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Sample records for water deficit stress

  1. Response mechanisms of Brachiaria brizantha cultivars to water deficit stress

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    Patricia Menezes Santos

    2013-11-01

    Full Text Available Two cultivars of Brachiaria brizantha (Hochst ex. A. Rich Stapf. (Syn. Urochloa were evaluated for their adaptation to water deficit and the stress response mechanisms in a greenhouse experiment. The experimental design was in completely randomized blocks with a 2 × 2 × 4 factorial arrangement. The Marandu and BRS Piatã cultivars were evaluated under two water availability conditions, with or without water restriction. The harvests were carried out 0, 7, 14 and 28 days after the start of water restriction. For both cultivars, the water deficit stress caused a reduction in shoot biomass and leaf area and an increase in the percentage of roots in the deeper soil layers. The B. brizantha cv. Marandu reached critical levels of leaf water potential in a shorter period of water restriction than did the B. brizantha cv. BRS Piatã. The osmoregulation and deepening of the root system are mechanisms of adaptation to water stress observed in both Marandu and BRS Piatã cultivars. Besides that, the Marandu cultivar also increases its leaf senescence and, consequentially, decreases its leaf area, as a response to water deficit.

  2. Analysis of the Citrullus colocynthis transcriptome during water deficit stress.

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    Wang, Zhuoyu; Hu, Hongtao; Goertzen, Leslie R; McElroy, J Scott; Dane, Fenny

    2014-01-01

    Citrullus colocynthis is a very drought tolerant species, closely related to watermelon (C. lanatus var. lanatus), an economically important cucurbit crop. Drought is a threat to plant growth and development, and the discovery of drought inducible genes with various functions is of great importance. We used high throughput mRNA Illumina sequencing technology and bioinformatic strategies to analyze the C. colocynthis leaf transcriptome under drought treatment. Leaf samples at four different time points (0, 24, 36, or 48 hours of withholding water) were used for RNA extraction and Illumina sequencing. qRT-PCR of several drought responsive genes was performed to confirm the accuracy of RNA sequencing. Leaf transcriptome analysis provided the first glimpse of the drought responsive transcriptome of this unique cucurbit species. A total of 5038 full-length cDNAs were detected, with 2545 genes showing significant changes during drought stress. Principle component analysis indicated that drought was the major contributing factor regulating transcriptome changes. Up regulation of many transcription factors, stress signaling factors, detoxification genes, and genes involved in phytohormone signaling and citrulline metabolism occurred under the water deficit conditions. The C. colocynthis transcriptome data highlight the activation of a large set of drought related genes in this species, thus providing a valuable resource for future functional analysis of candidate genes in defense of drought stress.

  3. Effects of Nutrients Foliar Application on Agrophysiological Characteristics of Maize under Water Deficit Stress

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    Nour Ali SAJEDI

    2010-09-01

    Full Text Available To investigate effects of nutrients foliar application on agrophysiological characteristics of maize hybrid �KSC 704� water deficit stress conditions, an experiment was arranged in a split plot factorial based on a randomized complete block design with four replications to the Research Station of Islamic Azad University-Arak Branch, Iran in 2007-2008. Main factors studied were four irrigation levels including irrigation equal to crop water requirement, water deficit stress at eight-leaf stage (V8, blister stage (R2 and filling grain stage (R4 in the main plot. Combined levels of selenium treatment (without and with application 20 gha-1 and micronutrients (without and with application 2 lha-1 were situated in sub plots. Results showed that water deficit stress decreased grain yield 19.7% in blister stage as compared with control. Using selenium increased relative content water at R2 and R4 stages significantly. Using selenium in water deficit stress condition increased measured traits except plant height as compared with treatment without selenium. A negative antagonistic interaction was found between selenium and micronutrients on some measured traits. Between treatments of water deficit stress, highest grain yield equal 6799.52 and 6736.97 kgha-1 was obtained from combined treatments of water deficit stress at eight-leaf stage+without selenium+without micronutrients and water deficit stress at eight-leaf stage+selenium+without micronutrients respectively which compared with treatment of irrigation equal to crop water requirement+selenium+microelements did not differ significant. According to the results of experiment, it is concluded that with micronutrients fertilizer spray under optimum irrigation and selenium spray under water deficit obtain optimum yield.

  4. Tall fescue endophyte effects on tolerance to water-deficit stress

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    Nagabhyru, Padmaja; Dinkins, Randy D; Wood, Constance L; Bacon, Charles W.; Schardl, Christopher L.

    2013-01-01

    Background The endophytic fungus, Neotyphodium coenophialum, can enhance drought tolerance of its host grass, tall fescue. To investigate endophyte effects on plant responses to acute water deficit stress, we did comprehensive profiling of plant metabolite levels in both shoot and root tissues of genetically identical clone pairs of tall fescue with endophyte (E+) and without endophyte (E-) in response to direct water deficit stress. The E- clones were generated by treating E+ plants with fun...

  5. Response of Maize to Nutrients Foliar Application Under Water Deficit Stress Conditions

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    N. A. Sajedi

    2009-01-01

    Full Text Available Problem statement: To investigate the effect of nutrient application on agronomical characteristic and water use efficiency under water deficit stress of hybrid maize 704, an experiment was arranged in a split plot factorial based on a complete randomized block design with four replicates in the research station of Islamic Azad University-Arak Branch, Iran in 2007. Approach: Main factors studied were four irrigation levels including irrigation equal to crop water requirement, water deficit stress at eight-leaf stage (V8, stage of blister (R2 and stage of filling grain in the main plot. Combined levels of selenium treatment (without and with application 20 g ha-1 were applied 2 weeks before execution of water stress treatment and micronutrients (without and with application that was provided by specific fertilizer for maize called "Biomin", which contained Fe, Zn, Cu, Mn, B, Mo and Mg in the form of foliar application at six-leaf stage and 1 week before tasseling stage at the rate of 2 L ha-1 were situated in sub plots. Results: Results indicated that effect of water deficit stress on 1000 grain weight, grain yield, harvest index and water use efficiency at different growth stages was significant at 1% level. Water deficit stress decreased grain yield 33% in grain filling stage as compared with control. Using selenium increased mentioned traits but the increase was non significant. Effects of twofold interactions of water deficit stress and selenium showed that using selenium in water deficit stress condition increased measured traits as compared with treatment without selenium. A negative antagonistic interaction was found between selenium and micronutrients on some measured traits. In between treatments of water deficit stress, highest grain yield (8159.33 kg ha-1 was obtained from combined treatment of water deficit stress at eight-leaf stage with selenium application and without micronutrients which compared with treatment of irrigation equal

  6. Does morphological and anatomical plasticity during the vegetative stage make wheat more tolerant of water deficit stress than rice?

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    Kadam, N.N.; Yin, X.; Bindraban, P.S.; Struik, P.C.; Jagadish, K.S.V.

    2015-01-01

    Water scarcity and the increasing severity of water deficit stress are major challenges to sustaining irrigated rice (Oryza sativa) production. Despite the technologies developed to reduce the water requirement, rice growth is seriously constrained under water deficit stress compared with other

  7. The Response of Rice Root to Time Course Water Deficit Stress-Two Dimensional Electrophoresis Approach

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    Mahmood Toorchi

    2015-11-01

    Full Text Available Rice (Oryza sativa L. is the staple food of more than half of the population worldwide. Water deficit stress is one of the harsh limiting factors for successful production of crops. Rice during its growing period comes a cross different environmental hazards like drought stress. Recent advance in molecular physiology are promising for more progress in increasing rice yield by identification of novel candidate proteins for drought tolerance. To investigate the effect of water deficit on rice root protein expression pattern, an experiment was conducted in completely randomize design with four replications. With holding water for 24, 36 and 48 hours along with control constituted the experimental treatments. The experiment was conducted in growth chamber under controlled condition and root samples, after stress imposition, were harvested for two-dimensional electrophorese (2-DE. Proteome analysis of root tissue by 2-DE indicated that out of 135 protein spots diagnosed by Coomassie blue staining, 14 spots showed significant expression change under water deficit condition, seven of them at 1% and the other seven at 5% probability levels. Differentially changed proteins were taken into account for search in data bank using isoelectric point and molecular weight to identify the most probable responsive proteins. Up- regulation of ferredoxin oxidoreductase at first 24 hour after applying stress indicates the main role of this protein in reducing water deficit stress effects. On the other hand ribosomal proteins, GAP-3 and ATP synthase were down regulated under water deficit stress. Fructose 1,6-bisphosphate aldolase, glucose- 6-phosphate dehydrogenase and chitinase down regulated up to 36 h of stress imposition but, were later up- regulated by prolonging stress up to 48 h. It could be inferred the plant tries to decrease the effect of oxidative stress.

  8. Tomato plants ectopically expressing Arabidopsis CBF1 show enhanced resistance to water deficit stress.

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    Hsieh, Tsai-Hung; Lee, Jent-turn; Charng, Yee-yung; Chan, Ming-Tsair

    2002-10-01

    A DNA cassette containing an Arabidopsis C repeat/dehydration-responsive element binding factor 1 (CBF1) cDNA and a nos terminator, driven by a cauliflower mosaic virus 35S promoter, was transformed into the tomato (Lycopersicon esculentum) genome. These transgenic tomato plants were more resistant to water deficit stress than the wild-type plants. The transgenic plants exhibited growth retardation by showing dwarf phenotype, and the fruit and seed numbers and fresh weight of the transgenic tomato plants were apparently less than those of the wild-type plants. Exogenous gibberellic acid treatment reversed the growth retardation and enhanced growth of transgenic tomato plants, but did not affect the level of water deficit resistance. The stomata of the transgenic CBF1 tomato plants closed more rapidly than the wild type after water deficit treatment with or without gibberellic acid pretreatment. The transgenic tomato plants contained higher levels of Pro than those of the wild-type plants under normal or water deficit conditions. Subtractive hybridization was used to isolate the responsive genes to heterologous CBF1 in transgenic tomato plants and the CAT1 (CATALASE1) was characterized. Catalase activity increased, and hydrogen peroxide concentration decreased in transgenic tomato plants compared with the wild-type plants with or without water deficit stress. These results indicated that the heterologous Arabidopsis CBF1 can confer water deficit resistance in transgenic tomato plants.

  9. Tall fescue endophyte effects on tolerance to water-deficit stress

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    2013-01-01

    Background The endophytic fungus, Neotyphodium coenophialum, can enhance drought tolerance of its host grass, tall fescue. To investigate endophyte effects on plant responses to acute water deficit stress, we did comprehensive profiling of plant metabolite levels in both shoot and root tissues of genetically identical clone pairs of tall fescue with endophyte (E+) and without endophyte (E-) in response to direct water deficit stress. The E- clones were generated by treating E+ plants with fungicide and selectively propagating single tillers. In time course studies on the E+ and E- clones, water was withheld from 0 to 5 days, during which levels of free sugars, sugar alcohols, and amino acids were determined, as were levels of some major fungal metabolites. Results After 2–3 days of withholding water, survival and tillering of re-watered plants was significantly greater for E+ than E- clones. Within two to three days of withholding water, significant endophyte effects on metabolites manifested as higher levels of free glucose, fructose, trehalose, sugar alcohols, proline and glutamic acid in shoots and roots. The fungal metabolites, mannitol and loline alkaloids, also significantly increased with water deficit. Conclusions Our results suggest that symbiotic N. coenophialum aids in survival and recovery of tall fescue plants from water deficit, and acts in part by inducing rapid accumulation of these compatible solutes soon after imposition of stress. PMID:24015904

  10. Effect of water deficit stress on yield, physiological and biochemical parameters of two Iranian cantaloupe accessions

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    Hadi Lotfi

    2016-06-01

    Full Text Available Water deficit stress is one of the most important environmental factors limitting plant growth and crop production. In order to evaluate the tolerance of two Iranian melons to water deficit stress, an experiment in research filed of University of Zanjan was conducted. Treatments consisted of three Irrigation levels, starting irrigation at (100, 66 and 33 % Crop Evapotranspiration and two accessions of Iranian cantaloupes (Tile-Zard and Tile-Sabz. In this experiment, total chlorophyll content, carotenoids, proline content, leaf relative water content (RWC, ascorbic acid, peroxidase and catalase activity, yield and water use efficiency (WUE were evaluated. The results indicated that water deficit stress significantly increased proline content, peroxidase and catalase activity and WUE, but decreased RWC, yield and total chlorophyll content. The highest increase in proline content (34.8 %, catalase (18 % and proxidase (42.3 % activity and reduction in yield (61.6 % and RWC (8 % was obtained in 33 % ETc Irrigation. There has been significant difference between accesesions in relation to RWC, proline, total chlorophyll and peroxidase and catalase activity. The highest value of yield and WUE was observed in 'Tile-Zard'. According to the interaction results, both accessions, 'Tile-Sabz' and 'Tile-Zard' with 63.6 % and 59.7 % Reduction in fruit yield under deficit water stress, are.

  11. Response of antioxidant system of tomato to water deficit stress and its interaction with ascorbic acid

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    Fatemeh Daneshmand

    2014-03-01

    Full Text Available Environmental stresses including water deficit stress may produce oxidants such as reactive oxygen species that damage the membrane structure in plants. Among the antioxidants, ascorbic acid has a critical role in the cell and scavenges reactive oxygen species. In this research, effects of ascorbic acid at two levels (0 and 10 mM and water deficit stress based on 3 levels of field capacity (100, 60 and 30% were studied in tomato plants. Both levels of stress increased lipid peroxidation, reduced the amount of ascorbic acid and glutathione and increased the activity of enzymes superoxide dismutase, catalase, ascorbate peroxidase, glutathione reductase, guaiacol peroxidase and reduced the growth parameters. Ascorbic acid treatment, reduced lipid peroxidation, increased ascorbic acid and glutathione levels and decreased the activity of superoxide dismutase, catalase, ascorbate peroxidase, glutathione peroxidase and guaiacol peroxidase and positive effects of ascorbic acid treatment appeared to improve the plant growth parameters.

  12. Effect of Foliar Application of Chitosan on Growth and Biochemical Characteristics of Safflower (Carthamus tinctorius L. under Water Deficit Stress

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    batool mahdavi

    2014-09-01

    Full Text Available In order to study the effects of water deficit stress and foliar application of chitosan in safflower (Carthamus tinctorius L., a pot experiment was conducted in 2009. Experimental design was a randomized complete block in factorial arrangement with three replications. Experimental factors were water deficit levels (unstressed (control and 70% available water depletion from soil (water deficit stress, chitosan concentrations (0, 0.05, 0.1%, all dissolved in 1% acetic acid along with an additional treatment of distilled water and foliar application times (before and during stem elongation. The results showed that water deficit stress reduced plant height, leaf area, shoot and root dry weight, root height and volume. Whereas, foliar application of chitosan increased mentioned traits. In addition, water deficit stress decreased chlorophyll fluorescence, chlorophyll concentration and relative water content. Carotenoid, proline and malondialdehyde (MDA content were increased in response to stress. Foliar application of chitosan increased chlorophyll fluorescence, relative water content (68.77% and chlorophyll b in the water deficit stressed plants, whereas decreased MDA content. The results of the present study indicate that application of chitosan can reduce the harmful effects of water deficit and improve plant growth.

  13. Reactive oxygen species regulate leaf pulvinus abscission zone cell separation in response to water-deficit stress in cassava.

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    Liao, Wenbin; Wang, Gan; Li, Yayun; Wang, Bin; Zhang, Peng; Peng, Ming

    2016-01-01

    Cassava (Manihot esculenta Crantz) plant resists water-deficit stress by shedding leaves leading to adaptive water-deficit condition. Transcriptomic, physiological, cellular, molecular, metabolic, and transgenic methods were used to study the mechanism of cassava abscission zone (AZ) cell separation under water-deficit stress. Microscopic observation indicated that AZ cell separation initiated at the later stages during water-deficit stress. Transcriptome profiling of AZ suggested that differential expression genes of AZ under stress mainly participate in reactive oxygen species (ROS) pathway. The key genes involved in hydrogen peroxide biosynthesis and metabolism showed significantly higher expression levels in AZ than non-separating tissues adjacent to the AZ under stress. Significantly higher levels of hydrogen peroxide correlated with hydrogen peroxide biosynthesis related genes and AZ cell separation was detected by microscopic observation, colorimetric detection and GC-MS analyses under stress. Co-overexpression of the ROS-scavenging proteins SOD and CAT1 in cassava decreased the levels of hydrogen peroxide in AZ under water-deficit stress. The cell separation of the pulvinus AZ also delayed in co-overexpression of the ROS-scavenging proteins SOD and CAT1 plants both in vitro and at the plant level. Together, the results indicated that ROS play an important regulatory role in the process of cassava leaf abscission under water-deficit stress.

  14. Interaction of Methanol Spray and Water-Deficit Stress on Photosynthesis and Biochemical Characteristics of Phaseolus vulgaris L. cv. Sadry.

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    Armand, Nezam; Amiri, Hamzeh; Ismaili, Ahmad

    2016-01-01

    This study was a factorial experiment with a completely randomized design and three replications. The four levels of methanol spraying were used. Spraying was carried out three times during the growing season at 10-day intervals beginning at 4 weeks after sowing. The spraying of solution continued until saturation of droplets on the leaves was achieved. The levels of water-deficit stress applied were nonstress, moderate water stress and severe water stress. The results showed that there was a significant difference (P ≤ 0.05) between the methanol and water-deficit stress treatments for chlorophyll (Chl) a and Chl b, carotenoid, total chlorophyll, net photosynthesis (PN ), intercellular CO2 (Ci ), maximal quantum yield of photosystem II photochemistry (Fv /Fm ), leaf moisture, water use efficiency and relative water content. The application of foliar methanol at all levels of water-deficit stress significantly decreased the catalase activity of the roots. Under all levels of water-deficit stress, the 30% (v/v) methanol treatment significantly decreased peroxidase activity in the roots over that for the control. The results suggest that foliar application of methanol can decrease the negative effects of water-deficit stress on Phaseolus vulgaris L. cv. Sadry.

  15. Does morphological and anatomical plasticity during the vegetative stage make wheat more tolerant of water deficit stress than rice?

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    Kadam, Niteen N; Yin, Xinyou; Bindraban, Prem S; Struik, Paul C; Jagadish, Krishna S V

    2015-04-01

    Water scarcity and the increasing severity of water deficit stress are major challenges to sustaining irrigated rice (Oryza sativa) production. Despite the technologies developed to reduce the water requirement, rice growth is seriously constrained under water deficit stress compared with other dryland cereals such as wheat (Triticum aestivum). We exposed rice cultivars with contrasting responses to water deficit stress and wheat cultivars well adapted to water-limited conditions to the same moisture stress during vegetative growth to unravel the whole-plant (shoot and root morphology) and organ/tissue (root anatomy) responses. Wheat cultivars followed a water-conserving strategy by reducing specific leaf area and developing thicker roots and moderate tillering. In contrast, rice 'IR64' and 'Apo' adopted a rapid water acquisition strategy through thinner roots under water deficit stress. Root diameter, stele and xylem diameter, and xylem number were more responsive and varied with different positions along the nodal root under water deficit stress in wheat, whereas they were relatively conserved in rice cultivars. Increased metaxylem diameter and lower metaxylem number near the root tips and exactly the opposite phenomena at the root-shoot junction facilitated the efficient use of available soil moisture in wheat. Tolerant rice 'Nagina 22' had an advantage in root morphological and anatomical attributes over cultivars IR64 and Apo but lacked plasticity, unlike wheat cultivars exposed to water deficit stress. The key traits determining the adaptation of wheat to dryland conditions have been summarized and discussed. © 2015 American Society of Plant Biologists. All Rights Reserved.

  16. Role of Bradyrhizobium japonicum induced by genistein on soybean stressed by water deficit

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    Napoles, M. C.; Guevara, E.; Montero, F.; Roosi, A.; Ferreira, A.

    2009-07-01

    Abstract The soybean (Glycine max (L.) Merr.) is a crop mainly grown under rain fed conditions although irrigation is increasingly being used. Water deficiency is the main factor limiting seed production. The symbiosis process is also negatively affected by water stress. The isoflavone genistein have been recognized as a powerful inducer of Nod factors production by Bradyrhizobium and its addition to inocula has been shown to increase nodule number and promote soybean nitrogen (N) fixation at low temperatures. This study looks for answers about the possible role of genistein in countering the stress on nodulation produced by water deficit in soybeans. Bradyrhizobium japonicum SEMIA 5079 was grown in culture media induced or not induced with genistein. Inocula were applied to plants growing at different moisture levels. The effect of the treatments on nodulation and N content was evaluated. An improved response to drought stress was observed when the bacteria were grown in presence of genistein as a Nod factors inducer. Nodulation values under moisture stress differed from 8.9 nodules plant{sup -}1 with genistein at 10 {mu}M to 1.8 nodules plant{sup -}1 when no inducer was used. Genistein reduced the negative effect on nodulation caused by water deficiency. (Author) 43 refs.

  17. Silicon improves seed germination and alleviates oxidative stress of bud seedlings in tomato under water deficit stress.

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    Shi, Yu; Zhang, Yi; Yao, Hejin; Wu, Jiawen; Sun, Hao; Gong, Haijun

    2014-05-01

    The beneficial effects of silicon on plant growth and development under drought have been widely reported. However, little information is available on the effects of silicon on seed germination under drought. In this work, the effects of exogenous silicon (0.5 mM) on the seed germination and tolerance performance of tomato (Solanum lycopersicum L.) bud seedlings under water deficit stress simulated by 10% (w/v) polyethylene glycol (PEG-6000) were investigated in four cultivars ('Jinpengchaoguan', 'Zhongza No.9', 'Houpi L402' and 'Oubao318'). The results showed that the seed germination percentage was notably decreased in the four cultivars under water stress, and it was significantly improved by added silicon. Compared with the non-silicon treatment, silicon addition increased the activities of superoxide dismutase (SOD) and catalase (CAT), and decreased the production of superoxide anion (O2·) and hydrogen peroxide (H2O2) in the radicles of bud seedlings under water stress. Addition of silicon decreased the total phenol concentrations in radicles under water stress, which might contribute to the decrease of peroxidase (POD) activity, as observed in the in vivo and in vitro experiments. The decrease of POD activity might contribute to a less accumulation of hydroxyl radical (·OH) under water stress. Silicon addition also decreased the concentrations of malondialdehyde (MDA) in the radicles under stress, indicating decreased lipid peroxidation. These results suggest that exogenous silicon could improve seed germination and alleviate oxidative stress to bud seedling of tomato by enhancing antioxidant defense. The positive effects of silicon observed in a silicon-excluder also suggest the active involvement of silicon in biochemical processes in plants.

  18. Effects of Water Deficit Stress on Several Quantitative and Qualitative Characteristics of Canola (Brassica napus L. Cultivars

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    Mohammad HOSSEINI

    2011-08-01

    Full Text Available Water deficit stress considered as one of the most important limiting factors for oil seed canola (Brassica napus L. growth and productivity in Iran. To evaluate the effects of water deficit stress on some qualitative and quantitative characteristics of canola cultivars, this experiment in a greenhouse trial carried out as factorial based on completely randomized design with three replications in Shahid Chamran University of Ahwaz (Iran. Canola cultivars, including ‘Hyola 308’, ‘Hyola 401’ and ‘RGS 003’ as first factor, and the second one was three levels of water deficit stress, including stress at early stem elongation stage to early flowering (D1, early flowering stage to early emergence of sacs (D2, beginning of stem elongation stage to early emergence of sacs (D3 and normal irrigation (C, as check. Results showed that the interaction between water deficit stress and cultivars affected biological yield, seed oil yields and harvest index (p≤0.01, dry matter and economic yield (p≤0.05. Water deficit stress reduced grain oil yields. ‘Hyola 308’ under stress at beginning stem elongation stage to early flowering had the lowest oil yields (1.1 g plants-1 and ‘Hyola 401’ under non-stress conditions showed highest oil yields (4.3 g plants-1. The decrease of oil yields at the flowering stage to stem elongation stage was more than the other stages. In addition, water deficit stress reduced harvest index in the three stress levels due to reduced economic yield and reduced biological yield. Stress susceptibility index for ‘Hyola 401’ at the beginning of stem elongation stage to early emergence of sacs was 0.914 and the ‘Hyola 308’ showed 1.12 at the beginning of stem elongation stage to early emergence of sacs respectively, which it can implies that ‘Hyola 308’ is more sensitive than ‘Hyola 401’ to water deficit stress.

  19. Agronomic evaluation of Rapessed varieties (Brassica napus L. in Response to Late-Season Water Deficit Stress

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    Amir Hossein Shirani Rad

    2014-11-01

    Full Text Available Drought is a wide spread limiting problem seriously influencing rapeseed (Brassica napus L. growth, production and quality, mostly in dryland regions. However, identification and development of resistant varieties is prohibited by destitute of effective selection criteria. The aim of this study was to evaluate the prevention possibility of rapeseed varieties against terminal-season water deficit stress through selecting suitable varieties. Thirty-four rapeseed varieties were tested in a split plot design based on randomized complete block design (RCBD with four replications for two years (2005- 2006 and 2006-2007 at Seed and Plant Improvement Institute of Karaj, Iran. Two irrigation levels consisting of irrigation after 80 mm evaporation from class “A” pan during full growing season as normal irrigation (I and water deficit stress (S by restricting watering from the flowering phase until full maturity were established in main plots, and subplots were devoted to split application of varieties. Water deficit stress caused noticeable decrease in plant height, silique plant-1, seed silique-1, 1000-kernel weight, seed yield, oil percentage, oil yield and harvest index. There were significant positive correlations between seed yield and yield-related components. Meanwhile, the highest correlation was recorded for number of seeds per siliqua (r= 0.64; P -1 and oil yield (2317 kg ha-1 in normal irrigation, and ‘ORW20-3002’ had the highest seed yield (2348 kg ha-1 and oil yield (1000 kg ha-1 in water deficit stress conditions. Accordingly, ‘ORW20-3002’ and ‘Sunday’ can be reported as varieties with sustainable productivity in stress and non-stress conditions.

  20. Effect of phosphate solubilizing microorganisms on quantitative and qualitative characteristics of maize (Zea mays L.) under water deficit stress.

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    Ehteshami, S M R; Aghaalikhani, M; Khavazi, K; Chaichi, M R

    2007-10-15

    The effect of seed inoculation by phosphate solubilizing microorganisms on growth, yield and nutrient uptake of maize (Zea mays L. SC. 704) was studied in a field experiment. Positive effect on plant growth, nutrient uptake, grain yield and yield components in maize plants was recorded in the treatment receiving mixed inoculum of Glomus intraradices (AM) and Pseudomonas fluorescens (Pf). Co-inoculation treatment significantly increased grain yield, yield components, harvest index, grain N and P, soil available P, root colonization percentage and crop WUE under water deficit stress. In some of investigated characteristics under well-watered conditions, chemical fertilizer treatment was higher than double inoculated treatments, but this difference was not significant. Seed inoculation only with AM positively affected the measured parameters as amount as co-inoculated treatments. According to the results showed in contrast to the inoculated treatments with AM+Pf and AM, the application of alone Pf caused a comparatively poor response. Therefore, this microorganism needs to a complement for its activity in soil. All of measured parameters in inoculated treatments were higher than uninoculated treatments under water deficit stress conditions. Furthermore, the investigated characteristics of co-inoculated plants under severe water deficit stress conditions were significantly lower than co-inoculated plants under well-watered and moderate-stressed conditions. Therefore it could be stated, these microorganisms need more time to fix and establishing themselves in soil. The present finding showed that phosphate-solubilizing microorganisms can interact positively in promoting plant growth as well as P uptake of maize plants, leading to plant tolerance improving under water deficit stress conditions.

  1. A tomato bZIP transcription factor, SlAREB, is involved in water deficit and salt stress response.

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    Hsieh, Tsai-Hung; Li, Chia-Wen; Su, Ruey-Chih; Cheng, Chiu-Ping; Sanjaya; Tsai, Yi-Chien; Chan, Ming-Tsair

    2010-05-01

    Abiotic stresses such as cold, water deficit, and salt stresses severely reduce crop productivity. Tomato (Solanum lycopersicum) is an important economic crop; however, not much is known about its stress responses. To gain insight into stress-responsive gene regulation in tomato plants, we identified transcription factors from a tomato cDNA microarray. An ABA-responsive element binding protein (AREB) was identified and named SlAREB. In tomato protoplasts, SlAREB transiently transactivated luciferase reporter gene expression driven by AtRD29A (responsive to dehydration) and SlLAP (leucine aminopeptidase) promoters with exogenous ABA application, which was suppressed by the kinase inhibitor staurosporine, indicating that an ABA-dependent post-translational modification is required for the transactivation ability of SlAREB protein. Electrophoretic mobility shift assays showed that the recombinant DNA-binding domain of SlAREB protein is able to bind AtRD29A and SlLAP promoter regions. Constitutively expressed SlAREB increased tolerance to water deficit and high salinity stresses in both Arabidopsis and tomato plants, which maintained PSII and membrane integrities as well as water content in plant bodies. Overproduction of SlAREB in Arabidopsis thaliana and tomato plants regulated stress-related genes AtRD29A, AtCOR47, and SlCI7-like dehydrin under ABA and abiotic stress treatments. Taken together, these results show that SlAREB functions to regulate some stress-responsive genes and that its overproduction improves plant tolerance to water deficit and salt stress.

  2. Evaluating effect of biofertilizer on nodulation and soybean (Glycine max L plants growth characteristics under water deficit stress of seed

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    M. Tajik Khaveh

    2016-05-01

    Full Text Available In order to evaluate the effects of biofertilizer on soybean (Glycine max L. seed vigor that produced under water deficit condition and related traits, an experiment was conducted in a factorial layout based of complete randomized block design with four replications at the research greenhouse of Aboureihan campus- Tehran University, Iran. Experimental treatments were include biofertilizer (seed inoculation with Bradyrhizobium japonicum, co-inoculation with Bradyrhizobium japonicum and Pseudomonas fluorescens, co-inoculation with Bradyrhizobium japonicum and Glomus mosseae, Cultivar (Zalta Zalha and Clark×Hobbit line and water deficit stress [irrigation plants after 50 (normal irrigation, 100 (medium stress, 150 (sever stress mm evaporation from pan class A, in parents field]. Results showed that the water deficit stress had negative effects on seed quality and seedling emergence percentage, mean daily seedling emergence, root, leaf and shoot dry weight, number of nodule were decreased. ZaltaZalha cultivar had higher shoot dry weight and number of leaf compared with other cultivars. Applications of biofertilzer was effective on stem diameter, root, leaf and shoot dry weight, number of leaf and nodule and those attributes increased by co-inoculation of Bradyrhizobium japonicum and Glomus mosseae. Also, use of biofertilizer in stress levels was effective on stem dry weight. Stem dry weight was increased by Co-inoculation of cultivar seeds with Bradyrhizobium japonicum and Glomus mosseae.

  3. Three cycles of water deficit from seed to young plants of Moringa oleifera woody species improves stress tolerance.

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    Rivas, Rebeca; Oliveira, Marciel T; Santos, Mauro G

    2013-02-01

    The main objective of this study was to assess whether recurring water stress occurring from seed germination to young plants of Moringa oleifera Lam. are able to mitigate the drought stress effects. Germination, gas exchange and biochemical parameters were analysed after three cycles of water deficit. Young plants were used 50 days after germination under three osmotic potentials (0.0, -0.3 and -0.4 MPa). For each germination treatment, control (irrigated) and stressed (10% of water control) plants were compared for a total of six treatments. There were two cycles of drought interspersed with 10 days of rehydration. The young plants of M. oleifera showed increased tolerance to repeated cycles of drought, maintaining high relative water content (RWC), high water use efficiency (WUE), increased photosynthetic pigments and increased activity of antioxidant enzymes. There was rapid recovery of the photosynthetic rate during the rehydration period. The stressed plants from the -0.3 and -0.4 MPa treatments showed higher tolerance compared to the control plants. The results suggest that seeds of M. oleifera subjected to mild water deficit have had increased the ability for drought tolerance when young plant.

  4. Effects of External Chemical Regulation on Bt Transgenic Cotton Plants under Combined Stress of High Temperature and Water Deficit

    Institute of Scientific and Technical Information of China (English)

    ZHOU Gui-sheng; ZHANG Wang-ding; TONG Chen; LIN Yan; AN Lin-lin; LIU Gui-juan

    2011-01-01

    [Objective] The study aimed to find a possible way to combat or alleviate the negative effects caused by high temperature and water deficit at the growth stage of peak boll-setting.[Method] With Bt transgenic cotton GK22 as the test cultivar,a potted experiment was carried out to investigate the effects of the regulation of external substances(the water solutions of pix,urea and their mixture) on the physiological parameters,insecticidal protein content,yield and yield component of cotton plants in artificial climate chambers treated with high temperature and water deficit.[Result] The application of external pix,urea or their mixture was effective in stabilizing the physiological parameters of cotton plants,insecticidal protein content,yield and yield components.Compared with the exclusive application of pix and urea,the mixture of pix and urea played the most effective role in stabilizing the content of chlorophyll,soluble sugar and insecticidal protein,alleviating the increase of the content of free amino acids and proline,and increasing boll number per plant,boll weight and seed cotton yield.[Conclusion] The water solutions of pix,urea or their mixtures can be used to combat or alleviate the stress of high temperature and water deficit if they are sprayed onto cotton plants prior to stress occurrence.

  5. ROOT WATER-UPTAKE AND PLANT GROWTH IN TWO SYNTHETIC HEXAPLOID WHEAT GENOTYPES GROWN IN SALINE SOIL UNDER CONTROLLED WATER-DEFICIT STRESS

    Directory of Open Access Journals (Sweden)

    Masanori Inagaki

    2016-02-01

    Full Text Available A key breeding objective for bread wheat grown in the dry regions of Western Asia and North Africa is to enhance its adaptation to drought and its related salinity. Two newly-developed genotypes of synthetic hexaploid wheat, ‘SW-3’ and ‘SW-4’, their parental durum wheat variety ‘Jennah Khetifa’ and a dry-land bread wheat variety ‘Cham 6’, were compared for plant growth in saline hydroponic culture. They were also compared for root water-uptake and growth in soil culture in pots under combined water deficit and salinity stresses. Under saline hydroponic culture for five weeks, ‘SW-3’ developed a larger leaf area than the other genotypes. In saline soils for the period up to maturity, ‘SW-4’ and ‘Cham 6’ had higher root water uptake than the others. Only ‘SW-4’ developed normal grains and was clearly tolerant of soil salinity. ‘Cham 6’ developed normal spikes but ceased to fill the grains after heading. It may be assumed that salinity stress depressed root water-uptake at the early stages of growth, but the toxic effects of salinity stress increased in the later stages. The four wheat genotypes used in this study responded differently to salinity stress whereas water-deficit stress resulted in relatively few genotypic differences. ‘SW-4’ was more tolerant of soil salinity than its durum wheat variety parent ‘Jennah Khetifa’. This could be a useful genetic resource for improving ‘Cham 6’, which was relatively tolerant of water-deficit stress but sensitive to salinity stress after heading.

  6. ABA is required for the accumulation of APX1 and MBF1c during a combination of water deficit and heat stress

    Science.gov (United States)

    Zandalinas, Sara I.; Balfagón, Damián; Arbona, Vicent; Gómez-Cadenas, Aurelio; Inupakutika, Madhuri A.; Mittler, Ron

    2016-01-01

    Abscisic acid (ABA) plays a key role in plant acclimation to abiotic stress. Although recent studies suggested that ABA could also be important for plant acclimation to a combination of abiotic stresses, its role in this response is currently unknown. Here we studied the response of mutants impaired in ABA signalling (abi1-1) and biosynthesis (aba1-1) to a combination of water deficit and heat stress. Both mutants displayed reduced growth, biomass, and survival when subjected to stress combination. Focusing on abi1-1, we found that although its stomata had an impaired response to water deficit, remaining significantly more open than wild type, its stomatal aperture was surprisingly reduced when subjected to the stress combination. Stomatal closure during stress combination in abi1-1 was accompanied by higher levels of H2O2 in leaves, suggesting that H2O2 might play a role in this response. In contrast to the almost wild-type stomatal closure phenotype of abi1-1 during stress combination, the accumulation of ascorbate peroxidase 1 and multiprotein bridging factor 1c proteins, required for acclimation to a combination of water deficit and heat stress, was significantly reduced in abi1-1. Our findings reveal a key function for ABA in regulating the accumulation of essential proteins during a combination of water deficit and heat stress. PMID:27497287

  7. Water deficit during pit hardening enhances phytoprostanes content, a plant biomarker of oxidative stress, in extra virgin olive oil.

    Science.gov (United States)

    Collado-González, Jacinta; Pérez-López, David; Memmi, Houssem; Gijón, M Carmen; Medina, Sonia; Durand, Thierry; Guy, Alexandre; Galano, Jean-Marie; Ferreres, Federico; Torrecillas, Arturo; Gil-Izquierdo, Angel

    2015-04-15

    No previous information exists on the effects of water deficit on the phytoprostanes (PhytoPs) content in extra virgin olive oil from fruits of mature olive (Olea europaea L. cv. Cornicabra) trees during pit hardening. PhytoPs profile in extra virgin olive oil was characterized by the presence of 9-F1t-PhytoP, 9-epi-9-F1t-PhytoP, 9-epi-9-D1t-PhytoP, 9-D1t-PhytoP, 16-B1-PhytoP + ent-16-B1-PhytoP, and 9-L1-PhytoP + ent-9-L1-PhytoP. The qualitative and quantitative differences in PhytoPs content with respect to those reported by other authors indicate a decisive effect of cultivar, oil extraction technology, and/or storage conditions prone to autoxidation. The pit hardening period was critical for extra virgin olive oil composition because water deficit enhanced the PhytoPs content, with the concomitant potential beneficial aspects on human health. From a physiological and agronomical point of view, 9-F1t-PhytoP, 9-epi-9-F1t-PhytoP, and 16-B1-PhytoP + ent-16-B1-PhytoP could be considered as early candidate biomarkers of water stress in olive tree.

  8. 水分胁迫对植物基因表达的影响%Effect of Water-Deficit Stress on Plant Gene Expression

    Institute of Scientific and Technical Information of China (English)

    谢深喜; 张秋明; 熊兴耀; Carol Lavatt

    2005-01-01

    Many changes in gene expression occur in response to water-deficit stress. These changes may lead to cellular adaptation of water-deficit stress. A challenge is to determine which changes support plant adaptation to conditions of reduced soil water content and which occur in response to lesions in metabolic and cellular functions. Most work in this field has concentrated on the responses to water-deficit stress at the cellular level, but as people's understanding improves, it will be important to develop a framework to integrate the cellular responses with whole plant responses. Therefore, this paper reviewed the whole reaction of plant to the water-deficit stress on sensing cellular water deficit, genes regulated by the water-deficit stress and regulation of ABA synthesis.%水分胁迫会引起植物基因表达发生变化,这些变化可能导致植物从细胞水平上进行调节,并适应这种水分胁迫的环境.虽然前人从细胞水平上对水分胁迫的反映进行了大量的研究,但随着研究的不断深入,人们发现从分子水平上弄清楚植物对胁迫的反应显得更为重要.就植物细胞对水分胁迫感知、基因表达调控及ABA的合成与调控方面进行了综述.

  9. The comparative study of anatomical structure of stem and ovule development of four cultivars of Glycine max L. merr in water deficit stress

    Directory of Open Access Journals (Sweden)

    Parissa Jonoubi

    2014-08-01

    Full Text Available Drought stress is one of the most important limiting factors that affect different aspects of plants vegetative and reproductive growth. It is one of the most important limiting factors of crop productivity. Regarding to the importance of soybean as an oilseed plant, and in order to identify the drought tolerant cultivars as well as evaluating of the effects of drought stress on anatomical structureof four soybean cultivars (Clin, Clark, M9 and L17, two series of experiments were carried out as randomized complete design. In the first experiment, at optimum conditions, plants were irrigated after 50 mm evaporation from germination to the end of growing period, whereas the second experiment was irrigated after 150 mm (sever stress evaporation from evaporation pan. The results showed that the effect of water deficit stress on cortex thickness and number of layers, Phloem and xylem thickness, diameter of vessel elements, number of vessel element rows, number of vessel elements in stem, pith and stele thickness, stem diameter and number of trichomes were significant. Relative acceleration of embryo sac development was observed in all plants under water deficit stress except for Clark cultivar. Evaluation of anatomical factors on these cultivars showed that Clin cultivar was more tolerant to water deficit stress compared to other cultivars.

  10. Weak microwave can alleviate water deficit induced by osmotic stress in wheat seedlings.

    Science.gov (United States)

    Chen, Yi-Ping; Jia, Jing-Fen; Han, Xiao-Ling

    2009-01-01

    The aim of the investigation is to determine the effect of microwave pretreatment of wheat seeds on the resistance of seedlings to osmotic stress. Changes in biophysical, physiological and biochemical characters were measured. The results showed: (1) The magnetic field intensity and seeds temperature increased progressively with microwave pretreatments of 5, 10, 15, 20 s and 25 s compared with controls. Although each microwave pretreatment resulted in an increase in alpha-amylase activity and photon emission intensity, the increase of alpha-amylase activity and photon emission intensity was maximal at a microwave pretreatment of 10 s. (2) Osmotic stress induced by PEG treatment enhanced the concentration of malondialdehyde, while decreasing the activities of nitricoxide synthase, catalase, peroxidase, superoxide dismutase and the concentration of nitric oxide, ascorbic acid, glutathione in the seedlings compared with controls. However, compared to osmotic stress alone, in the seedlings treated with microwave irradiation plus osmotic stress the concentration of malondialdehyde decreased, while the activities of nitricoxide synthase, catalase, peroxidase, superoxide dismutase and the concentration of nitric oxide, ascorbic acid and glutathione increased. These results suggest that a suitable dose of microwave radiation can enhance the capability to eliminate free radicals induced by osmotic stress in wheat seedlings resulting in an increase in resistance to osmotic stress.

  11. Proline Accumulation, Photosynthetic Abilities and Growth Characters of Sugarcane (Saccharum officinarum L.) Plantlets in Response to Iso-Osmotic Salt and Water-Deficit Stress

    Institute of Scientific and Technical Information of China (English)

    Suriyan Cha-um; Chalennpol Kirdmanee

    2009-01-01

    The aim of this study was to investigate the biochemical, physiological and morphological responses of sugarcane to iso-osmotic salt and water-deficit stress. Disease-free sugarcane plantlets derived from meristem cuttings were photo-autotrophically grown in MS media and subsequently exposed to-0.23 (control), -0.67 or -1.20 Mpa iso-osmotic NaCI (salt stress) or mannitol (water-deficit stress). Chlorophyll a (Chl a), chlorophyll b (Chl b), total carotenoids (Cx+c), maximum quantum yield of PSⅡ(Fv/Fm), photon yield of PSⅡ(φPSⅡ), stomatal conductance(Gs)and transpiration rate(E)in the stressed plantlets were significantly reduced when compared to those of plantlets of the control group (without mannitol or NaCI), leading to net-photosynthetic rate (Pn) and growth reduction with positive correlation. In addition, physiological changes and growth parameters of plantlets in the salt stress conditions were more sharply reduced than those in water-deficit stress conditions. On the other hand, the proline content and non-photochemical quenching (NPQ) in the leaves of stressed plantlets increased significantly, especially in response to iso-osmotic salt stress. The chlorophyll pigments in iso-osmotic stressed leaves were significantly degraded (r2=0.93), related to low water oxidation (r2=0.87), low net-photosynthetic rate (r2=0.81), and growth reduction (r2=0.97). The multivariate biochemical, physiological and growth parameters in the present study should be further used to develop salt, or drought, tolerance indices in sugarcane breeding programs.

  12. Role of inoculation with multi-trait rhizobacteria on strawberries under water deficit stress

    OpenAIRE

    Erdogan, Ummugulsum; Cakmakci, Ramazan; Varmazyarı, Atafeh; Turan, Metin; Erdogan, Yasar; Kıtır, Nurgül

    2016-01-01

    This study was conducted during 2011 and 2012 to evaluate the effect of 1-aminocyclopropane-1-carboxylate (ACC) deaminase-containing, N2-fixing and P-solubilizing bacteria on the yield and morpho-physiological parameters of strawberry. A total of 8 applications at the trial set, with four water regimes were randomly distributed into the pots. The diminishing water supply caused a gradual decrease in the plant growth, chlorophyll content and berry yield, accompanied by increasing a...

  13. Moderate water stress from regulated deficit irrigation decreases transpiration similarly to net carbon exchange in grapevine canopies

    Science.gov (United States)

    To determine the effects of timing and extent of regulated deficit irrigation (RDI) on grapevine (Vitis vinifera) canopies, whole-canopy transpiration (TrV) and canopy conductance to water vapor (gc) were calculated from whole-vine gas exchange near key stages of fruit development. The vines were ma...

  14. Intermittent swim stress causes Morris water maze performance deficits in a massed-learning trial procedure that are exacerbated by reboxetine.

    Science.gov (United States)

    Warner, Timothy A; Stafford, Nathaniel P; Rompala, Gregory R; Van Hoogenstyn, Andrew J; Elgert, Emily; Drugan, Robert C

    2013-11-15

    Various animal models of depression have been used to seek a greater understanding of stress-related disorders. However, there is still a great need for research in this area, as many unanswered questions remain. Therefore, we sought to employ a novel animal model of depression known as intermittent swim stress (ISS). In this model, the animal experiences 100 trials of cold water swim stress. ISS has already shown subsequent immobility in the forced swim test (FST), deficits in instrumental and spatial (spaced-trial procedure), and responsiveness to norepinephrine. We are now examining how this will translate in the Morris water maze for rats in a massed-learning trial procedure, and further assessing ISS sensitivity toward norepinephrine selective anti-depressant drugs. The results indicated no difference in cued learning when the platform was visible in the water maze, but a hidden platform task revealed poorer spatial learning for ISS-exposed rats versus controls. In terms of spatial memory, there was a notable ISS-induced deficit 1h after the learning trials, regardless of performance on the previous platform task. Interestingly, the administration of reboxetine interfered with the spatial learning and memory trials for both ISS and CC groups. As a result, ISS exposure compromised spatial learning and memory in the Morris water maze, and norepinephrine does not appear to be a mediator of this deficit. The results demonstrate a key difference in the effects of reboxetine in a massed- vs. spaced-learning trial procedure in the Morris water maze following ISS exposure.

  15. A Soil-Plate Based Pipeline for Assessing Cereal Root Growth in Response to Polyethylene Glycol (PEG-Induced Water Deficit Stress

    Directory of Open Access Journals (Sweden)

    Sven K. Nelson

    2017-07-01

    Full Text Available 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

  16. Understanding water deficit stress-induced changes in the basic metabolism of higher plants - biotechnologically and sustainably improving agriculture and the ecoenvironment in arid regions of the globe.

    Science.gov (United States)

    Shao, Hong-Bo; Chu, Li-Ye; Jaleel, C Abdul; Manivannan, P; Panneerselvam, R; Shao, Ming-An

    2009-01-01

    Water is vital for plant growth, development and productivity. Permanent or temporary water deficit stress limits the growth and distribution of natural and artificial vegetation and the performance of cultivated plants (crops) more than any other environmental factor. Productive and sustainable agriculture necessitates growing plants (crops) in arid and semiarid regions with less input of precious resources such as fresh water. For a better understanding and rapid improvement of soil-water stress tolerance in these regions, especially in the water-wind eroded crossing region, it is very important to link physiological and biochemical studies to molecular work in genetically tractable model plants and important native plants, and further extending them to practical ecological restoration and efficient crop production. Although basic studies and practices aimed at improving soil water stress resistance and plant water use efficiency have been carried out for many years, the mechanisms involved at different scales are still not clear. Further understanding and manipulating soil-plant water relationships and soil-water stress tolerance at the scales of ecology, physiology and molecular biology can significantly improve plant productivity and environmental quality. Currently, post-genomics and metabolomics are very important in exploring anti-drought gene resources in various life forms, but modern agriculturally sustainable development must be combined with plant physiological measures in the field, on the basis of which post-genomics and metabolomics have further practical prospects. In this review, we discuss physiological and molecular insights and effects in basic plant metabolism, drought tolerance strategies under drought conditions in higher plants for sustainable agriculture and ecoenvironments in arid and semiarid areas of the world. We conclude that biological measures are the bases for the solutions to the issues relating to the different types of

  17. Effect of Chemical and Biological Phosphorus on Antioxidant Enzymes Activity and Some Biochemical Traits of Spring Safflower (Carthamus tinctorius L. under Water Deficit Stress Conditions

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    S. Heshmati

    2016-05-01

    Full Text Available To study the effects of biological and chemical phosphorus on antioxidant enzyme activity in safflower under water deficit conditions, an experiment was conducted in 2012 at the Research Field of the Faculty of Agriculture, Shahed University, Tehran, Iran. The experimental design was a split-factorial with three replicates. The main factor was the three levels of irrigation treatment: full irrigation (irrigation up to 50% soil moisture depletion relative to field capacity, water stress in the vegetative and flowering stages (irrigation up to 75% soil moisture depletion relative to field capacity. The sub-factor was the six treatments resulting from three levels of phosphate chemical fertilizer (0, 50, and 100 kg ha-1 Triple Super Phosphate, each at two levels of Barvar-2 bio-fertilizer (with and without inoculation with Barvar-2. According to the results of our experiment, antioxidant enzyme activity is affected by high levels of chemical phosphorus when there is no inoculation with biofertilizer (Barvar 2 under water stress in the vegetative and flowering stages. The results showed that inoculation with Barvar 2 in the absence of added chemical phosphorus increases the catalase activity and soluble protein concentration under drought stress in the vegetative and flowering stages. Also, using chemical phosphorus followed by Barvar 2 led to increase in the polyphenol oxidase activity and superoxide dismutase activity under these conditions. Inoculation with Barvar 2 in the absence of added chemical phosphorus significantly decreased the amount of malondialdehyde under stress condition at the flowering stage. It was demonstrated that inoculation with a biological fertilizer (Barvar 2 followed by application of a chemical phosphorus fertilizer under drought conditions could decrease the detrimental effects of drought stress on spring safflower.

  18. The Effect of Chemical, Biological and Organic Nutritional Treatments on Sunflowers Yield and Yield Components under the Influence of Water Deficit Stress

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    fatemeh soleymani

    2016-07-01

    Full Text Available Introduction To achieve the higher economic yield of crop plants, supplying enough nutrients to plants is very important. Moreover, nutrient uptakes by plants is influenced by the soil water contents. However, nowadays chemical fertilizer application is important agronomic factor that has significant effects on growth and quantity and quality of final yield, but traditional nutrient management and excessive use of chemical fertilizers may cause the environmental problems such as contamination of soil and water resources, low quality of agricultural products and reduction of soil fertility. These factors have drawn attention to health and ecological sustainable farming systems (Sharma, 2002. In this context, usage of organic and biological products for plant nutrition is considered as one of the solutions to achieve the goals of sustainable agriculture. Materials and methods To evaluate the effect of various feeding systems on yield and yield components of sunflower (Helianthus annuus L. under the influence of water deficit stress, a split-plot experiment based on randomized complete block design with three replications, was carried out in the Agricultural Faculty of Bu-Ali Sina University during the growing season of 2013-2014. Main plots consisted of two irrigation levels: optimum irrigation and deficit irrigation stress (irrigation after 60 and 120 mm evaporation from evaporation pan, class A, respectively and sub-plots included of nine nutrition systems: 1- no bio or chemical fertilizer application, 2- 100% of the recommended chemical fertilizer , 3- vermicompost, 4- phospho nitro kara, 5- vermicompost+ phospho nitro kara, 6- vermicompost+ ½ chemical fertilizer, 7- phospho nitro kara+ ½ chemical fertilizer, 8- vermicompost+ phospho nitro kara+ ½ chemical fertilizer, 9- ½ proposed chemical fertilizer. Phospho-nitro-kara which contains phosphate solubilizing and nitrogen fixing bacteria (Bacillus coagulans, azotobactr chroocuccum and

  19. Osmotic adjustment and the growth response of seven vegetable crops following water-deficit stress. [Phaseolus vulgaris L. ; Beta vulgaris L. ; Abelmoschus esculentus; Pisum sativum L. ; Capsicum annuum L. ; Spinacia oleracea L. ; Lycopersicon esculentum Mill

    Energy Technology Data Exchange (ETDEWEB)

    Wullschleger, S.D. (Oak Ridge National Lab., TN (United States)); Oosterhuis, D.M. (Univ. of Arkansas, Fayetteville (United States))

    1991-09-01

    Growth-chamber studies were conducted to examine the ability of seven vegetable crops- Blue Lake beam (Phaseolus vulgaris L.) Detroit Dark Red beet (Beta vulgaris L.) Burgundy okra (Abelmoschus esculentus) (Moench), Little Marvel pea (Pisum sativum L), California Wonder bell pepper (Capsicum annuum L), New Zealand spinach (Spinacia oleracea L), and Beefsteak tomato (Lycopersicon esculentum Mill.) - to adjust osmotically in response to water-deficit stress. Water stress was imposed by withholding water for 3 days, and the adjustment of leaf and root osmotic potentials upon relief of the stress and rehydration were monitored with thermocouple psychrometers. Despite similar reductions in leaf water potential and stomatal conductance among the species studied reductions in lead water potential an stomatal conductance among the species, crop-specific differences were observed in leak and root osmotic adjustment. Leaf osmotic adjustment was observed for bean, pepper, and tomato following water-deficit stress. Root osmotic adjustment was significant in bean, okra, pea and tomato. Furthermore, differences in leaf and root osmotic adjustment were also observed among five tomato cultivars. Leaf osmotic adjustment was not associated with the maintenance of leaf growth following water-deficit stress, since leaf expansion of water-stressed bean and pepper, two species capable of osmotic adjustment, was similar to that of spinach, which exhibited no leaf osmotic adjustment.

