birch only, condensed tannins increased with carbon dioxide enrichment; in maple, neither complex tannins nor hydrosable tannins appear to have been influenced by elevated carbon dioxide. It is suspected that the responses of the tree saplings to elevated carbon dioxide may be related to their successional status. 37 refs., 2 tabs

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

    Energy Technology Data Exchange (ETDEWEB)

    Brenchley, W E

    1938-11-01

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

  13. Automated Root Tracking with "Root System Analyzer"

    Science.gov (United States)

    Schnepf, Andrea; Jin, Meina; Ockert, Charlotte; Bol, Roland; Leitner, Daniel

    2015-04-01

    Crucial factors for plant development are water and nutrient availability in soils. Thus, root architecture is a main aspect of plant productivity and needs to be accurately considered when describing root processes. Images of root architecture contain a huge amount of information, and image analysis helps to recover parameters describing certain root architectural and morphological traits. The majority of imaging systems for root systems are designed for two-dimensional images, such as RootReader2, GiA Roots, SmartRoot, EZ-Rhizo, and Growscreen, but most of them are semi-automated and involve mouse-clicks in each root by the user. "Root System Analyzer" is a new, fully automated approach for recovering root architectural parameters from two-dimensional images of root systems. Individual roots can still be corrected manually in a user interface if required. The algorithm starts with a sequence of segmented two-dimensional images showing the dynamic development of a root system. For each image, morphological operators are used for skeletonization. Based on this, a graph representation of the root system is created. A dynamic root architecture model helps to determine which edges of the graph belong to an individual root. The algorithm elongates each root at the root tip and simulates growth confined within the already existing graph representation. The increment of root elongation is calculated assuming constant growth. For each root, the algorithm finds all possible paths and elongates the root in the direction of the optimal path. In this way, each edge of the graph is assigned to one or more coherent roots. Image sequences of root systems are handled in such a way that the previous image is used as a starting point for the current image. The algorithm is implemented in a set of Matlab m-files. Output of Root System Analyzer is a data structure that includes for each root an identification number, the branching order, the time of emergence, the parent

  14. Comparison of agrobacterium mediated wheat and barley transformation with nucleoside diphosphate kinase 2 (NDPK2) gene

    International Nuclear Information System (INIS)

    Waheed, U.; Shah, M.M.; Smedley, M.; Harwood, W.

    2016-01-01

    An efficient and reliable transformation system is imperative for improvement of important crop species like barley and wheat. Wheat transformation is complex due to larger genome size and polyploidy while barley has a limitation of genotypic dependency. The objective of current study was to compare the relative transformation efficiency of wheat and barley using specific expression vector pBRACT 214-NDPK2 constructed through gateway cloning carrying Nucleoside Diphosphate Kinase 2 (NDPK2) gene. The vector was used to compare the transformation response in both crops using immature embryos through Agrobacterium mediated transformation. Both wheat and barley showed different responses towards callus induction and regeneration. Immature embryos of 1.5 to 2 mm in diameter was found optimum for wheat callus induction while 1 to 1.5 mm for barley. Both embryogenic and non-embryogenic calli were found in wheat with significantly greater tendency for embryogenecity in barley. The overall regeneration response was found different for all transformed wheat and barley cultivars. Wheat cultivars showed good response initially that drastically slowed down in later stages with the exception of Fielder that reached to the green shoots with good roots. The barley transformed lines showed good regeneration response as compared to wheat. PCR analysis of putative transformants using genomic DNA showed a maximum of 27% transformation efficiency in barely. No true transformation response was obtained in all cultivars of wheat used in this study. The protocol developed for wheat and barley transformation will greatly be helpful in crop improvement programme through genetic engineering especially in diploid relatives of cereals. (author)

  15. A Soil-Plate Based Pipeline for Assessing Cereal Root Growth in Response to Polyethylene Glycol (PEG)-Induced Water Deficit Stress.

    Science.gov (United States)

    Nelson, Sven K; Oliver, Melvin J

    2017-01-01

    Drought is a serious problem that causes losses in crop-yield every year, but the mechanisms underlying how roots respond to water deficit are difficult to study under controlled conditions. Methods for assaying root elongation and architecture, especially for seedlings, are commonly achieved on artificial media, such as agar, moistened filter paper, or in hydroponic systems. However, it has been demonstrated that measuring root characteristics under such conditions does not accurately mimic what is observed when plants are grown in soil. Morphological changes in root behavior occur because of differences in solute diffusion, mechanical impedance, exposure to light (in some designs), and gas exchange of roots grown under these conditions. To address such deficiencies, we developed a quantitative method for assaying seedling root lengths and germination in soil using a plate-based approach with wheat as a model crop. We also further developed the method to include defined water deficits stress levels using the osmotic properties of polyethylene glycol (PEG). Seeds were sown into soil-filled vertical plates and grown in the dark. Root length measurements were collected using digital photography through the transparent lid under green lighting to avoid effects of white light exposure on growth. Photographs were analyzed using the cross-platform ImageJ plugin, SmartRoot, which can detect root edges and partially automate root detection for extraction of lengths. This allowed for quick measurements and straightforward and accurate assessments of non-linear roots. Other measurements, such as root width or angle, can also be collected by this method. An R function was developed to collect exported root length data, process and reformat the data, and output plots depicting root/shoot growth dynamics. For water deficit experiments, seedlings were transplanted side-by-side into well-watered plates and plates containing PEG solutions to simulate precise water deficits.

  16. Nano titania aided clustering and adhesion of beneficial bacteria to plant roots to enhance crop growth and stress management

    Science.gov (United States)

    Palmqvist, N. G. M.; Bejai, S.; Meijer, J.; Seisenbaeva, G. A.; Kessler, V. G.

    2015-05-01

    A novel use of Titania nanoparticles as agents in the nano interface interaction between a beneficial plant growth promoting bacterium (Bacillus amyloliquefaciens UCMB5113) and oilseed rape plants (Brassica napus) for protection against the fungal pathogen Alternaria brassicae is presented. Two different TiO2 nanoparticle material were produced by the Sol-Gel approach, one using the patented Captigel method and the other one applying TiBALDH precursor. The particles were characterized by transmission electron microscopy, thermogravimetric analysis, X-ray diffraction, dynamic light scattering and nano particle tracking analysis. Scanning electron microscopy showed that the bacterium was living in clusters on the roots and the combined energy-dispersive X-ray spectroscopy analysis revealed that titanium was present in these cluster formations. Confocal laser scanning microscopy further demonstrated an increased bacterial colonization of Arabidopsis thaliana roots and a semi-quantitative microscopic assay confirmed an increased bacterial adhesion to the roots. An increased amount of adhered bacteria was further confirmed by quantitative fluorescence measurements. The degree of infection by the fungus was measured and quantified by real-time-qPCR. Results showed that Titania nanoparticles increased adhesion of beneficial bacteria on to the roots of oilseed rape and protected the plants against infection.