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

    Directory of Open Access Journals (Sweden)

    Ahmad Afkari

    2016-09-01

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

  1. Monitoring water stress and fruit quality in an orange orchard under regulated deficit irrigation using narrow-band structural and physiological remote sensing indices

    Science.gov (United States)

    Stagakis, S.; González-Dugo, V.; Cid, P.; Guillén-Climent, M. L.; Zarco-Tejada, P. J.

    2012-07-01

    This paper deals with the monitoring of water status and the assessment of the effect of stress on citrus fruit quality using structural and physiological remote sensing indices. Four flights were conducted over a citrus orchard in 2009 using an unmanned aerial vehicle (UAV) carrying a multispectral camera with six narrow spectral bands in the visible and near infrared. Physiological indices such as the Photochemical Reflectance Index (PRI570), a new structurally robust PRI formulation that uses the 515 nm as the reference band (PRI515), and a chlorophyll ratio (R700/R670) were compared against the Normalized Difference Vegetation Index (NDVI), Renormalized Difference Vegetation Index (RDVI) and Modified Triangular Vegetation Index (MTVI) canopy structural indices for their performance in tracking water status and the effects of sustained water stress on fruit quality at harvest. The irrigation setup in the commercial orchard was compared against a treatment scheduled to satisfy full requirements (based on estimated crop evapotranspiration) using two regulated deficit irrigation (RDI) strategies. The water status of the trees throughout the experiment was monitored with frequent field measurements of stem water potential (Ψx), while titratable acidity (TA) and total soluble solids (TSS) were measured at harvest on selected trees from each irrigation treatment. The high spatial resolution of the multispectral imagery (30 cm pixel size) enabled identification of pure tree crown components, extracting the tree reflectance from shaded, sunlit and aggregated pixels. The physiological and structural indices were then calculated from each tree at the following levels: (i) pure sunlit tree crown, (ii) entire crown, aggregating the within-crown shadows, and (iii) simulating a lower resolution pixel, including tree crown, sunlit and shaded soil pixels. The resulting analysis demonstrated that both PRI formulations were able to track water status, except when water stress

  2. Hippocampal ER stress and learning deficits following repeated pyrethroid exposure.

    Science.gov (United States)

    Hossain, Muhammad M; DiCicco-Bloom, Emanuel; Richardson, Jason R

    2015-01-01

    Endoplasmic reticulum (ER) stress is implicated as a significant contributor to neurodegeneration and cognitive dysfunction. Previously, we reported that the widely used pyrethroid pesticide deltamethrin causes ER stress-mediated apoptosis in SK-N-AS neuroblastoma cells. Whether or not this occurs in vivo remains unknown. Here, we demonstrate that repeated deltamethrin exposure (3 mg/kg every 3 days for 60 days) causes hippocampal ER stress and learning deficits in adult mice. Repeated exposure to deltamethrin caused ER stress in the hippocampus as indicated by increased levels of C/EBP-homologous protein (131%) and glucose-regulated protein 78 (96%). This was accompanied by increased levels of caspase-12 (110%) and activated caspase-3 (50%). To determine whether these effects resulted in learning deficits, hippocampal-dependent learning was evaluated using the Morris water maze. Deltamethrin-treated animals exhibited profound deficits in the acquisition of learning. We also found that deltamethrin exposure resulted in decreased BrdU-positive cells (37%) in the dentate gyrus of the hippocampus, suggesting potential impairment of hippocampal neurogenesis. Collectively, these results demonstrate that repeated deltamethrin exposure leads to ER stress, apoptotic cell death in the hippocampus, and deficits in hippocampal precursor proliferation, which is associated with learning deficits.

  3. Buffering growth variations against water deficits through timely carbon usage.

    Science.gov (United States)

    Pantin, Florent; Fanciullino, Anne-Laure; Massonnet, Catherine; Dauzat, Myriam; Simonneau, Thierry; Muller, Bertrand

    2013-01-01

    Water stresses reduce plant growth but there is no consensus on whether carbon metabolism has any role in this reduction. Sugar starvation resulting from stomatal closure is often proposed as a cause of growth impairment under long-term or severe water deficits. However, growth decreases faster than photosynthesis in response to drought, leading to increased carbohydrate stores under short-term or moderate water deficits. Here, we addressed the question of the role of carbon availability on growth under moderate water deficits using two different systems. Firstly, we monitored the day/night pattern of leaf growth in Arabidopsis plants. We show that a moderate soil water deficit promotes leaf growth at night in mutants severely disrupted in their nighttime carbohydrate availability. This suggests that soil water deficit promotes carbon satiation. Secondly, we monitored the sub-hourly growth variations of clementine fruits in response to daily, natural fluctuations in air water deficit, and at contrasting source-sink balances obtained by defoliation. We show that high carbohydrate levels prevent excessive, hydraulic shrinkage of the fruit during days with high evaporative demand, most probably through osmotic adjustment. Together, our results contribute to the view that growing organs under moderate soil or air water deficit are not carbon starved, but use soluble carbohydrate in excess to partly release a hydromechanical limitation of growth.

  4. Buffering growth variation against water deficits through timely carbon usage

    Directory of Open Access Journals (Sweden)

    Florent ePantin

    2013-11-01

    Full Text Available Water stresses reduce plant growth but there is no consensus on whether carbon metabolism has any role in this reduction. Sugar starvation resulting from stomatal closure is often proposed as a cause of growth impairment under long-term or severe water deficits. However, growth decreases faster than photosynthesis in response to drought, leading to increased carbohydrate stores under short-term or moderate water deficits. Here, we addressed the question of the role of carbon availability on growth under moderate water deficits using two different systems. Firstly, we monitored the day/night pattern of leaf growth in Arabidopsis plants. We show that a moderate soil water deficit promotes leaf growth at night in mutants severely disrupted in their nighttime carbohydrate availability. This suggests that soil water deficit promotes carbon satiation. Secondly, we monitored the sub-hourly growth fluctuations of clementine fruits in response to daily, natural fluctuation in air water deficit, and at contrasting source-sink balance obtained by defoliation. We show that high carbohydrate levels obtained under favourable source-sink balance prevent excessive, hydraulic shrinkage of the fruit during days with high evaporative demand, most probably by modulating osmotic adjustment. Together, our results contribute to the view that growing organs under moderate soil or air water deficit are not carbon starved, but use soluble carbohydrate in excess to partly release a hydromechanical limitation of growth.

  5. Salicylic Acid Ameliorates the Effects of Oxidative Stress Induced by Water Deficit in Hydroponic Culture of Nigella sativa

    Directory of Open Access Journals (Sweden)

    Rozita Kabiri

    2012-08-01

    Full Text Available Osmotic stress associated with drought, and salinity is a serious problem that inhibits the growth of plants, mainly due to disturbance of the balance between production of ROS and antioxidant defense and causing oxidative stress. The results obtained in the last few years strongly prove that salicylic acid could be a very promising and protective compound for the reduction of biotic and abiotic stresses in sensitive of crops, because under certain conditions, it has been found to mitigate the damaging effects of various stress factors in plants. In this research, salicylic acid was used in control, and drought stressed plants, and the role of this compound in reduction of oxidative damages in Nigella plant was investigated. Data presented in this study indicated that SA application through the root medium brought on the increased levels of drought tolerance in black cumin seedlings. Plants pre-treated with SA exhibited slight injury symptoms whereas those that were not pre-treated with SA had moderate damage and lost considerable portions of their foliage. SA very profoundly inducing the activity of CAT, APX and GPX in plants, which led to reduction in H2O2 content, lipid peroxidation (MDA and LOX activity so it seems that the application of SA greatly improves the dehydration tolerance through elevated activities of antioxidant systems or may be the expression of genes encoding some ROS-scavenging enzymes under drought stress, which would maintain the redox homeostasis and integrity of cellular components.

  6. Evaluation of Oxygen Deficit Stress on Germination Indicators and Seedling

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    F Hoseini

    2012-06-01

    Full Text Available To investigate the relationship oxygen deficit stress on germination indicators and seedling growth of five wheat cultivars in laboratory condition, an experiment with Randomized Complete Block design in factorial arrangement with three replications was conducted in 2008. The treatments consisted of five wheat cultivars (Chamran, Flat, Roshan, Stare and Shole as A factor, and two oxygen level (normal seed and seed under oxygen deficit stress conditions as B factor in each of these figures was done. Results showed that oxygen deficit stress caused to decrease for various cultivars germination percentage, germination rate, allometric coefficient, seed vigor index and other germination indicators. Therefore, this test as a suitable method for determining the quality of various seed lot can be used in the water logging condition. In addition, among different cultivars characterized that Roshan cultivar was more resistant to oxygen deficit stress than Chamran, Flat and Star cultivars. Although Chamran cultivar is common cultivar in Khouzestan, but of look most germination indicators arranged as weak seed class. The highest correlation coefficients among the tested cultivars have been related to seed vigor with seedling length and dry weight of radicle with seedling with 0.92 and 0.90, respectively.

  7. Effects of Zinc and Phosphorus on Nutrients, Starch and Reducing Sugar Concentrations of Potato Tubers under with or without Water Deficit Stress

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    rahim motalebifard

    2017-02-01

    Full Text Available Introduction: In natural environments, plants are subjected to biotic (insects, bacteria, fungi, and viruses and abiotic (light, temperature, water availability, nutrients, and soil structure stresses that can have negative effect on growth, metabolism, and yield. Among these, drought is a major abiotic factor that limits agricultural crop production. Potato production has fourth rank in the world after rice, wheat, and maize with the production of 321 million tons from 19.6 million hectares. By about 3 percent of cultivation area, potato had 7.2 percent of total agricultural production (5.57 million tons in our country (Iran. Limited studies have been conducted on the interactive effects of Zn and P on potato tubers quality under water deficit conditions. Materials and Methods: This study was conducted for evaluating the effects of soil moisture, phosphorus (P and zinc (Zn levels on the chemical composition and nutrients content of potato (Solanum tuberosum L. cv. Agria as a factorial experiment based on randomized complete blocks design with three factors under greenhouse conditions. The study was performed with factors of Zn at three levels (0, 10 and 20 mg Zn per kg dry soil as ZnSO4.7H2O, P at three levels (0, 30 and 60 mg P per kg dry soil as Ca(H2PO42.H2O (monocalcium phosphate and soil moisture at three levels (0.5FC-0.6FC, 0.7FC-0.8FC and 0.9FC-FC using three replications and 81 pots. The soil moisture levels were imposed three weeks from the flowering (64th day until harvest (85th day after planting. After imposing of soil moisture levels and at the harvest, the yield and yield components, reducing sugars concentration in fresh weight by di- nitro phenol method (Mostofi and Najafi, 2005 and starch by Antron method (Mostofi and Najafi, 2005, N, P, K, Mg, Na, Fe and Zn concentrations in dried potato tubers were measured. Data were subjected to analysis of variance as factorial 3×3×3 with n=3 by using MSTATC software. Duncan's multiple

  8. Transcriptome profiling of tobacco under water deficit conditions

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    Roel C. Rabara

    2015-09-01

    Full Text Available Drought is one of the limiting environmental factors that affect crop production. Understanding the molecular basis of how plants respond to this water deficit stress is key to developing drought tolerant crops. In this study we generated time course-based transcriptome profiles of tobacco plants under water deficit conditions using microarray technology. In this paper, we describe in detail the experimental procedures and analyses performed in our study. The data set we generated (available in the NCBI/GEO database under GSE67434 has been analysed to identify genes that are involved in the regulation of tobacco's responses to drought.

  9. Plant genetic and molecular responses to water deficit

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    Silvio Salvi

    2011-02-01

    Full Text Available Plant productivity is severely affected by unfavourable environmental conditions (biotic and abiotic stresses. Among others, water deficit is the plant stress condition which mostly limits the quality and the quantity of plant products. Tolerance to water deficit is a polygenic trait strictly dependent on the coordinated expression of a large set of genes coding for proteins directly involved in stress-induced protection/repair mechanisms (dehydrins, chaperonins, enzymes for the synthesis of osmoprotectants and detoxifying compounds, and others as well as genes involved in transducing the stress signal and regulating gene expression (transcription factors, kinases, phosphatases. Recently, research activities in the field evolved from the study of single genes directly involved in cellular stress tolerance (functional genes to the identification and characterization of key regulatory genes involved in stress perception and transduction and able to rapidly and efficiently activate the complex gene network involved in the response to stress. The complexity of the events occurring in response to stress have been recently approached by genomics tools; in fact the analysis of transcriptome, proteome and metabolome of a plant tissue/cell in response to stress already allowed to have a global view of the cellular and molecular events occurring in response to water deficit, by the identification of genes activated and co-regulated by the stress conditions and the characterization of new signalling pathways. Moreover the recent application of forward and reverse genetic approaches, trough mutant collection development, screening and characterization, is giving a tremendous impulse to the identification of gene functions with key role in stress tolerance. The integration of data obtained by high-throughput genomic approaches, by means of powerful informatic tools, is allowing nowadays to rapidly identify of major genes/QTLs involved in stress tolerance

  10. Overexpression of Grain Amaranth (Amaranthus hypochondriacus) AhERF or AhDOF Transcription Factors in Arabidopsis thaliana Increases Water Deficit- and Salt-Stress Tolerance, Respectively, via Contrasting Stress-Amelioration Mechanisms

    Science.gov (United States)

    Massange-Sánchez, Julio A.; Palmeros-Suárez, Paola A.; Espitia-Rangel, Eduardo; Rodríguez-Arévalo, Isaac; Sánchez-Segura, Lino; Martínez-Gallardo, Norma A.; Alatorre-Cobos, Fulgencio; Tiessen, Axel; Délano-Frier, John P.

    2016-01-01

    Two grain amaranth transcription factor (TF) genes were overexpressed in Arabidopsis plants. The first, coding for a group VII ethylene response factor TF (i.e., AhERF-VII) conferred tolerance to water-deficit stress (WS) in transgenic Arabidopsis without affecting vegetative or reproductive growth. A significantly lower water-loss rate in detached leaves coupled to a reduced stomatal opening in leaves of plants subjected to WS was associated with this trait. WS tolerance was also associated with an increased antioxidant enzyme activity and the accumulation of putative stress-related secondary metabolites. However, microarray and GO data did not indicate an obvious correlation between WS tolerance, stomatal closure, and abscisic acid (ABA)-related signaling. This scenario suggested that stomatal closure during WS in these plants involved ABA-independent mechanisms, possibly involving reactive oxygen species (ROS). WS tolerance may have also involved other protective processes, such as those employed for methyl glyoxal detoxification. The second, coding for a class A and cluster I DNA binding with one finger TF (i.e., AhDof-AI) provided salt-stress (SS) tolerance with no evident fitness penalties. The lack of an obvious development-related phenotype contrasted with microarray and GO data showing an enrichment of categories and genes related to developmental processes, particularly flowering. SS tolerance also correlated with increased superoxide dismutase activity but not with augmented stomatal closure. Additionally, microarray and GO data indicated that, contrary to AhERF-VII, SS tolerance conferred by AhDof-AI in Arabidopsis involved ABA-dependent and ABA-independent stress amelioration mechanisms. PMID:27749893

  11. Water-deficit tolerant classification in mutant lines of indica rice

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    Suriyan Cha-um

    2012-04-01

    Full Text Available Water shortage is a major abiotic stress for crop production worldwide, limiting the productivity of crop species, especially in dry-land agricultural areas. This investigation aimed to classify the water-deficit tolerance in mutant rice (Oryza sativa L. spp. indica genotypes during the reproductive stage. Proline content in the flag leaf of mutant lines increased when plants were subjected to water deficit. Relative water content (RWC in the flag leaf of different mutant lines dropped in relation to water deficit stress. A decrease RWC was positively related to chlorophyll a degradation. Chlorophyll a , chlorophyll b , total chlorophyll , total carotenoids , maximum quantum yield of PSII , stomatal conductance , transpiration rate and water use efficiency in mutant lines grown under water deficit conditions declined in comparison to the well-watered, leading to a reduction in net-photosynthetic rate. In addition, when exposed to water deficit, panicle traits, including panicle length and fertile grains were dropped. The biochemical and physiological data were subjected to classify the water deficit tolerance. NSG19 (positive control and DD14 were identified as water deficit tolerant, and AA11, AA12, AA16, BB13, BB16, CC12, CC15, EE12, FF15, FF17, G11 and IR20 (negative control as water deficit sensitive, using Ward's method.

  12. Water supply and tree growth. Part I. Water deficits

    Energy Technology Data Exchange (ETDEWEB)

    Kozlowski, T.T.

    1982-02-01

    Water supply is the most important environmental factor determining distribution, species composition and growth of forests. Net annual primary production of forests varies from as much as 3000 g/m/sub 2/ in wet regions to negligible amounts in dry regions. The water balance of trees has been characterized by visible wilting, tissue moisture content, relative water content, saturation deficit, and water potential. Water deficits develop readily in forest trees, even in trees growing in wet soil, because of excess transpiration over absorption of water. Water deficits adversely affect seed germination and cause shrinkage of leaves, stems, roots, fruits, and cones. Some of the decrease in photosynthesis during drought is the result of increased resistance to diffusion of CO/sub 2/ to chloroplasts and some to decrease in photosynthetic capacity. Water deficits inhibit shoot growth, wood production, and root growth. Yield of fruits and seeds can be inhibited at various stages of reproductive growth such as flower bud initiation, anthesis, pollination, fertilization, embryo growth, and fruit and seed enlargement. Water deficits may also induce leaf scorching and abscission, dieback of twigs and branches, and drought cracks. Severe water deficits often kill trees. Drought tolerance of trees may reflect desiccation avoidance or desiccation tolerance, with the former much more important. Among the most important of these are reduction in number and size of leaves; small, few, and sunken stomata; rapid stomatal closure; abundant leaf waxes; leaf shedding during droughts; extensive root development; capacity for twig and stem photosynthesis; living wood fibers; and strong development of palisade mesophyll.

  13. The effects of seed quality and pipecolic and djenkolic acids on bruchid beetle infestation in water deficit-stressed Acacia trees.

    Science.gov (United States)

    Or, K; Ward, D

    2004-11-01

    Acacia trees in the Negev desert and the Arava valley of Israel are suffering high levels of mortality due to water stress. Additionally, recruitment is negatively affected by bruchid beetles. We hypothesized that water-stressed trees would be less able to produce secondary defense compounds, such as the nonprotein amino acids, pipecolic acid and djenkolic acid, in their seeds to decrease seed herbivory. We further hypothesized that the high seed infestation reported is due to increased fitness of beetles infesting trees that are in a poor physiological state. Contrary to our prediction, pipecolic acid concentration was higher in water-stressed Acacia raddiana trees. We found that infestation rates and beetle fitness were higher in trees in a poor physiological state, despite the higher levels of pipecolic acid in these trees. There was a significant positive correlation between infestation level and the amounts of djenkolic acid in the seeds, indicating that the beetles may have found a means of utilizing djenkolic acid for their own benefit.

  14. WATER MANAGEMENT STRATEGIES UNDER DEFICIT IRRIGATION

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    Antonino Capra

    2008-12-01

    Full Text Available Deficit irrigation (DI is an optimization strategy whereby net returns are maximized by reducing the amount of irrigation water; crops are deliberated allowed to sustain some degree of water deficit and yield reduction. Although the DI strategy dates back to the 1970s, this technique is not usually adopted as a practical alternative to full irrigation by either academics or practitioners. Furthermore, there is a certain amount of confusion regarding its concept. In fact, a review of recent literature dealing with DI has shown that only a few papers use the concept of DI in its complete sense (e.g. both the agronomic and economic aspects. A number of papers only deal with the physiological and agronomical aspects of DI or concern techniques such as Regulated Deficit Irrigation (RDI and Partial Root Drying (PRD. The paper includes two main parts: i a review of the principal water management strategies under deficit conditions (e.g. conventional DI, RDI and PRD; and ii a description of a recent experimental research conducted by the authors in Sicily (Italy that integrates agronomic, engineering and economic aspects of DI at farm level. Most of the literature reviewed here showed, in general, quite positive effects from DI application, mostly evidenced when the economics of DI is included in the research approach. With regard to the agronomic effects, total fresh mass and total production is generally reduced under DI, whereas the effects on dry matter and product quality are positive, mainly in crops for which excessive soil water availability can cause significant reductions in fruit size, colour or composition (grapes, tomatoes, mangos, etc.. The experimental trial on a lettuce crop in Sicily, during 2005 and 2006, shows that the highest mean marketable yield of lettuce (55.3 t ha-1 in 2005 and 51.9 t ha-1 in 2006 was recorded in plots which received 100% of ET0-PM (reference evapotranspiration by the Penman- Monteith method applied water. In

  15. Response of Eucalyptus grandis trees to soil water deficits.

    Science.gov (United States)

    Dye, P. J.

    1996-01-01

    The use of potential transpiration models to simulate transpiration rates in areas prone to soil water deficits leads to overestimates of water use as the soil dries. Therefore, I carried out studies on Eucalyptus grandis W. Hill ex Maiden trees subjected to soil drying at two field sites in the Mpumalanga province of South Africa to determine the relation between transpiration rate and soil water availability. I hypothesized that, with this relationship defined, simple modeling of the soil water balance could be used to predict what fraction of potential transpiration was taking place at a given time. Site 1 supported a stand of 3-year-old E. grandis trees, whereas 9-year-old trees were growing on Site 2, situated 2 km away. At each site, plastic sheeting was laid over the ground to prevent soil water recharge and thereby allow the roots in the soil to induce a continuous progressive depletion of soil water. Measurements of predawn xylem pressure potential, leaf area index, growth and sap flow rates revealed that prevention of soil water recharge resulted in only moderate drought stress. At Site 1, the trees abstracted water down to 8 m below the surface, whereas trees at Site 2 obtained most of their water from depths below 8 m. I found that modeling the water balance of deep rooting zones is impractical for the purpose of simulating nonpotential transpiration rates because of uncertainties about the depth of the root system, the soil water recharge mechanism and the water retention characteristics of the deep subsoil strata. I conclude that predicting the occurrence and severity of soil water deficits from the soil water balance is not feasible at these sites.

  16. [Effects of water deficit and nitrogen fertilization on winter wheat growth and nitrogen uptake].

    Science.gov (United States)

    Qi, You-Ling; Zhang, Fu-Cang; Li, Kai-Feng

    2009-10-01

    Winter wheat plants were cultured in vitro tubes to study their growth and nitrogen uptake under effects of water deficit at different growth stages and nitrogen fertilization. Water deficit at any growth stages could obviously affect the plant height, leaf area, dry matter accumulation, and nitrogen uptake. Jointing stage was the most sensitive stage of winter wheat growth to water deficit, followed by flowering stage, grain-filling stage, and seedling stages. Rewatering after the water deficit at seedling stage had a significant compensation effect on winter wheat growth, and definite compensation effect was observed on the biomass accumulation and nitrogen absorption when rewatering was made after the water deficit at flowering stage. Under the same nitrogen fertilization levels, the nitrogen accumulation in root with water deficit at seedling, jointing, flowering, and grain-filling stages was reduced by 25.82%, 55.68%, 46.14%, and 16.34%, and the nitrogen accumulation in aboveground part was reduced by 33.37%, 51.71%, 27.01%, and 2.60%, respectively, compared with no water deficit. Under the same water deficit stages, the nitrogen content and accumulation of winter wheat decreased with decreasing nitrogen fertilization level, i. e., 0.3 g N x kg(-1) FM > 0.2 g N x kg(-1) FM > 0.1 g N x kg(-1) FM. Nitrogen fertilization had obvious regulation effect on winter wheat plant growth, dry matter accumulation, and nitrogen uptake under water stress.

  17. Adaptation to high temperature mitigates the impact of water deficit during combined heat and drought stress in C3 sunflower and C4 maize varieties with contrasting drought tolerance.

    Science.gov (United States)

    Killi, Dilek; Bussotti, Filippo; Raschi, Antonio; Haworth, Matthew

    2017-02-01

    Heat and drought stress frequently occur together, however, their impact on plant growth and photosynthesis (PN ) is unclear. The frequency, duration and severity of heat and drought stress events are predicted to increase in the future, having severe implications for agricultural productivity and food security. To assess the impact on plant gas exchange, physiology and morphology we grew drought tolerant and sensitive varieties of C3 sunflower (Helianthus annuus) and C4 maize (Zea mays) under conditions of elevated temperature for 4 weeks prior to the imposition of water deficit. The negative impact of temperature on PN was most apparent in sunflower. The drought tolerant sunflower retained ribulose-1,5-bisphosphate carboxylase/oxygenase (RubisCO) activity under heat stress to a greater extent than its drought sensitive counterpart. Maize exhibited no varietal difference in response to increased temperature. In contrast to previous studies, where a sudden rise in temperature induced an increase in stomatal conductance (Gs ), we observed no change or a reduction in Gs with elevated temperature, which alongside lower leaf area mitigated the impact of drought at the higher temperature. The drought tolerant sunflower and maize varieties exhibited greater investment in root-systems, allowing greater uptake of the available soil water. Elevated temperatures associated with heat-waves will have profound negative impacts on crop growth in both sunflower and maize, but the deleterious effect on PN was less apparent in the drought tolerant sunflower and both maize varieties. As C4 plants generally exhibit water use efficiency (WUE) and resistance to heat stress, selection on the basis of tolerance to heat and drought stress would be more beneficial to the yields of C3 crops cultivated in drought prone semi-arid regions. © 2016 Scandinavian Plant Physiology Society.

  18. A Framework for Assessing Soil Moisture Deficit and Crop Water Stress at Multiple Space and Time Scales Under Climate Change Scenarios Using Model Platform, Satellite Remote Sensing, and Decision Support System

    KAUST Repository

    Mohanty, Binayak P.

    2016-11-03

    Better understanding of water cycle at different space–time scales would be a key for sustainable water resources, agricultural production, and ecosystems health in the twenty-first century. Efficient agricultural water management is necessary for sustainability of the growing global population. This warrants better predictive tools for aridity (based on precipitation, temperature, land use, and land cover), root zone (~top 1 m) soil moisture deficit, and crop water stress at farm, county, state, region, and national level, where decisions are made to allocate and manage the water resources. It will provide useful strategies for not only efficient water use but also for reducing potential risk of crop failure due to agricultural drought. Leveraging heavily on ongoing multiscale hydrologic modeling, data assimilation, soil moisture dynamics, and inverse model development research activities, and ongoing Land Data Assimilation (LDAS) and National Climate Assessment (NCA) indexing efforts we are developing a drought assessment framework. The drought assessment platform includes: (1) developing disaggregation methods for extracting various field-scale (1-km or less) climate indicators from the (SMOS, VIIRS, SMAP, AMSR-2) satellite / LDAS-based soil moisture in conjunction with a multimodel simulation–optimization approach using ensemble of Soil Vegetation Atmosphere Transfer, SVAT (Noah, CLM, VIC, Mosaic in LIS) models; (2) predicting farm/field-scale long-term root zone soil moisture status under various land management and climate scenarios for the past decades in hindcast mode and for the next decades in forecast mode across the USA using effective land surface parameters and meteorological input from Global Circulation Model (GCM) outputs; (3) assessing the potential risk of agricultural drought at different space–time scales across the USA based on predicted root zone soil moisture; and (4) evaluating various water management and cropping practices (e

  19. Chronic administration of quercetin prevent spatial learning and memory deficits provoked by chronic stress in rats.

    Science.gov (United States)

    Mohammadi, Hadis Said; Goudarzi, Iran; Lashkarbolouki, Taghi; Abrari, Kataneh; Elahdadi Salmani, Mahmoud

    2014-08-15

    There are several reports that cognitive impairment is observed in stress related disorders and chronic stress impairs learning and memory. However, very few studies have looked into the possible ways of preventing this stress-induced deficit. This research study was conducted to evaluate the effects of quercetin, a natural flavonoid, with strong antioxidant and free radical scavenger properties, on chronic stress induced learning and memory deficits and oxidative stress in hippocampus. For chronic stress, rats were restrained daily for 6h/day (from 9:00 to 15:00) for 21 days in well-ventilated plexiglass tubes without access to food and water. The animals were injected with quercetin or vehicle 60 min before restraint stress over a period of 21 days. Then, rats trained with six trials per day for 6 consecutive days in the water maze. On day 28, a probe test was done to measure memory retention. In addition, oxidative stress markers in the hippocampus were evaluated. Results of this study demonstrated that chronic stress exposure rats exhibited higher escape latency during training trials and reduced time spent in target quadrant, higher escape location latency and average proximity in probe trial test. Quercetin (50mg/kg) treatment during restraint stress (21 days) markedly decreased escape latency and increased time spent in target quadrant during Morris water maze task. In comparison to vehicle treated group, chronic-stress group had significantly higher malondialdehyde (MDA) levels, significantly higher superoxide dismutase (SOD) activity and significantly lower glutathione peroxidase (GPx) activity in the hippocampus. Quercetin treatment caused a significant decrease in the hippocampus MDA levels and improves SOD and GPx activities in stressed animals. Finally, quercetin significantly decreased plasma corticosterone levels in stressed animals. Based on results of this study, chronic stress has detrimental effects on learning and memory and quercetin treatment

  20. Response of Eucalyptus grandis trees to soil water deficits

    Energy Technology Data Exchange (ETDEWEB)

    Dye, P. J. [Commonwealth Scientific and Industrial Research, Division of Forest Science and Technology, Nelspruit (South Africa)

    1996-01-01

    Eucalyptus grandis trees subjected to soil drying at two field sites in the Mpumalanga province of South Africa were studied to determine the relation between transpiration rate and soil water availability. It was expected that by defining this relationship, modeling of the soil water balance could be used to predict the fraction of transpiration taking place at any given time. As part of the experimental procedure soil water recharge was prevented by plastic sheeting, thus allowing the roots in the soil to induce continuous progressive depletion of soil water. Measurements of predawn xylem pressure potential, leaf area index, growth and sap flow rates revealed only moderate drought stress; trees at both sites extracted water down to eight meters and more, below the surface. These results suggest that because of uncertainties about the depth of the root system, the soil water recharge mechanisms and other related factors, soil water balance studies are not useful in predicting the occurrence and severity of soil water deficits at these sites. 13 refs., 2 tabs., 8 figs.

  1. Genetic and physiological controls of growth under water deficit.

    Science.gov (United States)

    Tardieu, François; Parent, Boris; Caldeira, Cecilio F; Welcker, Claude

    2014-04-01

    The sensitivity of expansive growth to water deficit has a large genetic variability, which is higher than that of photosynthesis. It is observed in several species, with some genotypes stopping growth in a relatively wet soil, whereas others continue growing until the lower limit of soil-available water. The responses of growth to soil water deficit and evaporative demand share an appreciable part of their genetic control through the colocation of quantitative trait loci as do the responses of the growth of different organs to water deficit. This result may be caused by common mechanisms of action discussed in this paper (particularly, plant hydraulic properties). We propose that expansive growth, putatively linked to hydraulic processes, determines the sink strength under water deficit, whereas photosynthesis determines source strength. These findings have large consequences for plant modeling under water deficit and for the design of breeding programs.

  2. REPEATED MEASURES ANALYSIS OF CHANGES IN PHOTOSYNTHETIC EFFICIENCY IN SOUR CHERRY DURING WATER DEFICIT

    Directory of Open Access Journals (Sweden)

    Marija Viljevac

    2012-06-01

    Full Text Available The objective of this study was to investigate changes in photosynthetic efficiency applying repeated measures ANOVA using the photosynthetic performance index (PIABS of the JIP-test as a vitality parameter in seven genotypes of sour cherry (Prunus cerasus, L. during 10 days of continuous water deficit. Both univariate and multivariate ANOVA repeated measures revealed highly significant time effect (Days and its subsequent interactions with genotype and water deficit. However, the multivariate Pillai’s trace test detected the interaction Time × Genotype × Water deficit as not significant. According to the Tukey’s Studentized Range (HSD test, differences between the control and genotypes exposed to water stress became significant on the fourth day of the experiment, indicating that the plants on the average, began to lose their photosynthetic efficiency four days after being exposed to water shortage. It corroborates previous findings in other species that PIABS is very sensitive tool for detecting drought stress.

  3. Metabolic responses to water deficit in two Eucalyptus globulus clones with contrasting drought sensitivity.

    Science.gov (United States)

    Shvaleva, A L; Costa E Silva, F; Breia, E; Jouve, J; Hausman, J F; Almeida, M H; Maroco, J P; Rodrigues, M L; Pereira, J S; Chaves, M M

    2006-02-01

    We compared the metabolic responses of leaves and roots of two Eucalyptus globulus Labill. clones differing in drought sensitivity to a slowly imposed water deficit. Responses measured included changes in concentrations of soluble and insoluble sugars, proline, total protein and several antioxidant enzymes. In addition to the general decrease in growth caused by water deficit, we observed a decrease in osmotic potential when drought stress became severe. In both clones, the decrease was greater in roots than in leaves, consistent with the observed increases in concentrations of soluble sugars and proline in these organs. In roots of both clones, glutathione reductase activity increased significantly in response to water deficit, suggesting that this enzyme plays a protective role in roots during drought stress by catalyzing the catabolism of reactive oxygen species. Clone CN5 has stress avoidance mechanisms that account for its lower sensitivity to drought compared with Clone ST51.

  4. Effect of Foliar Zinc Application on Yield, Physiological Traits and Seed Vigor of Two Soybean Cultivars under Water Deficit

    Directory of Open Access Journals (Sweden)

    Somayeh KARAMI

    2016-06-01

    Full Text Available In order to study the effect of water deficit stress and zinc foliar application on yield, physiological traits and also on seed vigor and seedling emergence percentage in two soybean cultivars, an experiment was conducted as randomized complete block arrangement in split factorial design with three replications. The main factor was drought stress in three levels of optimal irrigation, withholding irrigation from vegetative growth stage and withholding irrigation from flowering stage; subordinate factors were the combination of foliar zinc application in three levels and two cultivars (‘L17’ and ‘Clark 63’. Water deficit stress obviously decreased the yield, soluble protein and chlorophyll content in leaves. Proline and soluble sugars content were significantly increased in response to stress. Water deficit stress increased antioxidant enzymes activity. Also, water deficit stress decreased the germination rate, radicle and plumule dry weight. Foliar application with zinc sulfate increased the yield, germination rate and percentage, radicle and plumule weight. Zinc prevented the harmful effects of stress which caused decreasing of leaf protein, chlorophyll content and increasing proline and carbohydrate accumulation. In general, foliar application of zinc decreased the harmful effects of oxidative stress due to water deficit stress and improved growth conditions of plants.

  5. Water-deficit inducible expression of a cytokinin biosynthetic gene IPT improves drought tolerance in cotton.

    Directory of Open Access Journals (Sweden)

    Sundaram Kuppu

    Full Text Available Water-deficit stress is a major environmental factor that limits agricultural productivity worldwide. Recent episodes of extreme drought have severely affected cotton production in the Southwestern USA. There is a pressing need to develop cotton varieties with improved tolerance to water-deficit stress for sustainable production in water-limited regions. One approach to engineer drought tolerance is by delaying drought-induced senescence via up-regulation of cytokinin biosynthesis. The isopentenyltransferase gene (IPT that encodes a rate limiting enzyme in cytokinin biosynthesis, under the control of a water-deficit responsive and maturation specific promoter P(SARK was introduced into cotton and the performance of the P(SARK::IPT transgenic cotton plants was analyzed in the greenhouse and growth chamber conditions. The data indicate that P(SARK::IPT-transgenic cotton plants displayed delayed senescence under water deficit conditions in the greenhouse. These plants produced more root and shoot biomass, dropped fewer flowers, maintained higher chlorophyll content, and higher photosynthetic rates under reduced irrigation conditions in comparison to wild-type and segregated non-transgenic lines. Furthermore, P(SARK::IPT-transgenic cotton plants grown in growth chamber condition also displayed greater drought tolerance. These results indicate that water-deficit induced expression of an isopentenyltransferase gene in cotton could significantly improve drought tolerance.

  6. Rootstock control of scion transpiration and its acclimation to water deficit are controlled by different genes.

    Science.gov (United States)

    Marguerit, Elisa; Brendel, Oliver; Lebon, Eric; Van Leeuwen, Cornelis; Ollat, Nathalie

    2012-04-01

    The stomatal control of transpiration is one of the major strategies by which plants cope with water stress. Here, we investigated the genetic architecture of the rootstock control of scion transpiration-related traits over a period of 3 yr. The rootstocks studied were full sibs from a controlled interspecific cross (Vitis vinifera cv. Cabernet Sauvignon × Vitis riparia cv. Gloire de Montpellier), onto which we grafted a single scion genotype. After 10 d without stress, the water supply was progressively limited over a period of 10 d, and a stable water deficit was then applied for 15 d. Transpiration rate was estimated daily and a mathematical curve was fitted to its response to water deficit intensity. We also determined δ(13) C values in leaves, transpiration efficiency and water extraction capacity. These traits were then analysed in a multienvironment (year and water status) quantitative trait locus (QTL) analysis. Quantitative trait loci, independent of year and water status, were detected for each trait. One genomic region was specifically implicated in the acclimation of scion transpiration induced by the rootstock. The QTLs identified colocalized with genes involved in water deficit responses, such as those relating to ABA and hydraulic regulation. Scion transpiration rate and its acclimation to water deficit are thus controlled genetically by the rootstock, through different genetic architectures. © 2012 INRA. New Phytologist © 2012 New Phytologist Trust.

  7. Partitioning and mobilization of photoassimilate in alfalfa subjected to water deficits. [Medicago sativa L

    Energy Technology Data Exchange (ETDEWEB)

    Hall, M.H. (Univ. of Idaho, Moscow (USA)); Sheaffer, C.C.; Heichel, G.H. (Univ. of Minnesota, St. Paul (USA))

    Faster regrowth of a stressed alfalfa (Medicago sativa L.) crop compared to an unstressed crop after rewatering has been reported. The bases of this compensatory response are unknown, but they may be important to understanding adaptation to water stress and to developing crop water management strategies. The authors objectives was to determine the effect of stress induced by water deficit on photoassimilate partitioning and the utilization of stored assimilates during regrowth of alfalfa. Field and greenhouse experiments were conducted using cultivars differing in winterhardiness. Plants were subjected to water stress, pulse-labeled with {sup 14}CO{sub 2}, and sampled following 0, 1, 14, 21, and 28-d translocation periods. Following the 14-d sampling, herbage was harvested and water stress was removed. Cultivars contrasting in winterhardiness responded similarly to water stress. Stressed plant roots contained 73 and 114% more total plant radioactivity (TPR) than the control at the 1 and 14-d translocation periods, respectively. Water stress significantly increased root starch and TPR percentage in the starch fraction, but had much smaller effects on root soluble-sugar concentration and TPR percentage of the root sugar fraction. Herbage regrowth mass following harvest and rewatering of the water-stressed plants was similar to that of the control. Compared to the control, water-stressed alfalfa has greater total nonstructural carbohydrates in the roots, apparently due to increased photoassimilate partitioning to the roots. However, the greater root carbohydrate concentrations did not result in compensatory herbage regrowth following rewatering.

  8. Modulation of soybean lipoxygenase expression and membrane oxidation by water deficit

    NARCIS (Netherlands)

    Vliegenthart, J.F.G.; Maccarrone, M.; Veldink, G.A.; Finazzi Agrò, A.

    1995-01-01

    The modulation of the activity and expression of soybean lipoxygenases 1 (LOX-1) [Vliegenthart, J.F.G. and Veldink, G.A. (1982) in: Free Radicals in Biology (Pryor, W.A., Ed.) pp. 29–64, Academic Press, New York] and 2 (LOX-2) by water deficit (osmotic stress) has been investigated, by following gen

  9. Impact of long term water deficit on production and flowering occurrence in the ‘Granny Smith’ apple tree cultivar

    OpenAIRE

    Pallas, Benoit; Yang, Weiwei; Durand, Jean-Baptiste; Martinez, Sébastien; Costes, Evelyne

    2016-01-01

    Apple trees are usually irrigated to avoid yield losses due to water deficit but the shortage of water has become a critical problem in apple orchards. Nevertheless, most of the studies that have been conducted on tree responses to water stress have focused on shoot, leaf and fruit growth during a single growing season. This study presents the results of an experiment performed over 8 years on Granny Smith trees subjected to well watered and water stressed conditions. The yearly production of...

  10. Enhanced learning deficits in female rats following lifetime pb exposure combined with prenatal stress.

    Science.gov (United States)

    Cory-Slechta, Deborah A; Stern, Sander; Weston, Doug; Allen, Joshua L; Liu, Sue

    2010-10-01

    Pb (lead) exposure and stress are co-occurring risk factors (particularly in low socioeconomic communities) that also act on common biological substrates and produce common adverse outcomes, including cognitive impairments. This study sought to determine whether lifetime Pb exposure combined with prenatal stress would enhance the cognitive deficits independently associated with each of these risk factors and to explore associated mechanisms of any observed impairments. Learning was evaluated using a multiple schedule of repeated learning and performance in female rats subjected to lifetime Pb exposure (0 or 50 ppm Pb in drinking water beginning in dams 2 months prior to breeding; blood Pb levels ∼10 μg/dl), to prenatal restraint stress on gestational days 16 and 17, or to both. Blood Pb, corticosterone levels, brain monoamines, and hippocampal nerve growth factor levels were also measured. Sequence-specific learning deficits produced by Pb, particularly the number of responses to correctly learn response sequences, were further enhanced by stress, whereas performance measures were unimpaired. Statistical analyses indicated significant relationships among corticosterone levels, frontal cortex dopamine (DA), nucleus accumbens dopamine turnover, and total responses required to learn sequences. This study demonstrates that Pb and stress can act together to produce selective and highly condition-dependent deficits in learning in female rats that may be related to glucocorticoid-mediated interactions with mesocorticolimbic regions of brain. These findings also underscore the critical need to evaluate toxicants in the context of other risk factors pertinent to human diseases and disorders.

  11. The environmental vegetation index: A tool potentially useful for arid land management. [Texas and Mexico, plant growth stress due to water deficits

    Science.gov (United States)

    Gray, T. I., Jr.; Mccrary, D. G. (Principal Investigator)

    1981-01-01

    The NOAA-6 AVHRR data sets acquired over South Texas and Mexico during the spring of 1980 and after Hurricane Allen passed inland are analyzed. These data were processed to produce the Gray-McCrary Index (GMI's) for each pixel location over the selected area, which area contained rangeland and cropland, both irrigated and nonirrigated. The variations in the GMI's appear to reflect well the availability of water for vegetation. The GMI area maps are shown to delineate and to aid in defining the duration of drought; suggesting the possibility that time changes over a selected area could be useful for irrigation management.

  12. Effect of Salicylic Acid on Yield, Component Yield and Essential Oil of Black Cumin (Nigella sativa L. under Water Deficit Stress

    Directory of Open Access Journals (Sweden)

    E. Rezaei Chiyaneh

    2014-12-01

    Full Text Available Since the production of medicinal plants can be influenced by environmental factors such as water limitation. In other hand salicylic acid as a plant regulator can enhance drought resistance in plants. In order to investigate the effect of different irrigation intervals on yield, yield components and essential oil of black cumin (Nigella sativa L., a field experiment was conducted a farm located in West Azerbaijan province- city Nagadeh, West- Azerbaijan, during growing season of 2011- 2012. The experiment was arranged as split plot based on a randomized complete block design with three replications. Irrigation intervals (6, 12 and 18 days and three levels of salicylic acid concentration (0, 0.5 and 1 mM considered as in main plots and sub-plots, respectively. Results showed that irrigation had significant effects on all characteristics such as Plant height, number of follicule per plant, number of seed per follicule, biological yield, grain yield, essential oil content and essential oil yield with the exception of 1000- seed weight. With increasing irrigation intervals from 6 to 18 days, plant height, number of follicule per plant, number of seed per follicule, biological yield, grain yield, essential oil percentage and essential oil yield were decreased up to 49, 52, 40, 35, 43, 20 and 55 %, respectively. In contrast, yield components and yield were enhanced up to treatments 0.5 mM of salicylic acid. Grain yield and essential oil yield with application of 0.5 mM salicylic acid increased up to 13 and 11 % compared to control, respectively. It seems that due to the limited sources of water in the region irrigation after 12 days and 0.5 mM salicylic acid concentration are suitable for black cumin grain production.

  13. Antioxidant and carbohydrate changes of two pomegranate cultivars under deficit irrigation stress

    Directory of Open Access Journals (Sweden)

    Morteza Ebtedaie

    2016-12-01

    Full Text Available The purpose of this study was to evaluate the biochemical responses to water stress tolerance of two pomegranate cultivars, ‘Rabbab’ and ‘Shishehgap’. After the establishment of rooted stem cuttings of both cultivars under greenhouse conditions, they were treated with four levels of deficit irrigations (100%, 75%, 50% and 25% of field capacity in a completely randomized design with four replications. The results showed a significant difference between the two cultivars regarding antioxidant enzymes activities. In both cultivars, the water stress increased the activity of superoxide dismutase, catalase and ascorbate peroxidase. However, at high water deficit (25% field capacity, FC, ‘Rabbab’ showed significantly higher enzyme activity than ‘Shishehgap’. In each level of irrigation, there were not considerable differences in peroxidase activity between the two cultivars. An increment of 162% and 65.5% in soluble sugar was gained at 50% FC in ‘Rabbab’ and ‘Shishehgap’, respectively. ‘Rabbab’ showed better growth performance in each level of irrigation than ‘Shishehgap’. Therefore, it can be concluded that 'Rabbab', with lesser decline in leaf relative water content (RWC, a strong antioxidant system and accumulation of more soluble carbohydrates, can resist higher water stress than 'Shishehgap'.

  14. Rate and duration of seed filling and yield of soybean affected by water and radiation deficits

    Directory of Open Access Journals (Sweden)

    Kazem GHASSEMI-GOLEZANI

    2015-11-01

    Full Text Available Seed filling and yield of soybean under water and radiation deficits were investigated during 2011 and 2012. Treatments were irrigations (I1, I2, I3 and I4 for irrigation after 60, 90, 120 and 150 mm evaporation from class A pan, respectively in main plots and light interceptions (L1: 100 %, L2: 65 % and L3: 25 % sunlight in sub-plots. Seeds per plant under I1 and I2 decreased, but under I3 and I4 increasedas a result of radiation deficit. Maximum seed weight and seed filling duration of plants under 25 % light interception (L3 were higher than those under full sunlight (L1 and 65 % light interception (L2. In contrast, plants under full sunlight had the highest seed filling rate, particularly under water stress. Seed filling duration under severe light deficit (L3 was about 9 days longer than that under full sunlight (L1, leading to 15.8 % enhancement in maximum seed weight. Decreasing seed yield of soybean under well watering and mild water stress and improving it under moderate and severe water deficit due to low solar radiation are directly related with changes in seed filling duration and consequently in seed weight and number of seeds per plant under these conditions.

  15. Deficit irrigation of peach trees to reduce water consumption

    Science.gov (United States)

    Lack of water is a major limiting factor for production tree fruits such as peaches in the San Joaquin Valley of California and many other arid- or semi-arid regions in the world. Deficit irrigation can be used in some cropping systems as a water resource management strategy to reduce non-productiv...

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

    Institute of Scientific and Technical Information of China (English)

    Hatem ZGALLA(I); Kathy STEPPE; Raoul LEMEUR

    2005-01-01

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

  17. Regulation of Water Deficit-Induced Abscisic Acid Accumulation by Apoplastic Ascorbic Acid in Maize Seedlings

    Institute of Scientific and Technical Information of China (English)

    Jian-Fang HU; Gui-Fen LI; Zhi-Hui GAO; Lin CHEN; Hui-Bo REN; Wen-Suo JIA

    2005-01-01

    Water deficit-induced abscisic acid (ABA) accumulation is one of the most important stress signaling pathways in plant cells. Redox regulation of cellular signaling has currently attracted particular attention, but much less is known about its roles and mechanisms in plant signaling. Herein, we report that water deficit-induced ABA accumulation could be regulated by ascorbic acid (AA)-controlled redox status in leave apoplast. The AA content in non-stressed leaves was approximately 3 μmol/g FW, corresponding to a mean concentration of 3 mmol/L in a whole cell. Because AA is mainly localized in the cytosol and chloroplasts, the volume of which is much smaller than that of the whole cell, AA content in cytosolic and chloroplast compartments should be much higher than 3 mmol/L. Water deficit-induced ABA accumulation in both leaf and root tissues of maize seedlings was significantly inhibited by AA and reduced glutathione (GSH) at concentrations of 500 μmol/L and was completely blocked by 50 mmol/L AA and GSH. These results suggest that the AA-induced inhibition of ABA accumulation should not occur at sites where AA exists in high concentrations. Although water deficit led to a small increase in the dehydroascorbic acid (DHA) content, no significant changes in AA content were observed in either leaf or root tissues. When compared with the whole leaf cell, the AA content in the apoplastic compartment was much lower (i.e.approximately 70 nmol/g FW, corresponding to 0.7 mmol/L). Water deficit induced a significant decrease (approximately 2.5-fold) in the AA content and an increase (approximately 3.4-fold) in the DHA content in the apoplastic compartment, thus leading to a considerably decreased redox status there, which may have contributed to the relief of AA-induced inhibition of ABA accumulation, alternatively, promoting water deficit-induced ABA accumulation. Reactive oxygen species (ROS) could not mimic water deficit in inducing ABA accumulation, suggesting that

  18. Deficit Irrigation as a Strategy to Save Water: Physiology and Potential Application to Horticulture

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Water is an increasingly scarce resource worldwide and irrigated agriculture remains one of the largest and most inefficient users of this resource. Low water use efficiency (WUE) together with an increased competition for water resources with other sectors (e.g. tourism or industry) are forcing growers to adopt new irrigation and cultivation practices that use water more judiciously. In areas with dry and hot climates, drip irrigation and protected cultivation have improved WUE mainly by reducing runoff and evapotranspiration losses. However, complementary approaches are still needed to increase WUE in irrigated agriculture. Deficit irrigation strategies like regulated deficit irrigation or partial root drying have emerged as potential ways to increase water savings in agriculture by allowing crops to withstand mild water stress with no or only marginal decreases of yield and quality. Grapevine and several fruit tree crops seem to be well adapted to deficit irrigation,but other crops like vegetables tend not to cope so well due to losses in yield and quality. This paper aims at providing an overview of the physiological basis of deficit irrigation strategies and their potential for horticulture by describing the major consequences of their use to vegetative growth, yield and quality of different crops (fruits, vegetables and ornamentals).

  19. Changes in content of free, conjugated and bound polyamines and osmotic adjustment in adaptation of vetiver grass to water deficit.

    Science.gov (United States)

    Zhou, Qiang; Yu, Bingjun

    2010-06-01

    Osmotic adjustment and alteration of polyamines (PAs) have been suggested to play roles in plant adaptation to water deficit/drought stress. In this study, the changes in cell intactness, photosynthesis, compatible solutes and PAs [including putrescine (Put), spermidine (Spd) and spermine (Spm) each in free, conjugated and bound forms] were investigated in leaves of vetiver grass exposed to different intensity of water deficit stress and subsequent rewatering. The results showed that, when vetiver grass was exposed to the moderate (20% and 40% PEG-6000 solutions) and severe (60% PEG solution) water deficit for 6days, the plant injury degree (expressed as the parameters of plant growth, cell membrane integrity, water relations and photosynthesis) increased and contents of free and conjugated Put decreased with the rise of PEG concentration. Under the moderate water deficit, the plants could survive by the reduced osmotic potential (psi(s)), increased free and conjugated Spd and Spm in leaves. After subsequent rewatering, the osmotic balance was re-established, most of the above investigated physiological parameters were fully or partly recovered to the control levels. However, it was not the case for the severely-stressed and rewatering plants. It indicates that, vetiver grass can cope well with the moderate water deficit/drought stress by using the strategies of osmotic adjustment and maintenance of total contents of free, conjugated and bound PAs in leaves.

  20. Addiction is a Reward Deficit and Stress Surfeit Disorder.

    Science.gov (United States)

    Koob, George F

    2013-01-01

    Drug addiction can be defined by a three-stage cycle - binge/intoxication, withdrawal/negative affect, and preoccupation/anticipation - that involves allostatic changes in the brain reward and stress systems. Two primary sources of reinforcement, positive and negative reinforcement, have been hypothesized to play a role in this allostatic process. The negative emotional state that drives negative reinforcement is hypothesized to derive from dysregulation of key neurochemical elements involved in the brain reward and stress systems. Specific neurochemical elements in these structures include not only decreases in reward system function (within-system opponent processes) but also recruitment of the brain stress systems mediated by corticotropin-releasing factor (CRF) and dynorphin-κ opioid systems in the ventral striatum, extended amygdala, and frontal cortex (both between-system opponent processes). CRF antagonists block anxiety-like responses associated with withdrawal, block increases in reward thresholds produced by withdrawal from drugs of abuse, and block compulsive-like drug taking during extended access. Excessive drug taking also engages the activation of CRF in the medial prefrontal cortex, paralleled by deficits in executive function that may facilitate the transition to compulsive-like responding. Neuropeptide Y, a powerful anti-stress neurotransmitter, has a profile of action on compulsive-like responding for ethanol similar to a CRF1 antagonist. Blockade of the κ opioid system can also block dysphoric-like effects associated with withdrawal from drugs of abuse and block the development of compulsive-like responding during extended access to drugs of abuse, suggesting another powerful brain stress system that contributes to compulsive drug seeking. The loss of reward function and recruitment of brain systems provide a powerful neurochemical basis that drives the compulsivity of addiction.

  1. Addiction is a reward deficit and stress surfeit disorder

    Directory of Open Access Journals (Sweden)

    George F Koob

    2013-08-01

    Full Text Available Drug addiction can be defined by a three-stage cycle—binge/intoxication, withdrawal/negative affect, and preoccupation/anticipation—that involves allostatic changes in the brain reward and stress systems. Two primary sources of reinforcement, positive and negative reinforcement, have been hypothesized to play a role in this allostatic process. The negative emotional state that drives negative reinforcement is hypothesized to derive from dysregulation of key neurochemical elements involved in the brain reward and stress systems. Specific neurochemical elements in these structures include not only decreases in reward system function (within-system opponent processes but also recruitment of the brain stress systems mediated by corticotropin-releasing factor (CRF and dynorphin-κ opioid systems in the ventral striatum, extended amygdala, and frontal cortex (both between-system opponent processes. CRF antagonists block anxiety-like responses associated with withdrawal, block increases in reward thresholds produced by withdrawal from drugs of abuse, and block compulsive-like drug taking during extended access. Excessive drug taking also engages the activation of CRF in the medial prefrontal cortex, paralleled by deficits in executive function that may facilitate the transition to compulsive-like responding. Neuropeptide Y, a powerful anti-stress neurotransmitter, has a profile of action on compulsive-like responding for ethanol similar to a CRF1 antagonist. Blockade of the κ opioid system can also block dysphoric-like effects associated with withdrawal from drugs of abuse and block the development of compulsive-like responding during extended access to drugs of abuse, suggesting another powerful brain stress system that contributes to compulsive drug seeking. The loss of reward function and recruitment of brain systems provide a powerful neurochemical basis that drives the compulsivity of addiction.

  2. Azospirillum Inoculation Alters Nitrate Reductase Activity and Nitrogen Uptake in Wheat Plant under Water Deficit Conditions

    Directory of Open Access Journals (Sweden)

    N. Aliasgharzad N. Aliasgharzad

    2014-01-01

    Full Text Available Water deficit stress usually diminishes nitrogen uptake by plants. There are evidences that some nitrogen fixing bacteria can alleviate this stress by supplying nitrogen and improving its metabolism in plants. Four Azospirillum strains, A. lipoferum AC45-II, A. brasilense AC46-I, A. irakense AC49-VII and A. irakense AC51-VI were tested for nitrate reductase activity (NRA. In a pot culture experiment using a sandy loam soil, wheat plants (Triticum aestivum L. cv. Sardari were inoculated with these bacterial strains and three ranges of soil water potential (W1: -10 to -20, W2: -40 to -50 and W3: -65 to -75 kPa were applied to the pots. All strains were positive in NRA test and the highest (7.63mg NO2-N.L-1.48h-1 was recorded for AC49-VII and the least (0.23mg NO2-N.L-1.48h-1 was belong to AC51-VI. Leaf and root NRA, root and shoot nitrogen concentrations, and dry weights of root and shoot decreased by increasing water deficit stress. All four bacterial strains caused a significant enhancement in root NRA and in each water deficit level, the higher root NRA was recorded in AC46-I and AC49-VII inoculated plants. The highest leaf NRA was achieved by AC49-VII. The mean increment of root NRA by bacterial strains was 171% compared to the non-bacterial plants. Moreover, at the highest level of water deficit stress, the highest dry weight and nitrogen concentration in root and shoot were obtained by AC46-I and AC49-VII treatments.

  3. Interact to survive: Phyllobacterium brassicacearum improves Arabidopsis tolerance to severe water deficit and growth recovery.

    Directory of Open Access Journals (Sweden)

    Justine Bresson

    Full Text Available Mutualistic bacteria can alter plant phenotypes and confer new abilities to plants. Some plant growth-promoting rhizobacteria (PGPR are known to improve both plant growth and tolerance to multiple stresses, including drought, but reports on their effects on plant survival under severe water deficits are scarce. We investigated the effect of Phyllobacterium brassicacearum STM196 strain, a PGPR isolated from the rhizosphere of oilseed rape, on survival, growth and physiological responses of Arabidopsis thaliana to severe water deficits combining destructive and non-destructive high-throughput phenotyping. Soil inoculation with STM196 greatly increased the survival rate of A. thaliana under several scenarios of severe water deficit. Photosystem II efficiency, assessed at the whole-plant level by high-throughput fluorescence imaging (Fv/Fm, was related to the probability of survival and revealed that STM196 delayed plant mortality. Inoculated surviving plants tolerated more damages to the photosynthetic tissues through a delayed dehydration and a better tolerance to low water status. Importantly, STM196 allowed a better recovery of plant growth after rewatering and stressed plants reached a similar biomass at flowering than non-stressed plants. Our results highlight the importance of plant-bacteria interactions in plant responses to severe drought and provide a new avenue of investigations to improve drought tolerance in agriculture.

  4. Water deficit modulates the response of Vitis vinifera to the Pierce's disease pathogen Xylella fastidiosa.

    Science.gov (United States)

    Choi, Hong-Kyu; Iandolino, Alberto; da Silva, Francisco Goes; Cook, Douglas R

    2013-06-01

    Pierce's disease, caused by the bacterium Xylella fastidiosa, is one of the most devastating diseases of cultivated grape, currently restricted to the Americas. To test the long-standing hypothesis that Pierce's disease results from pathogen-induced drought stress, we used the Affymetrix Vitis GeneChip to compare the transcriptional response of Vitis vinifera to Xylella infection, water deficit, or a combination of the two stresses. The results reveal a redirection of gene transcription involving 822 genes with a minimum twofold change (P related proteins, abscisic acid- and jasmonic acid-responsive biosynthesis, and downregulation of transcripts related to photosynthesis, growth, and nutrition. Although the transcriptional response of plants to Xylella infection was largely distinct from the response of healthy plants to water stress, we find that 138 of the pathogen-induced genes exhibited a significantly stronger transcriptional response when plants were simultaneously exposed to infection and drought stress, suggesting a strong interaction between disease and water deficit. This interaction between drought stress and disease was mirrored in planta at the physiological level for aspects of water relations and photosynthesis and in terms of the severity of disease symptoms and the extent of pathogen colonization, providing a molecular correlate of the classical concept of the disease triangle in which environment impacts disease severity.

  5. Trichoderma harzianum enhances antioxidant defense of tomato seedlings and resistance to water deficit.

    Science.gov (United States)

    Mastouri, Fatemeh; Björkman, Thomas; Harman, Gary E

    2012-09-01

    Some plant-symbiotic strains of the genus Trichoderma colonize roots and induce profound changes in plant gene expression that lead to enhanced growth, especially under biotic and abiotic stresses. In this study, we tested the hypothesis that one of the protective mechanisms enhanced by T. harzianum T22 colonization is the antioxidant defense mechanism. Having established that strain T22 modulates the expression of the genes encoding antioxidant enzymes, the status of antioxidant defense of tomato seedlings in response to colonization by T22 and water deficit was investigated. Total ascorbate or glutathione levels were not affected by either stimuli, but under water deficit, antioxidant pools became more oxidized (lower ratios of reduced to oxidized forms), whereas colonized plants maintained redox state as high as or higher than unstressed and untreated plants. The enhanced redox state of colonized plants could be explained by their higher activity of ascorbate and glutathione-recycling enzymes, higher activity of superoxide dismutase, catalase, and ascorbate peroxidase, in both root and shoot throughout the experiment. Similar enzymes were induced in uncolonized plants in response to water-deficit stress but to a lower extent when compared with colonized plants. This orchestrated enhancement in activity of reactive oxygen species (ROS)-scavenging pathways in colonized plants in response to stress supports the hypothesis that enhanced resistance of colonized plants to water deficit is at least partly due to higher capacity to scavenge ROS and recycle oxidized ascorbate and glutathione, a mechanism that is expected to enhance tolerance to abiotic and biotic stresses.

  6. Separate and combined responses to water deficit and UV-B radiation.

    Science.gov (United States)

    Bandurska, Hanna; Niedziela, Justyna; Chadzinikolau, Tamara

    2013-12-01

    Crops and other plants in natural conditions are routinely affected by several stresses acting simultaneously or in sequence. In areas affected by drought, plants may also be exposed to enhanced UV-B radiation (280-315nm). Each of these stress factors differently affects cellular metabolism. A common consequence of plant exposure to the separate action of water deficit and UV-B radiation is the enhanced generation of reactive oxygen species (ROS) causing damage to proteins, lipids, carbohydrates and DNA. Despite this destructive activity, ROS also act as signalling molecules in cellular processes responsible for defence responses. Plants have evolved many physiological and biochemical mechanisms that avoid or tolerate the effects of stress factors. Water deficit avoidance leads to stomatal closure, stimulation of root growth, and accumulation of free proline and other osmolytes. Secondary metabolites (flavonols, flavones and anthocyanins) that accumulate in epidermal cells effectively screen UV-B irradiation and reduce its penetration to mesophyll tissue. The coordinated increased activity of the enzymatic antioxidant defence system such as up-regulation of superoxide dismutase, catalase, guaiacol peroxidase, ascorbate peroxidase and glutathione reductase is an important mechanism of tolerance to water deficit and UV-B radiation. The accumulation of low molecular antioxidants (proline, glycine betaine, ascorbate and glutathione) can also contribute to tolerance to water deficit. Polyamines, tocopherol, carotenoids, alkaloids, flavonoids and other secondary metabolites participate in the removal of ROS under conditions of increased UV-B radiation. The combination of water deficit and UV-B radiation induces responses that can be antagonistic, additive or synergistic in comparison with the action of single stresses. UV-B radiation may enhance resistance to water deficit and vice versa. Hydrogen peroxide, nitric oxide (NO), abscisic acid (ABA), jasmonic acid, ethylene

  7. Cytokinin-dependent photorespiration and the protection of photosynthesis during water deficit.

    Science.gov (United States)

    Rivero, Rosa M; Shulaev, Vladimir; Blumwald, Eduardo

    2009-07-01

    We investigated the effects of P(SARK)IPT (for Senescence-Associated Receptor KinaseIsopentenyltransferase) expression and cytokinin production on several aspects of photosynthesis in transgenic tobacco (Nicotiana tabacum cv SR1) plants grown under optimal or restricted (30% of optimal) watering regimes. There were no significant differences in stomatal conductance between leaves from wild-type and transgenic P(SARK)-IPT plants grown under optimal or restricted watering. On the other hand, there was a significant reduction in the maximum rate of electron transport as well as the use of triose-phosphates only in wild-type plants during growth under restricted watering, indicating a biochemical control of photosynthesis during growth under water deficit. During water deficit conditions, the transgenic plants displayed an increase in catalase inside peroxisomes, maintained a physical association among chloroplasts, peroxisomes, and mitochondria, and increased the CO(2) compensation point, indicating the cytokinin-mediated occurrence of photorespiration in the transgenic plants. The contribution of photorespiration to the tolerance of transgenic plants to water deficit was also supported by the increase in transcripts coding for enzymes involved in the conversion of glycolate to ribulose-1,5-bisphosphate. Moreover, the increase in transcripts indicated a cytokinin-induced elevation in photorespiration, suggesting the contribution of photorespiration in the protection of photosynthetic processes and its beneficial role during water stress.

  8. The effect of interspecies interactions and water deficit on spring barley and red clover biomass accumulation at successive growth stages

    Directory of Open Access Journals (Sweden)

    Magdalena Jastrzębska

    2016-12-01

    Full Text Available A pot experiment was conducted in a greenhouse in Olsztyn, Poland, in the period 2010–2012. The aim of the study was to examine whether soil water deficit would change biomass volume and distribution of pure sown spring barley and red clover as well as growth rate during their joint vegetation and mutual interactions. The interactions between spring barley and red clover were of a competitive character, and the cereal was the stronger crop. The strength of this competition increased in time with the growing season. Through most of the growing season, the competition was poorer in water deficit conditions. The impact of clover on barley before the heading stage showed facilitation symptoms. Interspecific competition reduced the rate of barley biomass accumulation and decreased stem and leaf biomass towards the end of the growing season. Intensified translocation of assimilates from the vegetative parts to grain minimized the decrease in spike biomass. Water deficit stress had a more inhibitory effect on the biomass and growth rate of barley than competition, and competition did not exacerbate the adverse influence of water deficit stress on barley. Competition from barley significantly reduced the biomass and biomass accumulation rate of clover. Water deficit stress did not exacerbate barley’s competitive effect on clover, but it strongly inhibited the growth of aboveground biomass in pure-sown clover.

  9. Differential expression of isoflavone biosynthetic genes in soybean during water deficits.

    Science.gov (United States)

    Gutierrez-Gonzalez, Juan J; Guttikonda, Satish K; Tran, Lam-Son Phan; Aldrich, Donavan L; Zhong, Rui; Yu, Oliver; Nguyen, Henry T; Sleper, David A

    2010-06-01

    Numerous environmental factors influence isoflavone accumulation and have long hampered their genetic dissection. Temperature and water regimes are two of the most significant abiotic factors. However, while the effects of temperature have been widely studied, little is known about how water scarcity might affect isoflavone concentration in seeds. Studies have shown that accumulation of isoflavones is promoted by well-watered conditions, but the molecular basis remains elusive. The length and severity of the water stress required to induce changes are also still unknown. In the present work, several intensities of water stress were evaluated at various critical stages for soybean [Glycine max (L.) Merr.] seed development, in both field and controlled environments. The results suggested that only long-term progressive drought, spanning most of the seed developmental stages, significantly decreased isoflavone content in seeds. The reduction is proportional to the intensity of the stress and appears to occur in a genotype-dependent manner. However, regardless of water regime, isoflavone compounds were mainly accumulated in the later seed developmental stages. Transcripts of the most important genes for isoflavone biosynthesis were also quantified from samples collected at key seed developmental stages under well-watered and long-term water deficit conditions. Expression of CHS7, CHS8 and IFS2 correlated with isoflavone accumulation under well-watered conditions. Interestingly, we found that the two isoflavone synthase genes in soybean (IFS1 and IFS2) showed different patterns of expression. The abundance of IFS1 transcripts was maintained at a constant rate, whereas IFS2 was down-regulated and highly correlated with isoflavone accumulation under both water deficit and well-watered conditions, suggesting IFS2 as a main contributor to isoflavone diminution under drought.

  10. Methyl Jasmonate Reduces Water Stress in Strawberry.

    Science.gov (United States)

    Wang

    1999-11-01

    The effect of methyl jasmonate (MJ) on changes of oxygen-scavenging enzyme activities and membrane lipid composition was studied in strawberry leaves under water stress. Under water stress, MJ treatment reduced the increase of peroxidase (EC 1.11.1.7; POD) activity, maintained higher catalase (EC 1.11.1.6; CAT) and superoxide dismutase (EC 1.15.1.1; SOD) activities, and ascorbic acid content. In addition, MJ treatment reduced transpiration and membrane-lipid peroxidation as expressed by malondialdehyde (MDA) content, lessened the reduction of membrane lipids, glycolipids [monogalactosyl diglyceride (MGDG), digalactosyl diglyceride (DGDG)], and phospholipids [phosphatidylcholine (PC), phosphatidylethanolamine (PE), phosphatidylglycerol (PG), and phosphatidylinositol (PI)]. In water-deficit conditions, MJ treatment also alleviated the decline in the degree of fatty acid unsaturation and the ratio of linolenic (18:3) to linoleic acid (18:2). These results indicate that MJ treatment appears to alter the metabolism of strawberry plants rendering the tissue better able to withstand water stress.

  11. Vapour pressure deficit control in relation to water transport and water productivity in greenhouse tomato production during summer

    Science.gov (United States)

    Zhang, Dalong; Du, Qingjie; Zhang, Zhi; Jiao, Xiaocong; Song, Xiaoming; Li, Jianming

    2017-01-01

    Although atmospheric vapour pressure deficit (VPD) has been widely recognized as the evaporative driving force for water transport, the potential to reduce plant water consumption and improve water productivity by regulating VPD is highly uncertain. To bridge this gap, water transport in combination with plant productivity was examined in tomato (Solanum lycopersicum L.) plants grown under contrasting VPD gradients. The driving force for water transport was substantially reduced in low-VPD treatment, which consequently decreased water loss rate and moderated plant water stress: leaf desiccation, hydraulic limitation and excessive negative water potential were prevented by maintaining water balance. Alleviation in water stress by reducing VPD sustained stomatal function and photosynthesis, with concomitant improvements in biomass and fruit production. From physiological perspectives, suppression of the driving force and water flow rate substantially reduced cumulative transpiration by 19.9%. In accordance with physiological principles, irrigation water use efficiency as criterions of biomass and fruit yield in low-VPD treatment was significantly increased by 36.8% and 39.1%, respectively. The reduction in irrigation was counterbalanced by input of fogging water to some extent. Net water saving can be increased by enabling greater planting densities and improving the evaporative efficiency of the mechanical system. PMID:28266524

  12. Nitric oxide increases tolerance responses to moderate water deficit in leaves of Phaseolus vulgaris and Vigna unguiculata bean species.

    Science.gov (United States)

    Zimmer-Prados, Lucas Martins; Moreira, Ana Sílvia Franco Pinheiro; Magalhaes, Jose Ronaldo; França, Marcel Giovanni Costa

    2014-07-01

    Drought stress is one of the most intensively studied and widespread constraints, and nitric oxide (NO) is a key signaling molecule involved in the mediation of abiotic stresses in plants. We demonstrated that a sprayed solution of NO from donor sodium nitroprusside increased drought stress tolerance responses in both sensitive (Phaseolus vulgaris) and tolerant (Vigna unguiculata) beans. In intact plants subjected to halting irrigation, NO increased the leaf relative water content and stomatal conductance in both species. After cutting leaf discs and washing them, NO induced increased electrolyte leakage, which was more evident in the tolerant species. These leaf discs were then subjected to different water deficits, simulating moderate and severe drought stress conditions through polyethylene glycol solutions. NO supplied at moderate drought stress revealed a reduced membrane injury index in sensitive species. In hydrated discs and at this level of water deficit, NO increased the electron transport rate in both species, and a reduction of these rates was observed at severe stress levels. Taken together, it can be shown that NO has an effective role in ameliorating drought stress effects, activating tolerance responses at moderate water deficit levels and in both bean species which present differential drought tolerance.

  13. Water deficits are more important in delaying growth than in changing patterns of carbon allocation in Eucalyptus globulus.

    Science.gov (United States)

    Osório, J.; Osório, M. L.; Chaves, M. M.; Pereira, J. S.

    1998-06-01

    Potted cuttings of three Eucalyptus globulus Labill. clones (AR3, CN44, MP11) were either well watered or subjected to one of two soil water deficit regimes for six months in a greenhouse. Reductions in lateral branching, leaf production and leaf expansion were the leading contributors to the large differences observed in biomass production between well-watered and water-stressed plants. Although no significant differences among clones were observed in dry matter accumulation or in the magnitude of the response to soil water deficits, sensitivity of lateral branching, leaf initiation and whole-plant foliage to water stress was significantly lower in CN44 than in AR3 and MP11. When the confounding effect of differences in plant size resulting from the different watering regimes was removed, allometric analysis indicated that the genotypes differed in biomass allocation patterns. In addition to a drought-induced reduction in leaf number, water deficits also resulted in smaller leaves because leaf expansion was inhibited during dehydration events. Resumption of leaf expansion following stress relief occurred in all of the clones, but was particularly evident in severely stressed plants of Clone AR3, possibly as a result of the osmotic adjustment observed in this genotype.

  14. Diurnal variations in water relations of deficit irrigated lemon trees during fruit growth period

    Directory of Open Access Journals (Sweden)

    Y. García-Orellana

    2013-01-01

    Full Text Available Field-grown lemon trees (Citrus limon (L. Burm. fil. cv. Fino were subjected to different drip irrigation treatments: a control treatment, irrigated daily above crop water requirements in order to obtain non-limiting soil water conditions and two deficit irrigation treatments, reducing the water applied according to the maximum daily trunk shrinkage (MDS signal intensity (actual MDS/control treatment MDS threshold values of 1.25 (T1 treatment and 1.35 (T2 treatment, which induced two different drought stress levels. Daily variations in leaf (Yleaf and stem (Ystem water potentials, leaf conductance, net photosynthesis, sap flow (SF and trunk diameter fluctuations were studied on four occasions during the lemon fruit growth period. Ystem and Yleaf revealed a diurnal pattern in response to changes in evaporative demand of the atmosphere. Both water potentials decreased in response to water deficits, which were more pronounced in the T2 treatment. Ystem was seen to be a better plant water status indicator than Yleaf. The difference between the two values of Y (Ystem - Yleaf  = DY was closely correlated with sap flow, making it a suitable measure of leaf transpiration. Using the slope of this relationship, the canopy hydraulic conductance (KC was estimated. When other continuously recorded plant-based indicators are not accessible, the concurrent measurement of leaf and stem water potentials at midday, which are relatively inexpensive to measure and user-friendly, act as sufficiently good indicators of the plant water status in field grown Fino lemon trees.

  15. Water deficit induces swainsonine of some locoweed taxa, but with no swainsonine-growth trade-off

    Science.gov (United States)

    Vallotton, Amber D.; Murray, Leigh W.; Delaney, Kevin J.; Sterling, Tracy M.

    2012-08-01

    Environmental factors like nutrient availability (e.g., C:N) and water deficit can influence secondary metabolites levels in plants and fungal endophytes. Locoweeds (Astragalus and Oxytropis spp.) contain swainsonine (SWA), an alkaloid that causes chronic vertebrate toxicity. In two greenhouse experiments, we studied field transplants of three Astragalus mollissimus varieties that vary in SWA levels (barely detectable SWA in var. 'thompsonae', intermediate SWA in var. 'bigelovii', and high SWA in var. 'mollissimus'), and intermediate SWA in Oxytropis sericea; our results confirmed these rankings. We tested whether SWA induction after water deficit (three 14d water-deficit periods separated by two 7d water recovery periods) was taxon-specific and whether degree of induction was influenced by taxon average SWA. We also looked for signs of a trade-off between primary physiology (photosynthesis) or growth (biomass, relative growth rate) with fungal endophyte SWA production; and if so, whether water stress magnified such a trade-off. Leaf photosynthetic activity decreased during the experiments and often more in water-deficit than control plants; leaf gs and Ci results suggest that stomatal closure reduced photosynthetic activity from mild water deficit. Yet, water-deficit affected plants in other ways: there were more dropped senesced leaves for all tested taxa; higher water-use efficiency for var. mollissimus, var. thompsonae, and O. sericea; higher root mass ratios for var. bigelovii, var. thompsonae, and O. sericea; and lower relative water content for var. thompsonae. Positive SWA increases of 1.6-fold for var. mollissimus and 4-fold for var. bigelovii occurred, so positive SWA induction was taxon-specific and limited to medium/high SWA A. mollissimus varieties. There was little evidence for a clear SWA trade-off with total (shoot + root) biomass, relative growth rate, or photosynthetic rate. Additional studies will need to test whether water deficit positively

  16. Effect of Super Absorbent Polymer and Irrigation Deficit on Water Use Efficiency, Growth and Yield of Cotton

    Directory of Open Access Journals (Sweden)

    Hamid-Reza FALLAHI

    2015-09-01

    Full Text Available Sustainable use of water resources in agriculture is a necessity for many arid countries. In order to investigate the effect of water deficit, irrigation after 120 (control, 155 (moderate water stress and 190 mm (sever water stress pan evaporation and super absorbent polymer rates (SAP (0, 30, 60 and 90 kg ha-1 on growth, yield and water use efficiency of cotton, an experiment was conducted as split plot based on a randomized complete block design with three replications. Moreover, the effect of water quality (distilled water and solutions of 0.25, 0.5, 0.75, 1 and 1.25% NaCl was investigated on water holding capacity by SAP. Results revealed that moderate water stress (irrigation intervals of aprox. 15 days along with 60 kg ha-1 SAP application was the best treatment in terms of growth and yield indices of cotton. The results for plant height, plant dry weight, boll number per plant and fiber yield in this treatment were 16, 28, 42 and 10% higher than control treatment, respectively. Water deficit and SAP application improved the water use efficiency (WUE of cotton. The amount of WUE in moderate water stress treatment along with consumption of 60 or 90 kg ha-1 SAP was 26% higher than for control treatment. In addition, water holding capacity by SAP in distilled water treatment was 7 times higher than in the case of 1.25% NaCl solution. The overall results showed that irrigation deficit and SAP application are two appropriate strategies for crop production in areas affected by drought stress, especially if low saline water sources are used.

  17. Molecular, physiological and biochemical responses of Theobroma cacao L. genotypes to soil water deficit.

    Science.gov (United States)

    Santos, Ivanildes C Dos; Almeida, Alex-Alan Furtado de; Anhert, Dário; Conceição, Alessandro S da; Pirovani, Carlos P; Pires, José L; Valle, Raúl René; Baligar, Virupax C

    2014-01-01

    Six months-old seminal plants of 36 cacao genotypes grown under greenhouse conditions were subjected to two soil water regimes (control and drought) to assess, the effects of water deficit on growth, chemical composition and oxidative stress. In the control, soil moisture was maintained near field capacity with leaf water potentials (ΨWL) ranging from -0.1 to -0.5 MPa. In the drought treatment, the soil moisture was reduced gradually by withholding additional water until ΨWL reached values of between -2.0 to -2.5 MPa. The tolerant genotypes PS-1319, MO-20 and MA-15 recorded significant increases in guaiacol peroxidase activity reflecting a more efficient antioxidant metabolism. In relation to drought tolerance, the most important variables in the distinguishing contrasting groups were: total leaf area per plant; leaf, stem and total dry biomass; relative growth rate; plant shoot biomass and leaf content of N, Ca, and Mg. From the results of these analyses, six genotypes were selected with contrasting characteristics for tolerance to soil water deficit [CC-40, C. SUL-4 and SIC-2 (non-tolerant) and MA-15, MO-20, and PA-13 (tolerant)] for further assessment of the expression of genes NCED5, PP2C, psbA and psbO to water deficit. Increased expression of NCED5, PP2C, psbA and psbO genes were found for non-tolerant genotypes, while in the majority of tolerant genotypes there was repression of these genes, with the exception of PA-13 that showed an increased expression of psbA. Mutivariate analysis showed that growth variables, leaf and total dry biomass, relative growth rate as well as Mg content of the leaves were the most important factor in the classification of the genotypes as tolerant, moderately tolerant and sensitive to water deficit. Therefore these variables are reliable plant traits in the selection of plants tolerant to drought.

  18. Differential Antioxidative Responses to Water Deficit Among four Barley (Hordeum vulgare L. Genotypes

    Directory of Open Access Journals (Sweden)

    Z Amini

    2013-08-01

    Full Text Available Future climate changes are expected to increase risks of drought, which already represent the most common stress factor for stable barley (Hordeum vulgare L. production in Iran. Up to now, extensive research projects have been done to study effects of drought stress on the antioxidant enzyme activity. While there is a few works of such studies on the field condition. In order to study of water deficit effects on the antioxidant enzymes activities as a secondary stress, we evaluate the effects of mild and severe drought stress on activities of antioxidative enzymes including superoxide dismutases, ascorbate peroxidase, catalase and peroxidase, among four barley genotypes, differing in the capacity to maintain the grain yield under drought condition during beginning on anthesis, kernel watery ripe and late milk stages under field condition. Results showed that drought increased the activity of antioxidant enzymes in all genotypes. At beginning of anthesis, POX activity of Q22 was higher than it in other genotypes ( P

  19. Deficit

    CERN Multimedia

    2002-01-01

    UCL's former provost, Sir Derek Roberts, has been drafted in for a year to run the college. UCL is expected to have a 6 million pounds deficit this year and up to a 10 million pounds deficit next year. Sir Christopher Llewellyn-Smith took over at UCL nearly 4 years ago and decided then that the finanical situation was serious enough to warrant a reduction in the vast expansion policy undertaken by his predecessor (1 page).

  20. Peach water relations, gas exchange, growth and shoot mortality under water deficit in semi-arid weather conditions.

    Directory of Open Access Journals (Sweden)

    Mitra Rahmati

    Full Text Available In this study the sensitivity of peach tree (Prunus persica L. to three water stress levels from mid-pit hardening until harvest was assessed. Seasonal patterns of shoot and fruit growth, gas exchange (leaf photosynthesis, stomatal conductance and transpiration as well as carbon (C storage/mobilization were evaluated in relation to plant water status. A simple C balance model was also developed to investigate sink-source relationship in relation to plant water status at the tree level. The C source was estimated through the leaf area dynamics and leaf photosynthesis rate along the season. The C sink was estimated for maintenance respiration and growth of shoots and fruits. Water stress significantly reduced gas exchange, and fruit, and shoot growth, but increased fruit dry matter concentration. Growth was more affected by water deficit than photosynthesis, and shoot growth was more sensitive to water deficit than fruit growth. Reduction of shoot growth was associated with a decrease of shoot elongation, emergence, and high shoot mortality. Water scarcity affected tree C assimilation due to two interacting factors: (i reduction in leaf photosynthesis (-23% and -50% under moderate (MS and severe (SS water stress compared to low (LS stress during growth season and (ii reduction in total leaf area (-57% and -79% under MS and SS compared to LS at harvest. Our field data analysis suggested a Ψstem threshold of -1.5 MPa below which daily net C gain became negative, i.e. C assimilation became lower than C needed for respiration and growth. Negative C balance under MS and SS associated with decline of trunk carbohydrate reserves--may have led to drought-induced vegetative mortality.

  1. Peach water relations, gas exchange, growth and shoot mortality under water deficit in semi-arid weather conditions.

    Science.gov (United States)

    Rahmati, Mitra; Davarynejad, Gholam Hossein; Génard, Michel; Bannayan, Mohammad; Azizi, Majid; Vercambre, Gilles

    2015-01-01

    In this study the sensitivity of peach tree (Prunus persica L.) to three water stress levels from mid-pit hardening until harvest was assessed. Seasonal patterns of shoot and fruit growth, gas exchange (leaf photosynthesis, stomatal conductance and transpiration) as well as carbon (C) storage/mobilization were evaluated in relation to plant water status. A simple C balance model was also developed to investigate sink-source relationship in relation to plant water status at the tree level. The C source was estimated through the leaf area dynamics and leaf photosynthesis rate along the season. The C sink was estimated for maintenance respiration and growth of shoots and fruits. Water stress significantly reduced gas exchange, and fruit, and shoot growth, but increased fruit dry matter concentration. Growth was more affected by water deficit than photosynthesis, and shoot growth was more sensitive to water deficit than fruit growth. Reduction of shoot growth was associated with a decrease of shoot elongation, emergence, and high shoot mortality. Water scarcity affected tree C assimilation due to two interacting factors: (i) reduction in leaf photosynthesis (-23% and -50% under moderate (MS) and severe (SS) water stress compared to low (LS) stress during growth season) and (ii) reduction in total leaf area (-57% and -79% under MS and SS compared to LS at harvest). Our field data analysis suggested a Ψstem threshold of -1.5 MPa below which daily net C gain became negative, i.e. C assimilation became lower than C needed for respiration and growth. Negative C balance under MS and SS associated with decline of trunk carbohydrate reserves--may have led to drought-induced vegetative mortality.

  2. Effects on Sucrose Metabolism,Dry Matter Distribution and Fruit Quality of Tomato Under Water Deficit

    Institute of Scientific and Technical Information of China (English)

    QI Hong-yan; LI Tian-lai; ZHANG Jie; WANG Lei; CHEN Yuan-hong

    2003-01-01

    Four irrigation treatments were designed with 2, 4, 6 and 8 d intervals to irrigate, respectively. Watering was stopped when the reading of the moisture tension sensor reached zero. The results indicated that glucose and fructose content of tomato's fruit were increased but sucrose content was decreased with fruit growth and development. In different stages, carbohydrate content of tomato fruit in the treatment 3 was the highest, in the treatment 2 was higher, and in the other treatments was the lowest. SS(sucrose synthase) activity was decreased but SPS(sucrose phosphate synthase) activity was increased with development of tomato. SS and SPS activity were increased but acid invertase and neutral invertase activity of ripe stage were decreased under deficit irrigation. Glucose and fructose content were increased in leaves of tomato under water deficit.Soluble sugars, organic acid and the ratio of sugar/acid in tomato fruits were increased and dry matter accumulation of plant was enhanced under water deficit. But the growth of fruits upside the plant and its dry matter accumulation were badly affected under water stress.

  3. Water Stress Projection Modeling

    Science.gov (United States)

    2016-09-01

    facility. Stationing analysis done with climate forecasting in mind recognizes an unpredictable future, while striving to best prepare for the...to support additional growth. This attribute places a threshold ca- pacity on water supply and treatment, which may be related to treat- ment plant ...et al. 2013). 3.3 Military impacts reduced water Extreme weather events such as droughts, floods, snow, and ice storms have significant impacts on

  4. Chronic stress-induced memory deficits are reversed by regular exercise via AMPK-mediated BDNF induction.

    Science.gov (United States)

    Kim, D-M; Leem, Y-H

    2016-06-02

    Chronic stress has a detrimental effect on neurological insults, psychiatric deficits, and cognitive impairment. In the current study, chronic stress was shown to impair learning and memory functions, in addition to reducing in hippocampal Adenosine monophosphate-activated protein kinase (AMPK) activity. Similar reductions were also observed for brain-derived neurotrophic factor (BDNF), synaptophysin, and post-synaptic density-95 (PSD-95) levels, all of which was counter-regulated by a regime of regular and prolonged exercise. A 21-day restraint stress regimen (6 h/day) produced learning and memory deficits, including reduced alternation in the Y-maze and decreased memory retention in the water maze test. These effects were reversed post-administration by a 3-week regime of treadmill running (19 m/min, 1 h/day, 6 days/week). In hippocampal primary culture, phosphorylated-AMPK (phospho-AMPK) and BDNF levels were enhanced in a dose-dependent manner by 5-amimoimidazole-4-carboxamide riboside (AICAR) treatment, and AICAR-treated increase was blocked by Compound C. A 7-day period of AICAR intraperitoneal injections enhanced alternation in the Y-maze test and reduced escape latency in water maze test, along with enhanced phospho-AMPK and BDNF levels in the hippocampus. The intraperitoneal injection of Compound C every 4 days during exercise intervention diminished exercise-induced enhancement of memory improvement during the water maze test in chronically stressed mice. Also, chronic stress reduced hippocampal neurogenesis (lower Ki-67- and doublecortin-positive cells) and mRNA levels of BDNF, synaptophysin, and PSD-95. Our results suggest that regular and prolonged exercise can alleviate chronic stress-induced hippocampal-dependent memory deficits. Hippocampal AMPK-engaged BDNF induction is at least in part required for exercise-induced protection against chronic stress. Copyright © 2016 IBRO. Published by Elsevier Ltd. All rights reserved.

  5. Dynamic changes in the leaf proteome of a C3 xerophyte, Citrullus lanatus (wild watermelon), in response to water deficit.

    Science.gov (United States)

    Akashi, Kinya; Yoshida, Kazuo; Kuwano, Masayoshi; Kajikawa, Masataka; Yoshimura, Kazuya; Hoshiyasu, Saki; Inagaki, Naoyuki; Yokota, Akiho

    2011-05-01

    Wild watermelon (Citrullus lanatus) is a xerophyte native to the Kalahari Desert, Africa. To better understand the molecular mechanisms of drought resistance in this plant, we examined changes in the proteome in response to water deficit. Wild watermelon leaves showed decreased transpiration and a concomitant increase in leaf temperature under water deficit conditions. Comparison of the proteome of stressed plants with that of unstressed plants by two-dimensional gel electrophoresis revealed that the intensity of 40 spots increased in response to the stress, and the intensity of 11 spots decreased. We positively identified 23 stress-induced and 6 stress-repressed proteins by mass spectrometry and database analyses. Interestingly, 15 out of the 23 up-regulated proteins (65% of annotated up-regulated proteins) were heat shock proteins (HSPs). Especially, 10 out of the 15 up-regulated HSPs belonged to the small heat shock protein (sHSP) family. Other stress-induced proteins included those related to antioxidative defense and carbohydrate metabolism. Fifteen distinct cDNA sequences encoding the sHSP were characterized from wild watermelon. Quantitative real-time PCR analysis of the representative sHSP genes revealed strong transcriptional up-regulation in the leaves under water deficit. Moreover, immunoblot analysis confirmed that protein abundance of sHSPs was massively increased under water deficit. Overall, these observations suggest that the defense response of wild watermelon may involve orchestrated regulation of a diverse array of functional proteins related to cellular defense and metabolism, of which HSPs may play a pivotal role on the protection of the plant under water deficit in the presence of strong light.

  6. Cotton Water Use Efficiency under Two Different Deficit Irrigation Scheduling Methods

    Directory of Open Access Journals (Sweden)

    Jeffrey T. Baker

    2015-08-01

    Full Text Available Declines in Ogallala aquifer levels used for irrigation has prompted research to identify methods for optimizing water use efficiency (WUE of cotton (Gossypium hirsutum L. In this experiment, conducted at Lubbock, TX, USA in 2014, our objective was to test two canopy temperature based stress indices, each at two different irrigation trigger set points: the Stress Time (ST method with irrigation triggers set at 5.5 (ST_5.5 and 8.5 h (ST_8.5 and the Crop Water Stress Index (CWSI method with irrigation triggers set at 0.3 (CWSI_0.3 and 0.6 (CWSI_0.6. When these irrigation triggers were exceeded on a given day, the crop was deficit irrigated with 5 mm of water via subsurface drip tape. Also included in the experimental design were a well-watered (WW control irrigated at 110% of potential evapotranspiration and a dry land (DL treatment that relied on rainfall only. Seasonal crop water use ranged from 353 to 625 mm across these six treatments. As expected, cotton lint yield increased with increasing crop water use but lint yield WUE displayed asignificant (p ≤ 0.05 peak near 3.6 to 3.7 kg ha−1 mm−1 for the ST_5.5 and CWSI_0.3 treatments, respectively. Our results suggest that WUE may be optimized in cotton with less water than that needed for maximum lint yield.

  7. Effects of Selenium on Maize Ovary Development at Pollination Stage Under Water Deficits

    Institute of Scientific and Technical Information of China (English)

    SHEN Qiang-yun; Marja Turakainen; Mervi Seppanen; Pirjo M(a)kel(a)

    2008-01-01

    Maize ovary development is linked to kernel formation. Soil water deficit results in ovary abortion because of low water potential (ψw) resulting in inhibition of photosynthesis from anthesis to silking stage. Thus, drought is a key factor causing yield losses in maize, especially near the time of pollination. Earlier studies have indicated that selenium (Se) maintains antioxidative defence systems and enhances sugar and starch accumulation. The effects of Se on maize ovary development were studied in drought stress conditions. Maize ovary development was studied through observations on starch, membrane integrity, fresh weight and dry weight in drought-treated or unstressed glasshouse-grown plants, and crop yield, yield structure, leaf, stem and ear biomass accumulation were also analyzed. Results indicated that Se increased the stress tolerance of the crop, even though ovary abortion was not eliminated by Se treatments under low ψw. Under well-watered control conditions, Se had also negative effects. When the first ear was not succesfully pollinated or the ovaries aborted, the plants developed more ears. Even though these later formed ears did not produce kernels, they significantly increased the dry weight of the plants under water deficit. It could be concluded that The optimal concentration for maize of Se applied through roots is about 0.01 mg kg-1 (supplied as Na2SeO4) soil or less.

  8. Effect of nitrogen and water deficit type on the yield gap between the potential and attainable wheat yield

    Directory of Open Access Journals (Sweden)

    Jiangang Liu

    2015-12-01

    Full Text Available Water deficit and N fertilizer are the two primary limiting factors for wheat yield in the North China plain, the most important winter wheat (Triticum aestivum L. production area in China. Analyzing the yield gap between the potential yield and the attainable yield can quantify the potential for increasing wheat production and exploring the limiting factors to yield gap in the high-yielding farming region of North China Plain. The Decision Support System for Agrotechnology Transfer (DSSAT model was used to identify methods to increase the grain yield and decrease the gap. In order to explore the impact of N and cultivars on wheat yield in the different drought types, the climate conditions during 1981 to 2011 growing seasons was categorized into low, moderate, and severe water deficit classes according to the anomaly percentage of the water deficit rate during the entire wheat growing season. There are differences (P < 0.0001 in the variations of the potential yields among three cultivars over 30 yr. For all three water deficit types, the more recent cultivars Jimai22 and Shijiazhuang8 had higher yields compared to the older 'Jinan17'. As the N fertilizer rate increased, the yield gap decreased more substantially during the low water deficit years because of the significant increase in attainable yield. Overall, the yield gaps were smaller with less water stress. Replacement of cultivars and appropriate N fertilizer application based on the forecasted drought types can narrow the yield gap effectively.

  9. WATER DEFICIT EFFECT ON YIELD AND FORAGE QUALITY OF MEDICAGO SATIVA POPULATIONS UNDER FIELD CONDITIONS IN MARRAKESH AREA (MOROCCO

    Directory of Open Access Journals (Sweden)

    Mohamed FARISSI

    2014-06-01

    Full Text Available The present study focused the effect of water deficit on agronomic potential and some traits related to forage quality in plants of Moroccan Alfalfa (Medicago sativa L. populations (Taf 1, Taf 2, Dem and Tata originated from Oasis and High Atlas of Morocco and an introduced variety from Australia (Siriver. The experiment was conducted under field conditions in experimental station of INRA-Marrakech and under two irrigation treatments. The first treatment was normal irrigation, providing an amount of water corresponding to the potential evapo-transpiration of the crop, and the second treatment was water deficit stress (one irrigation per cut. For each treatment, the experiment was conducted as a split plot based on a randomized complete block design with four replications. The plants were measured and analyzed over three cuts. Some agronomic traits as, plant height, fresh and dry forage yields were measured. The forage quality was evaluated by leaf:stem ratio and the contents of plants in proteins and nitrogen. The results indicated that the water deficit has negatively affected the plant height and forage yield. The decrease in leaf:stem ratio was observed under water deficit conditions. However, the proteins and nitrogen contents were unaffected. The behavior of tested alfalfa genotypes was significantly different. The Moroccan alfalfa populations were more adapted to water deficit conditions comparatively to Siriver variety and the Tata population was the most adapted one.

  10. The effect of water deficit on the activity of hydrogen peroxide-scavenging enzymes in two barley genotypes

    Directory of Open Access Journals (Sweden)

    Hanna Bandurska

    2014-01-01

    Full Text Available Two barley (Hordeum vulgare L. genotypes, the cv. Aramir and line R567, were subjected to water deficit by immersing their root systems in polyethylene glycol solution of osmotic potential -1.0 MPa. The stress caused a decline in the leaf-relative-water content (RWC and affected membrane damage in both the genotypes. A higher decline in RWC and a higher membrane injury index was observed in R567 in comparison to 'Aramir'. Water deficit induced an increase in the activity of guaiacol peroxidase (GPO and catalse (CAT. A higher increase of CAT than GPO peroxidase activity has been noted in both the genotypes. The results. together with our earlier reports (Bandurska et al. 1997 show that detoxification of hydrogen peroxide under water stress conditions in those two barley genotypes was associated with the action of GPO and CAT, and that the latter was more involved in that process.

  11. Preventive and therapeutic effect of treadmill running on chronic stress-induced memory deficit in rats.

    Science.gov (United States)

    Radahmadi, Maryam; Alaei, Hojjatallah; Sharifi, Mohammad Reza; Hosseini, Nasrin

    2015-04-01

    Previous results indicated that stress impairs learning and memory. In this research, the effects of preventive, therapeutic and regular continually running activity on chronic stress-induced memory deficit in rats were investigated. 70 male rats were randomly divided into seven groups as follows: Control, Sham, Stress-Rest, Rest-Stress, Stress-Exercise, Exercise-Stress and Exercise-Stress & Exercise groups. Chronic restraint stress was applied 6 h/day for 21days and treadmill running 1 h/day. Memory function was evaluated by the passive avoidance test. The results revealed that running activities had therapeutic effect on mid and long-term memory deficit and preventive effects on short and mid-term memory deficit in stressed rats. Regular continually running activity improved mid and long-term memory compared to Exercise-Stress group. The beneficial effects of exercise were time-dependent in stress conditions. Finally, data corresponded to the possibility that treadmill running had a more important role on treatment rather than on prevention on memory impairment induced by stress.

  12. Influence of arbuscular mycorrhiza on growth and reproductive response of plants under water deficit: a meta-analysis.

    Science.gov (United States)

    Jayne, Benjamin; Quigley, Martin

    2014-02-01

    Despite a large body of literature that describes the effects of arbuscular mycorrhizal colonization on plant response to water deficit, reviews of these works have been mainly in narrative form, and it is therefore difficult to quantify the magnitude of the effect. We performed a meta-analysis to examine the effect of mycorrhizal colonization on growth and yield of plants exposed to water deficit stress. Data were compared in the context of annual vs. perennial plants, herbaceous vs. woody plants, field vs. greenhouse conditions, degree of stress, functional group, regions of plant growth, and mycorrhizal and host species. We found that, in terms of biomass measurements, mycorrhizal plants have better growth and reproductive response under water stress compared to non-mycorrhizal plants. When variables such as habit, life cycle, or water stress level are considered, differences in mycorrhizal effect on plant growth between variables are observed. While growth of both annual and perennial plants is improved by symbiosis, perennials respond more favorably to colonization than annuals. Overall, our meta-analysis reveals a quantifiable corroboration of the commonly held view that, under water-deficit conditions, plants colonized by mycorrhizal fungi have better growth and reproductive response than those that are not.

  13. Transcriptomics analyses of soybean leaf and root samples during water-deficit

    Directory of Open Access Journals (Sweden)

    Prateek Tripathi

    2015-09-01

    Full Text Available Drought being a major challenge for crop productivity and yield affects multigenic and quantitative traits. It is also well documented that water stress shows a cross talk with other abiotic stresses such as high temperature and high light intensities (Tripathi et al., 2013 [1]. In this report, we documented the details of the methods and quality controls used and considered in our time course-based transcriptome profile of soybean plants under water deficit conditions using microarray technology. The findings of this study are recently published by the Rushton lab in BMC Genomics for a comparative study of tobacco and Soybean (Rabara et al., 2015 [2]. The raw microarray data set is deposited in GEO database with accession number GSE49537.

  14. Mechanisms underlying plant resilience to water deficits: prospects for water-saving agriculture.

    Science.gov (United States)

    Chaves, M M; Oliveira, M M

    2004-11-01

    Drought is one of the greatest limitations to crop expansion outside the present-day agricultural areas. It will become increasingly important in regions of the globe where, in the past, the problem was negligible, due to the recognized changes in global climate. Today the concern is with improving cultural practices and crop genotypes for drought-prone areas; therefore, understanding the mechanisms behind drought resistance and the efficient use of water by the plants is fundamental for the achievement of those goals. In this paper, the major constraints to carbon assimilation and the metabolic regulations that play a role in plant responses to water deficits, acting in isolation or in conjunction with other stresses, is reviewed. The effects on carbon assimilation include increased resistance to diffusion by stomata and the mesophyll, as well as biochemical and photochemical adjustments. Oxidative stress is critical for crops that experience drought episodes. The role of detoxifying systems in preventing irreversible damage to photosynthetic machinery and of redox molecules as local or systemic signals is revised. Plant capacity to avoid or repair membrane damage during dehydration and rehydration processes is pivotal for the maintenance of membrane integrity, especially for those that embed functional proteins. Among such proteins are water transporters, whose role in the regulation of plant water status and transport of other metabolites is the subject of intense investigation. Long-distance chemical signalling, as an early response to drought, started to be unravelled more than a decade ago. The effects of those signals on carbon assimilation and partitioning of assimilates between reproductive and non-reproductive structures are revised and discussed in the context of novel management techniques. These applications are designed to combine increased crop water-use efficiency with sustained yield and improved quality of the products. Through an understanding of

  15. Microeconomics of Deficit Irrigation and Subjective Water Response Function for Intensive Olive Groves

    Directory of Open Access Journals (Sweden)

    Alfonso Expósito

    2016-06-01

    Full Text Available This research paper analyzes the economics of deficit irrigation based on the use of subjective estimates of the crop yield–water relationship to determine water supply in irrigated olive groves. Interviewed farmers were asked to give three estimates for the yield-water relationship as a function of water supply (full irrigation, usual deficit irrigation and extreme deficit irrigation. Those responses are contrasted with the actual irrigation dose and the results appear to support the hypothesis that a majority of farmers use deficit irrigation as a strategy that maximizes the value of limited water input rather than the conventional microeconomic behavior of maximizing the return to land.

  16. ABA control of plant macroelement membrane transport systems in response to water deficit and high salinity.

    Science.gov (United States)

    Osakabe, Yuriko; Yamaguchi-Shinozaki, Kazuko; Shinozaki, Kazuo; Tran, Lam-Son Phan

    2014-04-01

    Plant growth and productivity are adversely affected by various abiotic stressors and plants develop a wide range of adaptive mechanisms to cope with these adverse conditions, including adjustment of growth and development brought about by changes in stomatal activity. Membrane ion transport systems are involved in the maintenance of cellular homeostasis during exposure to stress and ion transport activity is regulated by phosphorylation/dephosphorylation networks that respond to stress conditions. The phytohormone abscisic acid (ABA), which is produced rapidly in response to drought and salinity stress, plays a critical role in the regulation of stress responses and induces a series of signaling cascades. ABA signaling involves an ABA receptor complex, consisting of an ABA receptor family, phosphatases and kinases: these proteins play a central role in regulating a variety of diverse responses to drought stress, including the activities of membrane-localized factors, such as ion transporters. In this review, recent research on signal transduction networks that regulate the function ofmembrane transport systems in response to stress, especially water deficit and high salinity, is summarized and discussed. The signal transduction networks covered in this review have central roles in mitigating the effect of stress by maintaining plant homeostasis through the control of membrane transport systems.

  17. Arabidopsis growth under prolonged high temperature and water deficit: independent or interactive effects?

    Science.gov (United States)

    Vile, Denis; Pervent, Marjorie; Belluau, Michaël; Vasseur, François; Bresson, Justine; Muller, Bertrand; Granier, Christine; Simonneau, Thierry

    2012-04-01

    High temperature (HT) and water deficit (WD) are frequent environmental constraints restricting plant growth and productivity. These stresses often occur simultaneously in the field, but little is known about their combined impacts on plant growth, development and physiology. We evaluated the responses of 10 Arabidopsis thaliana natural accessions to prolonged elevated air temperature (30 °C) and soil WD applied separately or in combination. Plant growth was significantly reduced under both stresses and their combination was even more detrimental to plant performance. The effects of the two stresses were globally additive, but some traits responded specifically to one but not the other stress. Root allocation increased in response to WD, while reproductive allocation, hyponasty and specific leaf area increased under HT. All the traits that varied in response to combined stresses also responded to at least one of them. Tolerance to WD was higher in small-sized accessions under control temperature and HT and in accessions with high biomass allocation to root under control conditions. Accessions that originate from sites with higher temperature have less stomatal density and allocate less biomass to the roots when cultivated under HT. Independence and interaction between stresses as well as the relationships between traits and stress responses are discussed.