  17. The Role of α-Glucosidase in Germinating Barley Grains1[W][OA

    Science.gov (United States)

    Stanley, Duncan; Rejzek, Martin; Naested, Henrik; Smedley, Mark; Otero, Sofía; Fahy, Brendan; Thorpe, Frazer; Nash, Robert J.; Harwood, Wendy; Svensson, Birte; Denyer, Kay; Field, Robert A.; Smith, Alison M.

    2011-01-01

    The importance of α-glucosidase in the endosperm starch metabolism of barley (Hordeum vulgare) seedlings is poorly understood. The enzyme converts maltose to glucose (Glc), but in vitro studies indicate that it can also attack starch granules. To discover its role in vivo, we took complementary chemical-genetic and reverse-genetic approaches. We identified iminosugar inhibitors of a recombinant form of an α-glucosidase previously discovered in barley endosperm (ALPHA-GLUCOSIDASE97 [HvAGL97]), and applied four of them to germinating grains. All four decreased the Glc-to-maltose ratio in the endosperm 10 d after imbibition, implying inhibition of maltase activity. Three of the four inhibitors also reduced starch degradation and seedling growth, but the fourth did not affect these parameters. Inhibition of starch degradation was apparently not due to inhibition of amylases. Inhibition of seedling growth was primarily a direct effect of the inhibitors on roots and coleoptiles rather than an indirect effect of the inhibition of endosperm metabolism. It may reflect inhibition of glycoprotein-processing glucosidases in these organs. In transgenic seedlings carrying an RNA interference silencing cassette for HvAgl97, α-glucosidase activity was reduced by up to 50%. There was a large decrease in the Glc-to-maltose ratio in these lines but no effect on starch degradation or seedling growth. Our results suggest that the α-glucosidase HvAGL97 is the major endosperm enzyme catalyzing the conversion of maltose to Glc but is not required for starch degradation. However, the effects of three glucosidase inhibitors on starch degradation in the endosperm indicate the existence of unidentified glucosidase(s) required for this process. PMID:21098673

  18. High-throughput transcriptome analysis of barley (Hordeum vulgare) exposed to excessive boron.

    Science.gov (United States)

    Tombuloglu, Guzin; Tombuloglu, Huseyin; Sakcali, M Serdal; Unver, Turgay

    2015-02-15

    Boron (B) is an essential micronutrient for optimum plant growth. However, above certain threshold B is toxic and causes yield loss in agricultural lands. While a number of studies were conducted to understand B tolerance mechanism, a transcriptome-wide approach for B tolerant barley is performed here for the first time. A high-throughput RNA-Seq (cDNA) sequencing technology (Illumina) was used with barley (Hordeum vulgare), yielding 208 million clean reads. In total, 256,874 unigenes were generated and assigned to known peptide databases: Gene Ontology (GO) (99,043), Swiss-Prot (38,266), Clusters of Orthologous Groups (COG) (26,250), and the Kyoto Encyclopedia of Genes and Genomes (KEGG) (36,860), as determined by BLASTx search. According to the digital gene expression (DGE) analyses, 16% and 17% of the transcripts were found to be differentially regulated in root and leaf tissues, respectively. Most of them were involved in cell wall, stress response, membrane, protein kinase and transporter mechanisms. Some of the genes detected as highly expressed in root tissue are phospholipases, predicted divalent heavy-metal cation transporters, formin-like proteins and calmodulin/Ca(2+)-binding proteins. In addition, chitin-binding lectin precursor, ubiquitin carboxyl-terminal hydrolase, and serine/threonine-protein kinase AFC2 genes were indicated to be highly regulated in leaf tissue upon excess B treatment. Some pathways, such as the Ca(2+)-calmodulin system, are activated in response to B toxicity. The differential regulation of 10 transcripts was confirmed by qRT-PCR, revealing the tissue-specific responses against B toxicity and their putative function in B-tolerance mechanisms. Copyright © 2014. Published by Elsevier B.V.

  19. Spatial Distributions of Potassium, Solutes, and Their Deposition Rates in the Growth Zone of the Primary Corn Root 1

    Science.gov (United States)

    Silk, Wendy Kuhn; Hsiao, Theodore C.; Diedenhofen, Ulrike; Matson, Christina

    1986-01-01

    Densities of osmoticum and potassium were measured as a function of distance from the tip of the primary root of Zea mays L. (cv WF9 × mo17). Millimeter segments were excised and analyzed for osmotic potential by a miniaturized freezing point depression technique, and for potassium by flame spectrophotometry. Local deposition rates were estimated from the continuity equation with values for density and growth velocity. Osmotic potential was uniform, −0.73 ± 0.05 megapascals, throughout the growth zone of well-watered roots. Osmoticum deposition rate was 260 μosmoles per gram fresh weight per hour. Potassium density fell from 117 micromoles per gram in the first mm region to 48 micromoles per gram at the base of the growth zone. Potassium deposition rates had a maximum of 29 micromoles per gram per hour at 3.5 millimeters from the tip and were positive (i.e. potassium was being added to the tissue) until 8 millimeters from the tip. The results are discussed in terms of ion relations of the growing zone and growth physics. PMID:16665121

  20. Plant growth promotion and root colonization by EPS producing Enterobacter sp. RZS5 under heavy metal contaminated soil.

    Science.gov (United States)

    Sayyed, R Z; Patel, P R; Shaikh, S S

    2015-02-01

    The heavy metal resistant bacterium isolated from field soil and identified as Enterobacter sp. RZS5 tolerates a high concentration (100-2000 μM) of various heavy metal ions such as Mn2+, Ni2+, Zn2+, Cu2+, CO2+ and Fe2+ when grown in such environment and produces exopolysaccharides (EPS). Here, we have demonstrated EPS production by Enterobacter sp. RZS5 during 60 h of growth in yeast extract mannitol broth (YEMB). The yield increased by two fold after the addition of 60 μM of Ca2+; 50 μM of Fe2+ and 60 μM of Mg2+ ions in YEMB, and the optimization of physico-chemical parameters. EPS was extracted with 30% (v/v) of isopropanol as against the commonly used 50% (v/v) isopropanol method. EPS-rich broth promoted seed germination, shoot height, root length, number of leaves and chlorophyll content of wheat (Triticum aestivum) seed and peanut (Arachis hypogaea) seed. The higher colony-forming unit of Enterobacter sp. in soil inoculated with EPS rich broth of Enterobacter sp. indicated the root colonizing potential and rhizosphere competence of the isolate. The FTIR spectra of the EPS extract confirmed the presence of the functional group characteristics of EPS known to exhibit a high binding affinity towards certain metal ions. This overall growth and vigour in plants along with the effective root colonization, reflected the potential of the isolate as an efficient bio-inoculant in bioremediation.