  18. Deficient cardiovascular stress reactivity predicts poor executive functions in adults with attention-deficit/hyperactivity disorder.

    Science.gov (United States)

    Hirvikoski, Tatja; Olsson, Erik M G; Nordenstrom, Anna; Lindholm, Torun; Nordstrom, Anna-Lena; Lajic, Svetlana

    2011-01-01

    Associations between cardiovascular stress markers, subjective stress reactivity, and executive functions were studied in 60 adults (30 with attention-deficit/hyperactivity disorder, ADHD, and 30 controls) using the Paced Auditory Serial Addition Test (PASAT, a test of executive functions) as a cognitive stressor. Despite higher self-perceived stress, the adults with ADHD showed lower or atypical cardiovascular stress reactivity, which was associated with poorer performance on PASAT. Using cardiovascular stress markers, subjective stress, and results on PASAT as predictors in a logistic regression, 83.3% of the ADHD group and 86.9% of the controls could be classified correctly.

  19. Global monthly water stress: 2. Water demand and severity of water stress

    OpenAIRE

    Wada, Yoshihide; Van Beek, L. P. H.; Viviroli, Daniel; Dürr, Hans H.; Weingartner, Rolf; Bierkens, Marc F. P.

    2011-01-01

    This paper assesses global water stress at a finer temporal scale compared to conventional assessments. To calculate time series of global water stress at a monthly time scale, global water availability, as obtained from simulations of monthly river discharge from the companion paper, is confronted with global monthly water demand. Water demand is defined here as the volume of water required by users to satisfy their needs. Water demand is calculated for the benchmark year of 2000 and contras...

  20. Global monthly water stress: 2. Water demand and severity of water stress

    OpenAIRE

    Wada, Yoshihide; Beek, L. P. H.; Viviroli, Daniel; Dürr, Hans H; Weingartner, Rolf; Bierkens, Marc F.P.

    2011-01-01

    This paper assesses global water stress at a finer temporal scale compared to conventional assessments. To calculate time series of global water stress at a monthly time scale, global water availability, as obtained from simulations of monthly river discharge from the companion paper, is confronted with global monthly water demand. Water demand is defined here as the volume of water required by users to satisfy their needs. Water demand is calculated for the benchmark year of 2000 and contras...

  1. Assessment of Salicylic Acid Impacts on Seedling Characteristic of Cucumber (Cucumis sativus L. under Water Stress

    Directory of Open Access Journals (Sweden)

    Hossein MARDANI

    2012-02-01

    Full Text Available Impacts of various concentrations of salicylic acid (SA on cucumber (Cucumis sativus L. seedling characteristic were evaluated under different water stress levels by using a factorial arrangement based on completely randomized design with three replications at experimental greenhouse of Ferdowsi University of Mashhad, Iran. The studied factors included three water deficit levels (100% FC, 80% FC, and 60% FC considered as first factor and five levels of SA concentrations (0, 0.25, 0.5, 0.75, and 1 mM as second factor. Results showed that foliar application of SA at the highest concentration enhanced leaf area, leaf and dry weight while decreased stomatal conductance under high level of water deficit stress. Though, severe water deficit stress sharply raised the SPAD reading values. In general, exogenous SA application could develop cucumber seedling characteristic and improve water stress tolerance.

  2. Water stress detection in the Amazon using radar

    Science.gov (United States)

    van Emmerik, Tim; Steele-Dunne, Susan; Paget, Aaron; Oliveira, Rafael S.; Bittencourt, Paulo R. L.; Barros, Fernanda de V.; van de Giesen, Nick

    2017-07-01

    The Amazon rainforest plays an important role in the global water and carbon cycle, and though it is predicted to continue drying in the future, the effect of drought remains uncertain. Developments in remote sensing missions now facilitate large-scale observations. The RapidScat scatterometer (Ku band) mounted on the International Space Station observes the Earth in a non-Sun-synchronous orbit, which allows for studying changes in the diurnal cycle of radar backscatter over the Amazon. Diurnal cycles in backscatter are significantly affected by the state of the canopy, especially during periods of increased water stress. We use RapidScat backscatter time series and water deficit measurements from dendrometers in 20 trees during a 9 month period to relate variations in backscatter to increased tree water deficit. Morning radar bacskcatter dropped significantly with increased tree water deficit measured with dendrometers. This provides unique observational evidence that demonstrates the sensitivity of radar backscatter to vegetation water stress, highlighting the potential of drought detection and monitoring using radar.

  3. Using deficit irrigation with treated wastewater to improve crop water productivity of sweet corn, chickpea, faba bean and quinoa

    Directory of Open Access Journals (Sweden)

    Abdelaziz HIRICH

    2014-07-01

    Full Text Available Several experiments were conducted in the south of Morocco (IAV-CHA, Agadir during two seasons 2010 and 2011 in order to evaluate the effect of deficit irrigation with treated wastewater on several crops (quinoa, sweet corn, faba bean and chickpeas. During the first season (2010 three crops were tested, quinoa, chickpeas and sweet corn applying 6 deficit irrigation treatments during all crop stages alternating 100% of full irrigation as non-stress condition and 50% of full irrigation as water deficit condition applied during vegetative growth, flowering and grain filling stage. For all crops, the highest water productivity and yield were obtained when deficit irrigation was applied during the vegetative growth stage. During the second season (2011 two cultivars of quinoa, faba bean and sweet corn have been cultivated applying 6 deficit irrigation treatments (rainfed, 0, 25, 50, 75 and 100% of full irrigation only during the vegetative growth stage, while in the rest of crop cycle full irrigation was provided except for rainfed treatment. For quinoa and faba bean, treatment receiving 50% of full irrigation during vegetative growth stage recorded the highest yield and water productivity, while for sweet corn applying 75% of full irrigation was the optimal treatment in terms of yield and water productivity.

  4. Protein tyrosine phosphatase is possibly involved in cellular signal transduction and the regulation of ABA accumulation in response to water deficit in Maize L. coleoptile

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Water deficit-induced ABA accumulation is an ideal model or "stimulus-response" system to investigate cellular stress signaling in plant cells, using such a model the cellular stress signaling triggered by water deficit was investigated in Maize L. coleoptile. Water deficit-induced ABA accumulation was sensitively blocked by NaVO3, a potent inhibitor both to plasma membrane H+-ATPase (PM-H+- ATPase) and protein tyrosine phosphatase (PTPase). However, while PM- H+-ATPase activity was unaffected under water deficit and PM- H+-ATPase activator did not induce an ABA accumulation instead of water deficit, water deficit induced an increase in the protein phosphatase activity, and furthermore, ABA accumulation was inhibited by PAO, a specific inhibitor of PTPase. These results indicate that protein phosphtases may be involved in the cellular signaling in response to water deficit. Further studies identified at least four species of protein phosphtase as assayed by using pNPP as substrate, among which one component was especially sensitive to NaVO3. The NaVO3-sensitive enzyme was purified and finally showed a protein band about 66 kD on SDS/PAGE. The purified enzyme showed a great activity to some specific PTPase substrates at pH 6.0. In addition to NaVO3, the enzyme was also sensitive to some other PTPase inhibitors such as Zn2+ and MO33+, but not to Ca2+ and Mg2+, indicating that it might be a protein tyrosine phosphatase. Interestingly, the purified enzyme could be deactivated by some reducing agent DTT, which was previously proved to be an inhibitor of water deficit-induced ABA accumulation. This result further proved that PTPase might be involved in the cellular signaling of ABA accumulation in response to water deficit.

  5. Diurnal variations in water relations of deficit irrigated lemon trees during fruit growth period

    Energy Technology Data Exchange (ETDEWEB)

    Garcia-Orellana, Y.; Ortuno, M. F.; Conejero, W.; Ruiz-Sanchez, M. C.

    2013-05-01

    Field-grown lemon trees (Citrus limon (L.) Burm. fil. cv. Fino) were subjected to different drip irrigation treatments: a control treatment, irrigated daily above crop water requirements in order to obtain non-limiting soil water conditions and two deficit irrigation treatments, reducing the water applied according to the maximum daily trunk shrinkage (MDS) signal intensity (actual MDS/control treatment MDS) threshold values of 1.25 (T1 treatment) and 1.35 (T2 treatment), which induced two different drought stress levels. Daily variations in leaf (Y{sub l}eaf) and stem (Y{sub s}tem) water potentials, leaf conductance, net photosynthesis, sap flow (SF) and trunk diameter fluctuations were studied on four occasions during the lemon fruit growth period. Ystem and Y{sub l}eaf revealed a diurnal pattern in response to changes in evaporative demand of the atmosphere. Both water potentials decreased in response to water deficits, which were more pronounced in the T2 treatment. Y{sub s}tem was seen to be a better plant water status indicator than Y{sub l}eaf. The difference between the two values of Y (Y{sub s}tem - Y{sub l}eaf {Delta}{Psi}) was closely correlated with sap flow, making it a suitable measure of leaf transpiration. Using the slope of this relationship, the canopy hydraulic conductance (KC) was estimated. When other continuously recorded plant-based indicators are not accessible, the concurrent measurement of leaf and stem water potentials at midday, which are relatively inexpensive to measure and user-friendly, act as sufficiently good indicators of the plant water status in field grown Fino lemon trees. (Author) 40 refs.

  6. Parent Stress Management Training for Attention-Deficit/Hyperactivity Disorder

    Science.gov (United States)

    Treacy, Lee; Tripp, Gail; Baird, Amanda

    2005-01-01

    This study assessed the effectiveness of a targeted 9-week parent stress management program (PSM) on the parenting stress, mood, family functioning, parenting style, locus of control, and perceived social support of parents of children diagnosed with DSM-IV ADHD. Sixty-three parents from 42 families were randomly assigned to 1 of 2 conditions:…

  7. Evaluation of Selected Soybean Genotypes (GLYCINE MAX L. by Physiological Responses during Water Deficit

    Directory of Open Access Journals (Sweden)

    Eleonora KRIVOSUDSKA

    2013-06-01

    Full Text Available During the experiments were monitored the following varieties: Impala (South African Republic, Maverick (USA, Rankoshi No.1h (Japan and their reactions to the water supply at the beginning of the growth stage R1 and R2 blooming in an interaction with the Nitrazon inoculation of the seeds before a sowing. Mentioned genetic resources were provided for our research purposes by the Plant Production Research Center PRRC Piesany, Gene Bank of the Slovak Republic. Seeding of the particular soy genotypes was made into the containers whilst 50% of seed corn from each genotype was before the sowing inoculated by the usage of Nitrazon inoculant (supplier: Agrokomp, spol. s.r.o., Modra. Water stress was secured by an irrigation interruption for a 7-day period in the mentioned growth stage. This stress had a negative impact on the relative water content in RWC plants, proline content, osmotic potential, SPAD, stress index as well as an amount of nodules on the roots by the all monitored varieties. According to an evaluation of the mentioned indicators more significant proline accumulation was confirmed by the genotype Maverick especially by the variant exposed to water deficit 3,25 micro mol g 1 FW according to the calculations on 100 percent RWC without the inoculant Nitrazon use and inoculating variant 2.99 micro mol g 1 FW according to calculations on 100 percent RWC. Variety MAVERICK had got the best reaction to water stress and even more noticeable resistance to the stress was monitored in the variant with Nitrazon application in the foregoing seed treatment of soybean seeds. The opposite response to the inoculation was monitored by IMPALA genotype when RWC had dropped to 41.77% in the comparison with the variant without inoculation where RWC had dropped to 61.86%.

  8. Selective amotivation deficits following chronic psychosocial stress in mice.

    Science.gov (United States)

    Tsai Cabal, Alejandro; Ioanas, Horea-Ioan; Seifritz, Erich; Saab, Bechara J

    2017-01-15

    Amotivation is a major symptom of several psychiatric disorders. However, which specific motivations are most affected in various illnesses is not well understood. In major depressive disorder (MDD), anecdotal evidence suggests the motivation to explore may be especially affected, but direct evidence from either patients or animal models is lacking. To investigate the potential for, and nature of, exploratory drive deficits in MDD, we subjected mice to a chronic social defeat (CSD) manipulation that gives rise to a MDD-like behavioural ensemble, and performed a behavioural battery to examine bodyweight homeostasis, ambulation, anxiety, exploratory behaviour motivated by either novelty or fear, and short-term memory. Consistent with previous reports, we found a disruption of bodyweight homeostasis and reduced ambulation following CSD treatment, but we found no evidence for anxiogenic effects or impairments in short-term memory. Surprisingly, we also observed profoundly delayed and diminished exploration of novel, safe space following CSD, while exploration motivated by fear remained intact. These results extend our knowledge of the behavioural phenotypes in mice resulting from CSD by homing in on specific motivational drives. In MDD patients, reduced exploration could compound disease symptomatology by preventing engagement in what could be rewarding exploration experiences, and targeting deficits in the motivation to explore may represent a novel avenue for treatment. Copyright © 2016 Elsevier B.V. All rights reserved.

  9. Dopamine D1 receptors are responsible for stress-induced emotional memory deficit in mice.

    Science.gov (United States)

    Wang, Yongfu; Wu, Jing; Zhu, Bi; Li, Chaocui; Cai, Jing-Xia

    2012-03-01

    It is established that stress impairs spatial learning and memory via the hypothalamus-pituitary-adrenal axis response. Dopamine D1 receptors were also shown to be responsible for a stress-induced deficit of working memory. However, whether stress affects the subsequent emotional learning and memory is not elucidated yet. Here, we employed the well-established one-trial step-through task to study the effect of an acute psychological stress (induced by tail hanging for 5, 10, or 20 min) on emotional learning and memory, and the possible mechanisms as well. We demonstrated that tail hanging induced an obvious stress response. Either an acute tail-hanging stress or a single dose of intraperitoneally injected dopamine D1 receptor antagonist (SCH23390) significantly decreased the step-through latency in the one-trial step-through task. However, SCH23390 prevented the acute tail-hanging stress-induced decrease in the step-through latency. In addition, the effects of tail-hanging stress and/or SCH23390 on the changes in step-through latency were not through non-memory factors such as nociceptive perception and motor function. Our data indicate that the hyperactivation of dopamine D1 receptors mediated the stress-induced deficit of emotional learning and memory. This study may have clinical significance given that psychological stress is considered to play a role in susceptibility to some mental diseases such as depression and post-traumatic stress disorder.

  10. Stress Inducible Expression of AtDREB1A Transcription Factor in Transgenic Peanut (Arachis hypogaea L.) Conferred Tolerance to Soil-Moisture Deficit Stress.

    Science.gov (United States)

    Sarkar, Tanmoy; Thankappan, Radhakrishnan; Kumar, Abhay; Mishra, Gyan P; Dobaria, Jentilal R

    2016-01-01

    Peanut, an important oilseed crop, is gaining priority for the development of drought tolerant genotypes in recent times, since the area under drought is constantly on the rise. To achieve this, one of the important strategies is to genetically engineer the ruling peanut varieties using transcription factor regulating the expression of several downstream, abiotic-stress responsive gene(s). In this study, eight independent transgenic peanut (cv. GG20) lines were developed using AtDREB1A gene, encoding for a transcription factor, through Agrobacterium-mediated genetic transformation. The transgene insertion was confirmed in (T0) using PCR and Dot-blot analysis, while copy-number(s) was ascertained using Southern-blot analysis. The inheritance of AtDREB1A gene in individual transgenic plants (T1 and T2) was confirmed using PCR. In homozygous transgenic plants (T2), under soil-moisture deficit stress, elevated level of AtDREB1A transgene expression was observed by RT-PCR assay. The transgenic plants at 45-d or reproductive growth stage showed tolerance to severe soil-moisture deficit stress. Physio-biochemical parameters such as proline content, osmotic potential, relative water content, electrolytic leakage, and total-chlorophyll content were found positively correlated with growth-related traits without any morphological abnormality, when compared to wild-type. qPCR analysis revealed consistent increase in expression of AtDREB1A gene under progressive soil-moisture deficit stress in two homozygous transgenic plants. The transgene expression showed significant correlation with improved physio-biochemical traits. The improvement of drought-stress tolerance in combination with improved growth-related traits is very essential criterion for a premium peanut cultivar like GG20, so that marginal farmers of India can incur the economic benefits during seasonal drought and water scarcity.

  11. Effect of PEG-6000 Imposed Water Deficit on Chlorophyll Metabolism in Maize Leaves

    Directory of Open Access Journals (Sweden)

    Rekha Gadre

    2013-08-01

    Full Text Available Drought stress is one of the major abiotic constraint limiting plant growth and productivity world wide. The current study was undertaken with the aim to investigate the effect of water deficit imposed by PEG-6000, on chlorophyll metabolism in maize leaves to work out the mechanistic details. Leaf segments prepared from primary leaves of etiolated maize seedlings were treated with varying concentrations of polyethylene glycol-6000 (PEG-6000; w/v- 5%, 10%, 20%, 30% in continuous light of intensity 40 Wm-2 at 26±2 °C for 24 h in light chamber. The results demonstrate a concentration dependent decline in chlorophyll content with increasing concentration of polyethylene glycol-6000 (PEG-6000. Reduction in chlorophyll ‘a’ level was to a greater extent than the chlorophyll ‘b’. The RNA content decreased in a concentration dependent manner with PEG, however, proline content increased significantly. Relative water content decreased significantly with the supply of 30% PEG only. A substantial decrease in chlorophyll synthesis due to significant reduction in ALA content and ALAD activity, with no change in chlorophyllase activity with the supply of PEG suggests that water deficit affects chlorophyll formation rather than its degradation.

  12. Induction of ferritin synthesis by water deficit and iron excess in common bean (Phaseolus vulgaris L.).

    Science.gov (United States)

    DeLaat, Daiane Mariele; Colombo, Carlos Augusto; Chiorato, Alisson Fernando; Carbonell, Sergio Augusto Morais

    2014-03-01

    Ferritins are molecules for iron storage present in most living beings. In plants, ferritin is an essential iron homeostasis regulator and therefore plays a fundamental role in control of iron induced by oxidative stress or by excess of iron ions. Ferritin gene expression is modulated by various environmental factors, including the intensity of drought, cold, light and pathogenic attack. Common bean, one of the most important species in the Brazilian diet, is also affected by insufficiency or lack of water. Thus, the present study was conducted for the purpose of determining the levels of expression of ferritins transcripts in leaf tissues of three common bean cultivars (BAT 477, Carioca Comum and IAC-Diplomata) under osmotic shock caused by polyethylene glycol 6000 and by iron excess. The expression of three ferritins genes (PvFer1, PvFer2 and PvFer3), determined by quantitative PCR, indicated a difference in the expression kinetics among the cultivars. All the ferritin genes were actively transcribed under iron excess and water deficit conditions. The cultivars most responsive to treatments were BAT 477 and IAC-Diplomata. All the cultivars responded to treatments. Nevertheless, the ferritin genes were differentially regulated according to the cultivars. Analysis of variance indicated differences among cultivars in expression of the genes PvFer1 and PvFer3. Both genes were most responsive to treatments. This result suggests that ferritin genes may be functionally important in acclimatization of common bean under iron excess or water deficit conditions.

  13. Transcranial Stimulation of the Dorsolateral Prefrontal Cortex Prevents Stress-Induced Working Memory Deficits.

    Science.gov (United States)

    Bogdanov, Mario; Schwabe, Lars

    2016-01-27

    Stress is known to impair working memory performance. This disruptive effect of stress on working memory has been linked to a decrease in the activity of the dorsolateral prefrontal cortex (dlPFC). In the present experiment, we tested whether transcranial direct current stimulation (tDCS) of the dlPFC can prevent stress-induced working memory impairments. We tested 120 healthy participants in a 2 d, sham-controlled, double-blind between-subjects design. Participants completed a test of their individual baseline working memory capacity on day 1. On day 2, participants were exposed to either a stressor or a control manipulation before they performed a visuospatial and a verbal working memory task. While participants completed the tasks, anodal, cathodal, or sham tDCS was applied over the right dlPFC. Stress impaired working memory performance in both tasks, albeit to a lesser extent in the verbal compared with the visuospatial working memory task. This stress-induced working memory impairment was prevented by anodal, but not sham or cathodal, stimulation of the dlPFC. Compared with sham or cathodal stimulation, anodal tDCS led to significantly better working memory performance in both tasks after stress. Our findings indicate a causal role of the dlPFC in working memory impairments after acute stress and point to anodal tDCS as a promising tool to reduce cognitive deficits related to working memory in stress-related mental disorders, such as depression, schizophrenia, or post-traumatic stress disorder. Working memory deficits are prominent in stress-related mental disorders, such as depression, schizophrenia, or post-traumatic stress disorder. Similar working memory impairments have been observed in healthy individuals exposed to acute stress. So far, attempts to prevent such stress-induced working memory deficits focused mainly on pharmacological interventions. Here, we tested the idea that transcranial direct current stimulation of the dorsolateral prefrontal

  14. Growth hormone releasing hormone (GHRH) signaling modulates intermittent hypoxia-induced oxidative stress and cognitive deficits in mouse.

    Science.gov (United States)

    Nair, Deepti; Ramesh, Vijay; Li, Richard C; Schally, Andrew V; Gozal, David

    2013-11-01

    Intermittent hypoxia (IH) during sleep, such as occurs in obstructive sleep apnea (OSA), leads to degenerative changes in the hippocampus, and is associated with spatial learning deficits in adult mice. In both patients and murine models of OSA, the disease is associated with suppression of growth hormone (GH) secretion, which is actively involved in the growth, development, and function of the central nervous system (CNS). Recent work showed that exogenous GH therapy attenuated neurocognitive deficits elicited by IH during sleep in rats. Here, we show that administration of the Growth Hormone Releasing Hormone (GHRH) agonist JI-34 attenuates IH-induced neurocognitive deficits, anxiety, and depression in mice along with reduction in oxidative stress markers such as MDA and 8-hydroxydeoxyguanosine, and increases in hypoxia inducible factor-1α DNA binding and up-regulation of insulin growth factor-1 and erythropoietin expression. In contrast, treatment with a GHRH antagonist (MIA-602) during intermittent hypoxia did not affect any of the IH-induced deleterious effects in mice. Thus, exogenous GHRH administered as the formulation of a GHRH agonist may provide a viable therapeutic intervention to protect IH-vulnerable brain regions from OSA-associated neurocognitive dysfunction. Sleep apnea, characterized by chronic intermittent hypoxia (IH), is associated with substantial cognitive and behavioral deficits. Here, we show that administration of a GHRH agonist (JI-34) reduces oxidative stress, increases both HIF-1α nuclear binding and downstream expression of IGF1 and erythropoietin (EPO) in hippocampus and cortex, and markedly attenuates water maze performance deficits in mice exposed to intermittent hypoxia during sleep.

  15. Predicting attention-deficit/hyperactivity disorder severity from psychosocial stress and stress-response genes : a random forest regression approach

    NARCIS (Netherlands)

    van der Meer, D.; Hoekstra, P. J.; van Donkelaar, Marjolein M. J.; Bralten, Janita; Oosterlaan, J; Heslenfeld, Dirk J.; Faraone, S. V.; Franke, B.; Buitelaar, J. K.; Hartman, C. A.

    2017-01-01

    Identifying genetic variants contributing to attention-deficit/hyperactivity disorder (ADHD) is complicated by the involvement of numerous common genetic variants with small effects, interacting with each other as well as with environmental factors, such as stress exposure. Random forest regression

  16. Predicting attention-deficit/hyperactivity disorder severity from psychosocial stress and stress-response genes: a random forest regression approach

    NARCIS (Netherlands)

    Meer, D. van der; Hoekstra, P.J.; Donkelaar, M.M.J. van; Bralten, J.B.; Oosterlaan, J.; Heslenfeld, D.; Faraone, S.V; Franke, B.; Buitelaar, J.K.; Hartman, C.A.

    2017-01-01

    Identifying genetic variants contributing to attention-deficit/hyperactivity disorder (ADHD) is complicated by the involvement of numerous common genetic variants with small effects, interacting with each other as well as with environmental factors, such as stress exposure. Random forest regression

  17. Regulated deficit irrigation and the recovery of water relations in pistachio trees.

    Science.gov (United States)

    Guerrero, J; Moriana, A; Pérez-López, D; Couceiro, J F; Olmedilla, N; Gijón, M C

    2006-01-01

    Recovery of water status in water-stressed pistachio trees (Pistacia vera L. cv. Kerman) was investigated by subjecting trees to regulated deficit irrigation (RDI) (60% of crop evapotranspiration rate, ET(c)) during stages I and II of fruit development (FD) followed by full irrigation during FD stage III (kernel-filling). Trees irrigated at 100% ET(c) throughout FD stages I, II and III served as controls. Water-stress severity was characterized by changes in soil water content and midday stem water potential (Psi(md)). Midday leaf conductance (g(1)) and trunk diameter variation (TDV) were also measured. In RDI trees, the lowest Psi(md) value, -1.8 MPa, occurred at the end of the RDI period. The corresponding value for the control trees was around -1.1 MPa. Although the RDI treatment affected gas exchange later than Psi(md), the greatest reductions in gas exchange (60% of control values) also appeared at the end of the RDI period. There were significant differences in TDV between control and RDI trees at the end of the RDI period. Although plant water status recovered within 20 days of resuming irrigation, the TDV values indicated a longer period might be necessary for complete recovery. Recovery of g(1) was faster than that of Psi(md), although differences in TDV between control and RDI trees indicated that gas exchange recovered later than Psi(md). The slow recovery of pistachio trees during FD stage III from water stress imposed during FD stages I and II suggests that irrigation should exceed 100% ET(c) during FD stage III or that more extensive irrigation should commence before the end of FD stage II.

  18. A GRACE-based water storage deficit approach for hydrological drought characterization

    OpenAIRE

    Thomas, AC; Reager, JT; Famiglietti, JS; M. Rodell

    2014-01-01

    We present a quantitative approach for measuring hydrological drought occurrence and severity based on terrestrial water storage observations from NASA's Gravity Recovery and Climate Experiment (GRACE) satellite mission. GRACE measurements are applied by calculating the magnitude of the deviation of regional, monthly terrestrial water storage anomalies from the time series' monthly climatology, where negative deviations represent storage deficits. Monthly deficits explicitly quantify the volu...

  19. Tomato Leaf Photosynthetic Responses to Humidity and Temperature Under Salinity and Water Deficit

    Institute of Scientific and Technical Information of China (English)

    H.L.XU; L.GAUTHIER; 等

    1999-01-01

    Greenhouse tomato plants(Lycopersicon esculentum Mill cv.Capello)were grown on peat-based substrate and treated with high(4.5mS cm-1) and low (2.3mS cm-1)nutrient solution electric conductivity (EC) under high and low substrate water contents.Four weeks after the beginning of the treatments,photosynthesis(PN) was measured under different humidity and temperatures to examine the interactive effects with rhizosphere salinity and water deficit.A rectangular hyperboilc model fitted the light-photosynthesis curve.Photosynthetic capacity(PC)was decreased but quantum yield(YQ) was increased by rhizosphere salinity caused by high EC.PN was decreased by low humidity only in high EC-and/or water-stressed plants.Under high photosynthetic photon flux(PPF),low humidity induced PC decline in water-stressed plants and PN oscillation in high-EC-treated plants.PN increased steadily as the leaf temperature changed from 18℃to 23℃ and then decreased steadily from 23℃to 38℃,At 34℃,PN decreased significantly in waterstressed plants.Dark respiration (RD) increased in an exponential manner as the leaf temperature changed from 18℃ to 38℃ to an extent about ten times higher under38℃ than under 18℃,Our data suggested that PN decrease under high temperature was attributed ,at least in part,to the increased RD,RD in high EC-and/or water-stressed plants was higher than that in the plants of control under lower temperature but lower than that in the plants of control under high temperature,The analysis of stomatal and mesophyll conductance showed that low humidity effect was mainly through stomatal rsponse while temperature effect was mainly through biochemical functions.The result showed that environmental stresses affected PN in an additive or synergistic manner.

  20. The Effect of Water Deficit Imposing Methods on Quantitative and Qualitative Traits of New Potato Cultivar

    Directory of Open Access Journals (Sweden)

    Kh Parvizi

    2016-02-01

    overlapping time for different irrigation regimes. The differences of flowering dateand its longevity between clones in different water treatments demonstrated that although flower longevity of potato is a qualitative trait related to cultivar inherit but it can be affected by environment condition like temperature, light intensity and soil moisture. In this research there have been remarkable changes in reducing sugar of tubers under different irrigation levels. Therefore we can conclude that by determining good strategy for water use management in potato, both water stresses and higher reduction of sugar can be avoided. This result was consistent with previous studies (12, 14 and 18 that evaluated the effect of water stress and water deficiency on qualitative characters of potato. Decreasing 20 percent water requirement of potato, resulted only 0.7 kg decrease of total yield per square meter. As a result, it can be save more than 40 million cubic meter of water only in Hamedan state every year. Moreover, if we apply some suitable cultivars same as Savalan and other promising clones that have more tolerance to water deficit, it can be more efficient. Conclusions Totally, the result of the this research showed that decreasing water requirement of potato until 20% not only did not impair the growth and performance of potato but also did not show adverse effects on qualify of harvested tuber. It is also found that Savalan and two clone had more advantage in comparison with others.

  1. Levothyroxine replacement therapy with vitamin E supplementation prevents oxidative stress and cognitive deficit in experimental hypothyroidism.

    Science.gov (United States)

    Pan, Tianrong; Zhong, Mingkui; Zhong, Xing; Zhang, Yanqing; Zhu, Defa

    2013-04-01

    Hypothyroidism has a variety of adverse effects on cognitive function. The treatment of levothyroxine alone cannot restore cognitive defects of hypothyroid patients. Antioxidant vitamin E supplementation could be useful in disturbances which are associated with oxidative stress and could effectively slow the progression of Alzheimer disease. Thus, the purpose of this study was to evaluate oxidative stress status of the serum and hippocampus in hypothyroidism and to examine the effects of levothyroxine replacement therapy with vitamin E supplementation on cognitive deficit. Sprague-Dawley rats were randomly divided into five groups: control group, PTU group, PTU + Vit E group, PTU + L-T4 group, and PTU + L-T4 + Vit E group. Serum and hippocampus malondialdehyde (MDA) levels were determined using the thiobarbituric-acid reactive substances method. Serum and hippocampus superoxide dismutase (SOD) levels were determined by measuring its ability to inhibit the photoreduction of nitroblue tetrazolium. Learning and memory was assessed by Morris water maze test. In the present study, we found that the rats of PTU + Vit E group spent less time to find the platform on days 2, 3, 4, and 5 than the PTU group. Moreover, the rats of PTU + L-T4 + Vit E group spent less time to find the platform on days 4 and 5 than the PTU + L-T4 group. The time spent in the target quadrants was measured in the probe test and no difference was observed in all groups. Oxidative damage has been observed in the serum and hippocampus of hypothyroidism rat. SOD levels of serum and hippocampus tissue were significantly increased and MDA levels were significantly decreased in the PTU + Vit E and PTU + L-T4 + Vit E groups than the PTU and PTU + L-T4 groups. Therefore, these findings indicate that levothyroxine replacement therapy with vitamin E supplementation may ameliorate cognitive deficit in PTU-induced hypothyroidism through the decrease of oxidative stress status.

  2. Response of water deficit regime and soil amelioration on evapotranspiration loss and water use efficiency of maize ( Zea mays l.) in subtropical northeastern Himalayas

    Science.gov (United States)

    Marwein, M. A.; Choudhury, B. U.; Chakraborty, D.; Kumar, M.; Das, A.; Rajkhowa, D. J.

    2017-05-01

    Rainfed maize production in the hilly ecosystem of Northeastern Himalayas often suffers from moisture and soil acidity induced abiotic stresses. The present study measured evapotranspiration loss (ETc) of maize crop under controlled condition (pot experiment) of water deficit (W25-25 % and W50-50 % of field capacity soil moistures) and well watered (W100 = 100 % of field capacity (FC)) regimes in strong acid soils (pH = 4.3) of the Northeastern Himalayan Region of India. The response of soil ameliorants (lime) and phosphorus (P) nutrition under differential water regimes on ETc losses and water use efficiency was also studied. The measured seasonal ETc loss varied from 124.3 to 270.9 mm across treatment combinations. Imposition of water deficit stress resulted in significant ( p crop ETc loss was estimated highest during 11th-14th week after sowing (coincided with blistering stage) and then declined. Water use efficiency estimated from dry matter produced per unit ETc losses and irrigation water used varied from 4.33 to 9.43 g dry matter kg-1 water and 4.21 to 8.56 g dry matter kg-1, respectively. Among the input factors (water, P, and lime), water regime most strongly influenced the ETc loss, growth duration, grain formation, and water use efficiency of maize.

  3. Response of water deficit regime and soil amelioration on evapotranspiration loss and water use efficiency of maize (Zea mays l.) in subtropical northeastern Himalayas

    Science.gov (United States)

    Marwein, M. A.; Choudhury, B. U.; Chakraborty, D.; Kumar, M.; Das, A.; Rajkhowa, D. J.

    2016-10-01

    Rainfed maize production in the hilly ecosystem of Northeastern Himalayas often suffers from moisture and soil acidity induced abiotic stresses. The present study measured evapotranspiration loss (ETc) of maize crop under controlled condition (pot experiment) of water deficit (W25-25 % and W50-50 % of field capacity soil moistures) and well watered (W100 = 100 % of field capacity (FC)) regimes in strong acid soils (pH = 4.3) of the Northeastern Himalayan Region of India. The response of soil ameliorants (lime) and phosphorus (P) nutrition under differential water regimes on ETc losses and water use efficiency was also studied. The measured seasonal ETc loss varied from 124.3 to 270.9 mm across treatment combinations. Imposition of water deficit stress resulted in significant (p < 0.05) reduction (by 33-50 %) of seasonal ETc losses but was at the cost of delay in tasseling to silking, 47-65 % reduction in dry matter accumulation (DMA), 12-22 days shortening of grain formation period, and complete kernel abortion. Liming @ 4 t ha-1 significantly (p < 0.05) increased ETc losses and DMA across water regimes but the magnitude of increase was higher in severely water deficit (W25) regime. Unlike lime, P nutrition improved DMA only in well-watered regimes (W100) while seasonal ETc loss was unaffected. Vegetative stage (tillering to tasseling) contributed the maximum ETc losses while weekly crop ETc loss was estimated highest during 11th-14th week after sowing (coincided with blistering stage) and then declined. Water use efficiency estimated from dry matter produced per unit ETc losses and irrigation water used varied from 4.33 to 9.43 g dry matter kg-1 water and 4.21 to 8.56 g dry matter kg-1, respectively. Among the input factors (water, P, and lime), water regime most strongly influenced the ETc loss, growth duration, grain formation, and water use efficiency of maize.

  4. Addiction is a reward deficit and stress surfeit disorder

    OpenAIRE

    Koob, George F.

    2013-01-01

    Drug addiction can be defined by a three-stage cycle—binge/intoxication, withdrawal/negative affect, and preoccupation/anticipation—that involves allostatic changes in the brain reward and stress systems. Two primary sources of reinforcement, positive and negative reinforcement, have been hypothesized to play a role in this allostatic process. The negative emotional state that drives negative reinforcement is hypothesized to derive from dysregulation of key neurochemical elements involved in ...

  5. Addiction is a Reward Deficit and Stress Surfeit Disorder

    OpenAIRE

    Koob, George F.

    2013-01-01

    Drug addiction can be defined by a three-stage cycle – binge/intoxication, withdrawal/negative affect, and preoccupation/anticipation – that involves allostatic changes in the brain reward and stress systems. Two primary sources of reinforcement, positive and negative reinforcement, have been hypothesized to play a role in this allostatic process. The negative emotional state that drives negative reinforcement is hypothesized to derive from dysregulation of key neurochemical elements involved...

  6. A common genetic determinism for sensitivities to soil water deficit and evaporative demand: meta-analysis of quantitative trait Loci and introgression lines of maize.

    Science.gov (United States)

    Welcker, Claude; Sadok, Walid; Dignat, Grégoire; Renault, Morgan; Salvi, Silvio; Charcosset, Alain; Tardieu, François

    2011-10-01

    Evaporative demand and soil water deficit equally contribute to water stress and to its effect on plant growth. We have compared the genetic architectures of the sensitivities of maize (Zea mays) leaf elongation rate with evaporative demand and soil water deficit. The former was measured via the response to leaf-to-air vapor pressure deficit in well-watered plants, the latter via the response to soil water potential in the absence of evaporative demand. Genetic analyses of each sensitivity were performed over 21 independent experiments with (1) three mapping populations, with temperate or tropical materials, (2) one population resulting from the introgression of a tropical drought-tolerant line in a temperate line, and (3) two introgression libraries genetically independent from mapping populations. A very large genetic variability was observed for both sensitivities. Some lines maintained leaf elongation at very high evaporative demand or water deficit, while others stopped elongation in mild conditions. A complex architecture arose from analyses of mapping populations, with 19 major meta-quantitative trait loci involving strong effects and/or more than one mapping population. A total of 68% of those quantitative trait loci affected sensitivities to both evaporative demand and soil water deficit. In introgressed lines, 73% of the tested genomic regions affected both sensitivities. To our knowledge, this study is the first genetic demonstration that hydraulic processes, which drive the response to evaporative demand, also have a large contribution to the genetic variability of plant growth under water deficit in a large range of genetic material.

  7. Effect of end of season water deficit on phenolic compounds in peanut genotypes with different levels of resistance to drought.

    Science.gov (United States)

    Aninbon, C; Jogloy, S; Vorasoot, N; Patanothai, A; Nuchadomrong, S; Senawong, T

    2016-04-01

    Terminal drought reduces pod yield and affected the phenolic content of leaves, stems and seed of peanut (Arachis hypogaea L.). The aim of this study was to investigate the effects of end of season water deficit on phenolic content in drought tolerant and sensitive genotypes of peanuts. Five peanut genotypes were planted under two water regimes, field capacity and 1/3 available water. Phenolic content was analyzed in seeds, leaves, and stems. The results revealed that terminal drought decreased phenolic content in seeds of both tolerant and sensitive genotypes. Phenolic content in leaves and stems increased under terminal drought stress in both years. This study provides basic information on changes in phenolic content in several parts of peanut plants when subjected to drought stress. Future studies to define the effect of terminal drought stress on specific phenolic compounds and antioxidant properties in peanut are warranted.

  8. Effects of soil water deficits on three genotypes of potted Campanula medium plants during bud formation stage

    DEFF Research Database (Denmark)

    Mao, Hongyu; Sun, Yanqi; Müller, Renate;

    2014-01-01

    , the floral bud abortion rate in the D plants was significantly higher for G100 as compared with G102 and G104. It is concluded that in potted ornamentals, a low transpiration rate, hereby a slow rate of soil water depletion, is crucial for maintaining postharvest quality under drought stress.......Potted ornamental plants are often exposed to drought stress during shipping and retailing, which decreases the value and postharvest quality. Thus, selection of genotypes which can better withstand soil water deficits is essential for sustainable production. Here, the response of three genotypes...... of potted Campanula medium (denoted as G100, G102 and G104) to progressive soil drying was investigated and their post-production performance was evaluated for four weeks. The potted plants were grown in a climate controlled greenhouse and were either well-watered (W) or drought-stressed (D) at floral bud...

  9. Research on the Effects of Water Stress on Growth Traits and Water Use Efficiency of Winter Wheat

    Directory of Open Access Journals (Sweden)

    Sun Shuhong

    2015-01-01

    Full Text Available This research about the effects of water stress at different growth stages on the crop growth traits has a practical significance in guiding water-saving irrigation. The box test method is adopted to test the water stress of winter wheat at different stages, observe the plant height, leaf area and yield, and analyze the water use efficiency under the condition of water stress. The results show that the water stress in each growth period will play an inhibiting role in the plant height and leaf area of winter wheat; the water stress duration at a single stage is relatively short, and rehydration crop has a certain compensatory growth without making a big difference; the continuous water stress stage plays a significantly inhibiting role in the plant height and leaf area.; water stress has a largest effect on the plant height in the elongation period; the heading period suffers from water stress, so the leaf area decreases rapidly; water stress at a single stage in the appropriate period can increase water use efficiency. Regulated deficit irrigation can reduce luxury water consumption, which has a little effect on the yield and plays a guiding role in water saving and stable yield.

  10. Water deficit down-regulates miR398 and miR408 in pea (Pisum sativum L.).

    Science.gov (United States)

    Jovanović, Živko; Stanisavljević, Nemanja; Mikić, Aleksandar; Radović, Svetlana; Maksimović, Vesna

    2014-10-01

    MicroRNAs (miRNAs), recently recognized as important regulator of gene expression at posttranscriptional level, have been found to be involved in plant stress responses. The observation that some miRNAs are up- or down regulated by stress implies that they could play vital roles in plant resistance to abiotic and biotic stress. We investigated the effect of water stress treatment during 10 days on expression of conserved miRNAs-miR398a/b and miR408 in pea plants. This time frame reflects the changes as close as possible to the changes where water stress causes visible effects under field condition. It was observed that dehydration strongly down regulates the expression of both miR398a/b and miR408 in pea roots and shoots. The down-regulation of miR398a/b and the up-regulation of potential target genes - copper superoxide dismutase, CSD1, highlight the involvement of this miRNA in pea stress response. To the contrary, the mRNA level of cytochrome c oxidase subunit 5 (COX5b) did not change in roots and shoots of water-stressed plants, compared to control (well) hydrated plants. This suggests that COX5b is not the target of miR398, or that its expression is regulated by some other mechanism. P1B-ATPase expression increased during water deficit only in the shoots of pea; in the roots there were no changes in expression. Our results help to understand the possible role of investigated miRNAs and their contribution to pea capacity to cope with water deficit.

  11. Water relations of baobab trees (Adansonia spp. L.) during the rainy season: does stem water buffer daily water deficits?

    Science.gov (United States)

    Chapotin, Saharah Moon; Razanameharizaka, Juvet H; Holbrook, N Michele

    2006-06-01

    Baobab trees are often cited in the literature as water-storing trees, yet few studies have examined this assumption. We assessed the role of stored water in buffering daily water deficits in two species of baobabs (Adansonia rubrostipa Jum. and H. Perrier and Adansonia za Baill.) in a tropical dry forest in Madagascar. We found no lag in the daily onset of sap flow between the base and the crown of the tree. Some night-time sap flow occurred, but this was more consistent with a pattern of seasonal stem water replenishment than with diurnal usage. Intrinsic capacitance of both leaf and stem tissue (0.07-0.08 and 1.1-1.43 MPa(-1), respectively) was high, yet the amount of water that could be withdrawn before turgor loss was small because midday leaf and stem water potentials (WPs) were near the turgor-loss points. Stomatal conductance was high in the daytime but then declined rapidly, suggesting an embolism-avoidance strategy. Although the xylem of distal branches was relatively vulnerable to cavitation (P50: 1.1-1.7 MPa), tight stomatal control and minimum WPs near--1.0 MPa maintained native embolism levels at 30-65%. Stem morphology and anatomy restrict water movement between storage tissues and the conductive pathway, making stored-water usage more appropriate to longer-term water deficits than as a buffer against daily water deficits.

  12. CRF₂ receptor-deficiency reduces recognition memory deficits and vulnerability to stress induced by cocaine withdrawal.

    Science.gov (United States)

    Morisot, Nadège; Le Moine, Catherine; Millan, Mark J; Contarino, Angelo

    2014-12-01

    Psychostimulant drug abuse, dependence and withdrawal are associated with cognitive dysfunction and impact stress-sensitive systems. The corticotropin-releasing factor (CRF) system orchestrates stress responses via CRF1 and CRF2 receptors and is implicated in substance use disorders. However, CRF2 role in psychostimulant drug-induced cognitive dysfunction remains to be elucidated. In the present study, wild-type and CRF2-/- mice are injected with cocaine and memory assessed by the novel object recognition (NOR) task throughout relatively long periods of drug withdrawal. Following recovery from the drug-induced memory deficits, the mice are stressed prior to the NOR task and brain gene expression evaluated by in situ hybridization. Cocaine impairs NOR memory in wild-type and CRF2-/- mice. However, following cocaine withdrawal NOR memory deficits last less time in CRF2-/- than in wild-type mice. Furthermore, a relatively mild stressor induces the re-emergence of NOR deficits in long-term cocaine-withdrawn wild-type but not CRF2-/- mice. Cocaine-withdrawn mice show a genotype-independent higher c-fos expression in the NOR memory-relevant perirhinal cortex than drug-naïve mice. However neither genotype nor drug withdrawal affect the expression of tyrosine hydroxylase in the ventral tegmental area or the locus coeruleus and CRF in the central nucleus of the amygdala or the paraventricular nucleus of the hypothalamus, brain regions implicated in stress and drug responses. These data indicate a new role for the CRF2 receptor in cognitive deficits induced by cocaine withdrawal, both as regards to their duration and their re-induction by stress. Interestingly, prototypical brain stress systems other than CRF do not appear to be involved.

  13. Agrophysiological and biochemical properties associated with adaptation of Medicago sativa populations to water deficit

    OpenAIRE

    Farissi, Mohamed; BOUIZGAREN, Abdelaziz; FAGHIRE, Mustapha; Bargaz, Adnane; Ghoulam, Cherki

    2013-01-01

    The effect of water deficit on growth and some physiological and biochemical parameters related to water deficit tolerance was studied in 4 Moroccan alfalfa Medicago sativa L. populations that originated from the mountains and oases of Morocco. The experiment was conducted in greenhouse conditions. Seeds were allowed to germinate in pots filled with sand and peat at a 2:1 ratio, respectively. After 1 month of sowing, the plants were subjected to 3 water regimes: optimal irrigation (75% of fie...

  14. Stress Coefficients for Soil Water Balance Combined with Water Stress Indicators for Irrigation Scheduling of Woody Crops

    Directory of Open Access Journals (Sweden)

    Maria Isabel Ferreira

    2017-06-01

    Full Text Available There are several causes for the failure of empirical models to estimate soil water depletion and to calculate irrigation depths, and the problem is particularly critical in tall, uneven, deficit irrigated (DI crops in Mediterranean climates. Locally measured indicators that quantify water status are useful for addressing those causes and providing feed-back information for improving the adequacy of simple models. Because of their high aerodynamic resistance, the canopy conductance of woody crops is an important factor in determining evapotranspiration (ET, and accurate stress coefficient (Ks values are needed to quantify the impact of stomatal closure on ET. A brief overview of basic general principles for irrigation scheduling is presented with emphasis on DI applications that require Ks modelling. The limitations of existing technology related to scheduling of woody crops are discussed, including the shortcomings of plant-based approaches. In relation to soil water deficit and/or predawn leaf water potential, several woody crop Ks functions are presented in a secondary analysis. Whenever the total and readily available water data were available, a simple Ks model was tested. The ultimate aim of this discussion is to illustrate the central concept: that a combination of simple ET models and water stress indicators is required for scheduling irrigation of deep-rooted woody crops.

  15. Highly hydrophilic proteins in prokaryotes and eukaryotes are common during conditions of water deficit.

    Science.gov (United States)

    Garay-Arroyo, A; Colmenero-Flores, J M; Garciarrubio, A; Covarrubias, A A

    2000-02-25

    The late embryogenesis abundant (LEA) proteins are plant proteins that are synthesized at the onset of desiccation in maturing seeds and in vegetative organs exposed to water deficit. Here, we show that most LEA proteins are comprised in a more widespread group, which we call "hydrophilins." The defining characteristics of hydrophilins are high glycine content (>6%) and a high hydrophilicity index (>1.0). By data base searching, we show that this criterion selectively differentiates most known LEA proteins as well as additional proteins from different taxons. We found that within the genomes of Escherichia coli and Saccharomyces cerevisiae, only 5 and 12 proteins, respectively, meet our criterion. Despite their deceivingly loose definition, hydrophilins usually represent stress. Evidence for the participation of one of the E. coli hydrophilins in the adaptive response to hyperosmotic conditions is presented. Apparently, hydrophilins represent analogous adaptations to a common problem in such diverse taxons as prokaryotes and eukaryotes.

  16. Adaptogenic potential of curcumin in experimental chronic stress and chronic unpredictable stress-induced memory deficits and alterations in functional homeostasis.

    Science.gov (United States)

    Bhatia, Nitish; Jaggi, Amteshwar Singh; Singh, Nirmal; Anand, Preet; Dhawan, Ravi

    2011-07-01

    The present study was designed to investigate the role of curcumin in chronic stress and chronic unpredictable stress-induced memory deficits and alteration of functional homeostasis in mice. Chronic stress was induced by immobilizing the animal for 2 h daily for 10 days, whereas chronic unpredictable stress was induced by employing a battery of stressors of variable magnitude and time for 10 days. Curcumin was administered to drug-treated mice prior to induction of stress. Body weight, adrenal gland weight, ulcer index and biochemical levels of glucose, creatine kinase, cholesterol, corticosterone, thiobarbituric acid reactive substances (TBARS) and reduced glutathione (GSH) were evaluated to assess stress-induced functional changes. Memory deficits were evaluated using the elevated plus maze (EPM) model. Chronic stress and chronic unpredictable stress significantly increased the levels of corticosterone, glucose and creatine kinase and decreased cholesterol levels. Moreover, chronic stress and chronic unpredictable stress resulted in severe memory deficits along with adrenal hypertrophy, weight loss and gastric ulceration. Chronic stress and chronic unpredictable stress also increased oxidative stress assessed in terms of increase in TBARS and decrease in GSH levels. Pretreatment with curcumin (25 and 50 mg/kg p.o.) attenuated chronic stress and chronic unpredictable stress-associated memory deficits, biochemical alterations, pathological outcomes and oxidative stress. It may be concluded that curcumin-mediated antioxidant actions and decrease in corticosterone secretion are responsible for its adaptogenic and memory restorative actions in chronic and chronic unpredictable stress.

  17. Quantifying Water Stress Using Total Water Volumes and GRACE

    Science.gov (United States)

    Richey, A. S.; Famiglietti, J. S.; Druffel-Rodriguez, R.

    2011-12-01

    Water will follow oil as the next critical resource leading to unrest and uprisings globally. To better manage this threat, an improved understanding of the distribution of water stress is required today. This study builds upon previous efforts to characterize water stress by improving both the quantification of human water use and the definition of water availability. Current statistics on human water use are often outdated or inaccurately reported nationally, especially for groundwater. This study improves these estimates by defining human water use in two ways. First, we use NASA's Gravity Recovery and Climate Experiment (GRACE) to isolate the anthropogenic signal in water storage anomalies, which we equate to water use. Second, we quantify an ideal water demand by using average water requirements for the domestic, industrial, and agricultural water use sectors. Water availability has traditionally been limited to "renewable" water, which ignores large, stored water sources that humans use. We compare water stress estimates derived using either renewable water or the total volume of water globally. We use the best-available data to quantify total aquifer and surface water volumes, as compared to groundwater recharge and surface water runoff from land-surface models. The work presented here should provide a more realistic image of water stress by explicitly quantifying groundwater, defining water availability as total water supply, and using GRACE to more accurately quantify water use.

  18. Tomato Yield and Water Use Efficiency - Coupling Effects between Growth Stage Specific Soil Water Deficits

    DEFF Research Database (Denmark)

    Chen, Si; Zhenjiang, Zhou; Andersen, Mathias Neumann

    2015-01-01

    To investigate the sensitivity of tomato yield and water use efficiency (WUE) to soil water content at different growth stages, the central composite rotatable design (CCRD) was employed in a five-factor-five-level pot experiment under regulated deficit irrigation. Two regression models concerning...... the effects of stage-specific soil water content on tomato yield and WUE were established. The results showed that the lowest available soil water (ASW) content (around 28%) during vegetative growth stage (here denoted θ1) resulted in high yield and WUE. Moderate (around 69% ASW) during blooming and fruit...... of the regression model showed that the maximum yield, 1166 g per plant, was obtained by the combination of θ1 (c. 28% ASW), θ2 (c. 82% ASW), θ3 (c. 92% ASW), θ4 (c. 92% ASW), and θ5 (c. 92% ASW). This result may guide irrigation scheduling to achieve higher tomato yield and WUE based on specific soil water...

  19. Effect of water deficit and domestic storage on the procyanidin profile, size, and aggregation process in pear-jujube (Z. jujuba) fruits.

    Science.gov (United States)

    Collado-González, J; Cruz, Z N; Rodríguez, P; Galindo, A; Díaz-Baños, F G; García de la Torre, J; Ferreres, F; Medina, S; Torrecillas, A; Gil-Izquierdo, A

    2013-07-03

    No information exists on the proanthocyanidin content of pear-jujube (Ziziphus jujuba Mill) fruit, their polymeric types and sizes, and their self-aggregation, or on the effect of different water deficit levels during the fruit maturation period on these compounds. Two trimers, two tetramers, and six B type procyanidin pentamers were identified and quantified for the first time. Water deficit increased the content of procyanidins of low molecular mass, improving their potential bioavailability and possible physiological effects on human health. The tendency of procyanidins to self-aggregate was similar in the edible portion and pit, and was not affected by water deficit. The procyanidin content of fruit from well watered trees increased during domestic cold storage, whereas the fruits from trees suffering severe water stress lost some of their procyanidin content.

  20. Kaolin-based foliar reflectant alleviates heat stress in deficit-irrigated Malbec

    Science.gov (United States)

    We evaluated the interaction effects of a kaolin-based particle film and water deficit on leaf and berry surface temperature, light reflectance, gas exchange characteristics, berry composition and yield of Malbec vines under field conditions over three growing seasons to test the hypothesis that the...

  1. Memory deficit in patients with schizophrenia and posttraumatic stress disorder: relational vs item-specific memory

    Directory of Open Access Journals (Sweden)

    Jung W

    2016-05-01

    Full Text Available Wookyoung Jung,1 Seung-Hwan Lee1,2 1Clinical Emotions and Cognition Research Laboratory, Department of Psychiatry, Inje University, Ilsan-Paik Hospital, 2Department of Psychiatry, Inje University, Ilsan-Paik Hospital, Goyang, Korea Abstract: It has been well established that patients with schizophrenia have impairments in cognitive functioning and also that patients who experienced traumatic events suffer from cognitive deficits. Of the cognitive deficits revealed in schizophrenia or posttraumatic stress disorder (PTSD patients, the current article provides a brief review of deficit in episodic memory, which is highly predictive of patients’ quality of life and global functioning. In particular, we have focused on studies that compared relational and item-specific memory performance in schizophrenia and PTSD, because measures of relational and item-specific memory are considered the most promising constructs for immediate tangible development of clinical trial paradigm. The behavioral findings of schizophrenia are based on the tasks developed by the Cognitive Neuroscience Treatment Research to Improve Cognition in Schizophrenia (CNTRICS initiative and the Cognitive Neuroscience Test Reliability and Clinical Applications for Schizophrenia (CNTRACS Consortium. The findings we reviewed consistently showed that schizophrenia and PTSD are closely associated with more severe impairments in relational memory compared to item-specific memory. Candidate brain regions involved in relational memory impairment in schizophrenia and PTSD are also discussed. Keywords: schizophrenia, posttraumatic stress disorder, episodic memory deficit, relational memory, item-specific memory, prefrontal cortex, hippocampus

  2. Effect of Xiaoyaosan Decoction on Learning and Memory Deficit in Rats Induced by Chronic Immobilization Stress

    Directory of Open Access Journals (Sweden)

    Zhen-Zhi Meng

    2013-01-01

    Full Text Available Xiaoyaosan (XYS decoction is a famous prescription which can protect nervous system from stress and treat liver stagnation and spleen deficiency syndrome (LSSDS. In this experiment, we observed the effect of XYS decoction on chronic immobilization stress (CIS induced learning and memory deficit in rats from behaviors and changes of proteins in hippocampus. We used XYS decoction to treat CIS induced learning and memory deficit in rats with rolipram as positive control, used change of body weight and behavioral tests to determine whether the rats have LSSDS and have learning and memory deficit or not. We used Western blotting to determine the content of postsynaptic density protein 95 (PSD-95 and synaptophysin (SYP in hippocampus. Results showed that XYS could improve the situation of slow weight gain induced by CIS, improve the ability of learning and memory, reverse the symptom of liver stagnation and spleen deficiency syndrome (LSSDS in rats, and increase the levels of PSD-95 and SYP on the hippocampal nerve synapses. These findings suggested that XYS decoction may be helpful in reversing CIS induced learning and memory deficit by increasing the levels of PSD-95 and SYP on the hippocampal nerve synapses and improving synaptic plasticity.

  3. Climatic water deficit, tree species ranges, and climate change in Yosemite National Park

    Science.gov (United States)

    Lutz, James A.; Van Wagtendonk, Jan W.; Franklin, Jerry F.

    2010-01-01

    Aim  (1) To calculate annual potential evapotranspiration (PET), actual evapotranspiration (AET) and climatic water deficit (Deficit) with high spatial resolution; (2) to describe distributions for 17 tree species over a 2300-m elevation gradient in a 3000-km2 landscape relative to AET and Deficit; (3) to examine changes in AET and Deficit between past (c. 1700), present (1971–2000) and future (2020–49) climatological means derived from proxies, observations and projections; and (4) to infer how the magnitude of changing Deficit may contribute to changes in forest structure and composition.Location  Yosemite National Park, California, USA.Methods  We calculated the water balance within Yosemite National Park using a modified Thornthwaite-type method and correlated AET and Deficit with tree species distribution. We used input data sets with different spatial resolutions parameterized for variation in latitude, precipitation, temperature, soil water-holding capacity, slope and aspect. We used climate proxies and climate projections to model AET and Deficit for past and future climate. We compared the modelled future water balance in Yosemite with current species water-balance ranges in North America.Results  We calculated species climatic envelopes over broad ranges of environmental gradients – a range of 310 mm for soil water-holding capacity, 48.3°C for mean monthly temperature (January minima to July maxima), and 918 mm yr−1 for annual precipitation. Tree species means were differentiated by AET and Deficit, and at higher levels of Deficit, species means were increasingly differentiated. Modelled Deficit for all species increased by a mean of 5% between past (c. 1700) and present (1971–2000). Projected increases in Deficit between present and future (2020–49) were 23% across all plots.Main conclusions  Modelled changes in Deficit between past, present and future climate scenarios suggest that recent past changes in forest structure and

  4. Effects of (-)-sesamin on chronic stress-induced memory deficits in mice.

    Science.gov (United States)

    Zhao, Ting Ting; Shin, Keon Sung; Park, Hyun Jin; Kim, Kyung Sook; Lee, Kung Eun; Cho, Yoon Jeong; Lee, Myung Koo

    2016-11-10

    This study investigated the effects of (-)-sesamin on memory deficits induced by chronic electric footshock (EF)-induced stress in mice. Mice were treated with (-)-sesamin (25 and 50mg/kg, p.o., daily for 21day) prior to chronic EF stress (0.6mA, 1s every 5s for 3min, daily for 21day). Transfer retention latencies in the elevated plus maze test and N-methyl-d-aspartate (NMDA) receptor (type 1) phosphorylation in the hippocampus increased with chronic EF stress, and they were reduced by treatment with (-)-sesamin at both doses. Phosphorylation of extracellular signal-regulated kinase (ERK1/2) and cyclic AMP-responsive element binding protein (CREB), which were reduced by chronic EF stress, were increased by treatment with (-)-sesamin. Retention latencies in the passive avoidance test and dopamine levels in the substantia nigra-striatum were also reduced by chronic EF stress, and similarly recovered with (-)-sesamin treatment. These results suggest that (-)-sesamin ameliorates the effects of chronic EF stress-induced spatial and habit learning memory deficits by modulating both NMDA receptor and dopaminergic neuronal systems.

  5. Transpiration and leaf growth of potato clones in response to soil water deficit

    Directory of Open Access Journals (Sweden)

    André Trevisan de Souza

    2014-04-01

    Full Text Available Potato (Solanum tuberosum ssp. Tuberosum crop is particularly susceptible to water deficit because of its small and shallow root system. The fraction of transpirable soil water (FTSW approach has been widely used in the evaluation of plant responses to water deficit in different crops. The FTSW 34 threshold (when stomatal closure starts is a trait of particular interest because it is an indicator of tolerance to water deficit. The FTSW threshold for decline in transpiration and leaf growth was evaluated in a drying soil to identify potato clones tolerant to water deficit. Two greenhouse experiments were carried out in pots, with three advanced clones and the cultivar Asterix. The FTSW, transpiration and leaf growth were measured on a daily basis, during the period of soil drying. FTSW was an efficient method to separate potato clones with regard to their response to water deficit. The advancedclones SMINIA 02106-11 and SMINIA 00017-6 are more tolerant to soil water deficit than the cultivar Asterix, and the clone SMINIA 793101-3 is more tolerant only under high solar radiation.

  6. Water deficit-induced changes in transcription factor expression in maize seedlings

    Science.gov (United States)

    Plants tolerate water deficits by regulating gene networks controlling cellular and physiological traits to modify growth and development. Transcription factor (TFs) directed regulation of transcription within these gene networks is key to eliciting appropriate responses. In this study, reverse tran...

  7. Deficit irrigation and rootstock: their effects on water relations, vegetative development, yield, fruit quality and mineral nutrition of Clemenules mandarin.

    Science.gov (United States)

    Romero, P; Navarro, J M; Pérez-Pérez, J; García-Sánchez, F; Gómez-Gómez, A; Porras, I; Martinez, V; Botía, P

    2006-12-01

    Differences between rootstocks, 'Cleopatra' mandarin and 'Carrizo' citrange, in soil-plant water relations and the influence of these factors on vigor, crop yield, fruit quality and mineral nutrition were evaluated in field-grown Clemenules mandarin trees irrigated at 100% of potential seasonal evaporation (ET(c)) (control treatment), or irrigated at 100% ET(c), except during Phases I and III of fruit growth and post-harvest when no irrigation was applied (deficit irrigation (DI) treatment), for 3 years. Differences between rootstocks in plant-soil water relations were the primary cause of differences among trees in vegetative development and fruit yield. After 3 years of DI treatment, trees on 'Cleopatra' showed more efficient soil water extraction than trees on 'Carrizo', and maintained a higher plant water status, a higher gas exchange rate during periods of water stress and achieved faster recovery in gas exchange following irrigation after water stress. The DI treatment reduced vegetative development more in trees on 'Carrizo' than in trees on 'Cleopatra'. Cumulative fruit yield decreased more in DI trees on 'Carrizo' (40%) than on 'Cleopatra' (27%). The yield component most affected by DI in 'Cleopatra' was the number of fruit, whereas in 'Carrizo' it depended on the severity of water stress reached in each phase (severe water stress in Phase I affected mainly the number of fruit, whereas it affected fruit size the most in Phase III). In the third year of DI treatment, water-use efficiency decreased sharply in trees on 'Carrizo' (70%) compared to trees on 'Cleopatra' (30%). Thus, trees on 'Cleopatra' were able to tolerate moderate water stress, whereas trees on 'Carrizo' were more sensitive to changes in soil water content.

  8. Piromelatine ameliorates memory deficits associated with chronic mild stress-induced anhedonia in rats.

    Science.gov (United States)

    Fu, Wan; Xie, Heng; Laudon, Moshe; Zhou, Shouhong; Tian, Shaowen; You, Yong

    2016-06-01

    Previous studies have demonstrated that piromelatine (a melatonin and serotonin 5-HT1A and 5-HT1D agonist) exerts an antidepressant activity in rodent models of acute stress and improves cognitive impairments in a rat model of Alzheimer's disease (AD). However, the role of piromelatine in chronic stress-induced memory dysfunction remains unclear. The aim of this study was to determine whether piromelatine ameliorates chronic mild stress (CMS)-induced memory deficits and explore the underlying mechanisms. Rats were exposed randomly to chronic mild stressors for 7 weeks to induce anhedonia (reflected by a significant decrease in sucrose intake), which was used to select rats vulnerable (CMS-anhedonic, CMSA) or resistant (CMS-resistant, CMSR) to stress. Piromelatine (50 mg/kg) was administered daily during the last 2 weeks of CMS. The tail suspension and forced swimming tests were adopted to further characterize vulnerable and resilient rats. The Y-maze and novel object recognition (NOR) tests were used to evaluate memory performance. Brain-derived neurotrophic factor (BDNF), cAMP response element-binding protein (CREB), phosphorylated CREB (pCREB), and cytogenesis were measured in the hippocampus. We found that only CMSA rats displayed significant increases in immobility time in the tail suspension and forced swimming tests; memory deficits in the Y-maze and NOR tests; significant decreases in hippocampal BDNF, CREB, and pCREB expression; and cytogenesis. All these anhedonia-associated effects were reversed by piromelatine. Piromelatine ameliorates memory deficits associated with CMS-induced anhedonia in rats and this effect may be mediated by restoring hippocampal BDNF, CREB, and cytogenesis deficits.

  9. ESTABLISHMENT OF YOUNG “DWARF GREEN” COCONUT PLANTS IN SOIL AFFECTED BY SALTS AND UNDER WATER DEFICIT

    Directory of Open Access Journals (Sweden)

    ALEXANDRE REUBER ALMEIDA DA SILVA

    Full Text Available ABSTRACT The aim was to analyze the establishment of young “Green Dwarf” coconut plants in soils affected by salts and under water stress, by evaluating leaf area, biomass production and allocation. In the experiment, conducted in protected environment in Fortaleza, CE, in statistical design of randomized blocks in a split plot arrangement, the effects of different water deficit levels (plots were evaluated, by imposing different percentages of replacement of water losses by potential crop evapotranspiration - ETpc (20, 40, 60, 80 and 100%, associated with subplots consisting of increasing soil salinity levels (1.72, 6.25, 25.80 and 40.70 dS m-1 provided by soil collected at different parts of the Morada Nova Irrigated Perimeter - PIMN. Leaf area and biomass production were sharply reduced by the conditions of water stress and high soil salinity, apparently being more critical to the crop under water restriction condition. The degree of water stress can increase the susceptibility to salinity and plants can be considered, in general terms, as moderately tolerant to the effects of salinity, when combined with water deficiency. Coconut seedlings show full capacity of establishment in PIMN saline soils, corresponding to the level of electrical conductivity of 6.50 dS m-1, but only when the water supply remains adequate. For higher salinity levels, plants survive, but their size is reduced by around 50%, even when fully irrigated.

  10. Comparative study of putative 9-cis-epoxycarotenoid dioxygenase and abscisic acid accumulation in the responses of Sunki mandarin and Rangpur lime to water deficit.

    Science.gov (United States)

    Neves, D M; Filho, M A Coelho; Bellete, B S; Silva, M F G F; Souza, D T; Dos S Soares Filho, W; Costa, M G C; Gesteira, A S

    2013-09-01

    Abscisic acid is a plant hormone that participates in essential plant physiological processes, especially during adaptation to many environmental stresses, such as water deficit. The relationship between ABA accumulation and the expression of putative carotenoid cleavage dioxygenase (CCD) genes was investigated in the pot-cultivated leaves and roots of the 'Rangpur' lime and 'Sunki Maravilha' mandarin plants. Transpiration, stomatal resistance and leaf growth were evaluated when these genotypes were subjected to continuous water deficit. Under water deficit conditions, the 'Rangpur' lime extracts used greater amounts of water when compared to the 'Sunki Maravilha' plants, which reached the greatest stomatal resistance 5 days before 'Rangpur' lime. When subjected to water deficit, the roots and leaves of 'Sunki Maravilha' showed a progressive increase in ABA accumulation; however, in 'Rangpur' lime, alternations between high and low ABA concentrations were observed. These results suggest a retroactive feeding regulation by ABA. In 'Rangpur' lime the NCED2, NCED3 and CCD4a genes were expressed at the highest levels in the roots, and NCED5 was highly expressed in the leaves; in 'Sunki Maravilha', the NCED2 and NCED5 genes were most highly expressed in the roots, and NCED2 was most highly expressed in the leaves. However, for both genotypes, the transcription of these genes only correlated with ABA accumulation during the most severe water deficit conditions. The 'Rangpur' lime behaved as a vigorous rootstock; the leaf growth remained unaltered even when water was scarce. However, 'Sunki Maravilha' adaptation was based on the equilibrium of the response between the root and the aerial tissues due to water restriction. The use of the Sunki mandarin in combination with a scion with similar characteristics as its own, which responds to water deficit stress by accumulating ABA in the leaves, may display good drought tolerance under field conditions.

  11. Effects of ozone and water stress on canopy temperature, water use, and water use efficiency of alfalfa

    Energy Technology Data Exchange (ETDEWEB)

    Temple, P.J. (Univ. of California, Riverside (USA)); Benoit, L.F. (Univ. of California, Davis (USA))

    Ozone (O{sub 3}) and soil water deficit are two environmental stresses that significantly affect the growth and yield of alfalfa (Medicago sativa L). However, little is known of the responses of field-grown alfalfa to O{sub 3}, and the effects of the interaction between O{sub 3} and water stress on canopy temperature and water relations of alfalfa have not been previously reported. The objective of this 2-yr study was to determine the interactive effects of O{sub 3} and soil water deficits on canopy temperatures, water use, and water use efficiency (WUE) of alfalfa. Alfalfa (cv. WL-514) was grown in 30-3- by 5.5-m plots on Wasco sandy loam (coarse-loamy, mixed, nonacid, thermic Typic Torriorthents) in Shafter, CA, and was exposed in open-top chambers to five levels of O{sub 3} for 12 h daily, from March to October of 1984 and 1985. Ozone treatments ranged from charcoal-filtered air (CF) to twice ambient O{sub 3} concentrations. Each plot received either normal amounts of irrigation (NI) or 30% less than normal (WS). Canopy temperature-air temperature differentials ({Tc}-T{sub a}) were significantly reduced by water stress an average of 27.9% in 1984 and 44.0% in 1985. Ozone also significantly reduced {Tc}-T{sub a} by 31% in NI and 37% in WS plots in 1984, but in 1985 O{sub 3} had no effect on {Tc}-T{sub a}. Water use, rate of soil water depletion, or depth of effective rooting zone were not affected by O{sub 3}, whereas water stress significantly reduced all three. Water use efficiency was significantly reduced by O{sub 3}, averaging 12% lower in nonfiltered compared with CF plots. The effects of O{sub 3} on WUE were attributed to premature senescence and abscission of older alfalfa leaves.

  12. Grape Composition under Abiotic Constrains: Water Stress and Salinity.

    Science.gov (United States)

    Mirás-Avalos, José M; Intrigliolo, Diego S

    2017-01-01

    Water stress and increasing soil salt concentration represent the most common abiotic constrains that exert a negative impact on Mediterranean vineyards performance. However, several studies have proven that deficit irrigation strategies are able to improve grape composition. In contrast, irrigation with saline waters negatively affected yield and grape composition, although the magnitude of these effects depended on the cultivar, rootstock, phenological stage when water was applied, as well as on the salt concentration in the irrigation water. In this context, agronomic practices that minimize these effects on berry composition and, consequently, on wine quality must be achieved. In this paper, we briefly reviewed the main findings obtained regarding the effects of deficit irrigation strategies, as well as irrigation with saline water, on the berry composition of both red and white cultivars, as well as on the final wine. A meta-analysis was performed using published data for red and white varieties; a general liner model accounting for the effects of cultivar, rootstock, and midday stem water potential was able to explain up to 90% of the variability in the dataset, depending on the selected variable. In both red and white cultivars, berry weight, must titratable acidity and pH were fairly well simulated, whereas the goodness-of-fit for wine attributes was better for white cultivars.

  13. Grape Composition under Abiotic Constrains: Water Stress and Salinity

    Directory of Open Access Journals (Sweden)

    José M. Mirás-Avalos

    2017-05-01

    Full Text Available Water stress and increasing soil salt concentration represent the most common abiotic constrains that exert a negative impact on Mediterranean vineyards performance. However, several studies have proven that deficit irrigation strategies are able to improve grape composition. In contrast, irrigation with saline waters negatively affected yield and grape composition, although the magnitude of these effects depended on the cultivar, rootstock, phenological stage when water was applied, as well as on the salt concentration in the irrigation water. In this context, agronomic practices that minimize these effects on berry composition and, consequently, on wine quality must be achieved. In this paper, we briefly reviewed the main findings obtained regarding the effects of deficit irrigation strategies, as well as irrigation with saline water, on the berry composition of both red and white cultivars, as well as on the final wine. A meta-analysis was performed using published data for red and white varieties; a general liner model accounting for the effects of cultivar, rootstock, and midday stem water potential was able to explain up to 90% of the variability in the dataset, depending on the selected variable. In both red and white cultivars, berry weight, must titratable acidity and pH were fairly well simulated, whereas the goodness-of-fit for wine attributes was better for white cultivars.

  14. Climatic water deficit, tree species ranges, and climate change in Yosemite National Park

    Science.gov (United States)

    James A. Lutz; Jan W. van Wagtendonk; Jerry F. Franklin

    2010-01-01

    Modelled changes in climate water deficit between past, present and future climate scenarios suggest that recent past changes in forest structure and composition may accelerate in the future, with species responding individualistically to further declines in water availability. Declining water availability may disproportionately affect Pinus monticola...

  15. Linking Plant Water-Use Efficiency and Depth of Water Uptake to Field­-Level Productivity Under Surplus and Deficit Irrigation in Almond Orchards

    Science.gov (United States)

    Seely, T.; Shackel, K.; Silva, L. C. R.

    2016-12-01

    The impact of water stress on depth of water uptake, as well as water­-use efficiency (WUE) at the tree-level and field-level was examined in almond orchards under varying degrees of deficit and surplus irrigation treatments. Three different orchards, spanning a latitudinal gradient (35° to 39° N) were sampled during two growing seasons in the central valley of CA. The orchards encompass a range of climatic and edaphic conditions, providing an opportunity for comparisons of WUE and orchard yield under contrasting environmental conditions. In each orchard, the control treatment received 100% replacement of water lost to evapotranspiration (ET), while the surplus treatment received 110% and the deficit treatment received 70% replenishment of ET, the latter simulating conditions of water stress. Preliminary results based on the analysis of carbon isotope ratios (δ13C) in leaves throughout the 2015 and 2016 growing seasons, reveal a significant change in WUE in all three orchard sites, increasing up to 20% on average in the deficit irrigation treatment relative to controls. In contrast, trees growing under surplus irrigation had the lowest WUE across all orchard sites. The difference in WUE between surplus irrigated trees and control irrigated trees within each orchard was not always statistically significant. These physiological responses to levels of water availability were not reflected in field-level orchard productivity, which was highly variable across orchard sites and treatments. Additionally, analysis of oxygen (δ18O) and hydrogen (δ2H) isotope ratios of stem, leaf, and soil water has been undertaken to determine the effect of water stress on the depth of root water uptake. The hypothesis that almond trees can effectively acclimate to water stress through higher WUE and deeper root water uptake compared to well-watered trees will be tested. This multi-scale, ecohydrological study will elucidate the impacts of drought on almond orchards, one of the most

  16. The Effect of Water Stress and Polymer on Water Use Efficiency, Yield and several Morphological Traits of Sunflower under Greenhouse Condition

    OpenAIRE

    Hossein NAZARLI; Mohammad Reza ZARDASHTI; Reza DARVISHZADEH; Solmaz NAJAFI

    2010-01-01

    In many part of Iran, the reproductive growth stages of sunflower (Helianthus annuus L.) are exposed to water deficit stress. Therefore, the investigation of irrigation management in the farm conditions is a necessary element for increasing irrigation efficiency and decreasing water losses. The objective of present study was to investigate the effect of different rates of super absorbent polymer and levels of water stress on water use efficiency (WUE), yield and some morphological traits of s...

  17. Attenuation of stress induced memory deficits by nonsteroidal anti-inflammatory drugs (NSAIDs) in rats: Role of antioxidant enzymes.

    Science.gov (United States)

    Emad, Shaista; Qadeer, Sara; Sadaf, Sana; Batool, Zehra; Haider, Saida; Perveen, Tahira

    2017-04-01

    Repeated stress paradigms have been shown to cause devastating alterations on memory functions. Stress is linked with inflammation. Psychological and certain physical stressors could lead to neuroinflammation. Inflammatory process may occur by release of mediators and stimulate the production of prostaglandins through cyclooxygenase (COX). Treatment with COX inhibitors, which restrain prostaglandin production, has enhanced memory in a number of neuroinflammatory states showing a potential function for raised prostaglandins in these memory shortfalls. In the present study, potential therapeutic effects of indomethacin and diclofenac sodium on memory in both unrestraint and restraint rats were observed. Two components, long term memory and short term memory were examined by Morris water maze (MWM) and elevated plus maze (EPM) respectively. The present study also demonstrated the effect of nonsteroidal anti-inflammatory drugs (NSAIDs) on lipid peroxidation (LPO) and activities of antioxidant enzymes along with the activity of acetylcholinesterase (AChE). Results of MWM and EPM showed significant effects of drugs in both unrestraint and restraint rats as escape latency and transfer latency, in respective behavioral models were decreased as compared to that of control. This study also showed NSAIDs administration decreased LPO and increased antioxidant enzymes activity and decreased AChE activity in rats exposed to repeated stress. In conclusion this study suggests a therapeutic potential of indomethacin and diclofenac against repeated stress-induced memory deficits. Copyright © 2016. Published by Elsevier Urban & Partner Sp. z o.o.

  18. Water-deficit impact on fatty acid and essential oil composition and antioxidant activities of cumin (Cuminum cyminum L.) aerial parts.

    Science.gov (United States)

    Bettaieb, Iness; Knioua, Sana; Hamrouni, Ibtissem; Limam, Ferid; Marzouk, Brahim

    2011-01-12

    This study is designed to examine the effect of water deficit on growth, fatty acid and essential oil composition, and antioxidant activities of Cuminum cyminum aerial part extracts. Plants were treated with different levels of water deficit: control (C), moderate water deficit (MWD), and severe water deficit (SWD). Plant growth (height, fresh and dry matter weights) as well as yield components were significantly increased under moderate water deficit and conversely reduced at severe level. Total fatty acid content decreased significantly with severity of constraint. Drought reduced considerably the proportions of major fatty acids and the unsaturated to saturated fatty acid ratio. The essential oil yield was 0.14% (based on the dry weight); it increased by 2.21-fold at MWD but decreased by 42.8% under SWD in comparison to the control. Drought results in the modification of the essential oil chemotype from 1-phenyl-1-butanol to 1-phenyl-1,2-ethanediol. Antioxidant activities of the acetone extracts were determined by two complementary test systems, namely, DPPH and β-carotene/linoleic acid. The highest activity was exhibited by moderately stressed plants and was reduced significantly under SWD. In control plants, the total phenolic amount was 10.23 mg GAE/g DW, which increased by 1.5-fold under MWD and decreased by 42% under SWD.

  19. Impaired Driving Performance as Evidence of a Magnocellular Deficit in Dyslexia and Visual Stress.

    Science.gov (United States)

    Fisher, Carri; Chekaluk, Eugene; Irwin, Julia

    2015-11-01

    High comorbidity and an overlap in symptomology have been demonstrated between dyslexia and visual stress. Several researchers have hypothesized an underlying or causal influence that may account for this relationship. The magnocellular theory of dyslexia proposes that a deficit in visuo-temporal processing can explain symptomology for both disorders. If the magnocellular theory holds true, individuals who experience symptomology for these disorders should show impairment on a visuo-temporal task, such as driving. Eighteen male participants formed the sample for this study. Self-report measures assessed dyslexia and visual stress symptomology as well as participant IQ. Participants completed a drive simulation in which errors in response to road signs were measured. Bivariate correlations revealed significant associations between scores on measures of dyslexia and visual stress. Results also demonstrated that self-reported symptomology predicts magnocellular impairment as measured by performance on a driving task. Results from this study suggest that a magnocellular deficit offers a likely explanation for individuals who report high symptomology across both conditions. While conclusions about the impact of these disorders on driving performance should not be derived from this research alone, this study provides a platform for the development of future research, utilizing a clinical population and on-road driving assessment techniques. Copyright © 2015 John Wiley & Sons, Ltd.

  20. A triticale water-deficit-inducible phytocystatin inhibits endogenous cysteine proteinases in vitro.

    Science.gov (United States)

    Chojnacka, Magdalena; Szewińska, Joanna; Mielecki, Marcin; Nykiel, Małgorzata; Imai, Ryozo; Bielawski, Wiesław; Orzechowski, Sławomir

    2015-02-01

    Water-deficit is accompanied by an increase in proteolysis. Phytocystatins are plant inhibitors of cysteine proteinases that belong to the papain and legumain family. A cDNA encoding the protein inhibitor TrcC-8 was identified in the vegetative organs of triticale. In response to water-deficit, increases in the mRNA levels of TrcC-8 were observed in leaf and root tissues. Immunoblot analysis indicated that accumulation of the TrcC-8 protein occurred after 72h of water-deficit in the seedlings. Using recombinant protein, inhibitory activity of TrcC-8 against cysteine proteases from triticale and wheat tissues was analyzed. Under water-deficit conditions, there are increases in cysteine proteinase activities in both plant tissues. The cysteine proteinase activities were inhibited by addition of the recombinant TrcC-8 protein. These results suggest a potential role for the triticale phytocystatin in modulating cysteine proteinase activities during water-deficit conditions.

  1. Mount Everest: a space analogue for speech monitoring of cognitive deficits and stress.

    Science.gov (United States)

    Lieberman, Philip; Morey, Angie; Hochstadt, Jesse; Larson, Mara; Mather, Sandra

    2005-06-01

    In deep-space missions, the basal ganglia and hippocampus, subcortical structures of the brain that play critical roles in motor activity, cognition, and memory, will be vulnerable to damage from cosmic rays. These metabolically active structures are also sensitive to damage arising from the low oxygen content of air at extreme altitudes. We have, therefore, used Mount Everest as an analogue for deep space, where astronauts will be subject to danger and stress as well as neural damage. We can ethically obtain data because our climber-subjects already intend to climb Mt. Everest. We record speech and test cognitive and linguistic performance before, during, and after exposure to hypoxic conditions. From these data we have derived and validated computer-implemented acoustic voice measures that track slight as well as profound cognitive impairment. Vowel duration and speech motor sequencing errors increase as climbers ascend, reflecting degraded basal ganglia activity. These metrics detect deficits in language comprehension and the ability to change plans in changing circumstances. Preliminary analyses also reveal memory deficits reflecting hippocampal damage. Our speech metrics are unobtrusive and do not reveal the content of a verbal message; they could be derived automatically, allowing space crews to detect subtle motor and cognitive deficits and invoke countermeasures before performance is profoundly impaired. In future work we will be validating the voice metrics of stress in collaboration with the Dinges NSBRI laboratory study of task-induced stress. Our procedures can also be applied in general aviation and in the treatment of Parkinson's disease, Alzheimer's dementia, and other neurological disorders.

  2. P2X7 Receptor Antagonism Attenuates the Intermittent Hypoxia-induced Spatial Deficits in a Murine Model of Sleep Apnea Via Inhibiting Neuroinflammation and Oxidative Stress

    Directory of Open Access Journals (Sweden)

    Yan Deng

    2015-01-01

    Conclusions: The P2X7R antagonism attenuates the CIH-induced neuroinflammation, oxidative stress, and spatial deficits, demonstrating that the P2X7R is an important therapeutic target in the cognition deficits accompanied OSAS.

  3. Child attention deficit hyperactive disorder co morbidities on family stress: effect of medication.

    Science.gov (United States)

    Silva, Desiree; Houghton, Stephen; Hagemann, Erika; Jacoby, Peter; Jongeling, Brad; Bower, Carol

    2015-04-01

    We examined the degree of parental and child mental health in a community sample of children diagnosed with Attention Deficit Hyperactive Disorder and the effect on family stress prior to and during treatment using a community retrospective questionnaire study. In total 358 questionnaires were returned for analysis where 92 % of children had at least one co-morbid condition and mental health conditions in parents was common. Overall, the Family Strain Index was significantly reduced after commencement of medication (p disorders or autism spectrum disorder.

  4. Water Replacement Schedules in Heat Stress

    Science.gov (United States)

    Londeree, Ben R.; and others

    1969-01-01

    Although early ingestion of cold water appears to lead to greater relief from heat stress during physical exertion than late ingestion, this difference is reduced toward the end of an hour's work in high heat and humidity. (CK)

  5. Free proline accumulation in leaves of cultivated plant species under water deficit conditions

    Directory of Open Access Journals (Sweden)

    Hanna Bandurska

    2013-12-01

    Full Text Available The effect of water deficit caused by soil drought on the content of free proline as well as the degree of cell membrane damages in the leaves of three cultivated plant species having different farm usefulness and water requirements have been studied. The used pIants were: poinsettia (Euphorbia pulcherrima Willd., 'Regina' and 'Cortez' grown for decorative purposes, a green vegetable of broccoli (Brassica oleracea var. botrytis, subvar. cymosa, 'Colonel' and 'Marathon' and a cereal plant of barley (the wild form Hordeum spontaneumm and Hordeum vulgaree 'Maresi'. The examined species differed in the size of the experienced stress. the Iargest RWC reduction was found iii broccoli leaves, while somewhat smaller - in barley. In poinsettia leaves, the reduction of RWC level was not large or did not occur at all. The accumulation of free proline in the species under study was also variable. The largest amount of this amino acid tended to accumulate in broccoli leaves, whereas the increase of its level took place only at a strong dehydration of tissues. The increase of proline level was smaller in barley leaves than in broccoli, but that was found already at a smalI dehydration of tissues. In poinsettia leaves, a several f`old increase of proline level was found at the early stage of the stress. The level of that amino acid gradually increased at consecutive times and did not depend on tissue dehydration. Damage of cell membranes amounted to 8.5-9.5% in barley leaves, about 3% in brocolli and to 0-2.6% in poinsettia. The role of proline in prevention of leaf dehydration and in alleviation of dehydration effects in the studied species has been discussed.

  6. Responses of Moringa oleifera Lam. plants inoculated with mycorrhizal fungi and submitted to water stress

    Directory of Open Access Journals (Sweden)

    Séfora Gil Gomes Farias

    2008-12-01

    Full Text Available This study was to verify the efficiency of mycorrhizal in Moringa oleifera Lam. plants submitted to water deficit. The experiment was conducted in screenhouse distributted a completely randomized design in a 4x2 factorial with four replications. The first factor was the treatment of inoculation with Glomus etunicatum, Acaulospora scrobiculata, an indigenous community treatment and control (without inoculation. The second factor was the treatment of irrigation and water deficit. Plant height, accumulation of dry weight in the shoots, roots and total and mycorrhizal efficiency were evaluated. The plants inoculated with Glomus etunicatum increases in height, biomass and biomass underground when not subject to water stress. There was no contribution of mycorrhizae to increase the resistance of plants to water deficit, independent of the fungus employee. The efficiency of plants in mycorrhizal, was variable according to the species of fungi used.

  7. Comparative Morpho-Biochemical Responses of Wheat Cultivars Sensitive and Tolerant to Water Stress

    Directory of Open Access Journals (Sweden)

    Heshmat S. Aldesuquy

    2014-05-01

    Full Text Available Water stress is likely the most important factor that adversely affects plant growth and development. In this study two wheat cultivars Gemmieza-7 (sensitive and Sahel-1 (tolerant were subjected to water stress and compared in terms of growth parameters (growth vigor of root and shoot, water relations (relative water content and saturation water deficit and protein as well as nucleic acids (DNA and RNA content in flag leaves of both cultivars. In general, water stress caused noticeable reduction in almost all growth criteria of root, shoot and flag leaf which was consistent with the progressive alteration in water relations, protein and nucleic acids content of both cultivars during grain filling. Furthermore, degree of leaf succulence and degree of leaf sclerophylly were severely affected by water stress in both wheat cultivars. In relation to wheat cultivar, the sensitive was more affected by water stress than the tolerant one. Generally, the application of salicylic acid, trehalose or their interaction induced marked increase in growth vigor of root and shoot, water relations and protein as well as nucleic acids in flag leaves of both wheat cultivars in compare with control and water stressed plants. In conclusion, Sahel-1 has suitable mechanisms to enable it to respond more effectively to water stress than Gemmieza-7.

  8. Root water extraction under combined water and osmotic stress

    NARCIS (Netherlands)

    Jong van Lier, de Q.; Dam, van J.C.; Metselaar, K.

    2009-01-01

    Using a numerical implicit model for root water extraction by a single root in a symmetric radial flow problem, based on the Richards equation and the combined convection-dispersion equation, we investigated some aspects of the response of root water uptake to combined water and osmotic stress. The

  9. Brain Correlates of the Interaction Between 5-HTTLPR and Psychosocial Stress Mediating Attention Deficit Hyperactivity Disorder Severity

    NARCIS (Netherlands)

    van der Meer, Dennis; Hoekstra, Pieter J.; Zwiers, Marcel; Mennes, Maarten; Schweren, Lizanne J.; Franke, Barbara; Heslenfeld, Dirk J.; Oosterlaan, Jaap; Faraone, Stephen V.; Buitelaar, Jan K.; Hartman, Catharina A.

    2015-01-01

    Objective: The serotonin transporter 5-HTTLPR genotype has been found to moderate the effect of stress on severity of attention deficit hyperactivity disorder (ADHD), with stronger effects of stress in carriers of the short allele than in individuals homozygous for the tong allele. The underlying ne

  10. Caffeic acid attenuates oxidative stress, learning and memory deficit in intra-cerebroventricular streptozotocin induced experimental dementia in rats.

    Science.gov (United States)

    Deshmukh, Rahul; Kaundal, Madhu; Bansal, Vikas; Samardeep

    2016-07-01

    Oxidative stress has been implicated in cognitive decline as seen during normal aging and in sporadic Alzheimer's disease (AD). Caffeic acid, a polyphenolic compound, has been reported to possess potent antioxidant and neuroprotective properties. The role of caffeic acid in experimental dementia is not fully understood. Thus the present study was designed to investigate the therapeutic potential of caffeic acid in streptozotocin (STZ)-induced experimental dementia of Alzheimer's type in rats. Streptozotocin (STZ) was administered intracerebroventrically (ICV) on day 1 and 3 (3mg/kg, ICV bilaterally) in Wistar rats. Caffeic acid was administered (10, 20 and 40mg/kg/day p.o.) 1h following STZ infusion upto 21st day. Morris water maze and object recognition task were used to assess learning and memory in rats. Terminally, acetylcholinesterase (AChE) activity and the levels of oxido-nitrosative stress markers were determined in cortical and hippocampal brain regions of rats. STZ produced significant (plearning and memory impairment, oxido-nitrosative stress and cholinergic deficit in rats. Whereas, caffeic acid treatment significantly (p<0.001) and dose dependently attenuated STZ induced behavioral and biochemical abnormalities in rats. The observed cognitive improvement following caffeic acid in STZ treated rats may be due to its antioxidant activity and restoration of cholinergic functions. Our results suggest the therapeutic potential of caffeic acid in cognitive disorders such as AD.

  11. Oral treatment with Lactobacillus rhamnosus attenuates behavioural deficits and immune changes in chronic social stress.

    Science.gov (United States)

    Bharwani, Aadil; Mian, M Firoz; Surette, Michael G; Bienenstock, John; Forsythe, Paul

    2017-01-11

    Stress-related disorders involve systemic alterations, including disruption of the intestinal microbial community. Given the putative connections between the microbiota, immunity, neural function, and behaviour, we investigated the potential for microbe-induced gut-to-brain signalling to modulate the impact of stress on host behaviour and immunoregulation. Male C57BL/6 mice treated orally over 28 days with either Lactobacillus rhamnosus (JB-1) ™ or vehicle were subjected to chronic social defeat and assessed for alterations in behaviour and immune cell phenotype. 16S rRNA sequencing and mass spectrometry were employed to analyse the faecal microbial community and metabolite profile. Treatment with JB-1 decreased stress-induced anxiety-like behaviour and prevented deficits in social interaction with conspecifics. However, JB-1 did not alter development of aggressor avoidance following social defeat. Microbial treatment attenuated stress-related activation of dendritic cells while increasing IL-10+ regulatory T cells. Furthermore, JB-1 modulated the effect of stress on faecal metabolites with neuroactive and immunomodulatory properties. Exposure to social defeat altered faecal microbial community composition and reduced species richness and diversity, none of which was prevented by JB-1. Stress-related microbiota disruptions persisted in vehicle-treated mice for 3 weeks following stressor cessation. These data demonstrate that despite the complexity of the gut microbiota, exposure to a single microbial strain can protect against certain stress-induced behaviours and systemic immune alterations without preventing dysbiosis. This work supports microbe-based interventions for stress-related disorders.

  12. Mothers' parenting stress is associated with salivary cortisol profiles in children with Attention Deficit Hyperactivity Disorder.

    Science.gov (United States)

    Korpa, Terpsichori; Pervanidou, Panagiota; Angeli, Eleni; Apostolakou, Filia; Papanikolaou, Katerina; Papassotiriou, Ioannis; Chrousos, George P; Kolaitis, Gerasimos

    2017-03-06

    The aim of this study was to explore the relation between mothers' parenting stress and the functioning of the hypothalamic-pituitary-adrenal axis (HPAA), as expressed by daily salivary cortisol concentrations, in their children diagnosed with Attention Deficit Hyperactivity Disorder (ADHD). Seventy-five children aged 6-11 years diagnosed with ADHD predominant Hyperactive-Impulsive/Combined (ADHD-HI/C, N = 49) and Inattentive symptoms (ADHD-I, N = 26) and 45 healthy peers and their mothers participated in the study. Μothers completed measures assessing their children's ADHD status, perceived parenting stress (Parenting Stress Index - Short Form, PSI-SF), mothers' symptoms of psychopathology, social support and socio-economic status. Children's salivary cortisol samples were collected at six different time points on a single day. Mothers of children with ADHD-HI/C reported higher levels of parenting stress than mothers of children with ADHD-I and controls. All PSI-SF subscales showed significant associations with children's Cortisol Awakening Response (CAR) in both ADHD groups, with the exception of the Parental Distress subscale in the ADHD-I group. In both ADHD groups, the Parent-Child Dysfunctional Interaction subscale, the Difficult Child subscale and the PSI total score were significantly associated with children's CAR. An interrelation is revealed between mothers' high levels of parenting stress and HPAA functioning in children with ADHD. In this population, CAR has been identified as a sensitive peripheral measure of HPAA functioning in children.

  13. Synergistic Effect of Selenium Addition and Water Stress on Melilotus officinalis L. Mineral Content

    Directory of Open Access Journals (Sweden)

    Panagiota KOSTOPOULOU

    2015-12-01

    Full Text Available The objective of this study was to examine the combined effects of selenium (Se enrichment and water stress on the accumulation of available macro- and micronutrients in Melilotus officinalis L. aerial parts. Plants of M. officinalis were subjected to three levels of Se addition (0, 1 and 3 mg Se L-1 water and to two water treatments: a full irrigation and b limited irrigation (water stress. The above ground biomass (stems and leaves was analyzed for Se, potassium (K, sodium (Na, magnesium (Mg, iron (Fe, copper (Cu, calcium (Ca, manganese (Mn and zinc (Zn. Se addition differentially affected the K, Mg and Ca content of M. officinalis aerial parts, while it led to the reduction of the micronutrients Cu, Fe and Mn. Water stress resulted in the increase of K, Na, Mg, Ca and Cu, and to the decrease of the Fe, Zn and Mn content. An interaction between selenium addition and water treatment was more notable for Ca and Mg, which decreased under water stress at low Se level and for Zn and Cu, which increased under water stress at high Se level. According to our findings, Se-induced increased accumulation of some inorganic ions in the aerial parts of this species under water stress conditions could serve as a means to alleviate the adverse impact of water deficit on important metabolic processes, enhancing M. officinalis tolerance to water stress.

  14. Water stress in global transboundary river basins: significance of upstream water use on downstream stress

    Science.gov (United States)

    Munia, H.; Guillaume, J. H. A.; Mirumachi, N.; Porkka, M.; Wada, Y.; Kummu, M.

    2016-01-01

    Growing population and water demand have increased pressure on water resources in various parts of the globe, including many transboundary river basins. While the impacts of upstream water use on downstream water availability have been analysed in many of these international river basins, this has not been systematically done at the global scale using coherent and comparable datasets. In this study, we aim to assess the change in downstream water stress due to upstream water use in the world’s transboundary river basins. Water stress was first calculated considering only local water use of each sub-basin based on country-basin mesh, then compared with the situation when upstream water use was subtracted from downstream water availability. We found that water stress was generally already high when considering only local water use, affecting 0.95-1.44 billion people or 33%-51% of the population in transboundary river basins. After accounting for upstream water use, stress level increased by at least 1 percentage-point for 30-65 sub-basins, affecting 0.29-1.13 billion people. Altogether 288 out of 298 middle-stream and downstream sub-basin areas experienced some change in stress level. Further, we assessed whether there is a link between increased water stress due to upstream water use and the number of conflictive and cooperative events in the transboundary river basins, as captured by two prominent databases. No direct relationship was found. This supports the argument that conflicts and cooperation events originate from a combination of different drivers, among which upstream-induced water stress may play a role. Our findings contribute to better understanding of upstream-downstream dynamics in water stress to help address water allocation problems.

  15. Water Stress in Global Transboundary River Basins: Significance of Upstream Water Use on Downstream Stress

    Science.gov (United States)

    Munia, H.; Guillaume, J. H. A.; Mirumachi, N.; Porkka,M.; Wada, Yoshihide; Kummu, M.

    2016-01-01

    Growing population and water demand have increased pressure on water resources in various parts of the globe, including many transboundary river basins. While the impacts of upstream water use on downstream water availability have been analyzed in many of these international river basins, this has not been systematically done at the global scale using coherent and comparable datasets. In this study, we aim to assess the change in downstream water stress due to upstream water use in the world's transboundary river basins. Water stress was first calculated considering only local water use of each sub-basin based on country-basin mesh, then compared with the situation when upstream water use was subtracted from downstream water availability. Wefound that water stress was generally already high when considering only local water use, affecting 0.95-1.44 billion people or 33%-51% of the population in transboundary river basins. After accounting for upstream water use, stress level increased by at least 1 percentage-point for 30-65 sub-basins, affecting 0.29-1.13 billion people. Altogether 288 out of 298 middle-stream and downstream sub-basin areas experienced some change in stress level. Further, we assessed whether there is a link between increased water stress due to upstream water use and the number of conflictive and cooperative events in the transboundary river basins, as captured by two prominent databases. No direct relationship was found. This supports the argument that conflicts and cooperation events originate from a combination of different drivers, among which upstream-induced water stress may play a role. Our findings contribute to better understanding of upstream-downstream dynamics in water stress to help address water allocation problems.

  16. Impacts of Climate Variability on the Spatio-temporal Characteristics of Water Stress in Korea

    Science.gov (United States)

    Kim, Soojun; Devineni, Naresh; Lall, Upmanu; Kim, Hung Soo

    2017-04-01

    This study intended to evaluate water stress quantitatively targeted at the Korean Peninsula and to analyze the spatial and temporal characteristics of its occurrence. First, the severity and multiyear influence of water stress were analyzed by realizing water balance based on water supply and demand and by calculating the normalized deficit index (NDI) and the normalized deficit cumulated (NDC) for 113 small basins in the Korean Peninsula. Next, a change in the periodic characteristics of water stress was analyzed using wavelet transform of the NDI by small basins and 3 bands of periods of 1 year, 2-4 years, and 4-8 years were separated. Through an analysis of the empirical orthogonal function (EOF) on each band, it was found that water stress occurring in the Korean Peninsula has the characteristics of spatial distribution that it is extended from the south coast to the northern area and inland as its period gets longer. An analysis of the band with a period of 2-8 years for water stress showed that it has a relationship with El Niño-Southern Oscillation (ENSO). Acknowledgment This research was supported by a grant (14AWMP-B082564-01) from Advanced Water Management Research Program funded by Ministry of Land, Infrastructure and Transport of Korean government.

  17. Neurocognitive deficits in children and adolescents following maltreatment: Neurodevelopmental consequences and neuropsychological implications of traumatic stress.

    Science.gov (United States)

    Kavanaugh, Brian C; Dupont-Frechette, Jennifer A; Jerskey, Beth A; Holler, Karen A

    2017-01-01

    Childhood maltreatment is a significant risk factor for a host of psychiatric, developmental, medical, and neurocognitive conditions, often resulting in debilitating and long-term consequences. However, there is no available neuropsychological resource reviewing the literature on the associated neurocognitive deficits in children and adolescents. This review comprehensively examines the 23 prior studies that evaluated the intellectual, language, visual-spatial, memory, motor, and/or attention/executive functions in children and adolescents following an experience of childhood abuse and/or neglect. Neurocognitive impairments were frequently reported. Impairments in executive functions were the most frequent and severe reported impairments, although intelligence, language, visual-spatial skills, and memory are also at serious risk for compromised development following maltreatment. However, specific factors such as abuse/neglect duration, severity, type, and timing during development were all associated with neurocognition. This indicates that these factors are of greater importance than just the presence of abuse/neglect in identifying risk for neurocognitive compromise. Such neurocognitive deficits appear to be a consequence to the known neurobiological and brain development abnormalities of this population, suggesting traumatic stress can be a potential cause of neurodevelopmental disorders. These findings have critical implications for the clinical practice and research involving children following childhood maltreatment and other types of traumatic stress.

  18. Implications of high-temperature events and water deficits on protein profiles in wheat (Triticum aestivum L. cv. Vinjett) grain.

    Science.gov (United States)

    Yang, Fen; Jørgensen, Anders D; Li, Huawei; Søndergaard, Ib; Finnie, Christine; Svensson, Birte; Jiang, Dong; Wollenweber, Bernd; Jacobsen, Susanne

    2011-05-01

    Increased climatic variability is resulting in an increase of both the frequency and the magnitude of extreme climate events. Therefore, cereals may be exposed to more than one stress event in the growing season, which may ultimately affect crop yield and quality. Here, effects are reported of interaction of water deficits and/or a high-temperature event (32°C) during vegetative growth (terminal spikelet) with either of these stress events applied during generative growth (anthesis) in wheat. Influence of combinations of stress on protein fractions (albumins, globulins, gliadins and glutenins) in grains and stress-induced changes on the albumin and gliadin proteomes were investigated by 2-DE and MS. The synthesis of individual protein fractions was shown to be affected by both the type and time of the applied stresses. Identified drought or high-temperature-responsive proteins included proteins involved in primary metabolism, storage and stress response such as late embryogenesis abundant proteins, peroxiredoxins and α-amylase/trypsin inhibitors. Several proteins, e.g. heat shock protein and 14-3-3 protein changed in abundance only under multiple high temperatures.

  19. Photosynthetic characteristics of pineapple: Effects of CO{sub 2} enrichment, temperature variation and soil water deficit

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, J.; Goldstein, G.H.; Bartholomew, D.P. [Univ. of Hawaii, Honolulu, HI (United States)

    1995-06-01

    A six-month study of leaf gas exchange (GE; CO{sub 2} fixation, transpiration, conductance) and biomass of pineapple (Ananas Comosus (L.) Merr.), a plant with Crassulacean Acid Metabolism, was made using plants grown at 350 and 700 {mu}L L{sup -1} CO{sub 2} and day/night temperatures of 35/25, 30/25 and 30/20{degrees}C. After six months, a soil water deficit was imposed for two months. GE was monitored diurnally and leaf titratable acidity (TA), chlorophyll content, carbon isotope composition, chlorophyll fluorescence, and plant biomass were measured bimonthly. GE, TA, relative water content, and leaf osmotic and water potentials were measured every ten days during water stress. Daily carbon assimilation, water use efficiency, plant relative growth rate and net assimilation rate were significantly higher at 700 than at 350 {mu}L L{sup -1} CO{sub 2}. Total GE was greater during the day at 700 than at 350 {mu}L L{sup -1} CO{sub 2}. CO{sub 2} dark fixation was greater for plants in environments with a 10 {degrees}C diurnal temperature change (35/25 and 30/20{degrees}C). After imposing water stress, GE and TA declined substantially, and daytime GE decreased more than nocturnal values.

  20. Response of Eucalyptus grandis trees to soil water deficits

    CSIR Research Space (South Africa)

    Dye, PJ

    1996-01-01

    Full Text Available sites in the Mpu- malanga province of South Africa to determine the relation between transpiration rate and soil water availability. I hy- pothesized that, with this relationship defined, simple model- ing of the soil water balance could be used...