  1. Transgenic barley (Hordeum vulgare L.) expressing the wheat aluminium resistance gene (TaALMT1) shows enhanced phosphorus nutrition and grain production when grown on an acid soil.

    Science.gov (United States)

    Delhaize, Emmanuel; Taylor, Phillip; Hocking, Peter J; Simpson, Richard J; Ryan, Peter R; Richardson, Alan E

    2009-06-01

    Barley (Hordeum vulgare L.), genetically modified with the Al(3+) resistance gene of wheat (TaALMT1), was compared with a non-transformed sibling line when grown on an acidic and highly phosphate-fixing ferrosol supplied with a range of phosphorus concentrations. In short-term pot trials (26 days), transgenic barley expressing TaALMT1 (GP-ALMT1) was more efficient than a non-transformed sibling line (GP) at taking up phosphorus on acid soil, but the genotypes did not differ when the soil was limed. Differences in phosphorus uptake efficiency on acid soil could be attributed not only to the differential effects of aluminium toxicity on root growth between the genotypes, but also to differences in phosphorus uptake per unit root length. Although GP-ALMT1 out-performed GP on acid soil, it was still not as efficient at taking up phosphorus as plants grown on limed soil. GP-ALMT1 plants grown in acid soil possessed substantially smaller rhizosheaths than those grown in limed soil, suggesting that root hairs were shorter. This is a probable reason for the lower phosphorus uptake efficiency. When grown to maturity in large pots, GP-ALMT1 plants produced more than twice the grain as GP plants grown on acid soil and 80% of the grain produced by limed controls. Expression of TaALMT1 in barley was not associated with a penalty in either total shoot or grain production in the absence of Al(3+), with both genotypes showing equivalent yields in limed soil. These findings demonstrate that an important crop species can be genetically engineered to successfully increase grain production on an acid soil.

  2. Inhibition of histone deacetylation alters Arabidopsis root growth in response to auxin via PIN1 degradation.

    Science.gov (United States)

    Nguyen, Hoai Nguyen; Kim, Jun Hyeok; Jeong, Chan Young; Hong, Suk-Whan; Lee, Hojoung

    2013-10-01

    Our results showed the histone deacetylase inhibitors (HDIs) control root development in Arabidopsis via regulation of PIN1 degradation. Epigenetic regulation plays a crucial role in the expression of many genes in response to exogenous or endogenous signals in plants as well as other organisms. One of epigenetic mechanisms is modifications of histone, such as acetylation and deacetylation, are catalyzed by histone acetyltransferase (HAT) and histone deacetylase (HDAC), respectively. The Arabidopsis HDACs, HDA6, and HDA19, were reported to function in physiological processes, including embryo development, abiotic stress response, and flowering. In this study, we demonstrated that histone deacetylase inhibitors (HDIs) inhibit primary root elongation and lateral root emergence. In response to HDIs treatment, the PIN1 protein was almost abolished in the root tip. However, the PIN1 gene did not show decreased expression in the presence of HDIs, whereas IAA genes exhibited increases in transcript levels. In contrast, we observed a stable level of gene expression of stress markers (KIN1 and COR15A) and a cell division marker (CYCB1). Taken together, these results suggest that epigenetic regulation may control auxin-mediated root development through the 26S proteasome-mediated degradation of PIN1 protein.

  3. Cadmium and copper change root growth and morphology of Pinus pinea and Pinus pinaster seedlings

    Energy Technology Data Exchange (ETDEWEB)

    Arduini, I.; Onnis, A. (Dipart. di Agronomia e Gestione dell' Agro-Ecosistema, Univ. degli Studi Pisa, Pisa (Italy)); Boldbold, D.L. (Forstbotanishces Institut, Univ. Goettingen, Goettingen (Germany))

    1994-01-01

    Heavy metal loads in forest soils have been increasing over time due to atmospheric inputs. Accumulation in the upper soil layers could affect establishment of seedlings and forest regeneration. Mediterranean species show a high initial root development, allowing seedlings to reach the moisture of deeper soil layers. In the present work seedlings of stone pine (Pinus pinea L.) and maritime pine (Pinus pinaster Ait.), were grown in culture solution supplied with 0.0, 0.1, 1 or 5 [mu]M CdSO[sub 4] or with 1 [mu]M CdSO[sub 4] and 1 [mu]M CuSO[sub 4] combined. In both species tap-root elongation was drastically reduced in the 5 [mu]M Cd[sup 2+] and in the (Cd[sup 2+] - Cu[sup 2+]) treatments. A supply of 0.1 or 1 [mu]M Cd[sup 2+] however, enhanced root elongation in Pinus pinea without significantly influencing root elongation in Pinus pinaster. In both species the root density (weight per unit length) and the width of the cortex increased in response to Cd[sup 2+] exposure. In Pinus pinaster the mitotic index decreased at the higher Cd[sup 2+] concentrations and when Cd[sup 2+] and Cu[sup 2+] were combined. The data suggest that cell elongation is more sensitive to Cd[sup 2+] than cell division. The number and length of the lateral roots were also affected by Cd[sup 2+] treatment to a higher degree in Pinus pinaster than in Pinus pinea, reflecting the different Cd-tolerance of the two species. (au)

  4. Straw gasification biochar increases plant available water capacity and plant growth in coarse sandy soil

    DEFF Research Database (Denmark)

    Hansen, Veronika; Hauggaard-Nielsen, Henrik; Petersen, Carsten Tilbæk

    Gasification biochar (GB) contains recalcitrant carbon that can contribute to soil carbon sequestration and soil quality improvement. However, the impact of GB on plant available water capacity (AWC) and plant growth in diverse soil types needs further reserach. A pot experiment with spring barley...... the characteristic low compressibility and high friction giving much better conditions for root penetration increasing yield potentials. Furthermore, risk of drought in dry periods, and nutrient losses in wet periods in coarser soil types is also reduced...