  1. Using FAO-56 model to estimate soil and crop water status: Application to a citrus orchard under regulated deficit irrigation

    Science.gov (United States)

    Provenzano, Giuseppe; Gonzàles-Altozano, Pablo; Manzano-Juàrez, Juan; Rallo, Giovanni

    2015-04-01

    Agro-hydrological models allow schematizing exchange processes in the soil-plant-atmosphere continuum (SPAC) on a wide range of spatial and temporal scales. Each section of the SPAC system is characterized by complex behaviours arising, for instance, the adaptive plant strategies in response to soil water deficit conditions. Regulated deficit irrigation (RDI) has been considered as one of the potential strategies for sustainable crop production in regions characterized by water scarcity. Moreover, reducing water supply at certain growth stages can improve water use efficiency (WUE) and quality of productions, without affecting significantly crop yield. Environmental policy requires to improve WUE in crops with high water requirements, so that it is necessary to identify easy-to-use tools aimed at irrigation water saving strategies, without the need of tedious and time consuming experiments. Accurate evaluation of crop water status and actual transpiration plays a key role in irrigation scheduling under RDI, in order to avoid that water stress becomes too severe and detrimental to yield and fruit quality. Objective of the research was to assess the suitability of FAO56 agro-hydrological model (Allen et al., 1998) on citrus orchards under different water deficit conditions, to estimate soil and crop water status. The ability of the model to predict actual crop water stress was evaluated based on the temporal dynamic of simulated relative transpirations and on the similarities with the corresponding dynamic of measured midday stem water potentials, MSWP. During dry periods, simulated relative crop transpiration was correlated to MSWP with the aim to assess the model ability to predict crop water stress and to identify "plant-based" irrigation scheduling parameters. Experiments were carried out during three years from 2009 and 2011 in Senyera (39° 3' 35.4" N, 0° 30' 28.2" W), Spain, in a commercial orchard planted with Navelina/Cleopatra citrus trees. Three RDI

  2. Sex differences, hormones, and fMRI stress response circuitry deficits in psychoses.

    Science.gov (United States)

    Goldstein, Jill M; Lancaster, Katie; Longenecker, Julia M; Abbs, Brandon; Holsen, Laura M; Cherkerzian, Sara; Whitfield-Gabrieli, Susan; Makris, Nicolas; Tsuang, Ming T; Buka, Stephen L; Seidman, Larry J; Klibanski, Anne

    2015-06-30

    Response to stress is dysregulated in psychosis (PSY). fMRI studies showed hyperactivity in hypothalamus (HYPO), hippocampus (HIPP), amygdala (AMYG), anterior cingulate (ACC), orbital and medial prefrontal (OFC; mPFC) cortices, with some studies reporting sex differences. We predicted abnormal steroid hormone levels in PSY would be associated with sex differences in hyperactivity in HYPO, AMYG, and HIPP, and hypoactivity in PFC and ACC, with more severe deficits in men. We studied 32 PSY cases (50.0% women) and 39 controls (43.6% women) using a novel visual stress challenge while collecting blood. PSY males showed BOLD hyperactivity across all hypothesized regions, including HYPO and ACC by FWE-correction. Females showed hyperactivity in HIPP and AMYG and hypoactivity in OFC and mPFC, the latter FWE-corrected. Interaction of group by sex was significant in mPFC (F = 7.00, p = 0.01), with PSY females exhibiting the lowest activity. Male hyperactivity in HYPO and ACC was significantly associated with hypercortisolemia post-stress challenge, and mPFC with low androgens. Steroid hormones and neural activity were dissociated in PSY women. Findings suggest disruptions in neural circuitry-hormone associations in response to stress are sex-dependent in psychosis, particularly in prefrontal cortex. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  3. Water deficit and water surplus maps for Brazil, based on FAO Penman-Monteith potential evapotranspiration

    Directory of Open Access Journals (Sweden)

    Ronalton Evandro Machado

    2008-12-01

    Full Text Available The climatological water balance (CWB proposed by Thornthwaite and Mather (1957 is a useful tool for agricultural planning. This method requires the soil water holding capacity (SWHC, rainfall (R and potential evapotranspiration (PET data as input. Among the methods used to estimate PET, the one proposed by Thornthwaite (1948 is the simplest and the most used in Brazil, however it presents limitations of use, which is caused by its empirical relationships. When Thornthwaite PET method is used into the CWB, the errors associated to PET are transferred to the output variables, mainly water deficit (WD and water surplus (WS. As all maps of WD and WS for Brazil are based on Thornthwaite PET, the objective of this study was to produce new maps of these variables considering Penman-Monteith PET. For this purpose, monthly normal climate data base (1961-1990 from Brazilian Meteorological Service (INMET, with 219 locations in all country, was used. PET data were estimated by Thornthwaite (TH and FAO Penman-Monteith (PM methods. PET, from both methods, and R data were used to estimate the CWB for a SWHC of 100 mm, having as results actual ET (AET, WD and WS. Results obtained with PET from the two methods were compared by regression analysis. The results showed that TH method underestimated annual PM PET by 13% in 84% of the places. Such underestimation also led to AET and WD underestimations of 7% (in 69% of places and 40% (in 83% of places, respectively. For WS, the use of TH PET data in the CWB resulted in overestimations of about 80% in 78% of places. The differences observed in the CWB variables resulted in changes in the maps of WD and WS for Brazil. These new maps, based on PM PET, provide more accurate information, mainly for agricultural and hydrological planning and irrigation and drainage projects purposes.

  4. Inhibiting corticosterone synthesis during fear memory formation exacerbates cued fear extinction memory deficits within the single prolonged stress model.

    Science.gov (United States)

    Keller, Samantha M; Schreiber, William B; Stanfield, Briana R; Knox, Dayan

    2015-01-01

    Using the single prolonged stress (SPS) animal model of post-traumatic stress disorder (PTSD), previous studies suggest that enhanced glucocorticoid receptor (GR) expression leads to cued fear extinction retention deficits. However, it is unknown how the endogenous ligand of GRs, corticosterone (CORT), may contribute to extinction retention deficits in the SPS model. Given that CORT synthesis during fear learning is critical for fear memory consolidation and SPS enhances GR expression, CORT synthesis during fear memory formation could strengthen fear memory in SPS rats by enhancing GR activation during fear learning. In turn, this could lead to cued fear extinction retention deficits. We tested the hypothesis that CORT synthesis during fear learning leads to cued fear extinction retention deficits in SPS rats by administering the CORT synthesis inhibitor metyrapone to SPS and control rats prior to fear conditioning, and observed the effect this had on extinction memory. Inhibiting CORT synthesis during fear memory formation in control rats tended to decrease cued freezing, though this effect never reached statistical significance. Contrary to our hypothesis, inhibiting CORT synthesis during fear memory formation disrupted extinction retention in SPS rats. This finding suggests that even though SPS exposure leads to cued fear extinction memory deficits, CORT synthesis during fear memory formation enhances extinction retention in SPS rats. This suggests that stress-induced CORT synthesis in previously stressed rats can be beneficial.

  5. Water Deficits Affect Caffeate O-Methyltransferase, Lignification, and Related Enzymes in Maize Leaves. A Proteomic Investigation1[w

    Science.gov (United States)

    Vincent, Delphine; Lapierre, Catherine; Pollet, Brigitte; Cornic, Gabriel; Negroni, Luc; Zivy, Michel

    2005-01-01

    Drought is a major abiotic stress affecting all levels of plant organization and, in particular, leaf elongation. Several experiments were designed to study the effect of water deficits on maize (Zea mays) leaves at the protein level by taking into account the reduction of leaf elongation. Proteomic analyses of growing maize leaves allowed us to show that two isoforms of caffeic acid/5-hydroxyferulic 3-O-methyltransferase (COMT) accumulated mostly at 10 to 20 cm from the leaf point of insertion and that drought resulted in a shift of this region of maximal accumulation toward basal regions. We showed that this shift was due to the combined effect of reductions in growth and in total amounts of COMT. Several other enzymes involved in lignin and/or flavonoid synthesis (caffeoyl-CoA 3-O-methyltransferase, phenylalanine ammonia lyase, methylenetetrahydrofolate reductase, and several isoforms of S-adenosyl-l-methionine synthase and methionine synthase) were highly correlated with COMT, reinforcing the hypothesis that the zone of maximal accumulation corresponds to a zone of lignification. According to the accumulation profiles of the enzymes, lignification increases in leaves of control plants when their growth decreases before reaching their final size. Lignin levels analyzed by thioacidolysis confirmed that lignin is synthesized in the region where we observed the maximal accumulation of these enzymes. Consistent with the levels of these enzymes, we found that the lignin level was lower in leaves of plants subjected to water deficit than in those of well-watered plants. PMID:15728345

  6. Long-term moderate dose exogenous erythropoietin treatment protects from intermittent hypoxia-induced spatial learning deficits and hippocampal oxidative stress in young rats.

    Science.gov (United States)

    Al-Qahtani, Jobran M; Abdel-Wahab, Basel A; Abd El-Aziz, Samy M

    2014-01-01

    Exposure to intermittent hypoxia (IH) is associated with cognitive impairments and oxidative stress in brain regions involved in learning and memory. In earlier studies, erythropoietin (EPO) showed a neuroprotective effect in large doses. The aim of the present study was to explore the effect of smaller doses of EPO, such as those used in the treatment of anemia, on IH-induced cognitive deficits and hippocampal oxidative stress in young rats. The effect of concurrent EPO treatment (500 and 1,000 IU/kg/day ip) on spatial learning and memory deficits induced by long-term exposure to IH for 6 weeks was tested using the Morris water maze (MWM) test and the elevated plus maze (EPM) test. Moreover, the effect on hippocampal glutamate and oxidative stress were assessed. Exposure to IH induced a significant impairment of spatial learning and cognition of animals in both MWM and EPM performance parameters. Moreover, hippocampal glutamate and thiobarbituric acid reactive substances (TBARS) increased while antioxidant defenses (GSH and GSH-Px) decreased. EPO in the tested doses significantly reduced the IH-induced spatial learning deficits in both MWM and EPM tests and dose-dependently antagonized the effects of IH on hippocampal glutamate, TBARS, GSH levels, and GSH-Px activity. Treatment with EPO in moderate doses that used for anemia, concurrently with IH exposure can antagonize IH-induced spatial learning deficits and protect hippocampal neurons from IH-induced lipid peroxidation and oxidative stress-induced damage in young rats, possibly through multiple mechanisms involving a potential antioxidative effect.

  7. Water productivity, yield, and berry composition in sustained versus regulated deficit irrigation of Merlot grapevines

    Science.gov (United States)

    The wine grape cultivar Merlot (Vitis vinifera L.) was irrigated at incremental fractions of estimated crop evapotranspiration or a regulated deficit (RDI) regime to identify which practice best optimized water productivity and berry composition without compromising yield. Three severities of susta...

  8. Effect of water deficit on Argan tree seedlings (Argania spinosa L ...

    African Journals Online (AJOL)

    USER

    African Journal of Biotechnology ... seedlings have accumulated proteins in a very significant way in leaves (from ... activity of peroxidase is in relative increase according to the duration of the ... Author(s) agree that this article remains permanently open access under the ... resistant but vulnerable in view of the water deficit.

  9. An ecoclimatic framework for evaluating the resilience of vegetation to water deficit.

    Science.gov (United States)

    Mitchell, Patrick J; O'Grady, Anthony P; Pinkard, Elizabeth A; Brodribb, Timothy J; Arndt, Stefan K; Blackman, Chris J; Duursma, Remko A; Fensham, Rod J; Hilbert, David W; Nitschke, Craig R; Norris, Jaymie; Roxburgh, Stephen H; Ruthrof, Katinka X; Tissue, David T

    2016-05-01

    The surge in global efforts to understand the causes and consequences of drought on forest ecosystems has tended to focus on specific impacts such as mortality. We propose an ecoclimatic framework that takes a broader view of the ecological relevance of water deficits, linking elements of exposure and resilience to cumulative impacts on a range of ecosystem processes. This ecoclimatic framework is underpinned by two hypotheses: (i) exposure to water deficit can be represented probabilistically and used to estimate exposure thresholds across different vegetation types or ecosystems; and (ii) the cumulative impact of a series of water deficit events is defined by attributes governing the resistance and recovery of the affected processes. We present case studies comprising Pinus edulis and Eucalyptus globulus, tree species with contrasting ecological strategies, which demonstrate how links between exposure and resilience can be examined within our proposed framework. These examples reveal how climatic thresholds can be defined along a continuum of vegetation functional responses to water deficit regimes. The strength of this framework lies in identifying climatic thresholds on vegetation function in the absence of more complete mechanistic understanding, thereby guiding the formulation, application and benchmarking of more detailed modelling. © 2015 John Wiley & Sons Ltd.

  10. Functionally relevant climate variables for arid lands: Aclimatic water deficit approach for modelling desert shrub distributions

    Science.gov (United States)

    Thomas E. Dilts; Peter J. Weisberg; Camie M. Dencker; Jeanne C. Chambers

    2015-01-01

    We have three goals. (1) To develop a suite of functionally relevant climate variables for modelling vegetation distribution on arid and semi-arid landscapes of the Great Basin, USA. (2) To compare the predictive power of vegetation distribution models based on mechanistically proximate factors (water deficit variables) and factors that are more mechanistically removed...

  11. Diallelic analysis to obtain cowpea (Vigna unguiculata L. Walp.) populations tolerant to water deficit.

    Science.gov (United States)

    Rodrigues, E V; Damasceno-Silva, K J; Rocha, M M; Bastos, E A

    2016-05-13

    The purpose of this study was to identify parents and obtain segregating populations of cowpea (Vigna unguiculata L. Walp.) with the potential for tolerance to water deficit. A full diallel was performed with six cowpea genotypes, and two experiments were conducted in Teresina, PI, Brazil in 2011 to evaluate 30 F2 populations and their parents, one under water deficit and the other under full irrigation. A triple-lattice experimental design was used, with six 2-m-long rows in each plot. Sixteen plants were sampled per plot. The data were subjected to analysis of variance, and general and specific combining ability estimates were obtained based on the means. Additive effects were more important than non-additive effects, and maternal inheritance had occurred. The genotypes BRS Xiquexique, Pingo de Ouro-1-2, and MNC99-510F-16-1 were the most promising for use in selection programs aimed at water deficit tolerance. The hybrid combinations Pingo de Ouro-1-2 x BRS Xiquexique, BRS Xiquexique x Santo Inácio, CNCx 698-128G x MNC99-510F-16-1, Santo Inácio x CNCx 698-128G, MNC99-510F-16-1 x BRS Paraguaçu, MNC99- 510F-16-1 x Pingo de Ouro-1-2, and MNC99-510F-16-1 x BRS Xiquexique have the potential to increase grain production and tolerate water deficit.

  12. Antidepressant-like effects and possible mechanisms of amantadine on cognitive and synaptic deficits in a rat model of chronic stress.

    Science.gov (United States)

    Yu, Mei; Zhang, Yuan; Chen, Xiaoyu; Zhang, Tao

    2016-01-01

    The aim of this study was to examine whether amantadine (AMA), as a low-affinity noncompetitive N-methyl-d-aspartate (NMDA) receptor antagonist, is able to improve cognitive deficits caused by chronic stress in rats. Male Wistar rats were divided into four groups: control, control + AMA, stress and stress + AMA groups. The chronic stress model combined chronic unpredictable stress (CUS) with isolated feeding. Animals were exposed to CUS continued for 21 days. AMA (25 mg/kg) was administrated p.o. for 20 days from the 4th day of CUS to the 23rd. Weight and sucrose consumption were measured during model establishing period. Spatial memory was evaluated using the Morris water maze (MWM) test. Following MWM testing, both long-term potentiation (LTP) and depotentiation were recorded in the hippocampal CA1 region. NR2B and postsynaptic density protein 95 (PSD-95) proteins were measured by Western-blot analysis. AMA increased weight and sucrose consumption of stressed rats. Spatial memory and reversal learning in stressed rats were impaired relative to controls, whereas AMA significantly attenuated cognitive impairment. AMA also mitigated the chronic stress-induced impairment of hippocampal synaptic plasticity, in which both the LTP and depotentiation were significantly inhibited in stressed rats. Moreover, AMA enhanced the expression of hippocampal NR2B and PSD-95 in stressed rats. The data suggest that AMA may be an effective therapeutic agent for depression-like symptoms and associated cognitive disturbances.

  13. Deficit irrigation and sustainable water-resource strategies in agriculture for China's food security.

    Science.gov (United States)

    Du, Taisheng; Kang, Shaozhong; Zhang, Jianhua; Davies, William J

    2015-04-01

    More than 70% of fresh water is used in agriculture in many parts of the world, but competition for domestic and industrial water use is intense. For future global food security, water use in agriculture must become sustainable. Agricultural water-use efficiency and water productivity can be improved at different points from the stomatal to the regional scale. A promising approach is the use of deficit irrigation, which can both save water and induce plant physiological regulations such as stomatal opening and reproductive and vegetative growth. At the scales of the irrigation district, the catchment, and the region, there can be many other components to a sustainable water-resources strategy. There is much interest in whether crop water use can be regulated as a function of understanding of physiological responses. If this is the case, then agricultural water resources can be reallocated to the benefit of the broader community. We summarize the extent of use and impact of deficit irrigation within China. A sustainable strategy for allocation of agricultural water resources for food security is proposed. Our intention is to build an integrative system to control crop water use during different cropping stages and actively regulate the plant's growth, productivity, and development based on physiological responses. This is done with a view to improving the allocation of limited agricultural water resources. © The Author 2015. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  14. Rosiglitazone prevents gliosis, oxidative/nitrative stress and memory deficits induced by intracere-broventricular injection of streptozotocin in rats

    Institute of Scientific and Technical Information of China (English)

    OUYANG Chang-han; ZHANG Rui-xue; WU Ji-liang; CAI Fei

    2008-01-01

    Objective To study the preventive effect of rosiglitazone glial activation, oxidative/nitrative stress and spatial memory deficits induced by intracerebroventricular (ICV) injection of streptozotocin (STZ) in rats Methods 24 male Wistar rats were randomly divided into sham operated group, model group and rosiglitazone group. The model of ALzheimer's was induced by injection with ICV 10 % STZ bilaterally, on day 1 and 3 (3 Mg·kg-1). The rats were treated with rosiglitazone (2 Mg·kg-1, p. o. ) for a consecutive 21 days, once a day, beginning 7 days prior to STZ injection. The learning and memory behavior was assessed using Morris water maze task and Y-maze 21 d after ICV STZ injection. Malondialdehyde (MDA), superoxide dismutase (SOD), glutathione (GSH) levels and nitrotyrosine immunoreactivity in brain were estimated as parameters of oxidative/nitrative stress. Brain acetyl cholinesterase (AchE) activity was measured by Ell-Mann's method and activated miCroglia and astrocytes were detected by immunohistochemistry. Results ICV STZ injection resulted in a severe deficit in spatial learning and memory associated with increased MDA level (+69.5 % ) and nitrotyrosine immunoreactivity ( + 23.7 % ), decreased SOD activity ( - 29.2 % ) and GSH (- 25.1% ) in brain. It also showed the activated mieroglia and astrocytes in the cortex and hippocampal CA1 region and a significant decrease in acetylcholinesterase activity ( - 40.2 % ). Compared with model group, chronic administration of rosiglitazone significantly shorten the escape latency time from the third day in place navigation test, increase the number of passing through primary flat place in spatial probe test in Morris water maze test, and decrease the error times in Y-maze test (P<0.05 or P<0.01). In addition, it also prevented the glial changes, decreased the elevated MDA and nitrite levels and restored the depleted GSH and acetylcholinesterase activity in cortex (P<0.05), but had no effect on SOD activity in cortex

  15. Evidence of female-specific glial deficits in the hippocampus in a mouse model of prenatal stress.

    LENUS (Irish Health Repository)

    Behan, Aine T

    2011-01-01

    Prenatal stress (PS) has been associated with an increased incidence of numerous neuropsychiatric disorders, including depression, anxiety, schizophrenia, and autism. To determine the effects of PS on hippocampal-dependent behaviour hippocampal morphology, we examined behavioural responses and hippocampal cytoarchitecture of a maternal restraint stress paradigm of PS in C57BL6 mice. Female offspring only showed a reduction in hippocampal glial count in the pyramidal layer following PS. Additionally, only PS females showed increased depressive-like behaviour with cognitive deficits predominantly in female offspring when compared to males. This data provides evidence for functional female-specific glial deficits within the hippocampus as a consequence of PS.

  16. Evidence of female-specific glial deficits in the hippocampus in a mouse model of prenatal stress.

    LENUS (Irish Health Repository)

    Behan, Aine T

    2012-02-01

    Prenatal stress (PS) has been associated with an increased incidence of numerous neuropsychiatric disorders, including depression, anxiety, schizophrenia, and autism. To determine the effects of PS on hippocampal-dependent behaviour hippocampal morphology, we examined behavioural responses and hippocampal cytoarchitecture of a maternal restraint stress paradigm of PS in C57BL6 mice. Female offspring only showed a reduction in hippocampal glial count in the pyramidal layer following PS. Additionally, only PS females showed increased depressive-like behaviour with cognitive deficits predominantly in female offspring when compared to males. This data provides evidence for functional female-specific glial deficits within the hippocampus as a consequence of PS.

  17. Expression Analysis of Sugarcane Aquaporin Genes under Water Deficit

    Directory of Open Access Journals (Sweden)

    Manassés Daniel da Silva

    2013-01-01

    Full Text Available The present work is a pioneer study specifically addressing the aquaporin transcripts in sugarcane transcriptomes. Representatives of the four aquaporin subfamilies (PIP, TIP, SIP, and NIP, already described for higher plants, were identified. Forty-two distinct aquaporin isoforms were expressed in four HT-SuperSAGE libraries from sugarcane roots of drought-tolerant and -sensitive genotypes, respectively. At least 10 different potential aquaporin isoform targets and their respective unitags were considered to be promising for future studies and especially for the development of molecular markers for plant breeding. From those 10 isoforms, four (SoPIP2-4, SoPIP2-6, OsPIP2-4, and SsPIP1-1 showed distinct responses towards drought, with divergent expressions between the bulks from tolerant and sensitive genotypes, when they were compared under normal and stress conditions. Two targets (SsPIP1-1 and SoPIP1-3/PIP1-4 were selected for validation via RT-qPCR and their expression patterns as detected by HT-SuperSAGE were confirmed. The employed validation strategy revealed that different genotypes share the same tolerant or sensitive phenotype, respectively, but may use different routes for stress acclimation, indicating the aquaporin transcription in sugarcane to be potentially genotype-specific.

  18. Effects of Water Deficit and Increased Nitrogen Application in the Late Growth Stage on Physiological Characters of Anti-aging of Leaves in Different Hybrid Rice Varieties

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    related to ABA content. [Conclusion] The rate of leaf aging, physiological activity of anti-aging, and response to water deficit varied in different hy- bried rice varieties. The activity of antioxidant enzymes were not all induced to improve by ABA. SOD activity can be an indicator of resistance to stress. Increasing nitrogen ap- plication significantly postponed leave senescence in the late growth stage of rice.

  19. Effects of water stress and high temperature on photosynthetic rates of two species of Prosopis.

    Science.gov (United States)

    Delatorre, Jose; Pinto, Manuel; Cardemil, Liliana

    2008-08-21

    The main aim of this research was to compare the photosynthetic responses of two species of Prosopis, Prosopis chilensis (algarrobo) and Prosopis tamarugo (tamarugo) subjected to heat and water stress, to determine how heat shock or water deficit, either individually or combined, affect the photosynthesis of these two species. The photosynthetic rates expressed as a function of photon flow density (PFD) were determined by the O(2) liberated, in seedlings of tamarugo and algarrobo subjected to two water potentials: -0.3 MPa and -2.5 MPa and to three temperatures: 25 degrees C, 35 degrees C and 40 degrees C. Light response curves were constructed to obtain light compensation and light saturation points, maximum photosynthetic rates, quantum yields and dark respiration rates. The photochemical efficiency as the F(v)/F(m) ratio and the amount of RUBISCO were also determined under heat shock, water deficit, and under the combined action of both stress. Photosynthetic rates at a light intensity higher than 500 micromole photons m(-2)s(-1) were not significantly different (P>0.05) between species when measured at 25 degrees C under the same water potential. The maximum photosynthetic rates decreased with temperature in both species and with water deficit in algarrobo. At 40 degrees C and -2.5 MPa, the photosynthetic rate of algarrobo fell to 72% of that of tamarugo. The quantum yield decreased in algarrobo with temperature and water deficit and it was reduced by 50% when the conditions were 40 degrees C and -2.5 MPa. Dark respiration increased by 62% respect to the control at 40 degrees C in tamarugo while remained unchanged in algarrobo. The photochemical efficiency decreased with both, high temperature and water deficit, without differences between species. RUBISCO content increased in algarrobo 35 degrees C. Water deficit reduced the amount of RUBISCO in both species. The results of this work support the conclusion that in both Prosopis species, the interaction between

  20. Altered Pain Perception and Fear-Learning Deficits in Subjects With Posttraumatic Stress Disorder.

    Science.gov (United States)

    Jenewein, Josef; Erni, Jeannine; Moergeli, Hanspeter; Grillon, Christian; Schumacher, Sonja; Mueller-Pfeiffer, Christoph; Hassanpour, Katayun; Seiler, Annina; Wittmann, Lutz; Schnyder, Ulrich; Hasler, Gregor

    2016-12-01

    There is growing evidence that fear-learning abnormalities are involved in the development of posttraumatic stress disorder (PTSD) and chronic pain. More than 50% of PTSD patients suffer from chronic pain. This study aimed to examine the role of fear-learning deficits in the link between pain perception and PTSD. We included 19 subjects with PTSD and 21 age- and sex-matched healthy control subjects in a fear-conditioning experiment. The conditioned stimulus (CS) consisted of visual signs flashed upon a screen in front of each subject. The unconditioned stimulus was either a low or high temperature impulse delivered through a thermal contact thermode on the subjects' hand. A designation of 'CS-' was assigned to CS always followed by nonpainful low-temperature stimuli; a designation of 'CS+' was given to CS that were randomly followed by either a low or a more painful high temperature. Skin conductance was used as a physiological marker of fear. In healthy control subjects, CS+ induced more fear than CS-, and a low-temperature stimulus induced less subjective pain after CS- than after CS+. PTSD subjects failed to demonstrate such adaptive conditioning. Fear ratings after CS presentation were significantly higher in the PTSD group than in the control group. There were significant interaction effects between group and the type of CS on fear and pain ratings. Fear-learning deficits are a potentially promising, specific psychopathological factor in altered pain perception associated with PTSD. Deficits in safety learning may increase fear and, consequently, pain sensations. These findings may contribute to elucidating the pathogenesis behind the highly prevalent comorbidity that exists between PTSD and pain disorders, and to developing new treatments. This study provides new insights into the pathogenesis of chronic pain in patients with PTSD. The findings may help to develop new treatment strategies for this highly prevalent comorbidity in PTSD. Copyright © 2016

  1. THE EFFECT OF WATER STRESS ON SOME TRAITS OF WINTER BARLEY CULTIVARS DURING EARLY STAGES OF PLANT GROWTH

    Directory of Open Access Journals (Sweden)

    Smiljana Goreta Ban

    2017-01-01

    Full Text Available We conducted research on the effects of exposing barley plants to short water stress deficiency through their early growth stage. The measurements and parallel analyses of relative water content (RWC, the mass of the whole plant, leaf mass, root percentage, total root length and length of root fractions with plants exposed to stress (water deficit and with plants which were not exposed to water deficit have been conducted. Ten varieties were included in this research. The overall average of relative water content (RWC measured in winter barley varieties was 97.5% under non-stressful conditions, and 66.1% under stressful conditions. An average difference between non-stressful and stressful conditions of plant mass was 61.2 mg, leaf mass 42.5 mg, RWC 31.4%, root mass 18.5 mg and total root length 129 cm. Relative losses under effect of water stress were lower at smaller (finer root fractions. Significant differences among the examined barley varieties cultivated under or without the water stress were found for plant mass, leaf mass, root mass, total root length and root fractions. Varieties with the lowest losses in leaf and plant mass are Titan, Arturio and Bingo. Also, the varieties Titan, Bingo and Rex had the lowest losses of root length and mass under water stress during the early growth stage.

  2. Perfusion deficits and functional connectivity alterations in patients with post-traumatic stress disorder

    Science.gov (United States)

    Liu, Yang; Li, Baojuan; Zhang, Xi; Zhang, Linchuan; Li, Liang; Lu, Hongbing

    2016-03-01

    To explore the alteration in cerebral blood flow (CBF) and functional connectivity between survivors with recent onset post-traumatic stress disorder (PTSD) and without PTSD, survived from the same coal mine flood disaster. In this study, a processing pipeline using arterial spin labeling (ASL) sequence was proposed. Considering low spatial resolution of ASL sequence, a linear regression method was firstly used to correct the partial volume (PV) effect for better CBF estimation. Then the alterations of CBF between two groups were analyzed using both uncorrected and PV-corrected CBF maps. Based on altered CBF regions detected from the CBF analysis as seed regions, the functional connectivity abnormities in PTSD patients was investigated. The CBF analysis using PV-corrected maps indicates CBF deficits in the bilateral frontal lobe, right superior frontal gyrus and right corpus callosum of PTSD patients, while only right corpus callosum was identified in uncorrected CBF analysis. Furthermore, the regional CBF of the right superior frontal gyrus exhibits significantly negative correlation with the symptom severity in PTSD patients. The resting-state functional connectivity indicates increased connectivity between left frontal lobe and right parietal lobe. These results indicate that PV-corrected CBF exhibits more subtle perfusion changes and may benefit further perfusion and connectivity analysis. The symptom-specific perfusion deficits and aberrant connectivity in above memory-related regions may be putative biomarkers for recent onset PTSD induced by a single prolonged trauma exposure and help predict the severity of PTSD.

  3. Water deficit-induced changes in mesocarp cellular processes and the relationship between mesocarp and endocarp during olive fruit development.

    Science.gov (United States)

    Gucci, Riccardo; Lodolini, Enrico M; Rapoport, Hava F

    2009-12-01

    A field experiment was conducted during two consecutive growing seasons to determine and quantify the growth response of the olive (Olea europaea L. cv. Leccino) fruit and of its component tissues to tree water status. Pre-dawn leaf water potential (Psi(w)) and fruit volume were measured at about weekly intervals, and fresh weight (FW) and dry weight (DW) of the fruit tissues at 15, 20 and 21 weeks after full bloom (AFB). Fruit anatomical sections were prepared at 8, 15 and 21 weeks AFB for area determinations and cell counts. Fruit volume of the well-watered trees (average Psi(w) = -0.97 MPa) increased rapidly and reached the greatest final size, that from the most stressed (average Psi(w) = -2.81 MPa) grew most slowly and were smallest. In general, equatorial transverse areas of the mesocarp increased with increasing Psi(w), and this response was more evident at 21 than at 15 weeks AFB. By 21 weeks AFB, the mesocarp of the well-watered trees reached values more than three times higher than those measured at 8 weeks AFB. The endocarp FW and DW did not increase between 15 and 21 weeks AFB. Within each sampling date the endocarp area, FW and DW responded weakly to Psi(w). The mesocarp-to-endocarp ratio (FW and DW) increased from 15 to 21 weeks AFB regardless of water status, mainly due to the mesocarp growth. In both years at 20 and 21 weeks AFB, low values of the mesocarp-to-endocarp ratio were found with Psi(w) below -2.5 MPa. Within the mesocarp, cell size was more responsive to water deficit than to cell number. At 8 weeks AFB, the number of cells in the mesocarp was unaffected by tree water deficit, whereas cell size decreased, although slightly, in fruits sampled from trees in which Psi(w) was < -3.0 MPa. At 21 weeks AFB, cell size showed a linear decrease with increasing level of water deficit, whereas the number of cells at 21 weeks AFB decreased as the Psi(w) decreased below -2.5 MPa and seemed unaffected above that range. Overall, the results clarify the

  4. Behavioral deficit, oxidative stress, and mitochondrial dysfunction precede tau pathology in P301S transgenic mice.

    Science.gov (United States)

    Dumont, Magali; Stack, Cliona; Elipenahli, Ceyhan; Jainuddin, Shari; Gerges, Meri; Starkova, Natalia N; Yang, Lichuan; Starkov, Anatoly A; Beal, Flint

    2011-11-01

    Abnormal tau accumulation can lead to the development of neurodegenerative diseases. P301S mice overexpress the human tau mutated gene, resulting in tau hyperphosphorylation and tangle formation. Mice also develop synaptic deficits and microglial activation prior to any neurodegeneration and tangles. Oxidative stress can also affect tauopathy. We studied the role of oxidative stress in relationship to behavioral abnormalities and disease progression in P301S mice at 2, 7, and 10 mo of age. At 7 mo of age, P301S mice had behavioral abnormalities, such as hyperactivity and disinhibition. At the same age, we observed increased carbonyls in P301S mitochondria (∼215 and 55% increase, males/females), and deregulation in the activity and content of mitochondrial enzymes involved in reactive oxygen species formation and energy metabolism, such as citrate synthase (∼19 and ∼5% decrease, males/females), MnSOD (∼16% decrease, males only), cytochrome C (∼19% decrease, females only), and cytochrome C oxidase (∼20% increase, females only). These changes in mitochondria proteome appeared before tau hyperphosphorylation and tangle formation, which were observed at 10 mo and were associated with GSK3β activation. At that age, mitochondria proteome deregulation became more apparent in male P301S mitochondria. The data strongly suggest that oxidative stress and mitochondrial abnormalities appear prior to tau pathology.

  5. Optimization of Water Allocation between Different Crops in Water Stress Conditions in Qazvin Irrigation Network

    Directory of Open Access Journals (Sweden)

    Mehdi Mohammad khani

    2017-06-01

    minimum productivity index. Therefore, in water deficit conditions, the priority of water distribution in all options is for tomatoes and the last priority for sugar beets. In all of the options, wheat, barley and canola ascend in productivity index and corn and sugar beets descend in productivity index. Conclusion: Studying water- production index shows that considering instructions will result in optimal productivity that in turn will increase production and network total income. Optimal model results show that drought effects can be satisfied with optimal and targeted management in allocating water, so that network total income has not reduced in stress occurrences compared to network net income. Optimization method in model development has been selected according to aim of model and it is proposed that model results to be assessed by non- linear optimization methods. It is proposed that, different scenarios of climate are studied in region according to climate changes and optimal allocation of water is prepared according to the effect of these scenarios on temperature increase, raining decrease and products water need increase in present cultivation method. For model efficiency increase, it is proposed that using neural networks capabilities, intelligent prediction of the input discharge to the network is done and the possibility of comprehensive management and timely combining of network with water allocation optimal model is provided.

  6. Development of maize and palisadegrass plants cultivated in intercrop under water deficit

    Directory of Open Access Journals (Sweden)

    Leandro Coelho de Araujo

    2011-07-01

    Full Text Available The objective of this work was to evaluate the development and productive traits of palisadegrass single cultivated or intercropped with corn, in addition to corn intercropped with pasture, under water deficit at different development stages of the plants. It was used a complete block experimental design with split plots and three replicates. Periods of water deficit were placed in the plots and types of cultivation were placed in the subplots. Irrigation was stopped at germination and initial tillering of palisadegrass and at V4 and V15 stages of corn and returned when soil moisture was 40% of available water capacity. Tiller density and palisadegrass height were evaluated weekly. Dry matter (DM of fractions of herbage mass as well as leaf area of the plants were evaluated at corn tasseling and when grains reached physiological maturity. Components of corn production were determined in the second sampling. In palisadegrass, water influenced only tillering, which was reduced in the plots in which water defict was forced at the moment of germination or at the beginning of tilering, in both cultivation systems. Plant height and DM production were affected only by cultivation, reducing when intercropped with corn. Evaluated production components did not influence corn grain productivity, which was similar in all treatments (average of 10,145 kg/ha. Palisadegrass plants produce more DM in single cultivation than intercropped with corn. Water deficit during germination and initial tillering reduces tillering of palisadegrass during establishment phase. Water deficit, applied in this trial, does not reduce DM yield in palisadegrass or corn.

  7. Public participation and rural management of Brazilian waters: an alternative to the deficit model

    Directory of Open Access Journals (Sweden)

    Alessandro Luís Piolli

    2008-12-01

    Full Text Available The knowledge deficit model with regard to the public has been severely criticized in the sociology of the public perception of science. However, when dealing with public decisions regarding scientific matters, political and scientific institutions insist on defending the deficit model. The idea that only certified experts, or those with vast experience, should have the right to participate in decisions can bring about problems for the future of democracies. Through a type of "topography of ideas", in which some concepts from the social studies of science are used in order to think about these problems, and through the case study of public participation in the elaboration of the proposal of discounts in the fees charged for rural water use in Brazil, we will try to point out an alternative to the deficit model. This alternative includes a "minimum comprehension" of the scientific matters involved in the decision on the part of the participants, using criteria judged by the public itself.

  8. Structural Modifications of Fructans in Aloe barbadensis Miller (Aloe Vera Grown under Water Stress.

    Directory of Open Access Journals (Sweden)

    Carlos Salinas

    Full Text Available Aloe barbadensis Miller (Aloe vera has a Crassulaceae acid metabolism which grants the plant great tolerance to water restrictions. Carbohydrates such as acemannans and fructans are among the molecules responsible for tolerating water deficit in other plant species. Nevertheless, fructans, which are prebiotic compounds, have not been described nor studied in Aloe vera, whose leaf gel is known to possess beneficial pharmaceutical, nutritional and cosmetic properties. As Aloe vera is frequently cultivated in semi-arid conditions, like those found in northern Chile, we investigated the effect of water deficit on fructan composition and structure. For this, plants were subjected to different irrigation regimes of 100%, 75%, 50% and 25% field capacity (FC. There was a significant increase in the total sugars, soluble sugars and oligo and polyfructans in plants subjected to water deficit, compared to the control condition (100% FC in both leaf tips and bases. The amounts of fructans were also greater in the bases compared to the leaf tips in all water treatments. Fructans also increase in degree of polymerization with increasing water deficit. Glycosidic linkage analyses by GC-MS, led to the conclusion that there are structural differences between the fructans present in the leaves of control plants with respect to plants irrigated with 50% and 25% FC. Therefore, in non-stressed plants, the inulin, neo-inulin and neo-levan type of fructans predominate, while in the most stressful conditions for the plant, Aloe vera also synthesizes fructans with a more branched structure, the neofructans. To our knowledge, the synthesis and the protective role of neo-fructans under extreme water deficit has not been previously reported.

  9. Structural Modifications of Fructans in Aloe barbadensis Miller (Aloe Vera) Grown under Water Stress

    Science.gov (United States)

    Salinas, Carlos; Cardemil, Liliana

    2016-01-01

    Aloe barbadensis Miller (Aloe vera) has a Crassulaceae acid metabolism which grants the plant great tolerance to water restrictions. Carbohydrates such as acemannans and fructans are among the molecules responsible for tolerating water deficit in other plant species. Nevertheless, fructans, which are prebiotic compounds, have not been described nor studied in Aloe vera, whose leaf gel is known to possess beneficial pharmaceutical, nutritional and cosmetic properties. As Aloe vera is frequently cultivated in semi-arid conditions, like those found in northern Chile, we investigated the effect of water deficit on fructan composition and structure. For this, plants were subjected to different irrigation regimes of 100%, 75%, 50% and 25% field capacity (FC). There was a significant increase in the total sugars, soluble sugars and oligo and polyfructans in plants subjected to water deficit, compared to the control condition (100% FC) in both leaf tips and bases. The amounts of fructans were also greater in the bases compared to the leaf tips in all water treatments. Fructans also increase in degree of polymerization with increasing water deficit. Glycosidic linkage analyses by GC-MS, led to the conclusion that there are structural differences between the fructans present in the leaves of control plants with respect to plants irrigated with 50% and 25% FC. Therefore, in non-stressed plants, the inulin, neo-inulin and neo-levan type of fructans predominate, while in the most stressful conditions for the plant, Aloe vera also synthesizes fructans with a more branched structure, the neofructans. To our knowledge, the synthesis and the protective role of neo-fructans under extreme water deficit has not been previously reported. PMID:27454873

  10. Structural Modifications of Fructans in Aloe barbadensis Miller (Aloe Vera) Grown under Water Stress.

    Science.gov (United States)

    Salinas, Carlos; Handford, Michael; Pauly, Markus; Dupree, Paul; Cardemil, Liliana

    2016-01-01

    Aloe barbadensis Miller (Aloe vera) has a Crassulaceae acid metabolism which grants the plant great tolerance to water restrictions. Carbohydrates such as acemannans and fructans are among the molecules responsible for tolerating water deficit in other plant species. Nevertheless, fructans, which are prebiotic compounds, have not been described nor studied in Aloe vera, whose leaf gel is known to possess beneficial pharmaceutical, nutritional and cosmetic properties. As Aloe vera is frequently cultivated in semi-arid conditions, like those found in northern Chile, we investigated the effect of water deficit on fructan composition and structure. For this, plants were subjected to different irrigation regimes of 100%, 75%, 50% and 25% field capacity (FC). There was a significant increase in the total sugars, soluble sugars and oligo and polyfructans in plants subjected to water deficit, compared to the control condition (100% FC) in both leaf tips and bases. The amounts of fructans were also greater in the bases compared to the leaf tips in all water treatments. Fructans also increase in degree of polymerization with increasing water deficit. Glycosidic linkage analyses by GC-MS, led to the conclusion that there are structural differences between the fructans present in the leaves of control plants with respect to plants irrigated with 50% and 25% FC. Therefore, in non-stressed plants, the inulin, neo-inulin and neo-levan type of fructans predominate, while in the most stressful conditions for the plant, Aloe vera also synthesizes fructans with a more branched structure, the neofructans. To our knowledge, the synthesis and the protective role of neo-fructans under extreme water deficit has not been previously reported.

  11. An assessment of crop water deficits of the plants growing on the Małopolska Upland (Poland

    Directory of Open Access Journals (Sweden)

    Kowalczyk Agnieszka

    2016-06-01

    Full Text Available The problem of water scarcity is unfavourable for the economy, with the most significant water deficits felt by agriculture. In Poland water deficits in agriculture are occurring more frequently, causing losses in yield, not only in the Lowland areas but also in the Uplands. This paper presents an assessment of the water deficits at various excedance probability levels for four varieties of field crop and for soil types with various water retention capacity, which occur in the Małopolska Upland. Calculations were performed by balancing the amount of available soil water in the root zone. The study was based on the meteorological data from the Institute of Meteorology and Water Management for the years 1971–2010. Daily precipitation data from six rainfall stations: Borusowa, Igołomia, Książ Wielki, Miechów, Olewin and Sielec was utilised as well as average decadal air temperature, water vapour pressure, wind speed and sunshine hours from the meteorological station at Kraków–Balice. The water deficits at an excedance probability level of 20% fluctuated during the growing season from 5 mm (Phaeozems to 190 mm (Leptosols. In the Małopolska Upland in soils with a medium capacity to retain water (110–160 mm, water deficits have occurred even in years of average rainfall (with probability 50%. This study confirms the considerable impact of the high variability of the soil and pluvial conditions in the region on the water deficits of the field crops.

  12. Nicotine improves AF64A-induced spatial memory deficits in Morris water maze in rats.

    Science.gov (United States)

    Yamada, Kazuo; Furukawa, Satoshi; Iwasaki, Tsuneo; Ichitani, Yukio

    2010-01-18

    Ethylcholine mustard aziridinium ion (AF64A) is a neurotoxic derivative of choline that produces not only long-term presynaptic cholinergic deficits, but also various memory deficits in rats similar to some characteristics observed in Alzheimer's disease patients. This study investigated whether nicotine (NCT) administration attenuated spatial learning deficits induced by intracerebroventricular AF64A treatment. AF64A (6 nmol/6 microl)-or saline (SAL)-treated rats were trained in Morris water maze task. NCT (0.025-0.25mg/kg) was subcutaneously injected 5 min before the training every day. The results showed that moderate dose (0.10mg/kg) of NCT attenuated AF64A-induced prolongation of escape latency. Furthermore, NCT dose-dependently recovered the AF64A-induced decrease of time spent in the target quadrant in the probe test. These results suggest that NCT improves AF64A-induced spatial memory deficits, and thus it is a potential therapeutic agent for the treatment of memory deficits in dementia.

  13. Effect of water deficit irrigation and inoculation with Botrytis cinerea on strawberry (Fragaria x ananassa) fruit quality.

    Science.gov (United States)

    Terry, Leon A; Chope, Gemma A; Bordonaba, Jordi Giné

    2007-12-26

    Deficit irrigation (DI) detrimentally affected berry size but had a profound effect on fruit physiology and biochemistry. Strawberry cv. Elsanta fruit from DI-treated plants had higher levels of abscisic acid (ABA). Dry matter content as a proportion of fresh weight was increased by a quarter in fruit from water-stressed plants as compared to fruit harvested from plants held at or near field capacity. Concomitant to this, the concentration of some taste-related (viz. monosaccharides and sugar/acid ratios) and health-related compounds/parameters (viz. antioxidant capacity and total phenolics) were generally much greater in DI-treated fruit. The effect of inoculation with Botrytis cinerea on fruit quality was also tested. Fruit derived from inoculated plants displayed symptoms of gray mold postharvest disease earlier than noninoculated fruit and had double the concentration of ABA. Inoculation had no significant effects on all other target analytes measured. There was no interaction between water treatment and inoculation. The possible mechanisms for increased synthesis of ABA and the different effects of pathogen-induced stress versus drought stress on fruit quality are discussed.

  14. Water deficit alters differentially metabolic pathways affecting important flavor and quality traits in grape berries of Cabernet Sauvignon and Chardonnay

    Directory of Open Access Journals (Sweden)

    Deluc Laurent G

    2009-05-01

    Full Text Available Abstract Background Water deficit has significant effects on grape berry composition resulting in improved wine quality by the enhancement of color, flavors, or aromas. While some pathways or enzymes affected by water deficit have been identified, little is known about the global effects of water deficit on grape berry metabolism. Results The effects of long-term, seasonal water deficit on berries of Cabernet Sauvignon, a red-wine grape, and Chardonnay, a white-wine grape were analyzed by integrated transcript and metabolite profiling. Over the course of berry development, the steady-state transcript abundance of approximately 6,000 Unigenes differed significantly between the cultivars and the irrigation treatments. Water deficit most affected the phenylpropanoid, ABA, isoprenoid, carotenoid, amino acid and fatty acid metabolic pathways. Targeted metabolites were profiled to confirm putative changes in specific metabolic pathways. Water deficit activated the expression of numerous transcripts associated with glutamate and proline biosynthesis and some committed steps of the phenylpropanoid pathway that increased anthocyanin concentrations in Cabernet Sauvignon. In Chardonnay, water deficit activated parts of the phenylpropanoid, energy, carotenoid and isoprenoid metabolic pathways that contribute to increased concentrations of antheraxanthin, flavonols and aroma volatiles. Water deficit affected the ABA metabolic pathway in both cultivars. Berry ABA concentrations were highly correlated with 9-cis-epoxycarotenoid dioxygenase (NCED1 transcript abundance, whereas the mRNA expression of other NCED genes and ABA catabolic and glycosylation processes were largely unaffected. Water deficit nearly doubled ABA concentrations within berries of Cabernet Sauvignon, whereas it decreased ABA in Chardonnay at véraison and shortly thereafter. Conclusion The metabolic responses of grapes to water deficit varied with the cultivar and fruit pigmentation

  15. Cognitive deficits in the rat chronic mild stress model for depression: relation to anhedonic-like responses

    DEFF Research Database (Denmark)

    Henningsen, Kim; Andreasen T., Jesper; Bouzinova, Elena V.

    2009-01-01

    in consumption of a sucrose solution, indicating an anhedonic-like state. The remaining rats did not reduce their sucrose intake, but appeared resilient to the stress-induced effects on sucrose intake. Cognitive profiling of the CMS rats revealed that chronic stress had a negative effect on performance...... in the spontaneous alternation test, possibly reflecting a deficit in working memory. This effect was independent of whether the stressed rats were anhedonic-like or stress-resilient as measured by their sucrose intake. CMS did not influence performance in passive avoidance and auditory cued fear conditioning......The chronic mild stress (CMS) protocol is widely used to evoke depressive-like behaviours in laboratory rats. The aim of the present study was to examine the effects of chronic stress on cognitive performance. About 70% of rats exposed to 7 weeks of chronic mild stress showed a gradual reduction...

  16. Growth, leaf morphology, water use and tissue water relations of Eucalyptus globulus clones in response to water deficit.

    Science.gov (United States)

    Pita, P; Pardos, J A

    2001-06-01

    Changes in leaf size, specific leaf area (SLA), transpiration and tissue water relations were studied in leaves of rooted cuttings of selected clones of Eucalyptus globulus Labill. subjected to well-watered or drought conditions in a greenhouse. Significant differences between clones were found in leaf expansion and transpiration. There was a significant clone x treatment interaction on SLA. Water stress significantly reduced osmotic potential at the turgor loss point (Pi0) and at full turgor (Pi100), and significantly increased relative water content at the turgor loss point and maximum bulk elastic modulus. Differences in tissue water relations between clones were significant only in the mild drought treatment. Among clones in the drought treatments, the highest leaf expansion and the highest increase in transpiration during the experiment were measured in those clones that showed an early and large decrease in Pi0 and Pi100.

  17. Identification of Single-Nucleotide Polymorphic Loci Associated with Biomass Yield under Water Deficit in Alfalfa (Medicago sativa L.) Using Genome-Wide Sequencing and Association Mapping.

    Science.gov (United States)

    Yu, Long-Xi

    2017-01-01

    Alfalfa is a worldwide grown forage crop and is important due to its high biomass production and nutritional value. However, the production of alfalfa is challenged by adverse environmental factors such as drought and other stresses. Developing drought resistance alfalfa is an important breeding target for enhancing alfalfa productivity in arid and semi-arid regions. In the present study, we used genotyping-by-sequencing and genome-wide association to identify marker loci associated with biomass yield under drought in the field in a panel of diverse germplasm of alfalfa. A total of 28 markers at 22 genetic loci were associated with yield under water deficit, whereas only four markers associated with the same trait under well-watered condition. Comparisons of marker-trait associations between water deficit and well-watered conditions showed non-similarity except one. Most of the markers were identical across harvest periods within the treatment, although different levels of significance were found among the three harvests. The loci associated with biomass yield under water deficit located throughout all chromosomes in the alfalfa genome agreed with previous reports. Our results suggest that biomass yield under drought is a complex quantitative trait with polygenic inheritance and may involve a different mechanism compared to that of non-stress. BLAST searches of the flanking sequences of the associated loci against DNA databases revealed several stress-responsive genes linked to the drought resistance loci, including leucine-rich repeat receptor-like kinase, B3 DNA-binding domain protein, translation initiation factor IF2, and phospholipase-like protein. With further investigation, those markers closely linked to drought resistance can be used for MAS to accelerate the development of new alfalfa cultivars with improved resistance to drought and other abiotic stresses.

  18. Identification of Single-Nucleotide Polymorphic Loci Associated with Biomass Yield under Water Deficit in Alfalfa (Medicago sativa L. Using Genome-Wide Sequencing and Association Mapping

    Directory of Open Access Journals (Sweden)

    Long-Xi Yu

    2017-06-01

    Full Text Available Alfalfa is a worldwide grown forage crop and is important due to its high biomass production and nutritional value. However, the production of alfalfa is challenged by adverse environmental factors such as drought and other stresses. Developing drought resistance alfalfa is an important breeding target for enhancing alfalfa productivity in arid and semi-arid regions. In the present study, we used genotyping-by-sequencing and genome-wide association to identify marker loci associated with biomass yield under drought in the field in a panel of diverse germplasm of alfalfa. A total of 28 markers at 22 genetic loci were associated with yield under water deficit, whereas only four markers associated with the same trait under well-watered condition. Comparisons of marker-trait associations between water deficit and well-watered conditions showed non-similarity except one. Most of the markers were identical across harvest periods within the treatment, although different levels of significance were found among the three harvests. The loci associated with biomass yield under water deficit located throughout all chromosomes in the alfalfa genome agreed with previous reports. Our results suggest that biomass yield under drought is a complex quantitative trait with polygenic inheritance and may involve a different mechanism compared to that of non-stress. BLAST searches of the flanking sequences of the associated loci against DNA databases revealed several stress-responsive genes linked to the drought resistance loci, including leucine-rich repeat receptor-like kinase, B3 DNA-binding domain protein, translation initiation factor IF2, and phospholipase-like protein. With further investigation, those markers closely linked to drought resistance can be used for MAS to accelerate the development of new alfalfa cultivars with improved resistance to drought and other abiotic stresses.