  5. The effect of cutting length on the rooting and growth of subtropical ...

    African Journals Online (AJOL)

    The length of a cutting can affect both the rooting and plug colonisation of container-grown stock. Using hedges from conventional clonebanks established in the ground, four cutting length treatments (13, 10, 8 and 5 cm) were tested using five Eucalyptus grandis × E. urophylla clones. The smallest cutting length had the ...

  6. Phytotoxic grass residues reduce germination and initial root growth of ponderosa pine

    Science.gov (United States)

    W. J. Rietveld

    1975-01-01

    Extracts of green foliage of Arizona fescue and mountain muhly significantly reduced germination of ponderosa pine seeds, and retarded speed of elongation and mean radicle length. Three possible routes of release of the inhibitor were investigated: (1) leaching from live foliage, (2) root exudation, and (3) overwinter leaching from dead residues. The principal route...

  7. Root growth and NPK status of cassava as influenced by oil palm ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-09-15

    . 4.3. 3.3. 3.8. 3.4. 3.8. MAP = Month after planting; B = bitter cassava; S = sweet cassava. Table 3. Effect of palm bunch ash (OBA) on number of roots per cassava plant at Umudike. 3MAP. 6MAP. 9MAP. 12MAP. OBA (t/ha). B.

  8. Uptake and distribution of 232U in peas and barley

    International Nuclear Information System (INIS)

    Schreckhise, R.G.; Cline, J.F.

    1980-01-01

    The uptake of 232 U from soil and its distribution in peas and barley were examined under conditions which isolated root uptake from deposition on aboveground plant parts. Aboveground plant parts were harvested at maturity and analyzed for 232 U content by alpha-energy-analysis. The ratio of concentration (CR) of 232 U in the dry barley seeds to dry soil was 1.6 x 10 -4 while the CR values of the stem/leaf to dry soil fraction was 3.6 x 10 -3 . The Cr values for the pea seed, stem/pod and leaf components were 5.4 x 10 -4 , 3.3 x 10 -3 and 1.7 x 10 -2 , respectively. This indicates that the CR values used in certain radiological dose-assessment models may be high by about a factor of 100 when evaluating the consumption of seeds of legumes or cereal grains by man. (author)

  9. Root phosphatase activity, plant growth and phosphorus accumulation of maize genotypes

    Directory of Open Access Journals (Sweden)

    Machado Cynthia Torres de Toledo

    2004-01-01

    Full Text Available The activity of the enzyme phosphatase (P-ase is a physiological characteristic related to plant efficiency in relation to P acquisition and utilization, and is genetically variable. As part of a study on maize genotype characterization in relation to phosphorus (P uptake and utilization efficiency, two experiments were set up to measure phosphatase (P-ase activity in intact roots of six local and improved maize varieties and two sub-populations. Plants were grown at one P level in nutrient solution (4 mg L-1 and the P-ase activity assay was run using 17-day-old plants for varieties and 24-day-old plants for subpopulations. Shoot and root dry matter yields and P concentrations and contents in plant parts were determined, as well as P-efficiency indexes. Root P-ase activity differed among varieties, and highest enzimatic activities were observed in two local varieties -'Catetão' and 'Caiano' -and three improved varieties -'Sol da Manhã', 'Nitrodente' and 'BR 106'. 'Carioca', a local variety, had the lowest activity. Between subpopulations, 'ND2', with low yielding and poorly P-efficient plants, presented higher root P-ase activity as compared to 'ND10', high yielding and highly P-efficient plants. In general, subpopulations presented lower P-ase activities as compared to varieties. Positive and/or negative correlations were obtained between P-ase activity and P-efficiency characteristics, specific for the genotypes, not allowing inference on a general and clear association between root-secreted phosphatase and dry matter production or P acquisition. Genotypic variability must be known and considered before using P-ase activity as an indicator of P nutritional status, or P tolerance, adaptation and efficiency under low P conditions.

  10. Novel cytokinin derivatives do not show negative effects on root growth and proliferation in submicromolar range.

    Directory of Open Access Journals (Sweden)

    Kateřina Podlešáková

    Full Text Available BACKGROUND: When applied to a nutrition solution or agar media, the non-substituted aromatic cytokinins caused thickening and shortening of the primary root, had an inhibitory effect on lateral root branching, and even showed some negative effects on development of the aerial part at as low as a 10 nanomolar concentration. Novel analogues of aromatic cytokinins ranking among topolins substituted on N9-atom of adenine by tetrahydropyranyl or 4-chlorobutyl group have been prepared and tested in standardized cytokinin bioassays [1]. Those showing comparable activities with N(6-benzylaminopurine were further tested in planta. METHODOLOGY/PRINCIPAL FINDINGS: The main aim of the study was to explain molecular mechanism of function of novel cytokinin derivatives on plant development. Precise quantification of cytokinin content and profiling of genes involved in cytokinin metabolism and perception in treated plants revealed several aspects of different action of m-methoxytopolin base and its substituted derivative on plant development. In contrast to standard cytokinins, N9- tetrahydropyranyl derivative of m-topolin and its methoxy-counterpart showed the negative effects on root development only at three orders of magnitude higher concentrations. Moreover, the methoxy-derivative demonstrates a positive effect on lateral root branching and leaf emerging in a nanomolar range of concentrations, in comparison with untreated plants. CONCLUSIONS/SIGNIFICANCE: Tetrahydropyranyl substitution at N9-position of cytokinin purine ring significantly enhances acropetal transport of a given cytokinins. Together with the methoxy-substitution, impedes accumulation of non-active cytokinin glucoside forms in roots, allows gradual release of the active base, and has a significant effect on the distribution and amount of endogenous isoprenoid cytokinins in different plant tissues. The utilization of novel aromatic cytokinin derivatives can distinctively improve expected

  11. The simulation model of growth and cell divisions for the root apex with an apical cell in application to Azolla pinnata.

    Science.gov (United States)

    Piekarska-Stachowiak, Anna; Nakielski, Jerzy

    2013-12-01

    In contrast to seed plants, the roots of most ferns have a single apical cell which is the ultimate source of all cells in the root. The apical cell has a tetrahedral shape and divides asymmetrically. The root cap derives from the distal division face, while merophytes derived from three proximal division faces contribute to the root proper. The merophytes are produced sequentially forming three sectors along a helix around the root axis. During development, they divide and differentiate in a predictable pattern. Such growth causes cell pattern of the root apex to be remarkably regular and self-perpetuating. The nature of this regularity remains unknown. This paper shows the 2D simulation model for growth of the root apex with the apical cell in application to Azolla pinnata. The field of growth rates of the organ, prescribed by the model, is of a tensor type (symplastic growth) and cells divide taking principal growth directions into account. The simulations show how the cell pattern in a longitudinal section of the apex develops in time. The virtual root apex grows realistically and its cell pattern is similar to that observed in anatomical sections. The simulations indicate that the cell pattern regularity results from cell divisions which are oriented with respect to principal growth directions. Such divisions are essential for maintenance of peri-anticlinal arrangement of cell walls and coordinated growth of merophytes during the development. The highly specific division program that takes place in merophytes prior to differentiation seems to be regulated at the cellular level.