  19. Ecofisiologia de plantas jovens de mogno-africano submetidas a deficit hídrico e reidratação Ecophysiology of young African mahogany plants subjected to water deficit and rewetting

    Directory of Open Access Journals (Sweden)

    Marcos Paulo Ferreira de Albuquerque

    2013-01-01

    Full Text Available O objetivo deste trabalho foi avaliar a capacidade de plantas jovens de mogno-africano (Khaya ivorensis em recuperar seu status hídrico e trocas gasosas após período de deficit hídrico. Plantas com aproximadamente 315 dias, irrigadas (controle e não irrigadas, foram avaliadas aos 14 dias da suspensão da irrigação e após um, três e sete dias da retomada da irrigação (reidratação. No dia 14, o potencial hídrico foliar de antemanhã (Ψam das plantas estressadas foi reduzido a -2,66 MPa. Com a restrição hídrica, foram observadas reduções significativas no conteúdo relativo de água na antemanhã (redução de 32%, na taxa de assimilação líquida de CO2 (90%, na condutância estomática (95%, na transpiração (93% e na razão entre concentração intercelular e ambiental de CO2 (37%. Durante a reidratação, o status hídrico das plantas estressadas foi restabelecido após três dias. As trocas gasosas também se restabeleceram, mas de forma mais lenta que o status hídrico. Sob deficit hídrico, a concentração de prolina aumentou e a de carboidratos solúveis totais diminuiu. Plantas jovens de mogno-africano são tolerantes ao deficit hídrico moderado.The objective of this work was to evaluate the capacity of young plants of African mahogany (Khaya ivorensis to recover their water status and gas exchange after water deficit. Plants with approximately 315 days, irrigated (control and non-irrigated, were evaluated after water was withheld for 14 days, and after one, three, and seven days of irrigation resumption (rehydration. On day 14, the predawn leaf water potential (Ψam of stressed plants was reduced to -2.66 MPa. With water deficit, significant decreases were observed in predawn relative water content (32% reduction, in net assimilation rate of CO2 (90%, in stomatal conductance (95%, in transpiration (93%, and in intercellular to ambient ratio of CO2 concentration (37%. During rehydration, the water status of stressed

  20. Suitability of Stem Diameter Variations as an Indicator of Water Stress of Cotton

    Institute of Scientific and Technical Information of China (English)

    ZHANG Ji-yang; DUAN Ai-wang; MENG Zhao-jiang; LIU Zu-gui

    2006-01-01

    Water stress effects on stem diameter variations (SDV) were studied in a pot experiment on cotton (Gossypium hirustum L. Meimian99B). Water restriction was imposed at the flowering stage and were compared with a well-watered control treatment. The volumetric soil water content (θv) and SDV were monitored continuously. The objective was to determine the feasibility of using the parameters derived from stem diameter measurements, including maximum daily stem shrinkage (MDS), maximum daily stem diameter (MXSD), and minimum daily stem diameter (MNSD) as indicators of plant water stress. The different behavior of SDV was founded at different growth stages. At stem-maturing stage, MDS increased and MNSD decreased in deficit-irrigated plants compared with the control plants, therefore, it appeared that MDS and MNSD ccould be used as available indicators of plant water status. At stem growth stage, there were no significant differences in MDS values between treatments but MXSD and MNSD responded sharply to soil water deficits. Thus, for rapidly growing cotton, the course of MXSD or MNSD with time offered a consistent stress indicator. SDV was also closely related to atmospheric factors, solar radiation (Rs) and vapor pressure deficit (VPD) were found to be the predominant factors affecting MDS, followed by the relative humidity (RH), while air temperature (Ta) and wind velocity had the least effect. A good linear relationship was founded (r2 = 0.921) between MDS and environmental variables (Rs, VPD, RH, and θv), which can be used to establish a reference value for detecting plant water stress based on the MDS patterns.

  1. Increased water deficit decreases Douglas fir growth throughout western US forests

    Science.gov (United States)

    Restaino, Christina M; Peterson, David L.; Littell, Jeremy

    2016-01-01

    Changes in tree growth rates can affect tree mortality and forest feedbacks to the global carbon cycle. As air temperature increases, evaporative demand also increases, increasing effective drought in forest ecosystems. Using a spatially comprehensive network of Douglas-fir (Pseudotsuga menziesii) chronologies from 122 locations that experience distinctly different climate in the western United States, we show that increased temperature decreases growth via vapor pressure deficit (VPD) across all latitudes. Under an ensemble of global circulation models, we project an increase in both the mean VPD associated with the lowest growth extremes and the probability of exceeding these VPD values. As temperature continues to increase in future decades, we can expect deficit-related stress to increase and consequently Douglas-fir growth to decrease throughout its US range.

  2. Increased water deficit decreases Douglas fir growth throughout western US forests.

    Science.gov (United States)

    Restaino, Christina M; Peterson, David L; Littell, Jeremy

    2016-08-23

    Changes in tree growth rates can affect tree mortality and forest feedbacks to the global carbon cycle. As air temperature increases, evaporative demand also increases, increasing effective drought in forest ecosystems. Using a spatially comprehensive network of Douglas fir (Pseudotsuga menziesii) chronologies from 122 locations that represent distinct climate environments in the western United States, we show that increased temperature decreases growth via vapor pressure deficit (VPD) across all latitudes. Using an ensemble of global circulation models, we project an increase in both the mean VPD associated with the lowest growth extremes and the probability of exceeding these VPD values. As temperature continues to increase in future decades, we can expect deficit-related stress to increase and consequently Douglas fir growth to decrease throughout its US range.

  3. Global monthly water stress: II. Water demand and severity of water

    NARCIS (Netherlands)

    Wada, Y.; Beek, L.P.H. van; Viviroli, D.; Dürr, H.H.; Weingartner, R.; Bierkens, M.F.P.

    2011-01-01

    This paper assesses global water stress at a finer temporal scale compared to conventional assessments. To calculate time series of global water stress at a monthly time scale, global water availability, as obtained from simulations of monthly river discharge from the companion paper, is confronted

  4. Global monthly water stress: II. Water demand and severity of water

    NARCIS (Netherlands)

    Wada, Y.; Beek, L.P.H. van; Viviroli, D.; Dürr, H.H.; Weingartner, R.; Bierkens, M.F.P.

    2011-01-01

    This paper assesses global water stress at a finer temporal scale compared to conventional assessments. To calculate time series of global water stress at a monthly time scale, global water availability, as obtained from simulations of monthly river discharge from the companion paper, is confronted

  5. Control of expansive growth in water deficit: from phenotyping to field simulations

    OpenAIRE

    Parent, Boris; Cabrera Bosquet, Llorenç; Cané, Maria Angela; Chaumont, François; Alvarez Prado, Santiago; Caldeira, Cecilio Frois; Lacube, Sébastien; Fleury, Delphine; Welcker, Claude; Tuberosa, Roberto; Tardieu, Francois

    2015-01-01

    Maintenance of expansive growth under water deficit has been selected as a key target trait of DROPS because of its early response in drying conditions, its large genetic variability, its partially common control with reproductive growth and its consequences on light interception and transpiration. Development of methods to measure shoot growth in Phenotyping platforms (PhenoArch and Phenodyn, M3P, Montpellier, France; The Plant Accelerator, Adelaide, Australia) allowed identification of a...

  6. Deficit irrigation of a landscape halophyte for reuse of saline waste water in a desert city

    Science.gov (United States)

    Glenn, E.P.; Mckeon, C.; Gerhart, V.; Nagler, P.L.; Jordan, F.; Artiola, J.

    2009-01-01

    Saline waste waters from industrial and water treatment processes are an under-utilized resource in desert urban environments. Management practices to safely use these water sources are still in development. We used a deeprooted native halophyte, Atriplex lentiformis (quailbush), to absorb mildly saline effluent (1800 mg l-1 total dissolved solids, mainly sodium sulfate) from a water treatment plant in the desert community of Twentynine Palms, California. We developed a deficit irrigation strategy to avoid discharging water past the root zone to the aquifer. The plants were irrigated at about one-third the rate of reference evapotranspiration (ETo) calculated from meteorological data over five years and soil moisture levels were monitored to a soil depth of 4.7 m at monthly intervals with a neutron hydroprobe. The deficit irrigation schedule maintained the soil below field capacity throughout the study. Water was presented on a more or less constant schedule, so that the application rates were less than ETo in summer and equal to or slightly greater than ETo in winter, but the plants were able to consume water stored in the profile in winter to support summer ET. Sodium salts gradually increased in the soil profile over the study but sulfate levels remained low, due to formation of gypsum in the calcic soil. The high salt tolerance, deep roots, and drought tolerance of desert halophytes such as A. lentiformis lend these plants to use as deficit-irrigated landscape plants for disposal of effluents in urban setting when protection of the aquifer is important. ?? 2008 Elsevier B.V.

  7. Characterization of the adaptive response of grapevine (cv. Tempranillo) to UV-B radiation under water deficit conditions.

    Science.gov (United States)

    Martínez-Lüscher, J; Morales, F; Delrot, S; Sánchez-Díaz, M; Gomès, E; Aguirreolea, J; Pascual, I

    2015-03-01

    This work aims to characterize the physiological response of grapevine (Vitis vinifera L.) cv. Tempranillo to UV-B radiation under water deficit conditions. Grapevine fruit-bearing cuttings were exposed to three levels of supplemental biologically effective UV-B radiation (0, 5.98 and 9.66kJm(-2)day(-1)) and two water regimes (well watered and water deficit), in a factorial design, from fruit-set to maturity under glasshouse-controlled conditions. UV-B induced a transient decrease in net photosynthesis (Anet), actual and maximum potential efficiency of photosystem II, particularly on well watered plants. Methanol extractable UV-B absorbing compounds (MEUVAC) concentration and superoxide dismutase activity increased with UV-B. Water deficit effected decrease in Anet and stomatal conductance, and did not change non-photochemical quenching and the de-epoxidation state of xanthophylls, dark respiration and photorespiration being alternative ways to dissipate the excess of energy. Little interactive effects between UV-B and drought were detected on photosynthesis performance, where the impact of UV-B was overshadowed by the effects of water deficit. Grape berry ripening was strongly delayed when UV-B and water deficit were applied in combination. In summary, deficit irrigation did not modify the adaptive response of grapevine to UV-B, through the accumulation of MEUVAC. However, combined treatments caused additive effects on berry ripening. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  8. REUSE OF TREATED WASTEWATER IN AGRICULTURE: SOLVING WATER DEFICIT PROBLEMS IN ARID AREAS (REVIEW

    Directory of Open Access Journals (Sweden)

    Faissal AZIZ

    2014-12-01

    Full Text Available In the arid and semiarid areas, the availability and the management of irrigation water have become priorities of great importance. The successive years of drought, induced by climate change and population growth, increasingly reduced the amount of water reserved for agriculture. Consequently, many countries have included wastewater reuse as an important dimension of water resources planning. In the more arid areas wastewater is used in agriculture, releasing high resource of water supplies. In this context, the present work is a review focusing the reuse of treated wastewater in agriculture as an important strategy for solving water deficit problems in arid areas. Much information concerning the wastewater reuse in different regions of the world and in Morocco, the different wastewater treatment technologies existing in Morocco were discussed. The review focused also the fertilizing potential of wastewater in agriculture, the role of nutrients and their concentrations in wastewater and their advantages effects on plant growth and yield.

  9. Satureja bachtiarica ameliorate beta-amyloid induced memory impairment, oxidative stress and cholinergic deficit in animal model of Alzheimer's disease.

    Science.gov (United States)

    Soodi, Maliheh; Saeidnia, Soodabeh; Sharifzadeh, Mohammad; Hajimehdipoor, Homa; Dashti, Abolfazl; Sepand, Mohammad Reza; Moradi, Shahla

    2016-04-01

    Extracellular deposition of Beta-amyloid peptide (Aβ) is the main finding in the pathophysiology of Alzheimer's disease (AD), which damages cholinergic neurons through oxidative stress and reduces the cholinergic neurotransmission. Satureja bachtiarica is a medicinal plant from the Lamiaceae family which was widely used in Iranian traditional medicine. The aim of the present study was to investigate possible protective effects of S. bachtiarica methanolic extract on Aβ induced spatial memory impairment in Morris Water Maze (MWM), oxidative stress and cholinergic neuron degeneration. Pre- aggregated Aβ was injected into the hippocampus of each rat bilaterally (10 μg/rat) and MWM task was performed 14 days later to evaluate learning and memory function. Methanolic extract of S.bachtiarica (10, 50 and 100 mg/Kg) was injected intraperitoneally for 19 consecutive days, after Aβ injection. After the probe test the brain tissue were collected and lipid peroxidation, Acetylcholinesterase (AChE) activity and Cholin Acetyl Transferees (ChAT) immunorectivity were measured in the hippocampus. Intrahipocampal injection of Aβ impaired learning and memory in MWM in training days and probe trail. Methanolic extract of S. bachtiarica (50 and 100 mg/Kg) could attenuate Aβ-induced memory deficit. ChAT immunostaining revealed that cholinergic neurons were loss in Aβ- injected group and S. bachtiarica (100 mg/Kg) could ameliorate Aβ- induced ChAT reduction in the hippocampus. Also S. bachtiarica could ameliorate Aβ-induced lipid peroxidation and AChE activity increase in the hippocampus. In conclusion our study represent that S.bachtiarica methanolic extract can improve Aβ-induced memory impairment and cholinergic loss then we recommended this extract as a candidate for further investigation in treatment of AD.

  10. CHANGES IN LEVELS OF ACTIVITY OF SERINE PROTEASES ACCOMPANY THE EXPOSURE OF COMMON BEAN (PHASEOLUS VULGARIS L. TO WATER DEFICIT

    Directory of Open Access Journals (Sweden)

    M. Budič

    2008-09-01

    Full Text Available A wide variety of proteolytic enzymes exist in plants. On their levels depends protein turnover, a fundamental component in plant development and adaptation to environmental conditions. Cysteine proteases have frequently been reported to be influenced by drought, but only a few serine proteases (SP, among them the trypsin-like enzyme and two aminopeptidases from bean leaves (Bartels and Sunkar, 2005; Hieng et al., 2004. Our starting point was to identify proteolytic activities assigned to SPs that change with drought and then to characterize the corresponding proteases. A quantitative, analytical one-step method was used to separate endopeptidases and aminopeptidases active against a range of substrates in leaf extracts of plants grown in the field (FC. The influence of drought was determined for those of these activities which were confirmed as SPs, based on their inhibition by specific inhibitors. Under water deficit in plants grown under controlled conditions (CC their levels changed in different ways. The levels of SP activities in FC plants, observed during a period of relative drought, were similar to those measured in mildly stressed CC plants. The partial characterisations of some of these SPs will be presented. Our results point to a number of roles for different SPs in the plant response to water stress, which could range from enhanced protein turnover to limited proteolysis at specific sites.

  11. Exposure of two Eutrema salsugineum (Thellungiella salsuginea) accessions to water deficits reveals different coping strategies in response to drought.

    Science.gov (United States)

    MacLeod, Mitchell J R; Dedrick, Jeff; Ashton, Claire; Sung, Wilson W L; Champigny, Marc J; Weretilnyk, Elizabeth A

    2015-11-01

    Eutrema salsugineum is an extremophile related to Arabidopsis. Accessions from Yukon, Canada and Shandong, China, were evaluated for their tolerance to water deficits. Plants were exposed to two periods of water deficit separated by an interval of re-watering and recovery. All plants took the same time to wilt during the first drought exposure but Yukon plants took 1 day longer than Shandong plants following the second drought treatment. Following re-watering and turgor recovery, solute potentials of Shandong leaves returned to predrought values while those of Yukon leaves were lower than predrought levels consistent with having undergone osmotic adjustment. Polar metabolites profiled in re-watered plants showed that different metabolites are accumulated by Yukon and Shandong plants recovering from a water deficit with glucose more abundant in Yukon and fructose in Shandong leaves. The drought-responsive expression of dehydrin genes RAB18, ERD1, RD29A and RD22 showed greater changes in transcript abundance in Yukon relative to Shandong leaves during both water deficits and recovery with the greatest difference in expression appearing during the second drought. We propose that the initial exposure of Yukon plants to drought renders them more resilient to water loss during a subsequent water deficit leading to delayed wilting. Yukon plants also established a high leaf water content and increased specific leaf area during the second deficit. Shandong plants undergoing the same treatment regime do not show the same beneficial drought tolerance responses and likely use drought avoidance to cope with water deficits.

  12. Effects of Water Deficit and Chitosan Spraying on Osmotic Adjustment and Soluble Protein of Cultivars Castor Bean (Ricinus communis L.

    Directory of Open Access Journals (Sweden)

    Karimi Sara

    2012-08-01

    Full Text Available The present study was aimed investigating the effect of water deficit and chitosan spraying on osmotic adjustment and soluble protein of cultivars castor bean under field condition. experiment was carried out as a split factorial based on randomized complete block design with three replications. The results showed that water deficit caused increase a significant (P<0.05 in the concentration of sugars and proline content in the leaves of castor bean. The most amount of total soluble sugars obtain of Levels (D2: Water deficit in beginning of flowering stage, D3: Water deficit in beginning of seedling stage, 0.042% and minimum amount related to treatment control (D1: complete Irrigation , 0.014% and maximum proline content related to (D3: water deficit in beginning seedling stage and minimum proline content related to (D1: complete Irrigation. Also water Deficit caused decrease a significant (P<0.05 in Protein content. The mean comparison shows that maximum amount Protein related to (D1: complete Irrigation, 26.79% and the minimum amount Protein obtain from (D2: Water deficit in beginning of Flowering stage, 21.04%. also a had cultivars between different a significant (P<0.01 of total soluble sugars. Chitosan spraying no had a significant in osmotic Adjustment and soluble protein. The accumulation of the osmolytes can help the castor bean plant to maintain the cell turgor and the structural integrity of membranes. castor bean herb is drought tolerant, the experimental our, cultivars between no had a significant different of proline and protein content. But, cultivars between had a significant different of total soluble sugars, the result show that cultivar Ahvaz local the most amount of total soluble sugars. therefore suggested that Ahvaz Local cultivar in water deficit condition rate of other cultivar toleranter, we can be with attention Damghan Climate condition, there Cultivate Ahvaz local cultivar.

  13. THE REFERENCE EVAPOTRANSPIRATION AND THE CLIMATIC WATER DEFICIT IN THE WESTERN PLAIN OF ROMANIA, NORTH OF THE MUREŞ RIVER

    OpenAIRE

    2013-01-01

    The Reference Evapotranspiration and the Climatic Water Deficit in the Western Plain of Romania, North of the Mureş River. In the present paper, reference evapotranspiration (ET0) was calculated by the method proposed by C.W. Thornthwaite. The climatic water deficit, as the difference between atmospheric precipitation and ET0, has also been calculated and analyzed. In this respect, monthly and annual air temperature and precipitation data from 10 weather stations were used. The analysis perio...

  14. Multispectral airborne imagery in the field reveals genetic determinisms of morphological and transpiration traits of an apple tree hybrid population in response to water deficit.

    Science.gov (United States)

    Virlet, Nicolas; Costes, Evelyne; Martinez, Sébastien; Kelner, Jean-Jacques; Regnard, Jean-Luc

    2015-09-01

    Genetic studies of response to water deficit in adult trees are limited by low throughput of the usual phenotyping methods in the field. Here, we aimed at overcoming this bottleneck, applying a new methodology using airborne multispectral imagery and in planta measurements to compare a high number of individuals.An apple tree population, grafted on the same rootstock, was submitted to contrasting summer water regimes over two years. Aerial images acquired in visible, near- and thermal-infrared at three dates each year allowed calculation of vegetation and water stress indices. Tree vigour and fruit production were also assessed. Linear mixed models were built accounting for date and year effects on several variables and including the differential response of genotypes between control and drought conditions.Broad-sense heritability of most variables was high and 18 quantitative trait loci (QTLs) independent of the dates were detected on nine linkage groups of the consensus apple genetic map. For vegetation and stress indices, QTLs were related to the means, the intra-crown heterogeneity, and differences induced by water regimes. Most QTLs explained 15-20% of variance.Airborne multispectral imaging proved relevant to acquire simultaneous information on a whole tree population and to decipher genetic determinisms involved in response to water deficit.

  15. Effects of arbuscular mycorrhizae on tomato yield, nutrient uptake, water relations, and soil carbon dynamics under deficit irrigation in field conditions.

    Science.gov (United States)

    Bowles, Timothy M; Barrios-Masias, Felipe H; Carlisle, Eli A; Cavagnaro, Timothy R; Jackson, Louise E

    2016-10-01

    Plant strategies to cope with future droughts may be enhanced by associations between roots and soil microorganisms, including arbuscular mycorrhizal (AM) fungi. But how AM fungi affect crop growth and yield, together with plant physiology and soil carbon (C) dynamics, under water stress in actual field conditions is not well understood. The well-characterized mycorrhizal tomato (Solanum lycopersicum L.) genotype 76R (referred to as MYC+) and the mutant nonmycorrhizal tomato genotype rmc were grown in an organic farm with a deficit irrigation regime and control regime that replaced evapotranspiration. AM increased marketable tomato yields by ~25% in both irrigation regimes but did not affect shoot biomass. In both irrigation regimes, MYC+ plants had higher plant nitrogen (N) and phosphorus (P) concentrations (e.g. 5 and 24% higher N and P concentrations in leaves at fruit set, respectively), 8% higher stomatal conductance (gs), 7% higher photosynthetic rates (Pn), and greater fruit set. Stem water potential and leaf relative water content were similar in both genotypes within each irrigation regime. Three-fold higher rates of root sap exudation in detopped MYC+ plants suggest greater capacity for water uptake through osmotic driven flow, especially in the deficit irrigation regime in which root sap exudation in rmc was nearly absent. Soil with MYC+ plants also had slightly higher soil extractable organic C and microbial biomass C at anthesis but no changes in soil CO2 emissions, although the latter were 23% lower under deficit irrigation. This study provides novel, field-based evidence for how indigenous AM fungi increase crop yield and crop water use efficiency during a season-long deficit irrigation and thus play an important role in coping with increasingly limited water availability in the future.

  16. Intermittent cold water swim stress increases immobility and interferes with escape performance in rat.

    Science.gov (United States)

    Christianson, John P; Drugan, Robert C

    2005-11-30

    The behavioral consequences of intermittent, 5 s cold-water swims (15 degrees C) or confinement were assessed 24 h after stress in a 5 min forced swim test or an instrumental swim escape test (SET). The SET was conducted with temporal and instrumental parameters similar to the shock-motivated shuttle escape test. The tests detected significantly increased immobility in the forced swim test and increased latency to escape in the SET. These results extend previous findings with intermittent swim stress and provide evidence that intermittent swim stress produces behavioral deficits similar to other stress models. This new model may be a useful tool for exploring the physiological mechanisms underlying the stress response.

  17. Evidence for water deficit-induced mass increases of raffinose family oligosaccharides (RFOs in the leaves of three Craterostigma resurrection plant species

    Directory of Open Access Journals (Sweden)

    Aurelie eEgert

    2015-07-01

    Full Text Available The leaves of the resurrection plant Craterostigma plantagineum accumulate sucrose during dehydration, via a conversion from the unusual C8 ketose-sugar 2-octulose. However, raffinose family oligosaccharides (RFOs have been shown to be major photosynthetic products in this plant. The tetrasaccharide stachyose is the major phloem mobile carbohydrate and is used as a carbon store in roots. It has been suggested that this carbon store is remobilized during rehydration, presumably for cellular repair processes. We examined the effects of water deficit on the leaf water-soluble carbohydrate profiles of three Craterostigma species. Apart from the classical 2-octulose to sucrose interconversion, there was a strong water deficit-associated mass increase of RFOs up to the pentasaccharide verbascose. However, the activities of three dedicated RFO biosynthetic enzymes (raffinose, stachyose and verbascose synthase could not be correlated with RFO accumulation, suggesting that biosynthetic enzymes activities measured in the early stages of water-deficit was sufficient to synthesize enough Gol and lead to RFO accumulation in the leaves. Our findings are suggestive of RFOs providing additional carbohydrate-based stress protection to the leaves of these plants during the desiccated state.

  18. Evidence for water deficit-induced mass increases of raffinose family oligosaccharides (RFOs) in the leaves of three Craterostigma resurrection plant species.

    Science.gov (United States)

    Egert, Aurélie; Eicher, Barbara; Keller, Felix; Peters, Shaun

    2015-01-01

    The leaves of the resurrection plant Craterostigma plantagineum accumulate sucrose during dehydration, via a conversion from the unusual C8 ketose-sugar 2-octulose. However, raffinose family oligosaccharides (RFOs) have been shown to be major photosynthetic products in this plant. The tetrasaccharide stachyose is the major phloem-mobile carbohydrate and is used as a carbon store in roots. It has been suggested that this carbon store is remobilized during rehydration, presumably for cellular repair processes. We examined the effects of water deficit on the leaf water-soluble carbohydrate profiles of three Craterostigma species. Apart from the classical 2-octulose-to-sucrose interconversion, there was a strong water deficit-associated mass increase of RFOs up to the pentasaccharide verbascose. However, the activities of three dedicated RFO biosynthetic enzymes (raffinose, stachyose, and verbascose synthase) was not correlated with RFO accumulation, suggesting that biosynthetic enzyme activities measured in the early stages of water-deficit were sufficient to synthesize enough galactinol and lead to RFO accumulation in the leaves. Our findings are suggestive of RFOs providing additional carbohydrate-based stress protection to the leaves of these plants during the desiccated state.

  19. Water deficit induces chlorophyll degradation via the 'PAO/phyllobilin' pathway in leaves of homoio- (Craterostigma pumilum) and poikilochlorophyllous (Xerophyta viscosa) resurrection plants.

    Science.gov (United States)

    Christ, Bastien; Egert, Aurélie; Süssenbacher, Iris; Kräutler, Bernhard; Bartels, Dorothea; Peters, Shaun; Hörtensteiner, Stefan

    2014-11-01

    Angiosperm resurrection plants exhibit poikilo- or homoiochlorophylly as a response to water deficit. Both strategies are generally considered as effective mechanisms to reduce oxidative stress associated with photosynthetic activity under water deficiency. The mechanism of water deficit-induced chlorophyll (Chl) degradation in resurrection plants is unknown but has previously been suggested to occur as a result of non-enzymatic photooxidation. We investigated Chl degradation during dehydration in both poikilochlorophyllous (Xerophyta viscosa) and homoiochlorophyllous (Craterostigma pumilum) species. We demonstrate an increase in the abundance of PHEOPHORBIDE a OXYGENASE (PAO), a key enzyme of Chl breakdown, together with an accumulation of phyllobilins, that is, products of PAO-dependent Chl breakdown, in both species. Phyllobilins and PAO levels diminished again in leaves from rehydrated plants. We conclude that water deficit-induced poikilochlorophylly occurs via the well-characterized PAO/phyllobilin pathway of Chl breakdown and that this mechanism also appears conserved in a resurrection species displaying homoiochlorophylly. The roles of the PAO/phyllobilin pathway during different plant developmental processes that involve Chl breakdown, such as leaf senescence and desiccation, fruit ripening and seed maturation, are discussed. © 2014 John Wiley & Sons Ltd.

  20. The Effect of Water Stress on the Gas Exchange Parameters, Productivity and Seed Health of Buckwheat (Fagopyrum esculentum Moench

    Directory of Open Access Journals (Sweden)

    Agnieszka Pszczółkowska

    2012-12-01

    Full Text Available The present pot experiment studied the effect of different soil moisture contents (60 - 70% CWC (capillary water capacity - control; 30 - 35% CWC - water stress on buckwheat productivity, the gas exchange parameters and health of buckwheat nuts. It was found that water deficit affected adversely certain biometric features investigated (plant height, number of nuts per cluster and caused a decrease in seed weight per plant. It was also shown that water stress reduced the values of the investigated gas exchange parameters (photosynthesis rate, transpiration rate, intercellular-space CO2 concentration, and stomatal conductance relative to the control treatment. Different soil moisture contents did not have a clear effect on fungal colonization of seeds. The multiplex PCR assays did not enable the detection of the genes responsible for mycotoxin synthesis. Under water deficit conditions, an increase was found in the content of albumin and globulin fractions as well as of glutelin fractions.

  1. Enhanced Accumulation of BiP in Transgenic Plants Confers Tolerance to Water Stress1

    Science.gov (United States)

    Alvim, Fátima C.; Carolino, Sônia M.B.; Cascardo, Júlio C.M.; Nunes, Cristiano C.; Martinez, Carlos A.; Otoni, Wagner C.; Fontes, Elizabeth P.B.

    2001-01-01

    The binding protein (BiP) is an important component of endoplasmic reticulum stress response of cells. Despite extensive studies in cultured cells, a protective function of BiP against stress has not yet been demonstrated in whole multicellular organisms. Here, we have obtained transgenic tobacco (Nicotiana tabacum L. cv Havana) plants constitutively expressing elevated levels of BiP or its antisense cDNA to analyze the protective role of this endoplasmic reticulum lumenal stress protein at the whole plant level. Elevated levels of BiP in transgenic sense lines conferred tolerance to the glycosylation inhibitor tunicamycin during germination and tolerance to water deficit during plant growth. Under progressive drought, the leaf BiP levels correlated with the maintenance of the shoot turgidity and water content. The protective effect of BiP overexpression against water stress was disrupted by expression of an antisense BiP cDNA construct. Although overexpression of BiP prevented cellular dehydration, the stomatal conductance and transpiration rate in droughted sense leaves were higher than in control and antisense leaves. The rate of photosynthesis under water deficit might have caused a degree of greater osmotic adjustment in sense leaves because it remained unaffected during water deprivation, which was in marked contrast with the severe drought-induced decrease in the CO2 assimilation in control and antisense leaves. In antisense plants, the water stress stimulation of the antioxidative defenses was higher than in control plants, whereas in droughted sense leaves an induction of superoxide dismutase activity was not observed. These results suggest that overexpression of BiP in plants may prevent endogenous oxidative stress. PMID:11457955

  2. Effect of free and symbiotic nitrogen fixing bacterial co-inoculation on seed and seedling of soybean seeds produced under deficit water condition

    Directory of Open Access Journals (Sweden)

    Hamed Hadi

    2016-04-01

    Full Text Available Effect of free and symbiotic nitrogen fixing bacteria on seed and seedling produced seeds under deficit irrigation was conducted in laboratory and field experiments in 2006. In laboratory of karaj’s Seed and Plant Research and Certificate Institute an experiment was conducted based on factorial in form of completely randomized design with four replications and in field’s of Islamic Azad University, Varamin Branch were split factorial in form of randomized completely block design with three replications. Treatments included water stress [Irrigation after 50 (Normal irrigation, 100 (Middle stress, 150 (Severe stress mm evaporation from pan class A], Cultivar [Manokin & Williams and SRF×T3 Line] and inoculation [Inoculation with Bradyrhizobium japonicum, Bradyrhizobium japonicum co-inoculated with Azotobacter chroococcum, No seed inoculation]. Results showed that drought stress decreased the uniformity and germination speed and seedling emergence. Bacteria increased leaf dry weight, stem dry weight, leaf area and seedling vigor index but had no effect on emergence. In irrigation levels inoculated treatments had higher seedling length, leaf, stem, seedling dry weight and seedling vigor. Severs stress seeds inoculated with Bradyrhizobium japonicum had higher root dry weight than control. Therefore in seeds which were produced under deficit irrigation conditions, bacteria increased seedlings vigor.

  3. Learning deficits and suppression of the cell proliferation in the hippocampal dentate gyrus of offspring are attenuated by maternal chewing during prenatal stress.

    Science.gov (United States)

    Onishi, Mika; Iinuma, Mitsuo; Tamura, Yasuo; Kubo, Kin-Ya

    2014-02-07

    Prenatal stress in dams induces learning deficits and suppresses neurogenesis in the hippocampal dentate gyrus (DG) of offspring via increasing corticosterone levels in the dam. Chewing under stressful conditions prevents stress-induced behavioral impairments and morphologic changes. Here, we examined whether chewing during prenatal stress prevents the stress-induced learning deficits and the suppression of cell proliferation in the hippocampal DG in adult offspring. Pregnant mice were exposed to restraint stress beginning on day 12 of pregnancy and continuing until delivery. Half of the dams were given a wooden stick to chew on during restraint. The pups were raised to adulthood, and learning ability and cell proliferation in the hippocampal DG were assessed. In dams, chewing during prenatal stress attenuated the stress-induced increase in plasma corticosterone levels. In the adult offspring, prenatal stress impaired learning and decreased cell proliferation in the DG, whereas maternal chewing during prenatal stress significantly attenuated the prenatal stress-induced learning deficits and decreased cell proliferation in the DG in their offspring. These findings suggest that maternal chewing during prenatal stress is an effective stress-coping method for the dam to prevent learning deficits and suppression of cell proliferation in offspring.

  4. Resveratrol exerts anti-inflammatory and neuroprotective effects to prevent memory deficits in rats exposed to chronic unpredictable mild stress.

    Science.gov (United States)

    Yazir, Yusufhan; Utkan, Tijen; Gacar, Nejat; Aricioglu, Feyza

    2015-01-01

    A number of studies have recently focused on the neuroprotective and anti-inflammatory effects of resveratrol. In prior studies, we described its beneficial effects on scopolamine-induced learning deficits in rats. The aim of this study was to investigate the effects of resveratrol on emotional and spatial cognitive functions, neurotropic factor expression, and plasma levels of proinflammatory cytokines in rats exposed to chronic unpredictable mild stress (CUMS), which is known to induce cognitive deficits. Resveratrol (5 or 20mg/kg) was administered intraperitoneally for 35 days. Rats in the CUMS group and in the 5mg/kg resveratrol+CUMS group performed poorly in tasks designed to assess emotional and spatial learning and memory. The 20mg/kg resveratrol+CUMS group showed improved performance compared to the CUMS group. In addition, the CUMS procedure induced lower expression of brain-derived neurotrophic factor and c-Fos in hippocampal CA1 and CA3 and in the amygdala of stressed rats. These effects were reversed by chronic administration of resveratrol (20mg/kg). In addition, plasma levels of tumor necrosis factor-alpha and interleukin-1 beta were increased by CUMS, but were restored to normal by resveratrol. These results indicate that resveratrol significantly attenuates the deficits in emotional learning and spatial memory seen in chronically stressed rats. These effects may be related to resveratrol-mediated changes in neurotrophin factor expression in hippocampus and in levels of proinflammatory cytokines in circulation.

  5. Symbiosis with AMF and leaf Pi supply increases water deficit tolerance of woody species from seasonal dry tropical forest.

    Science.gov (United States)

    Frosi, Gabriella; Barros, Vanessa A; Oliveira, Marciel T; Santos, Mariana; Ramos, Diego G; Maia, Leonor C; Santos, Mauro G

    2016-12-01

    In seasonal dry tropical forests, plants are subjected to severe water deficit, and the arbuscular mycorrhizal fungi (AMF) or inorganic phosphorus supply (Pi) can mitigate the effects of water deficit. This study aimed to assess the physiological performance of Poincianella pyramidalis subjected to water deficit in combination with arbuscular mycorrhizal fungi (AMF) and leaf inorganic phosphorus (Pi) supply. The experiment was conducted in a factorial arrangement of 2 water levels (+H2O and -H2O), 2 AMF levels (+AMF and -AMF) and 2Pi levels (+Pi and -Pi). Leaf primary metabolism, dry shoot biomass and leaf mineral nutrients were evaluated. Inoculated AMF plants under well-watered and drought conditions had higher photosynthesis and higher shoot biomass. Under drought, AMF, Pi or AMF+Pi plants showed metabolic improvements in photosynthesis, leaf biochemistry and higher biomass compared to the plants under water deficit without AMF or Pi. After rehydration, those plants submitted to drought with AMF, Pi or AMF+Pi showed a faster recovery of photosynthesis compared to treatment under water deficit without AMF or Pi. However, plants under the drought condition with AMF showed a higher net photosynthesis rate. These findings suggest that AMF, Pi or AMF+Pi increase the drought tolerance in P. pyramidalis, and AMF associations under well-watered conditions increase shoot biomass and, under drought, promoted faster recovery of photosynthesis. Copyright © 2016 Elsevier GmbH. All rights reserved.

  6. Basolateral amygdala bidirectionally modulates stress-induced hippocampal learning and memory deficits through a p25/Cdk5-dependent pathway

    Science.gov (United States)

    Rei, Damien; Mason, Xenos; Seo, Jinsoo; Gräff, Johannes; Rudenko, Andrii; Wang, Jun; Rueda, Richard; Siegert, Sandra; Cho, Sukhee; Canter, Rebecca G.; Mungenast, Alison E.; Deisseroth, Karl; Tsai, Li-Huei

    2015-01-01

    Repeated stress has been suggested to underlie learning and memory deficits via the basolateral amygdala (BLA) and the hippocampus; however, the functional contribution of BLA inputs to the hippocampus and their molecular repercussions are not well understood. Here we show that repeated stress is accompanied by generation of the Cdk5 (cyclin-dependent kinase 5)-activator p25, up-regulation and phosphorylation of glucocorticoid receptors, increased HDAC2 expression, and reduced expression of memory-related genes in the hippocampus. A combination of optogenetic and pharmacosynthetic approaches shows that BLA activation is both necessary and sufficient for stress-associated molecular changes and memory impairments. Furthermore, we show that this effect relies on direct glutamatergic projections from the BLA to the dorsal hippocampus. Finally, we show that p25 generation is necessary for the stress-induced memory dysfunction. Taken together, our data provide a neural circuit model for stress-induced hippocampal memory deficits through BLA activity-dependent p25 generation. PMID:25995364

  7. Executive Dysfunctions: The role in Attention Deficit Hyperactivity and Post-traumatic Stress neuropsychiatric disorders

    Directory of Open Access Journals (Sweden)

    Lía Martínez

    2016-08-01

    Full Text Available Executive functions (EFs is an umbrella term for various cognitive processes controlled by a complex neural activity, which allow the production of different types of behaviors seeking to achieve specific objectives, one of them being inhibitory control. There is a wide consensus that clinical and behavioral alterations associated with EF, such as inhibitory control, are present in various neuropsychiatric disorders. This paper reviews the research literature on the relationship between executive dysfunction, frontal-subcortical neural circuit changes, and the psychopathological processes associated with Attention Deficit Hyperactivity Disorder (ADHD and Post-traumatic Stress Disorder (PTSD. A revision on the role of frontal-subcortical neural circuits and their presumable abnormal functioning and the high frequency of neuropsychiatric symptoms could explain the difficulties with putting effector mechanisms into action, giving individuals the necessary tools to act efficiently in their environment. Although neuronal substrate data about ADHD and PTSD has been reported in the literature, it is isolated. Therefore, this review highlights the overlapping of neural substrates in the symptomatology of ADHD and PTSD disorders concerning EFs, especially in the inhibitory component. Thus, the changes related to impaired EF that accompany disorders like ADHD and PTSD could be explained by disturbances that have a direct or indirect impact on the functioning of these loops. Initially, the theoretical model of EF according to current neuropsychology will be presented, focusing on the inhibitory component. In a second stage, this component will be analyzed for each of the disorders of interest, considering the clinical aspects, the etiology and the neurobiological basis. Additionally, commonalities between the two neuropsychiatric conditions will be taken into consideration from the perspectives of cognitive and emotional inhibition. Finally, the

  8. Executive Dysfunctions: The Role in Attention Deficit Hyperactivity and Post-traumatic Stress Neuropsychiatric Disorders

    Science.gov (United States)

    Martínez, Lía; Prada, Edward; Satler, Corina; Tavares, Maria C. H.; Tomaz, Carlos

    2016-01-01

    Executive functions (EFs) is an umbrella term for various cognitive processes controlled by a complex neural activity, which allow the production of different types of behaviors seeking to achieve specific objectives, one of them being inhibitory control. There is a wide consensus that clinical and behavioral alterations associated with EF, such as inhibitory control, are present in various neuropsychiatric disorders. This paper reviews the research literature on the relationship between executive dysfunction, frontal-subcortical neural circuit changes, and the psychopathological processes associated with attention deficit hyperactivity disorder (ADHD) and post-traumatic stress disorder (PTSD). A revision on the role of frontal-subcortical neural circuits and their presumable abnormal functioning and the high frequency of neuropsychiatric symptoms could explain the difficulties with putting effector mechanisms into action, giving individuals the necessary tools to act efficiently in their environment. Although, neuronal substrate data about ADHD and PTSD has been reported in the literature, it is isolated. Therefore, this review highlights the overlapping of neural substrates in the symptomatology of ADHD and PTSD disorders concerning EFs, especially in the inhibitory component. Thus, the changes related to impaired EF that accompany disorders like ADHD and PTSD could be explained by disturbances that have a direct or indirect impact on the functioning of these loops. Initially, the theoretical model of EF according to current neuropsychology will be presented, focusing on the inhibitory component. In a second stage, this component will be analyzed for each of the disorders of interest, considering the clinical aspects, the etiology and the neurobiological basis. Additionally, commonalities between the two neuropsychiatric conditions will be taken into consideration from the perspectives of cognitive and emotional inhibition. Finally, the implications and future

  9. Executive Dysfunctions: The Role in Attention Deficit Hyperactivity and Post-traumatic Stress Neuropsychiatric Disorders.

    Science.gov (United States)

    Martínez, Lía; Prada, Edward; Satler, Corina; Tavares, Maria C H; Tomaz, Carlos

    2016-01-01

    Executive functions (EFs) is an umbrella term for various cognitive processes controlled by a complex neural activity, which allow the production of different types of behaviors seeking to achieve specific objectives, one of them being inhibitory control. There is a wide consensus that clinical and behavioral alterations associated with EF, such as inhibitory control, are present in various neuropsychiatric disorders. This paper reviews the research literature on the relationship between executive dysfunction, frontal-subcortical neural circuit changes, and the psychopathological processes associated with attention deficit hyperactivity disorder (ADHD) and post-traumatic stress disorder (PTSD). A revision on the role of frontal-subcortical neural circuits and their presumable abnormal functioning and the high frequency of neuropsychiatric symptoms could explain the difficulties with putting effector mechanisms into action, giving individuals the necessary tools to act efficiently in their environment. Although, neuronal substrate data about ADHD and PTSD has been reported in the literature, it is isolated. Therefore, this review highlights the overlapping of neural substrates in the symptomatology of ADHD and PTSD disorders concerning EFs, especially in the inhibitory component. Thus, the changes related to impaired EF that accompany disorders like ADHD and PTSD could be explained by disturbances that have a direct or indirect impact on the functioning of these loops. Initially, the theoretical model of EF according to current neuropsychology will be presented, focusing on the inhibitory component. In a second stage, this component will be analyzed for each of the disorders of interest, considering the clinical aspects, the etiology and the neurobiological basis. Additionally, commonalities between the two neuropsychiatric conditions will be taken into consideration from the perspectives of cognitive and emotional inhibition. Finally, the implications and future

  10. Effects of Application of Nitrogen, Potassium and Glycinebetaine on Alleviation of Water Stress to Summer Maize

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    A pot experiment was conducted under water deficit and adequate water-supplied conditions with two maize genetypic varieties (Shaandan 9 and Shaandan 911) to study the effects of nitrogen, potassium and glycinebetaine (GlyBet) on the dry matter and grain yields as well as water use efficiency (WUE). Determinations were made at different stages of the two varieties for revealing the function of these factors in increasing plant resistance to drought. Results showed that under a water-stressed condition, dry matter and grain yield were significantly reduced. However, the response of the two varieties to water stress was different: Shaandan 9 was significantly higher in dry matter and grain yields, and therefore could be regarded as a drought-resistant variety compared to Shaandan 911.Application of nitrogen, potassium and glycinebetaine raised dry matter and grain yield to different levels, and thereby alleviated the water stress and increased water use efficiency. These effects were higher for Shaandan 911 than for Shaandan 9. Under water-stressed conditions, application of N fertilizer, either at low rate or at high rate, significantly increased dry matter, grain yield and water use efficiency.A significant different effect was found for Shaandan 911 between N rates, but not so for Shaandan9. However,with supplemental water supply, effects of N fertilization were obviously decreased, showing that in addition to supplying nutrient, N fertilizer has a function in increasing drought-resistance of the crop. Potassium and glycinebetaine exhibited a remarkable function in increasing dry matter and grain yields as well as water use efficiency under water stress while such effects were obviously declined, even vanished, with supplemental water supply, indicating the important contribution of these factors in rise of drought-resistance ability of a crop.

  11. Water stress, CO2 and photoperiod influence hormone levels in wheat

    Science.gov (United States)

    Nan, Rubin; Carman, John G.; Salisbury, Frank B.; Campbell, W. F. (Principal Investigator)

    2002-01-01

    'Super Dwarf' wheat (Triticum aestivum L.) plants have been grown from seed to maturity in the Mir space station where they were periodically exposed, because of microgravity and other constraints, to water deficit, waterlogging, high CO2 levels, and low light intensities. The plants produced many tillers, but none of them produced viable seed. Studies have been initiated to determine why the plants responded in these ways. In the present study, effects of the listed stresses on abscisic acid (ABA), indole-3-acetic acid (IAA) and isopentenyl adenosine ([9R]iP) levels in roots and leaves of plants grown under otherwise near optimal conditions on earth were measured. Hormones were extracted, purified by HPLC, and quantified by noncompetitive indirect ELISA. In response to water deficit, ABA levels increased in roots and leaves, IAA levels decreased in roots and leaves, and [9R]iP levels increased in leaves but decreased in roots. In response to waterlogging, ABA, IAA and [9R]iP levels briefly increased in roots and leaves and then decreased. When portions of the root system were exposed to waterlogging and/or water deficit, ABA levels in leaves increased while [9R]iP and IAA levels decreased. These responses were correlated with the percentage of the root system stressed. At a low photosynthetic photon flux (100 micromoles m-2 s-1), plants grown in continuous light had higher leaf ABA levels than plants grown using an 18 or 21 h photoperiod.

  12. Water stress, CO2 and photoperiod influence hormone levels in wheat

    Science.gov (United States)

    Nan, Rubin; Carman, John G.; Salisbury, Frank B.; Campbell, W. F. (Principal Investigator)

    2002-01-01

    'Super Dwarf' wheat (Triticum aestivum L.) plants have been grown from seed to maturity in the Mir space station where they were periodically exposed, because of microgravity and other constraints, to water deficit, waterlogging, high CO2 levels, and low light intensities. The plants produced many tillers, but none of them produced viable seed. Studies have been initiated to determine why the plants responded in these ways. In the present study, effects of the listed stresses on abscisic acid (ABA), indole-3-acetic acid (IAA) and isopentenyl adenosine ([9R]iP) levels in roots and leaves of plants grown under otherwise near optimal conditions on earth were measured. Hormones were extracted, purified by HPLC, and quantified by noncompetitive indirect ELISA. In response to water deficit, ABA levels increased in roots and leaves, IAA levels decreased in roots and leaves, and [9R]iP levels increased in leaves but decreased in roots. In response to waterlogging, ABA, IAA and [9R]iP levels briefly increased in roots and leaves and then decreased. When portions of the root system were exposed to waterlogging and/or water deficit, ABA levels in leaves increased while [9R]iP and IAA levels decreased. These responses were correlated with the percentage of the root system stressed. At a low photosynthetic photon flux (100 micromoles m-2 s-1), plants grown in continuous light had higher leaf ABA levels than plants grown using an 18 or 21 h photoperiod.

  13. THE EXPRESSION PROFILES OF SELECTED GENES IN DIFFERENT BEAN SPECIES (PHASEOLUS SPP. AS RESPONSE TO WATER DEFICIT

    Directory of Open Access Journals (Sweden)

    Tatjana KAVAR

    2012-01-01

    Full Text Available The aim of this study was to compare expression profiles of a number of transcripts from leaves of different Phaseolus species under drought stress, in order to ascertain whether changes in their expression in Phaseolus spp. are part of a general or a species specific response to drought. Relative gene expression analysis using quantitative PCR were carried out in P. coccineus, P. lunatus and P. acutifolius for 13 transcripts previously identified as up- or down-regulated in leaves of P. vulgaris. The mode of expression was found consistent within Phaseolus spp., despite the fact that the four species differ in their responses to drought at the physiological and morphological levels. The present results suggest that this is a common feature of the response of Phaseolus spp. The majority of the genes shown here to be influenced by water deficit in beans have been reported in other plant species under similar conditions, suggesting that they play a role in the general response to drought stress.

  14. Acclimation of biochemical and diffusive components of photosynthesis in rice, wheat and maize to heat and water deficit: implications for modeling photosynthesis

    Directory of Open Access Journals (Sweden)

    Juan Alejandro Perdomo

    2016-11-01

    Full Text Available The impact of the combined effects of heat stress, increased vapor pressure deficit (VPD and water deficit on the physiology of major crops needs to be better understood to help identifying the expected negative consequences of climate change and heat waves on global agricultural productivity. To address this issue, rice, wheat and maize plants were grown under control temperature (CT, 25°C, VPD 1.8 kPa, and a high temperature (HT, 38°C, VPD 3.5 kPa, both under well-watered (WW and water deficit (WD conditions. Gas-exchange measurements showed that, in general, WD conditions affected the leaf conductance to CO2, while growth at HT had a more marked effect on the biochemistry of photosynthesis. When combined, HT and WD had an additive effect in limiting photosynthesis. The negative impacts of the imposed treatments on the processes governing leaf gas-exchange were species-dependent. Wheat presented a higher sensitivity while rice and maize showed a higher acclimation potential to increased temperature. Rubisco and PEPC kinetic constants determined in vitro at 25°C and 38°C were used to estimate Vcmax, Jmax and Vpmax in the modeling of C3 and C4 photosynthesis. The results here obtained reiterate the need to use species-specific and temperature-specific values for Rubisco and PEPC kinetic constants for a precise parameterization of the photosynthetic response to changing environmental conditions in different crop species.

  15. Factors involved in alleviating water stress by partial crop removal in pear trees.

    Science.gov (United States)

    Marsal, Jordi; Mata, Merce; Arbones, Amadeu; Del Campo, Jesus; Girona, Joan; Lopez, Gerardo

    2008-09-01

    We studied the relief of water stress associated with fruit thinning in pear (Pyrus communis L.) trees during drought to determine what mechanisms, other than stomatal adjustment, were involved. Combinations of control irrigation (equal to crop water use less effective rainfall) and deficit irrigation (equal to 20% of control irrigation), fruit load (unthinned and thinned to 40 fruits per tree) and root pruning (pruned and unpruned) treatments were applied to pear (cv. 'Conference') trees during Stage II of fruit development. Daily patterns of midday stem water potential (Psi(stem)) and leaf conductance to water vapor (g(l)) of deficit-irrigated trees differed after fruit thinning. In response to fruit thinning, gl progressively declined with water stress until 30 days after fruit thinning and then leveled off, whereas the effects of decreased fruit load on Psi(stem) peaked 30-40 days after fruit thinning and then tended to decline. Soil water depletion was significantly correlated with fruit load during drought. Our results indicate that stomatal adjustment and the resulting soil water conservation were the factors determining the Psi(stem) response to fruit thinning. However, these factors could not explain differences in daily patterns between g(l) and Psi(stem) after fruit thinning. In all cases, effects of root pruning treatments on Psi(stem) in deficit-irrigated trees were transitory (Psi(stem) recovered from root pruning in less than 30 days), but the recovery of Psi(stem) after root pruning was faster in trees with low fruit loads. This behavior is compatible with the concept that the water balance (reflected by Psi(stem) values) was better in trees with low fruit loads compared with unthinned trees, perhaps because more carbon was available for root growth. Thus, a root growth component is hypothesized as a mechanism to explain the bimodal Psi(stem) response to fruit thinning during drought.

  16. Effects of temperature and water deficit on cambial activity and woody ring features in Picea mariana saplings.

    Science.gov (United States)

    Balducci, Lorena; Deslauriers, Annie; Giovannelli, Alessio; Rossi, Sergio; Rathgeber, Cyrille B K

    2013-10-01

    Increase in temperature under the projected future climate change would affect tree growth, including the physiological mechanisms related to sapling responses, which has been examined recently. The study investigated the plant water relations, cambial activity and wood formation in black spruce saplings [Picea mariana (Mill.) B.S.P.] subjected to water deficit and warming. Four-year-old saplings growing in three greenhouses were submitted to different thermal conditions: T0, with a temperature equal to the external air temperature; and T + 2 and T + 5, with temperatures set at 2 and 5 K higher than T0, respectively. We also submitted saplings to two irrigation regimes and studied the effects of a water deficit of 32 days in May-June. We evaluated plant water relations, cambial activity, wood formation and anatomical characteristics from May to October 2010. Lower needle physiology rates were observed during water deficit, with 20-day suspension of irrigation, but after re-watering, non-irrigated saplings attained the same values as irrigated ones in all thermal conditions. Significant differences between irrigation regimes were detected in cambial activity at the end of the water deficit and after resumption of irrigation. Under warmer conditions, the recovery of non-irrigated saplings was slower than T0 and they needed from 2 to 4 weeks to completely restore cambial activity. No significant differences in wood anatomy were observed between irrigation regimes, but there was a sporadic effect on wood density under warming. During wood formation, the warmer conditions combined with water deficit increased sapling mortality by 5 and 12.2% for T + 2 and T + 5, respectively. The black spruce saplings that survived were more sensitive to water availability, and the restoration of cambial activity was slower at temperatures higher than T0. Our results suggest that black spruce showed a plastic response to intense water deficit under warming, but this would compromise

  17. Environmental effects on stem water deficit in co-occurring conifers exposed to soil dryness

    Science.gov (United States)

    Oberhuber, Walter; Kofler, Werner; Schuster, Roman; Wieser, Gerhard

    2015-04-01

    We monitored dynamics of stem water deficit (Δ W) and needle water potential ( Ψ) during two consecutive growing seasons (2011 and 2012) in a dry inner Alpine environment (750 m above sea level, Tyrol, Austria), where Pinus sylvestris, Picea abies and Larix decidua form mixed stands. Δ W was extracted from stem circumference variations, which were continuously recorded by electronic band dendrometers (six trees per species) and correlations with environmental variables were performed. Results revealed that (i) Δ W reached highest and lowest values in P. abies and L. decidua, respectively, while mean minimum water potential ( Ψ ea) amounted to -3.0 MPa in L. decidua and -1.8 MPa in P. abies and P. sylvestris. (ii) Δ W and Ψ ea were significantly correlated in P. abies ( r = 0.630; P = 0.038) and L. decidua ( r = 0.646; P = 0.032). (iii) In all species, Δ W reached highest values in late summer and was most closely related to temperature ( P bark. Quite similar Δ W developed in drought-sensitive L. decidua and drought-tolerant P. sylvestris indicate that various water storage locations are depleted in species showing different strategies of water status regulation, i.e. anisohydric vs. isohydric behavior, respectively, and/or water uptake efficiency differs among these species. Close coupling of Δ W to temperature suggests that climate warming affects plant water status through its effect on atmospheric demand for moisture.