  12. Differential gene expression in Rhododendron fortunei roots colonized by an ericoid mycorrhizal fungus and increased nitrogen absorption and plant growth

    Directory of Open Access Journals (Sweden)

    Xiangying Wei

    2016-10-01

    Full Text Available Ericoid mycorrhizal (ERM fungi are specifically symbiotic with plants in the family Ericaceae. Little is known thus far about their symbiotic establishment and subsequent nitrogen (N uptake at the molecular level. The present study devised a system for establishing a symbiotic relationship between Rhododendron fortunei Lindl. and an ERM fungus (Oidiodendron maius var. maius strain Om19, quantified seedling growth and N uptake, and compared transcriptome profiling between colonized and uncolonized roots using RNA-Seq. The Om19 colonization induced 16,892 genes that were differentially expressed in plant roots, of which 14,364 were upregulated and 2,528 were downregulated. These genes included those homologous to ATP-binding cassette transporters, calcium/calmodulin-dependent kinases, and symbiosis receptor-like kinases. N metabolism was particularly active in Om19-colonized roots, and 51 genes were upregulated, such as nitrate transporters, nitrate reductase, nitrite reductase, ammonium transporters, glutamine synthetase, and glutamate synthase. Transcriptome analysis also identified a series of genes involving endocytosis, Fc-gamma R-mediated phagocytosis, glycerophospholipid metabolism, and GnRH signal pathway that have not been reported previously. Their roles in the symbiosis require further investigation. The Om19 colonization significantly increased N uptake and seedling growth. Total N content and dry weight of colonized seedlings were 36.6% and 46.6% greater than control seedlings. This is the first transcriptome analysis of a species from the family Ericaceae colonized by an ERM fungus. The findings from this study will shed light on the mechanisms underlying symbiotic relationships of ericaceous species with ERM fungi and the symbiosis-resultant N uptake and plant growth.

  13. Effects of anaerobic growth conditions on biomass accumulation, root morphology, and efficiencies of nutrient uptake and utilization in seedlings of some southern coastal plain pine species

    International Nuclear Information System (INIS)

    Topa, M.A.

    1984-01-01

    Seedlings of pond (Pinus serotina (Michx.)), sand (P. clausa (Engelm.) Sarg.), and loblolly pines (P. taeda L., drought-hardy and wet site seed sources) were grown in a non-circulating, continuously-flowing solution culture under anaerobic or aerobic conditions to determine the effects of anaerobics on overall growth, root morphology and efficiencies of nutrient uptake and utilization. Although shoot growth of the 11-week old loblolly and pond pines was not affected by anaerobic treatment, it did significantly reduce root biomass. Sand pine suffered the largest biomass reduction. Flooding tolerance was positively correlated with specific morphological changes which enhanced root internal aeration. Oxygen transport from shoot to the root in anaerobically-grown loblolly and pond pine seedlings was demonstrated via rhizosphere oxidation experiments. Tissue elemental analyses showed that anaerobic conditions interfered with nutrient absorption and utilization. Short-term 32 p uptake experiments with intact seedlings indicated that net absorption decreased because of the reduction in root biomass, since H 2 PO 4 - influx in the anaerobically-grown seedlings was more than twice that of their aerobic counterparts. Sand pine possessed the physiological but not morphological capacity to increase P uptake under anaerobic growth conditions. Pond and wet-site loblolly pine seedlings maintained root growth, perhaps through enhanced internal root aeration - an advantage in field conditions where the phosphorus supply may be limited or highly localized

  14. The interactive effect of phosphorus and nitrogen on "in vitro" spore germination of Glomus etunicatum Becker & Gerdemann, root growth and mycorrhizal colonization

    Directory of Open Access Journals (Sweden)

    Bressan Wellington

    2001-01-01

    Full Text Available The effects of P and N amendment and its interactions on spore germination, root growth and colonized root length by Glomus etunicatum Becker & Gerdemann (INVAM S329 was studied "in vitro" in RiT - DNA transformed roots of Anthylis vulneraria sub sp. Sampaiana (Kidney vetch. Three N media concentrations (5, 10 and 50 mg/l at P constant level (2 mg/l and three P media concentrations (2, 10 and 20 mg/l at N constant level (5 mg/l were utilized as a treatment. Bécard & Fortin medium was used as a basal medium for root growth and colonized root length, and water/agar (0.8% media was the control for spore germination. Spore germination of G. etunicatum at low P level was reduced by N addition in relation to the control media, and at low N level addition of P stimulated spore germination. Total root length was stimulated by N addtion at low P level, but no significant difference (p£0.05 was observed between 10 and 50 mg/l of N. P addition at low N level media also stimulated total root growth, and a significant difference (p£0.05 was observed among P concentrations. Colonized root length by G. etunicatum increased significantly (p£0.05 with P additions at low N levels. Under low P level no significant differences was found between 10 and 50 mg/l of N. These results demonstrate that the interaction between P and N affect differently spore germination, root growth and colonized root lenght.

  15. RNA-seq for gene identification and transcript profiling in relation to root growth of bermudagrass (Cynodon dactylon) under salinity stress.

    Science.gov (United States)

    Hu, Longxing; Li, Huiying; Chen, Liang; Lou, Yanhong; Amombo, Erick; Fu, Jinmin

    2015-08-04

    Soil salinity is one of the most significant abiotic stresses affecting plant shoots and roots growth. The adjustment of root architecture to spatio-temporal heterogeneity in salinity is particularly critical for plant growth and survival. Bermudagrass (Cynodon dactylon) is a widely used turf and forage perennial grass with a high degree of salinity tolerance. Salinity appears to stimulate the growth of roots and decrease their mortality in tolerant bermudagrass. To estimate a broad spectrum of genes related to root elongation affected by salt stress and the molecular mechanisms that control the positive response of root architecture to salinity, we analyzed the transcriptome of bermudagrass root tips in response to salinity. RNA-sequencing was performed in root tips of two bermudagrass genotypes contrasting in salt tolerance. A total of 237,850,130 high quality clean reads were generated and 250,359 transcripts were assembled with an average length of 1115 bp. Totally, 103,324 unigenes obtained with 53,765 unigenes (52 %) successfully annotated in databases. Bioinformatics analysis indicated that major transcription factor (TF) families linked to stress responses and growth regulation (MYB, bHLH, WRKY) were differentially expressed in root tips of bermudagrass under salinity. In addition, genes related to cell wall loosening and stiffening (xyloglucan endotransglucosylase/hydrolases, peroxidases) were identified. RNA-seq analysis identified candidate genes encoding TFs involved in the regulation of lignin synthesis, reactive oxygen species (ROS) homeostasis controlled by peroxidases, and the regulation of phytohormone signaling that promote cell wall loosening and therefore root growth under salinity.

  16. Physiological basis of barley yield under near optimal and stress conditions

    Directory of Open Access Journals (Sweden)

    Pržulj Novo

    2004-01-01

    Full Text Available Average barley yield fall below its potential due to incidence of stresses. Water stress is the main environmental factor limiting yield. The component a priori more sensitive to most stresses is the amount of radiation absorbed. The effect of stresses influence on the total amount of radiation absorbed by barley crop during its vegetation and the photosynthetic efficiency of radiation conversion. Growth inhibition is accompanied by reductions in leaf and cell wall extensibility. Grain yield under drought conditions is source limited. Supply of assimilates to the developing inflorescence plays a critical role in establishing final grain number and grain size. Grain weight is negatively affected by drought, high temperature, and any other factors that may reduce grain filling duration and grain filling rate. Awns and glaucousness confer better performance of barley under drought stress conditions. Barley responds with an increased accumulation of a number of proteins when subjected to different stress inducing cell dehydration. Screening techniques that are able to identify desirable genotypes based on the evaluation of physiological traits related to stress evasion and stress resistance maybe useful in breeding barley for resistance to stress, particularly drought stress. Crop management and breeding can reduce the incidence of stress on yield. The effect of these practices is sustained by an understanding of their physiology. In this paper the physiological basis of the processes determining barley yield and the incidence of stresses on photosynthetic metabolism that determine grain yield of barley is discussed. .

  17. Effect of exo-polysaccharides producing bacterial inoculation on growth of roots of wheat(Triticum aestivum L. ) plants grown in a salt-affected soil

    International Nuclear Information System (INIS)

    Ashraf, M.; Hasnain, S.; Berge, O.

    2006-01-01

    Effect of soil salinity on physico-chemical and biological properties renders the salt-affected soils unsuitable for soil microbial processes and growth of the crop plants. Soil aggregation around roots of the plants is a function of the bacterial exo-polysaccharides, however, such a role of the EPS-producing bacteria in the saline environments has rarely been investigated. Pot experiments were conducted to observe the effects of inoculating six strains of exo-polysaccharides-producing bacteria on growth of primary (seminal) roots and its relationship with saccharides, cations (Ca 2+, Na +, K +) contents and mass of rhizosheath soils of roots of the wheat plants grown in a salt-affected soil. A strong positive relationship of RS with different root growth parameters indicated that an integrated influence of various biotic and abiotic RS factors would have controlled and promoted growth of roots of the inoculated wheat plants. The increase in root growth in turn could help inoculated wheat plants to withstand the negative effects of soil salinity through an enhanced soil water uptake, a restricted Na +i nflux in the plants and the accelerated soil microbial process involved in cycling and availability of the soil nutrients to the plants. It was concluded that inoculation of the exo- polysaccharides producing would be a valuable tool for amelioration and increasing crop productivity of the salt-affected soils

  18. The Effect of Plant Growth Regulators on Shoot Proliferation and Rooting of Crataegus Pseudohetrophylla Pojark. Via in Vitro Culture

    Directory of Open Access Journals (Sweden)

    F. Ahmadloo

    2015-12-01

    Full Text Available Crataegus is a tree species from Rosaceae family with medicinal, ornamental and commercial utilizations. Effect of different concentrations of plant growth regulators on shoot proliferation of Crataegus pseudohetrophylla Pojark. via in vitro culture was studied using single node explants. The grown shoots were transferred to MS medium supplemented with different concentrations of cytokinins (BAP, KIN, 2iP and Zt in combination with NAA in 30 treatments, with 3 replications and each replication included 5 explants. Data were recorded after 3 subcultures. For rooting, basal end of shoots were dipped into 300mg/l of IBA at different durations (0, 5, 10, 20, 30, 40, 50 and 60 minutes, then the dipped shoots were cultured on hormone free 1/2 VS medium. The results of analysis of variance showed that there were significant differences in all of the traits. Results indicated that the highest number of shoots (39.33 was obtained on medium containing 8 mg / l BAP plus 2 mg / l NAA. The highest shoot length (4.67 cm and leaf size (3.73 cm was achieved on 7 mg / l BAP plus 2 mg / l NAA and 2 mg / l Zt plus 1 mg / l NAA, respectively. The highest rate of rooting (33.33% and root number (4n were induced on shoots dipped for 40 minutes in 300 mg / l IBA.

  19. Plant Growth Promotion Potential Is Equally Represented in Diverse Grapevine Root-Associated Bacterial Communities from Different Biopedoclimatic Environments

    Directory of Open Access Journals (Sweden)

    Ramona Marasco

    2013-01-01

    Full Text Available Plant-associated bacteria provide important services to host plants. Environmental factors such as cultivar type and pedoclimatic conditions contribute to shape their diversity. However, whether these environmental factors may influence the plant growth promoting (PGP potential of the root-associated bacteria is not widely understood. To address this issue, the diversity and PGP potential of the bacterial assemblage associated with the grapevine root system of different cultivars in three Mediterranean environments along a macrotransect identifying an aridity gradient were assessed by culture-dependent and independent approaches. According to 16S rRNA gene PCR-DGGE, the structure of endosphere and rhizosphere bacterial communities was highly diverse (P=0.03 and was associated with a cultivar/latitudinal/climatic effect. Despite being diverse, the bacterial communities associated with Egyptian grapevines shared a higher similarity with the Tunisian grapevines than those cultivated in North Italy. A similar distribution, according to the cultivar/latitude/aridity gradients, was observed for the cultivable bacteria. Many isolates (23% presented in vitro multiple stress resistance capabilities and PGP activities, the most frequent being auxin synthesis (82%, insoluble phosphate solubilisation (61%, and ammonia production (70%. The comparable numbers and types of potential PGP traits among the three different environmental settings indicate a strong functional homeostasis of beneficial bacteria associated with grape root.

  20. Toxic effects of boron on growth and antioxidant system parameters of maize (Zea mays L.) roots.

    Science.gov (United States)

    Esim, Nevzat; Tiryaki, Deniz; Karadagoglu, Omer; Atici, Okkes

    2013-10-01

    The aim of this study was to investigate the possible oxidative stress and the antioxidant response, which were caused on maize by boron (B). For this, 11- and 15-day-old maize seedlings were subjected to 2 or 4 mM B in the form of boric acid (H₃BO₃) for 2 and/or 6 days. At the end of the treatment period, root length, hydrogen peroxide (H₂O₂) content, malondialdehyde (MDA) content and the antioxidant enzymes superoxide dismutase (SOD), peroxidase (POX) and catalase (CAT) were measured. The results revealed that root length of plants, activity of antioxidative enzymes such as SOD, POX and CAT and also H₂O₂ contents and MDA levels were seriously affected by excess B. These results suggested that the oxidative stress occurred due to the toxic effect of B.

  1. Early Arabidopsis root hair growth stimulation by pathogenic strains of Pseudomonas syringae

    Czech Academy of Sciences Publication Activity Database

    Pečenková, Tamara; Janda, Martin; Ortmannová, Jitka; Hajná, Vladimíra; Stehlíková, Zuzana; Žárský, Viktor

    2017-01-01

    Roč. 120, č. 3 (2017), s. 437-446 ISSN 0305-7364 R&D Projects: GA ČR(CZ) GA15-14886S; GA ČR GA14-09685S Institutional support: RVO:61389030 Keywords : Arabidopsis * dde2/ein2/pad4/sid2 * exocyst * Flg22 * Pseudomonas * Root hair * vesicle trafficking Subject RIV: EB - Genetics ; Molecular Biology OBOR OECD: Plant sciences, botany Impact factor: 4.041, year: 2016

  2. Desmodium gangeticum root extract attenuates isoproterenol-induced cardiac hypertrophic growth in rats.

    OpenAIRE

    Divya Hitler; Parthasarathy Arumugam; Mathivanan Narayanasamy; Elangovan Vellaichamy

    2014-01-01

    Context: Desmodium gangeticum (L) DC (Fabaceae; DG), a medicinal plant that grows in tropical habitats, is widely used to treat various ailments including digestive and inflammatory disorders. Aims: To investigate the possible cardioprotective activity of a DG root extract against isoproterenol (ISO)-induced left ventricular cardiac hypertrophy (LVH) in adult Wistar rats. Methods: Daily intraperitoneal administration of ISO (10 mg/kg body weight, single injection) for 7 days induced LVH...

  3. Evidence for a role in growth and salt resistance of a plasma membrane H+-ATPase in the root endodermis

    Science.gov (United States)

    Vitart, V.; Baxter, I.; Doerner, P.; Harper, J. F.; Evans, M. L. (Principal Investigator)

    2001-01-01

    The plasma membrane of plant cells is energized by an electrochemical gradient produced by P-type H+-ATPases (proton pumps). These pumps are encoded by at least 12 genes in Arabidopsis. Here we provide evidence that isoform AHA4 contributes to solute transport through the root endodermis. AHA4 is expressed most strongly in the root endodermis and flowers, as suggested by promoter-GUS reporter assays. A disruption of this pump (aha4-1) was identified as a T-DNA insertion in the middle of the gene (after VFP(574)). Truncated aha4-1 transcripts accumulate to approximately 50% of the level observed for AHA4 mRNA in wild-type plants. Plants homozygous for aha4-1 (-/-) show a subtle reduction in root and shoot growth compared with wild-type plants when grown under normal conditions. However, a mutant phenotype is very clear in plants grown under salt stress (e.g., 75 or 110 mM NaCl). In leaves of mutant plants subjected to Na stress, the ratio of Na to K increased 4-5-fold. Interestingly, the aha4-1 mutation appears to be semidominant and was only partially complemented by the introduction of additional wild-type copies of AHA4. These results are consistent with the hypothesis that aha4-1 may produce a dominant negative protein or RNA that partially disrupts the activity of other pumps or functions in the root endodermal tissue, thereby compromising the function of this cell layer in controlling ion homeostasis and nutrient transport.

  4. Regulation of nitrogen uptake and assimilation: Effects of nitrogen source and root-zone and aerial environment on growth and productivity of soybean

    Science.gov (United States)

    Raper, C. David, Jr.

    1994-01-01

    The interdependence of root and shoot growth produces a functional equilibrium as described in quantitative terms by numerous authors. It was noted that bean seedlings grown in a constant environment tended to have a constant distribution pattern of dry matter between roots and leaves characteristic of the set of environmental conditions. Disturbing equilibrium resulted in a change in relative growth of roots and leaves until the original ratio was restored. To define a physiological basis for regulation of nitrogen uptake within the balance between root and shoot activities, the authors combined a partioning scheme and a utilization priority assumption in which: (1) all carbon enters the plant through photosynthesis in leaves and all nitrogen enters the plant through active uptake by roots, (2) nitrogen uptake by roots and secretion into the xylem for transport to the shoots are active processes, (3) availability of exogenous nitrogen determines concentration of soluble carbohydrates within the roots, (4) leaves are a source and a sink for carbohydrates, and (5) the requirement for nitrogen by leaf growth is proportionally greater during initiation and early expansion than during later expansion.

  5. The use of stored carbon reserves in growth of temperate tree roots and leaf buds: Analyses using radiocarbon measurements and modeling

    Energy Technology Data Exchange (ETDEWEB)

    Gaudinski, J.B.; Torn, M.S.; Riley, W.J.; Swanston, C.; Trumbore, S.E.; Joslin, J.D.; Majdi, H.; Dawson, T.E.; Hanson, P.J.

    2009-02-01

    Characterizing the use of carbon (C) reserves in trees is important for understanding regional and global C cycles, stress responses, asynchrony between photosynthetic activity and growth demand, and isotopic exchanges in studies of tree physiology and ecosystem C cycling. Using an inadvertent, whole-ecosystem radiocarbon ({sup 14}C) release in a temperate deciduous oak forest and numerical modeling, we estimated that the mean age of stored C used to grow both leaf buds and new roots is 0.7 years and about 55% of new-root growth annually comes from stored C. Therefore, the calculated mean age of C used to grow new-root tissue is {approx}0.4 years. In short, new roots contain a lot of stored C but it is young in age. Additionally, the type of structure used to model stored C input is important. Model structures that did not include storage, or that assumed stored and new C mixed well (within root or shoot tissues) before being used for root growth, did not fit the data nearly as well as when a distinct storage pool was used. Consistent with these whole-ecosystem labeling results, the mean age of C in new-root tissues determined using 'bomb-{sup 14}C' in three additional forest sites in North America and Europe (one deciduous, two coniferous) was less than 1-2 years. The effect of stored reserves on estimated ages of fine roots is unlikely to be large in most natural abundance isotope studies. However, models of root C dynamics should take stored reserves into account, particularly for pulse-labeling studies and fast-cycling roots (<1 years).

  6. Root colonization and growth promotion of sunflower (Helianthus annuus L.) by phosphate solubilizing Enterobacter sp. Fs-11.

    Science.gov (United States)

    Shahid, Muhammad; Hameed, Sohail; Imran, Asma; Ali, Saira; van Elsas, Jan Dirk

    2012-08-01

    An Enterobacter sp. Fs-11 was isolated from sunflower rhizosphere, identified on the basis of 16S rRNA gene sequence analysis (GeneBank accession no. GQ179978) and studied for its root colonization and growth promotion ability in sunflower. Morphologically, it was rod shaped Gram-negative, motile bacterium, producing 4.5 μg mL(-1) indole acetic acid in tryptophan-supplemented medium. It utilized 27 out of 95 substrates in BIOLOG GN2 micro plate system. It was able to convert insoluble tri-calcium phosphate to soluble phosphorus up to 43.5 μg mL(-1) with decrease in pH of the medium up to 4.5 after 10 days incubation at 28 ± 2 °C in the Pikovskaya's broth. High performance liquid chromatography of cell free supernatant showed that Fs-11 produced malic acid and gluconic acid (2.43 and 16.64 μg mL(-1), respectively) in Pikovskaya's broth. Analysis of 900 bp fragment of pyrroloquinoline quinine pqqE gene sequence showed 98 % homology with that of E. cloacae pqqE gene. Confocal laser scanning microscope revealed strong colonization of fluorescently labeled Fs-11 with sunflower roots. Sunflower inoculation with Fs-11 and its rifampicin resistant derivative in sterile sand and natural soil showed that Fs-11 colonized sunflower roots up to 30 days after transplanting in both sterile sand as well as natural soil. Moreover, Fs-11 inoculation resulted in increased plant height, fresh weight, dry weight and total phosphorus contents as compared to un-inoculated plants. The data showed that Enterobacter sp. Fs-11 is an efficient phosphate solubilizing and plant growth promoting rhizobacterium and has great potential to be used as bio-inoculant for sunflower under phosphorus deficient conditions.

  7. [Effects of neighbor competition on growth, fine root morphology and distribution of Schima superba and Cunninghamia lanceolata in different nutrient environments].

    Science.gov (United States)

    Yao, Jia Bao; Chu, Xiu Li; Zhou, Zhi Chun; Tong, Jian She; Wang, Hui; Yu, Jia Zhong

    2017-05-18

    Taking Schima superba and Cunninghamia lanceolata as test materials, a pot experiment was conducted to simulate the heterogeneous and homogeneous forest soil nutrient environments, and design three planting modes including single plant, two-strain pure plant and two-strain mixed ones to reason the promotion in mixed S. superba and C. lanceolata plantation and the competitive advantage of S. superba. Results showed that compared with the homogeneous nutrient environment, both S. superba and C. lanceolata had the higher seedling height and dry matter accumulation, when mixed in the heterogeneous nutrient environment, S. superba displayed the obviously competitive advantage, which related to its root plasticity. The fine root of S. superba mixed in each diameter class showed a lot of hyperplasia, and the root total length, surface area and volume of which were 80%-180% higher than that of C. lanceolata. S. superba took the advantage of the compensatory growth strategy of vertical direction in fine roots, namely, they still multiplied to gain greater competitive advantage in low nutrient patches, besides occupying eutrophic surface. The different soil colonization and niche differentiation in fine root of S. superba and C. lanceolata alleviated the strong competition for nutrients of the roots of the two species, and improved the mixed-plantation production. Pure plantation of S. superba harvested the lower yield, which due to the root self-recognition inhibited the growth of root system. Fine roots staggered and evenly distributed on the space might be a reason for stable structure of pure S. superba plantation. So, it was recommended that block surface layer soil preparation and fertilization are used to improve the soil nutrient distribution, and the mixed plantation is constructed to promote the growth of S. superba and C. lanceolata, at the same time, the stand density is regulated to promote tree growth for the pure artificial S. superba plantation which had

  8. Biocontrol traits of plant growth suppressive arbuscular mycorrhizal fungi against root rot in tomato caused by Pythium aphanidermatum

    DEFF Research Database (Denmark)

    Larsen, John; Graham, James H.; Cubero, Jaime

    2012-01-01

    Arbuscular mycorrhizal (AM) fungi known to cause plant growth depressions in tomato were examined for their biocontrol effects against root rot caused by Pythium aphanidermatum. The main hypothesis was that plant growth suppressive AM fungi would elicit a defence response in the host plant reduci...

  9. Barley HvPAPhy_a as transgene provides high and stable phytase activities in mature barley straw and in grains.

    Science.gov (United States)

    Holme, Inger Baeksted; Dionisio, Giuseppe; Madsen, Claus Krogh; Brinch-Pedersen, Henrik

    2017-04-01

    The phytase purple acid phosphatase (HvPAPhy_a) expressed during barley seed development was evaluated as transgene for overexpression in barley. The phytase was expressed constitutively driven by the cauliflower mosaic virus 35S-promoter, and the phytase activity was measured in the mature grains, the green leaves and in the dry mature vegetative plant parts left after harvest of the grains. The T 2 -generation of HvPAPhy_a transformed barley showed phytase activity increases up to 19-fold (29 000 phytase units (FTU) per kg in mature grains). Moreover, also in green leaves and mature dry straw, phytase activities were increased significantly by 110-fold (52 000 FTU/kg) and 57-fold (51 000 FTU/kg), respectively. The HvPAPhy_a-transformed barley plants with high phytase activities possess triple potential utilities for the improvement of phosphate bioavailability. First of all, the utilization of the mature grains as feed to increase the release of bio-available phosphate and minerals bound to the phytate of the grains; secondly, the utilization of the powdered straw either directly or phytase extracted hereof as a supplement to high phytate feed or food; and finally, the use of the stubble to be ploughed into the soil for mobilizing phytate-bound phosphate for plant growth. © 2016 The Authors. Plant Biotechnology Journal published by Society for Experimental Biology and The Association of Applied Biolo