  18. Interactive effects of rice residue and water stress on growth and metabolism of wheat seedlings

    Directory of Open Access Journals (Sweden)

    Nimisha Amist

    2014-08-01

    Full Text Available In the present study effects of rice residue with and without water stress were studied on Triticum aestivum L. cv. Shatabadi. The mixture of residue and garden soil in 1:1 ratio was considered as 50% (R1 and only decomposed residue as 100% (R2. Garden soil was taken as control. Twenty five seeds were sown in each experimental trays filled with soil mixture according to the treatments. Trays were arranged in two groups. After 15 days one set was subjected to water stress (WS by withholding water supply for 3 days. Morphological and biochemical parameters of 18 days old seedlings were recorded. Seedling height decreased in all treatments. A gradual decrease in relative water content, pigment and protein contents of wheat seedlings were observed. Sugar and proline contents increased in treatments. An increase in malondialdehyde (MDA content and antioxidative enzyme activities was recorded. Elevation in catalase activity was observed in all treatments except in plants with water deficit. Ascorbate peroxidase (APX and guaiacol peroxidase (GPX activities increased when residue mixed with soil but decreased in seedlings under the combined influence of the residue and water stress. Higher amount of MDA and lower activities of APX and GPX reflected the oxidative damage in seedlings under combined treatments. Rice residue inhibited growth of wheat seedlings. Water stress intensified the effects of residue.

  19. Hyperactivity and attention deficits in mice with decreased levels of stress-inducible phosphoprotein 1 (STIP1).

    Science.gov (United States)

    Beraldo, Flavio H; Thomas, Anu; Kolisnyk, Benjamin; Hirata, Pedro H; De Jaeger, Xavier; Martyn, Amanda C; Fan, Jue; Goncalves, Daniela F; Cowan, Matthew F; Masood, Talal; Martins, Vilma R; Gros, Robert; Prado, Vania F; Prado, Marco A M

    2015-11-01

    Stress-inducible phosphoprotein I (STIP1, STI1 or HOP) is a co-chaperone intermediating Hsp70/Hsp90 exchange of client proteins, but it can also be secreted to trigger prion protein-mediated neuronal signaling. Some mothers of children with autism spectrum disorders (ASD) present antibodies against certain brain proteins, including antibodies against STIP1. Maternal antibodies can cross the fetus blood-brain barrier during pregnancy, suggesting the possibility that they can interfere with STIP1 levels and, presumably, functions. However, it is currently unknown whether abnormal levels of STIP1 have any impact in ASD-related behavior. Here, we used mice with reduced (50%) or increased STIP1 levels (fivefold) to test for potential ASD-like phenotypes. We found that increased STIP1 regulates the abundance of Hsp70 and Hsp90, whereas reduced STIP1 does not affect Hsp70, Hsp90 or the prion protein. Interestingly, BAC transgenic mice presenting fivefold more STIP1 show no major phenotype when examined in a series of behavioral tasks, including locomotor activity, elevated plus maze, Morris water maze and five-choice serial reaction time task (5-CSRTT). In contrast, mice with reduced STIP1 levels are hyperactive and have attentional deficits on the 5-CSRTT, but exhibit normal performance for the other tasks. We conclude that reduced STIP1 levels can contribute to phenotypes related to ASD. However, future experiments are needed to define whether it is decreased chaperone capacity or impaired prion protein signaling that contributes to these phenotypes.

  20. An Integrated Analysis of Changes in Water Stress in Europe

    DEFF Research Database (Denmark)

    Henrichs, T.; Lehner, B.; Alcamo, J.

    2002-01-01

    that today high water stress exists in one-fifth of European river basin area. Under a scenario projection, increases in water use throughout Eastern Europe are accompanied by decreases in water availability in most of Southern Europe--combining these trends leads to a marked increase in water stress......Future changes in water availability with climate change and changes in water use due to socio-economic development are to occur in parallel. In an integrated analysis we bring together these aspects of global change in a consistent manner, and analyse the water stress situation in Europe. We find...

  1. Productivity of irrigated bean submitted to water deficit in different phenological stages

    Science.gov (United States)

    Miorini, T. J. J.; Saad, J. C. C.

    2012-04-01

    Water scarcity is the most important factor limiting crop yields worldwide. An increased sustainable use of irrigation water will be necessary to feed our growing population. Bean (Phaseolus vulgaris L.) is widespread in the social and economic scene in Brazil, as well it is Brazilian population main dish, and it also helps small and medium farmers' income. The damage caused by water deficit depends on the duration, severity and stage of plant development. The bean plant is classified as sensitive to both water deficit and excess water in the soil. The hypothesis is that if the water supply is suppressed in just one of the five development stages of irrigated beans, it can result in productivity reduction lower than 20%, allowing water economy. The objective of this study was to compare the performance of bean Carioca group IAC Alvorada yield components, with irrigation suppression in each of the five phenological phases (emergence, vegetative, flowering, grain filling and maturation) and no irrigation and irrigated in all stages. The study was conducted at Agronomical Sciences College, UNESP, Botucatu, SP, Brazil. The statistical design was the randomized block with seven treatments and four replications. Data were subjected to analysis of variance and "t" test at 5% probability. The irrigation suppression only during emergence, filling, and maturation phases did not show any statistical difference in productivity when compared with the irrigated at all stages. The irrigation suppression at vegetative and flowering phase, reduced the production at 75.1 and 76.2%, respectively, when compared with irrigation at all stages, despite the reduction of the water depth being around 20% for flowering and 33.8% for the vegetative phase when compared to the irrigated at all stages. Irrigation suppression in all phases generated a reduction of approximately 87.3% when compared with irrigation at all stages. During the experiment there was a total recorded rainfall of 156mm

  2. Differential responses between mature and young leaves of sunflower plants to oxidative stress caused by water deficit Diferentes respostas entre folhas adultas e jovens de plantas de girassol ao estresse oxidativo causado pelo déficit hídrico

    Directory of Open Access Journals (Sweden)

    Inês Cechin

    2010-06-01

    Full Text Available The effects of water stress and rehydration on leaf gas exchange characteristics along with changes in lipid peroxidation and pirogalol peroxidase (PG-POD were studied in mature and in young leaves of sunflower (Helianthus annuus L., which were grown in a greenhouse. Water stress reduced photosynthesis (Pn, stomatal conductance (g s, and transpiration (E in both young and mature leaves. However, the amplitude of the reduction was dependent on leaf age. The intercellular CO2 concentration (Ci was increased in mature leaves but it was not altered in young leaves. Instantaneous water use efficiency (WUE in mature stressed leaves was reduced when compared to control leaves while in young stressed leaves it was maintained to the same level as the control. After 24h of rehydration, most of the parameters related to gas exchange recovered to the same level as the unstressed plants except gs and E in mature leaves. Water stress did not activated PG-POD independently of leaf age. However, after rehydration the enzyme activity was increased in mature leaves and remained to the same as the control in young leaves. Malondialdehyde (MDA content was increased by water stress in both mature and young leaves. The results suggest that young leaves are more susceptible to water stress in terms of gas exchange characteristics than mature leaves although both went through oxidative estresse.Os efeitos do estresse hídrico e da reidratação nas trocas gasosas juntamente com alterações na lipoperoxidação e atividade da pirogalol peroxidase (PG-POD foram estudados em folhas adultas e jovens de plantas de girassol (Helianthus annuus L. cultivadas em casa de vegetação. O estresse hídrico reduziu a fotossíntese (P N, a condutância estomática (g s e a transpiração (E nas folhas adultas e jovens. No entanto, a amplitude da redução foi dependente da idade da folha. A concentração intercelular de CO2 (Ci aumentou nas folhas adultas, mas não apresentou

  3. Water stress induces overexpression of superoxide dismutases that ...

    African Journals Online (AJOL)

    SERVER

    2007-09-05

    Sep 5, 2007 ... aim of this study was to determine the effect of water stress on superoxide ... In the same time, photosynthesis characteristics were deter- ... tion rate per reaction centre. ..... Factors affecting the enhancement of oxidative stress.

  4. Alteration of neurotrophin and cytokine expression in lymphocytes as novel peripheral markers of spatial memory deficits induced by prenatal stress.

    Science.gov (United States)

    Pascuan, C G; Di Rosso, M E; Pivoz-Avedikian, J E; Wald, M R; Zorrilla Zubilete, M A; Genaro, A M

    2017-05-01

    Much evidence has suggested that early life adversity can have a lasting effect on behavior. The aim of this study was to explore the impact of prenatal exposure to stress on cognition in adult life and how it impacts chronic stress situations. In addition, we investigated the participation of glucocorticoids, neurotrophins and cytokines in prenatal stress effects. For this purpose, pregnant mice were placed in a cylindrical restraint tube for 2h daily during the last week of pregnancy. Control pregnant females were left undisturbed during their entire pregnancy period. Object-in-place task results showed that adult female mice exposed to prenatal stress exhibited an impairment in spatial memory. However, in the alternation test this memory deficit was only found in prenatally stressed mice submitted to chronic stress. This alteration occurred in parallel with a decrease in BDNF, an increase in glucocorticoid receptors and an alteration of Th1/Th2 in the hippocampus. Interestingly, these changes were observed in peripheral lymph nodes as well. However, none of the mentioned changes were observed in adult male mice. These results indicate that lymphoid cells could be good candidates as peripheral markers of susceptibility to behavioral alterations associated with prenatal exposure to stress. Copyright © 2017 Elsevier Inc. All rights reserved.

  5. Forcing variables in simulation of transpiration of water stressed plants determined by principal component analysis

    Science.gov (United States)

    Durigon, Angelica; Lier, Quirijn de Jong van; Metselaar, Klaas

    2016-10-01

    To date, measuring plant transpiration at canopy scale is laborious and its estimation by numerical modelling can be used to assess high time frequency data. When using the model by Jacobs (1994) to simulate transpiration of water stressed plants it needs to be reparametrized. We compare the importance of model variables affecting simulated transpiration of water stressed plants. A systematic literature review was performed to recover existing parameterizations to be tested in the model. Data from a field experiment with common bean under full and deficit irrigation were used to correlate estimations to forcing variables applying principal component analysis. New parameterizations resulted in a moderate reduction of prediction errors and in an increase in model performance. Ags model was sensitive to changes in the mesophyll conductance and leaf angle distribution parameterizations, allowing model improvement. Simulated transpiration could be separated in temporal components. Daily, afternoon depression and long-term components for the fully irrigated treatment were more related to atmospheric forcing variables (specific humidity deficit between stomata and air, relative air humidity and canopy temperature). Daily and afternoon depression components for the deficit-irrigated treatment were related to both atmospheric and soil dryness, and long-term component was related to soil dryness.

  6. Inhibition of immobilization stress-induced anorexia, behavioral deficits, and plasma corticosterone secretion by injected leptin in rats.

    Science.gov (United States)

    Haque, Zeba; Akbar, Nazia; Yasmin, Farzana; Haleem, Muhammad A; Haleem, Darakhshan J

    2013-05-01

    Leptin, originally identified as an anti-obesity hormone, also has an important role in the regulation of mood and emotion. The present study was designed to monitor effects of injected leptin on immobilization stress-induced anorexia, behavioral deficits, and plasma corticosterone secretion in rats. Exposure to 2 h immobilization stress decreased food intake and body weight in saline-injected animals. Animals exposed to open field, elevated plus maze, and light-dark transition tests the day following immobilization exhibited anxiety-like behavior. Leptin injected at doses of 0.1 and 0.5 mg/kg also decreased food intake and body weight in unstressed animals and elicited anxiolytic effects at dose of 0.5 mg/kg, monitored on the following day. Immobilization-induced decreases in food intake, body weight, as well as stress-induced behavioral deficits in the open field, elevated plus maze, and light-dark transition test were reversed by exogenous leptin in a dose-dependent (0.1-0.5 mg/kg) manner. Acute exposure to 2 h immobilization produced a fourfold rise in plasma levels of corticosterone. Animals injected with leptin at a dose of 0.1 mg/kg, but not at dose of 0.5 mg/kg, exhibited a marginal increase in plasma corticosterone. Immobilization-induced increases of plasma corticosterone were reversed by leptin injected at doses of 0.1 or 0.5 mg/kg. The data suggest that exogenous leptin can reduce stress perception, resulting in an inhibition of stress effects on the activity of hypothalamic-pituitary-adrenal axis and behavior. The reported pharmacological effects of leptin represent an innovative approach for the treatment of stress-related disorders.

  7. Cytogenetic Effects of Chronic Methylphenidate Treatment and Chronic Social Stress in Adults with Attention-Deficit/Hyperactivity Disorder.

    Science.gov (United States)

    Kittel-Schneider, S; Spiegel, S; Renner, T; Romanos, M; Reif, A; Reichert, S; Heupel, J; Schnetzler, L; Stopper, H; Jacob, C

    2016-07-01

    Methylphenidate (MPH) is widely used to treat childhood and adult attention-deficit/hyperactivity disorder (ADHD). However, there are still safety concerns about side effects in long-term treatment. The aim of this study was to assess cytogenetic effects of chronic MPH treatment in adult ADHD and to find out if chronic social stress is attenuated by medication and to investigate whether chronic psychosocial stress leads to mutagenic effects by itself. Lymphocytes for micronucleus assay and saliva samples for cortisol measurement were collected from adult ADHD patients and healthy controls. Stress exposure of the last 3 months was assessed by TICS (Trier Inventory for Chronic Stress). We could not detect an influence of MPH treatment on cytogenetic markers. ADHD patients displayed significantly higher chronic stress levels measured by TICS compared to healthy controls which were influenced by duration of MPH treatment. ADHD patients also showed significantly lower basal cortisol levels. We could corroborate that there are neither cytogenetic effects of chronic stress nor of chronic MPH intake even after several years of treatment. © Georg Thieme Verlag KG Stuttgart · New York.

  8. The sunflower transcription factor HaHB11 confers tolerance to water deficit and salinity to transgenic Arabidopsis and alfalfa plants.

    Science.gov (United States)

    Cabello, Julieta V; Giacomelli, Jorge I; Gómez, María C; Chan, Raquel L

    2017-09-10

    Homeodomain-leucine zipper (HD-Zip) transcription factors are unique to the plant kingdom; members of subfamily I are known to be involved in abiotic stress responses. HaHB11 belongs to this subfamily and it was previously shown that it is able to confer improved yield and tolerance to flooding via a quiescent strategy. Here we show that HaHB11 expression is induced by ABA, NaCl and water deficit in sunflower seedlings and leaves. Arabidopsis transgenic plants expressing HaHB11, controlled either by its own promoter or by the constitutive 35S CaMV, presented rolled leaves and longer roots than WT when grown under standard conditions. In addition, these plants showed wider stems and more vascular bundles. To deal with drought, HaHB11 transgenic plants closed their stomata faster and lost less water than controls, triggering an enhanced tolerance to such stress condition and also to salinity stress. Concomitantly, ABA-synthesis and sensing related genes were differentially regulated in HaHB11 transgenic plants. Either under long-term salinity stress or mild drought stress, HaHB11 transgenic plants did not exhibit yield penalties. Moreover, alfalfa transgenic plants were generated which also showed enhanced drought tolerance. Altogether, the results indicated that HaHB11 was able to confer drought and salinity tolerance via a complex mechanism which involves morphological, physiological and molecular changes. Copyright © 2016 Elsevier B.V. All rights reserved.

  9. Ammonia production and assimilation: its importance as a tolerance mechanism during moderate water deficit in tomato plants.

    Science.gov (United States)

    Sánchez-Rodríguez, Eva; Rubio-Wilhelmi, María del Mar; Ríos, Juan José; Blasco, Begoña; Rosales, Miguel Ángel; Melgarejo, Rubén; Romero, Luis; Ruiz, Juan Manuel

    2011-05-15

    Nitrate assimilation diminishes under water stress. This can augment the photorespiratory rate as a protection mechanism, increasing the ammonium concentration, which must be rapidly assimilated. We therefore examined the effect of moderate water stress in photorespiration and N assimilation, as possible tolerance mechanisms in cherry tomato. Five cherry tomato cultivars with different degrees of water stress tolerance were submitted to two water treatments: well-watered (100% FC) and water stress (50% FC). In the susceptible cultivars, nitrate assimilation declined but without stimulating photorespiration. Zarina, a stress-tolerant cultivar, showed increased activity of the main enzymes involved in photorespiration, together with greater assimilation of nitrates and of the resulting ammonium. This translates as higher concentrations of N as well as amino acids and proteins. We characterize these mechanisms in the cv. Zarina (tolerant) as essential to water stress tolerance, acting on N metabolism as well as helping to maintain or augment biomass.

  10. Molecular interactions of the γ-clade homeodomain-leucine zipper class I transcription factors during the wheat response to water deficit.

    Science.gov (United States)

    Harris, John C; Sornaraj, Pradeep; Taylor, Mathew; Bazanova, Natalia; Baumann, Ute; Lovell, Ben; Langridge, Peter; Lopato, Sergiy; Hrmova, Maria

    2016-03-01

    The γ-clade of class I homeodomain-leucine zipper (HD-Zip I) transcription factors (TFs) constitute members which play a role in adapting plant growth to conditions of water deficit. Given the importance of wheat (Triticum aestivum L.) as a global food crop and the impact of water deficit upon grain yield, we focused on functional aspects of wheat drought responsive HD-Zip I TFs. While the wheat γ-clade HD-Zip I TFs share significant sequence similarities with homologous genes from other plants, the clade-specific features in transcriptional response to abiotic stress were detected. We demonstrate that wheat TaHDZipI-3, TaHDZipI-4, and TaHDZipI-5 genes respond differentially to a variety of abiotic stresses, and that proteins encoded by these genes exhibit pronounced differences in oligomerisation, strength of DNA binding, and trans-activation of an artificial promoter. Three-dimensional molecular modelling of the protein-DNA interface was conducted to address the ambiguity at the central nucleotide in the pseudo-palindromic cis-element CAATNATTG that is recognised by all three HD-Zip I proteins. The co-expression of these genes in the same plant tissues together with the ability of HD-Zip I TFs of the γ-clade to hetero-dimerise suggests a role in the regulatory mechanisms of HD-Zip I dependent transcription. Our findings highlight the complexity of TF networks involved in plant responses to water deficit. A better understanding of the molecular complexity at the protein level during crop responses to drought will enable adoption of efficient strategies for production of cereal plants with enhanced drought tolerance.

  11. Estimating yields of salt- and water-stressed forages with remote sensing in the visible and near infrared.

    Science.gov (United States)

    Poss, J A; Russell, W B; Grieve, C M

    2006-01-01

    In arid irrigated regions, the proportion of crop production under deficit irrigation with poorer quality water is increasing as demand for fresh water soars and efforts to prevent saline water table development occur. Remote sensing technology to quantify salinity and water stress effects on forage yield can be an important tool to address yield loss potential when deficit irrigating with poor water quality. Two important forages, alfalfa (Medicago sativa L.) and tall wheatgrass (Agropyron elongatum L.), were grown in a volumetric lysimeter facility where rootzone salinity and water content were varied and monitored. Ground-based hyperspectral canopy reflectance in the visible and near infrared (NIR) were related to forage yields from a broad range of salinity and water stress conditions. Canopy reflectance spectra were obtained in the 350- to 1000-nm region from two viewing angles (nadir view, 45 degrees from nadir). Nadir view vegetation indices (VI) were not as strongly correlated with leaf area index changes attributed to water and salinity stress treatments for both alfalfa and wheatgrass. From a list of 71 VIs, two were selected for a multiple linear-regression model that estimated yield under varying salinity and water stress conditions. With data obtained during the second harvest of a three-harvest 100-d growing period, regression coefficients for each crop were developed and then used with the model to estimate fresh weights for preceding and succeeding harvests during the same 100-d interval. The model accounted for 72% of the variation in yields in wheatgrass and 94% in yields of alfalfa within the same salinity and water stress treatment period. The model successfully predicted yield in three out of four cases when applied to the first and third harvest yields. Correlations between indices and yield increased as canopy development progressed. Growth reductions attributed to simultaneous salinity and water stress were well characterized, but the

  12. Growing Out of Stress: The Role of Cell- and Organ-Scale Growth Control in Plant Water-Stress Responses[OPEN

    Science.gov (United States)

    Robbins, Neil E.

    2016-01-01

    Water is the most limiting resource on land for plant growth, and its uptake by plants is affected by many abiotic stresses, such as salinity, cold, heat, and drought. While much research has focused on exploring the molecular mechanisms underlying the cellular signaling events governing water-stress responses, it is also important to consider the role organismal structure plays as a context for such responses. The regulation of growth in plants occurs at two spatial scales: the cell and the organ. In this review, we focus on how the regulation of growth at these different spatial scales enables plants to acclimate to water-deficit stress. The cell wall is discussed with respect to how the physical properties of this structure affect water loss and how regulatory mechanisms that affect wall extensibility maintain growth under water deficit. At a higher spatial scale, the architecture of the root system represents a highly dynamic physical network that facilitates access of the plant to a heterogeneous distribution of water in soil. We discuss the role differential growth plays in shaping the structure of this system and the physiological implications of such changes. PMID:27503468

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

    African Journals Online (AJOL)

    Growth and physiological responses to water and nutrient stress in oil palm. ... conditions) and to two nutrient regimes (with or without fertilization) of oil ... Moreover, deficiency of both water and nutrients in combination had the greatest impact ...

  14. Identification of Resilient Individuals and Those at Risk for Performance Deficits under Stress

    Directory of Open Access Journals (Sweden)

    Brent eWinslow

    2015-09-01

    Full Text Available Human task performance is affected by exposure to physiological and psychological stress. The ability to measure the physiological response to stressors and correlate that to task performance could be used to identify resilient individuals or those at risk for stress-related performance decrements. Accomplishing this prior to performance under severe stress or the development of clinical stress disorders could facilitate focused preparation such as tailoring training to individual needs. Here we measure the effects of stress on physiological response and performance through behavior, physiological sensors, and subjective ratings, and identify which individuals are at risk for stress-related performance decrements. Participants performed military-relevant training tasks under stress in a virtual environment, with autonomic and hypothalamic-pituitary-adrenal axis (HPA reactivity analyzed. Self-reported stress, as well as physiological indices of stress, increased in the group pre-exposed to socioevaluative stress. Stress response was effectively captured via electrodermal and cardiovascular measures of heart rate and skin conductance level. A resilience classification algorithm was developed based upon physiological reactivity, which correlated with baseline unstressed physiological and self-reported stress values. Outliers were identified in the experimental group that had a significant mismatch between self-reported stress and salivary cortisol. Baseline stress measurements were predictive of individual resilience to stress, including the impact stress had on physiological reactivity and performance. Such an approach may have utility in identifying individuals at risk for problems performing under severe stress. Continuing work has focused on adapting this method for military personnel, and assessing the utility of various coping and decision-making strategies on performance and physiological stress.

  15. Identification of resilient individuals and those at risk for performance deficits under stress.

    Science.gov (United States)

    Winslow, Brent D; Carroll, Meredith B; Martin, Jonathan W; Surpris, Glenn; Chadderdon, George L

    2015-01-01

    Human task performance is affected by exposure to physiological and psychological stress. The ability to measure the physiological response to stressors and correlate that to task performance could be used to identify resilient individuals or those at risk for stress-related performance decrements. Accomplishing this prior to performance under severe stress or the development of clinical stress disorders could facilitate focused preparation such as tailoring training to individual needs. Here we measure the effects of stress on physiological response and performance through behavior, physiological sensors, and subjective ratings, and identify which individuals are at risk for stress-related performance decrements. Participants performed military-relevant training tasks under stress in a virtual environment, with autonomic and hypothalamic-pituitary-adrenal axis (HPA) reactivity analyzed. Self-reported stress, as well as physiological indices of stress, increased in the group pre-exposed to socioevaluative stress. Stress response was effectively captured via electrodermal and cardiovascular measures of heart rate and skin conductance level. A resilience classification algorithm was developed based upon physiological reactivity, which correlated with baseline unstressed physiological and self-reported stress values. Outliers were identified in the experimental group that had a significant mismatch between self-reported stress and salivary cortisol. Baseline stress measurements were predictive of individual resilience to stress, including the impact stress had on physiological reactivity and performance. Such an approach may have utility in identifying individuals at risk for problems performing under severe stress. Continuing work has focused on adapting this method for military personnel, and assessing the utility of various coping and decision-making strategies on performance and physiological stress.

  16. Water deficit in field-grown Gossypium hirsutum primarily limits net photosynthesis by decreasing stomatal conductance, increasing photorespiration, and increasing the ratio of dark respiration to gross photosynthesis.

    Science.gov (United States)

    Chastain, Daryl R; Snider, John L; Collins, Guy D; Perry, Calvin D; Whitaker, Jared; Byrd, Seth A

    2014-11-01

    Much effort has been expended to improve irrigation efficiency and drought tolerance of agronomic crops; however, a clear understanding of the physiological mechanisms that interact to decrease source strength and drive yield loss has not been attained. To elucidate the underlying mechanisms contributing to inhibition of net carbon assimilation under drought stress, three cultivars of Gossypium hirsutum were grown in the field under contrasting irrigation regimes during the 2012 and 2013 growing season near Camilla, Georgia, USA. Physiological measurements were conducted on three sample dates during each growing season (providing a broad range of plant water status) and included, predawn and midday leaf water potential (ΨPD and ΨMD), gross and net photosynthesis, dark respiration, photorespiration, and chlorophyll a fluorescence. End-of-season lint yield was also determined. ΨPD ranged from -0.31 to -0.95MPa, and ΨMD ranged from -1.02 to -2.67MPa, depending upon irrigation regime and sample date. G. hirsutum responded to water deficit by decreasing stomatal conductance, increasing photorespiration, and increasing the ratio of dark respiration to gross photosynthesis, thereby limiting PN and decreasing lint yield (lint yield declines observed during the 2012 growing season only). Conversely, even extreme water deficit, causing a 54% decline in PN, did not negatively affect actual quantum yield, maximum quantum yield, or photosynthetic electron transport. It is concluded that PN is primarily limited in drought-stressed G. hirsutum by decreased stomatal conductance, along with increases in respiratory and photorespiratory carbon losses, not inhibition or down-regulation of electron transport through photosystem II. It is further concluded that ΨPD is a reliable indicator of drought stress and the need for irrigation in field-grown cotton.

  17. 冬小麦不同生育时期水分亏缺胁迫对叶片保护酶系统的影响%Effects of water limited deficit stress during different growth stages on leaf protective enzymes of winter wheat

    Institute of Scientific and Technical Information of China (English)

    王俊儒; 李生秀; 李凯丽

    2001-01-01

    Using pot experiment with or without N fertilizer supply,the effects of water limited dificit stress during different stages on leaf protective enzymes were studied.The results showed that without N fertilizer supply,water dificit stress lowered the activities of protective enzymes,but with N fertiliser supply are mostly higher.The analysis of the relationship between MDA and the activities of protective enzymes showed that SOD activity was extremly significant related with MDA on seedling stage,POD activity was negatively related with MDA in extremly significant level on jointing stage,but in filling stage these protective enzymes activities were not so related with MDA and MDA was concentrated to a higher level.Total chlorophyll content in leaf in different stages after water dificit stress was negative related to MDA in extremely significant level.All these showed that affected by water status and N supply,the activities of protective enzymes changed apparently in different growth stages.%利用盆栽试验研究了施N(底肥)与不施N条件下冬小麦不同生育时期水分有限亏缺对叶片保护酶系统的影响。结果表明,在无底肥条件下,3个生育时期水分亏缺均使保护酶系统活性有所降低,而在有底肥时酶活性多数则升高。各保护酶活性与MDA相关分析表明,苗期SOD活性与MDA呈极显著负相关;拔节期却是POD活性与MDA呈极显著负相关;在灌浆期SOD、POD、CAT与MDA含量均无显著相关性,但MDA在叶片中累积至较高水平。各生育期水分处理叶片叶绿素含量与MDA含量达极显著负相关。这些说明在不同生育时期,受水分亏缺和供肥的影响,保护酶系统各酶的变化有明显差异,其生理作用也有差异。

  18. Rapid recovery of photosynthetic rate following soil water deficit and re-watering in cotton plants (Gossypium herbaceum L.) is related to the stability of the photosystems.

    Science.gov (United States)

    Yi, Xiao-Ping; Zhang, Ya-Li; Yao, He-Sheng; Luo, Hong-Hai; Gou, Ling; Chow, Wah Soon; Zhang, Wang-Feng

    2016-05-01

    The responses of gas exchange, chlorophyll fluorescence and the anti-oxidative system of cotton leaves were studied during water deficit and recovery. The results show that water deficit led to a reversible reduction in the photosynthetic rate. This reduction was mainly accompanied by stomatal limitation. The activity of photosystem II (PSII) and photosystem I (PSI) was relatively stable during water deficit and recovery. Water deficit caused an enhanced production of reactive oxygen species (ROS) and increased lipid peroxidation. Proline accumulation and the anti-oxidative enzymes such as superoxide dismutase (SOD), ascorbate peroxidase (APX) and peroxidase (POD), along with the antioxidant ascorbate (AsA), increased during water deficit. On re-watering, the ROS generation rate, anti-oxidative enzymes activities and the extent of the lipid peroxidation returned to near control values. Overall, rapid recovery of the photosynthetic rate is related to the stability of the photosystems which appears to be a critical mechanism allowing cotton plants to withstand and survive drought environments.

  19. Determination of moisture deficit and heat stress tolerance in corn using physiological measurements and a low-cost microcontroller-based monitoring system

    Science.gov (United States)

    In the southern United States, corn production encounters moisture deficit coupled with high temperature stress, particularly during the reproductive stage of the plant. In evaluating plants for environmental stress tolerance, it is important to monitor changes in their physical environment under na...

  20. Memory deficits and oxidative stress in cerebral ischemia-reperfusion: neuroprotective role of physical exercise and green tea supplementation.

    Science.gov (United States)

    Schimidt, Helen L; Vieira, Aline; Altermann, Caroline; Martins, Alexandre; Sosa, Priscila; Santos, Francielli W; Mello-Carpes, Pâmela B; Izquierdo, Ivan; Carpes, Felipe P

    2014-10-01

    Ischemic stroke is a major cause of morbidity and mortality all over the world. Among impairments observed in survivors there is a significant cognitive learning and memory deficit. Neuroprotective strategies are being investigated to minimize such deficits after an ischemia event. Here we investigated the neuroprotective potential of physical exercise and green tea in an animal model of ischemia-reperfusion. Eighty male rats were divided in 8 groups and submitted to either transient brain ischemia-reperfusion or a sham surgery after 8 weeks of physical exercise and/or green tea supplementation. Ischemia-reperfusion was performed by bilateral occlusion of the common carotid arteries during 30 min. Later, their memory was evaluated in an aversive and in a non-aversive task, and hippocampus and prefrontal cortex were removed for biochemical analyses of possible oxidative stress effects. Ischemia-reperfusion impaired learning and memory. Reactive oxygen species were increased in the hippocampus and prefrontal cortex. Eight weeks of physical exercise and/or green tea supplementation before the ischemia-reperfusion event showed a neuroprotective effect; both treatments in separate or together reduced the cognitive deficits and were able to maintain the functional levels of antioxidant enzymes and glutathione.

  1. LPHN3 and Attention-Deficit/Hyperactivity Disorder: Interaction with Maternal Stress during Pregnancy

    Science.gov (United States)

    Choudhry, Zia; Sengupta, Sarojini M.; Grizenko, Natalie; Fortier, Marie-Eve; Thakur, Geeta A.; Bellingham, Johanne; Joober, Ridha

    2012-01-01

    Background: Attention-deficit/hyperactivity disorder (ADHD) is a heterogeneous behavioral disorder, complex both in etiology and clinical expression. Both genetic and environmental factors have been implicated, and it has been suggested that gene-environment interactions may play a pivotal role in the disorder. Recently, a significant association…

  2. Anatomical and hydraulic properties of sorghum roots exposed to water deficit. [Sorghum bicolor

    Energy Technology Data Exchange (ETDEWEB)

    Cruz, R.T.; Jordan, W.R.; Drew, M.C. (Texas A and M Univ., College Station (United States))

    1991-05-01

    The effects of a severe water stress in the upper 0-0.15 m rooting zone on development of the exodermis, endodermis and xylem and on radial (Lp) and axial (Ls) hydraulic conductances were studied for Sorghum bicolor. Lp and Lx were based on water flow rates obtained by applying a negative hydrostatic pressure to the proximal xylem ends of excised roots placed in aerated nutrient solution. The same roots were stained with fluorescent berberine and acid phloroglucinol to describe the development of the exodermal and endodermal cell walls from formation of the Casparian band (State I), to deposition of suberin lamellae (State II), and lignification (State III). Lp of 1.5 {times} 10{sup {minus}11} m{sup 3}s{sup {minus}1}MPa{sup {minus}1} was 80% lower in stressed roots than in unstressed controls. At 0.01 and 0.07 m from the root apex, stressed roots were in State III while control roots were in States I and II, respectively. SEM-image analysis for stressed roots indicated that in the exodermis a greater proportion of the cross sectional area was occupied by lignified walls than in the endodermis. Cellufluor, an apoplastic tracer, was blocked at the lignified exodermis even at 0.01 m from the apex in stressed roots. Uranin, a symplastic tracer, was taken up only in the apical region in stressed roots but farther from the apex in the controls. Lx of 7.1 {times} 10{sup {minus}11}m{sup 3}s{sup {minus}1}MPa{sup {minus}1} was 90% lower in stressed roots compared with the controls. Cellufluor test and image analysis showed that although the protoxylem and early metaxylem were conductive in both treatments, stress caused more than a 50% reduction in the diameter of the xylem elements. Results suggest that lignification of the exodermis and endodermis to a large extent decreased apoplastic and symplastic flows and hence Lp in stressed roots. The low Lx in stressed roots was due to a decrease in the diameters of the conductive xylem elements.

  3. Inhibitor of Phosphodiestearse-4 improves memory deficits, oxidative stress, neuroinflammation and neuropathological alterations in mouse models of dementia of Alzheimer's Type.

    Science.gov (United States)

    Kumar, Amit; Singh, Nirmal

    2017-04-01

    The study investigates the potential of Rolipram a phosphodiesterase-4 inhibitor in cognitive deficits induced by streptozotocin (STZ, 3mg/kg intracerebroventricularly) and natural ageing in mice. Morris water maze (MWM) test was employed to evaluate learning and memory of the animals. Extent of oxidative stress was measured by estimating the levels of brain glutathione (GSH) and thiobarbituric acid reactive species (TBARS). Brain acetylcholinestrase (AChE) activity was also estimated. The brain activity of myeloperoxidase (MPO) was measured as a marker of inflammation. STZ and ageing results in marked decline in MWM performance of the animals, reflecting impairment of learning and memory. STZ treated mice and aged mice exhibited a marked accentuation of AChE activity, TBARS and MPO activity along with fall in GSH level. Further the stained micrographs of STZ treated mice and aged mice indicate pathological changes, severe neutrophilic infiltration and amyloid deposition. Rolipram treatment significantly attenuated STZ induced and age related memory deficits, biochemical and histopathological alterations. The findings demonstrate the potential of Rolipram in memory dysfunctions which may probably be attributed to its anti-cholinesterase, anti-amyloid, anti-oxidative and anti-inflammatory effects. The study concludes that PDE-4 can be explored as a potential therapeutic target in dementia.

  4. Green Tea Extract Ameliorates Learning and Memory Deficits in Ischemic Rats via Its Active Component Polyphenol Epigallocatechin-3-gallate by Modulation of Oxidative Stress and Neuroinflammation

    Directory of Open Access Journals (Sweden)

    Kuo-Jen Wu

    2012-01-01

    Full Text Available Ischemic stroke results in brain damage and behavioral deficits including memory impairment. Protective effects of green tea extract (GTex and its major functional polyphenol (−-epigallocatechin gallate (EGCG on memory were examined in cerebral ischemic rats. GTex and EGCG were administered 1 hr before middle cerebral artery ligation in rats. GTex, EGCG, and pentoxifylline (PTX significantly improved ishemic-induced memory impairment in a Morris water maze test. Malondialdehyde (MDA levels, glutathione (GSH, and superoxide dismutase (SOD activity in the cerebral cortex and hippocampus were increased by long-term treatment with GTex and EGCG. Both compounds were also associated with reduced cerebral infraction breakdown of MDA and GSH in the hippocampus. In in vitro experiments, EGCG had anti-inflammatory effects in BV-2 microglia cells. EGCG inhibited lipopolysaccharide- (LPS- induced nitric oxide production and reduced cyclooxygenase-2 and inducible nitric oxide synthase expression in BV-2 cells. GTex and its active polyphenol EGCG improved learning and memory deficits in a cerebral ischemia animal model and such protection may be due to the reduction of oxidative stress and neuroinflammation.

  5. Identification of resilient individuals and those at risk for performance deficits under stress

    OpenAIRE

    Brent eWinslow; Meredith B Carroll; Martin, Jonathan W.; Glenn eSurpris; George L. Chadderdon

    2015-01-01

    Human task performance is affected by exposure to physiological and psychological stress. The ability to measure the physiological response to stressors and correlate that to task performance could be used to identify resilient individuals or those at risk for stress-related performance decrements. Accomplishing this prior to performance under severe stress or the development of clinical stress disorders could facilitate focused preparation such as tailoring training to individual needs. H...

  6. Posttraumatic stress disorder in adult attention-deficit/hyperactivity disorder: clinical features and familial transmission.

    Science.gov (United States)

    Antshel, Kevin M; Kaul, Prashant; Biederman, Joseph; Spencer, Thomas J; Hier, Bridget O; Hendricks, Kaitlin; Faraone, Stephen V

    2013-03-01

    Attention-deficit/hyperactivity disorder (ADHD) is characterized by clinically significant functional impairment due to symptoms of inattention and/or hyperactivity and impulsivity. Previous research suggests a link, in child samples, between ADHD and posttraumatic stress disorder (PTSD), which is characterized by (1) chronically reexperiencing a traumatic event, (2) hyperarousal, and (3) avoiding stimuli associated with the trauma while exhibiting numbed responsiveness. This study sought to address the link between ADHD and PTSD in adults by providing a comprehensive comparison of ADHD patients with and without PTSD across multiple variables including demographics, patterns of psychiatric comorbidities, functional impairments, quality of life, social adjustment, and familial transmission. Participants in our controlled family study conducted between 1998 and 2003 were 190 adults with DSM-IV ADHD who were attending an outpatient mental health clinic in Boston, Massachusetts; 16 adults with DSM-IV ADHD who were recruited by advertisement from the greater Boston area; and 123 adult controls without ADHD who were recruited by advertisement from the greater Boston area. All available first-degree relatives also participated. Subjects completed a large battery of self-report measures (the Quality of Life Enjoyment and Satisfaction Questionnaire, items from the Current Behavior Scale, the Social Adjustment Scale Self-Report, and the Four Factor Index of Social Status) designed to assess various psychiatric and functional parameters. Diagnoses were made using data obtained from structured psychiatric interviews (Structured Clinical Interview for DSM-IV Axis I Disorders, Clinician Version, and the Schedule for Affective Disorders and Schizophrenia for School-Aged Children-Epidemiologic Version). The lifetime prevalence of PTSD was significantly higher among adults with ADHD compared with controls (10.0% vs 1.6%; P = .004). Participants with ADHD and those with ADHD + PTSD

  7. Interactive Contributions of Cumulative Peer Stress and Executive Function Deficits to Depression in Early Adolescence

    Science.gov (United States)

    Agoston, Anna M.; Rudolph, Karen D.

    2016-01-01

    Exposure to peer stress contributes to adolescent depression, yet not all youth experience these effects. Thus, it is important to identify individual differences that shape the consequences of peer stress. This research investigated the interactive contribution of cumulative peer stress during childhood (second-fifth grades) and executive…

  8. Interactive Contributions of Cumulative Peer Stress and Executive Function Deficits to Depression in Early Adolescence

    Science.gov (United States)

    Agoston, Anna M.; Rudolph, Karen D.

    2016-01-01

    Exposure to peer stress contributes to adolescent depression, yet not all youth experience these effects. Thus, it is important to identify individual differences that shape the consequences of peer stress. This research investigated the interactive contribution of cumulative peer stress during childhood (second-fifth grades) and executive…

  9. Micronutrients reduce stress and anxiety in adults with Attention-Deficit/Hyperactivity Disorder following a 7.1 earthquake.

    Science.gov (United States)

    Rucklidge, Julia; Johnstone, Jeanette; Harrison, Rachel; Boggis, Anna

    2011-09-30

    The role of good nutrition for resilience in the face of stress is a topic of interest, but difficult to study. A 7.1 earthquake took place in the midst of research on a micronutrient treatment for Attention-Deficit/Hyperactivity Disorder (ADHD), providing a unique opportunity to examine whether individuals with ADHD taking micronutrients demonstrated more emotional resilience post-earthquake than individuals with ADHD not taking micronutrients. Thirty-three adults with ADHD were assessed twice following the earthquake using a measure of depression, anxiety and stress also completed at some point pre-earthquake (baseline). Seventeen were not taking micronutrients at the time of the earthquake (control group), 16 were (micronutrient group). While there were no between-group differences one week post-quake (Time 1), at two weeks post-quake (Time 2), the micronutrient group reported significantly less anxiety and stress than the controls (effect size 0.69). These between group differences could not be explained by other variables, such as pre-earthquake measures of emotions, demographics, psychiatric status, and personal loss or damage following the earthquake. The results suggest that micronutrients may increase resilience to ongoing stress and anxiety associated with a highly stressful event in individuals with ADHD and are consistent with controlled studies showing benefit of micronutrients for mental health. Copyright © 2011 Elsevier Ltd. All rights reserved.

  10. [Responses of tomato leaf photosynthesis to rapid water stress].

    Science.gov (United States)

    Han, Guo-Jun; Chen, Nian-lai; Huang, Hai-xia; Zhang, Ping; Zhang, Kai; Guo, Yan-hong

    2013-04-01

    By using polyethylene glycol (PEG-6000) solution to regulate the water potential of tomato (Lycopersicon esculentum) rhizosphere to simulate water stress, this paper studied the dynamic changes of net photosynthetic rate, dark respiratory rate and CO2 compensatory concentration of detached tomato leaves in the process of photosynthetic induction. Under 1000 micromol m-2 s-1 of light induction, the time required to reach the maximum net photosynthetic rate of water-stressed tomato leaves was shortened by 1/3, while the stomatal conductance was increased by 1.5 times, as compared to the non-stress control. Also, the light saturation point (LSP) of water-stressed tomato leaves was lowered by 65% to 85%, and the light compensation point (LCP) was increased by 75% to 100%, suggesting that the effective range of light utilized by tomato leaves was reduced. Furthermore, water stress decreased the maximum photosynthetic capacity of tomato leaves by 40%, but increased the dark respiration rate by about 45% . It was suggested that rapid water stress made the stomata of tomato leaves quickly opened, without initial photosynthetic induction stage. In conclusion, water stress could induce the decrease of plant light-energy use efficiency and potential, being the main reason for the decrease of plant productivity, and stomatal regulation could be the main physiological mechanism of tomato plants to adapt to rapid water stress.

  11. Selenium Supplementation Affects Physiological and Biochemical Processes to Improve Fodder Yield and Quality of Maize (Zea mays L.) under Water Deficit Conditions.

    Science.gov (United States)

    Nawaz, Fahim; Naeem, Muhammad; Ashraf, Muhammad Y; Tahir, Muhammad N; Zulfiqar, Bilal; Salahuddin, Muhammad; Shabbir, Rana N; Aslam, Muhammad

    2016-01-01

    Climate change is one of the most complex challenges that pose serious threats to livelihoods of poor people who rely heavily on agriculture and livestock particularly in climate-sensitive developing countries of the world. The negative effects of water scarcity, due to climate change, are not limited to productivity food crops but have far-reaching consequences on livestock feed production systems. Selenium (Se) is considered essential for animal health and has also been reported to counteract various abiotic stresses in plants, however, understanding of Se regulated mechanisms for improving nutritional status of fodder crops remains elusive. We report the effects of exogenous selenium supply on physiological and biochemical processes that may influence green fodder yield and quality of maize (Zea mays L.) under drought stress conditions. The plants were grown in lysimeter tanks under natural conditions and were subjected to normal (100% field capacity) and water stress (60% field capacity) conditions. Foliar spray of Se was carried out before the start of tasseling stage (65 days after sowing) and was repeated after 1 week, whereas, water spray was used as a control. Drought stress markedly reduced the water status, pigments and green fodder yield and resulted in low forage quality in water stressed maize plants. Nevertheless, exogenous Se application at 40 mg L(-1) resulted in less negative leaf water potential (41%) and enhanced relative water contents (30%), total chlorophyll (53%), carotenoid contents (60%), accumulation of total free amino acids (40%) and activities of superoxide dismutase (53%), catalase (30%), peroxidase (27%), and ascorbate peroxidase (27%) with respect to control under water deficit conditions. Consequently, Se regulated processes improved fodder yield (15%) and increased crude protein (47%), fiber (10%), nitrogen free extract (10%) and Se content (36%) but did not affect crude ash content in water stressed maize plants. We propose that

  12. Selenium Supplementation Affects Physiological and Biochemical Processes to Improve Fodder Yield and Quality of Maize (Zea mays L. under Water Deficit Conditions

    Directory of Open Access Journals (Sweden)

    Fahim Nawaz

    2016-09-01

    Full Text Available Climate change is one of the most complex challenges that pose serious threats to livelihoods of poor people who rely heavily on agriculture and livestock particularly in climate-sensitive developing countries of the world. The negative effects of water scarcity, due to climate change, are not limited to productivity food crops but have far-reaching consequences on livestock feed production systems. Selenium (Se is considered essential for animal health and has also been reported to counteract various abiotic stresses in plants however, understanding of Se regulated mechanisms for improving nutritional status of fodder crops remains elusive. We report the effects of exogenous selenium (Se supply on physiological and biochemical processes that may influence green fodder yield and quality of maize (Zea mays L. under drought stress conditions. The plants were grown in lysimeter tanks under natural conditions and were subjected to normal (100% field capacity and water stress (60% field capacity conditions. Foliar spray of Se was carried out before the start of tasseling stage (65 days after sowing and was repeated after one week, whereas water spray was used as a control. Drought stress markedly reduced the water status, pigments and green fodder yield and resulted in low forage quality in water stressed maize plants. Nevertheless, exogenous Se application at 40 mg L-1 resulted in less negative leaf water potential (41% and enhanced relative water contents (30%, total chlorophyll (53%, carotenoid contents (60%, accumulation of total free amino acids (40% and activities of superoxide dismutase (53%, catalase (30%, peroxidase (27% and ascorbate peroxidase (27% with respect to control under water deficit conditions. Consequently, Se regulated processes improved fodder yield (15% and increased crude protein (47%, fibre (10%, nitrogen free extract (10% and Se content (36% but did not affect crude ash content in water stressed maize plants. We propose

  13. Selenium Supplementation Affects Physiological and Biochemical Processes to Improve Fodder Yield and Quality of Maize (Zea mays L.) under Water Deficit Conditions

    Science.gov (United States)

    Nawaz, Fahim; Naeem, Muhammad; Ashraf, Muhammad Y.; Tahir, Muhammad N.; Zulfiqar, Bilal; Salahuddin, Muhammad; Shabbir, Rana N.; Aslam, Muhammad

    2016-01-01

    Climate change is one of the most complex challenges that pose serious threats to livelihoods of poor people who rely heavily on agriculture and livestock particularly in climate-sensitive developing countries of the world. The negative effects of water scarcity, due to climate change, are not limited to productivity food crops but have far-reaching consequences on livestock feed production systems. Selenium (Se) is considered essential for animal health and has also been reported to counteract various abiotic stresses in plants, however, understanding of Se regulated mechanisms for improving nutritional status of fodder crops remains elusive. We report the effects of exogenous selenium supply on physiological and biochemical processes that may influence green fodder yield and quality of maize (Zea mays L.) under drought stress conditions. The plants were grown in lysimeter tanks under natural conditions and were subjected to normal (100% field capacity) and water stress (60% field capacity) conditions. Foliar spray of Se was carried out before the start of tasseling stage (65 days after sowing) and was repeated after 1 week, whereas, water spray was used as a control. Drought stress markedly reduced the water status, pigments and green fodder yield and resulted in low forage quality in water stressed maize plants. Nevertheless, exogenous Se application at 40 mg L-1 resulted in less negative leaf water potential (41%) and enhanced relative water contents (30%), total chlorophyll (53%), carotenoid contents (60%), accumulation of total free amino acids (40%) and activities of superoxide dismutase (53%), catalase (30%), peroxidase (27%), and ascorbate peroxidase (27%) with respect to control under water deficit conditions. Consequently, Se regulated processes improved fodder yield (15%) and increased crude protein (47%), fiber (10%), nitrogen free extract (10%) and Se content (36%) but did not affect crude ash content in water stressed maize plants. We propose that Se

  14. Modeling psychotic and cognitive symptoms of affective disorders: Disrupted latent inhibition and reversal learning deficits in highly stress reactive mice.

    Science.gov (United States)

    Knapman, A; Heinzmann, J-M; Holsboer, F; Landgraf, R; Touma, C

    2010-09-01

    Increased stress reactivity has repeatedly been reported in patients suffering from psychiatric diseases including schizophrenia and major depression. These disorders also have other symptoms in common, such as cognitive deficits and psychotic-like behavior. We have therefore investigated if increased stress reactivity is associated with these phenotypic endpoints in an animal model of affective disorders. The stress reactivity mouse model used in this study consists of three CD-1-derived mouse lines, that have been selectively bred for high (HR), intermediate (IR) or low (LR) stress reactivity. Male mice from these three breeding lines were subjected to a reversal learning task and latent inhibition (Li) was assessed using a conditioned taste aversion paradigm. Furthermore, as the dopaminergic system is involved in both Li and reversal learning, the dopamine 1 receptor (D1R), dopamine 2 receptor (D2R) and dopamine transporter (DAT) mRNA expression levels were assessed in relevant brain areas of these animals. The results demonstrate that HR mice show perseveration in the reversal learning task and have disrupted Li. Furthermore, compared to LR mice, HR mice have decreased D2R mRNA levels in the ventral tegmental area, as well as decreased D1R mRNA levels in the cingulate cortex, and an increased expression of D2R mRNA in the nucleus accumbens. Taken together, these results demonstrate that the HR mice display cognitive deficits associated with psychotic-like behavior, similar to those observed in patients suffering from schizophrenia and major depression and could be utilized in the search for better treatment strategies for these symptoms of psychiatric disorders.

  15. Prefrontal cortical volume loss is associated with stress-related deficits in verbal learning and memory in HIV-infected women.

    Science.gov (United States)

    Rubin, Leah H; Meyer, Vanessa J; J Conant, Rhoda; Sundermann, Erin E; Wu, Minjie; Weber, Kathleen M; Cohen, Mardge H; Little, Deborah M; Maki, Pauline M

    2016-08-01

    Deficits in verbal learning and memory are a prominent feature of neurocognitive function in HIV-infected women, and are associated with high levels of perceived stress. To understand the neurobiological factors contributing to this stress-related memory impairment, we examined the association between stress, verbal memory, and brain volumes in HIV-infected women. Participants included 38 HIV-infected women (Mean age=43.9years) from the Chicago Consortium of the Women's Interagency HIV Study (WIHS). Participants underwent structural magnetic resonance imaging (MRI) and completed standardized measures of verbal learning and memory and stress (Perceived Stress Scale-10; PSS-10). Brain volumes were evaluated in a priori regions of interest, including the medial temporal lobe (MTL) and prefrontal cortex (PFC). Compared to HIV-infected women with lower stress (PSS-10 scores in lower two tertiles), HIV-infected women with higher stress (scores in the top tertile), performed worse on measures of verbal learning and memory and showed smaller volumes bilaterally in the parahippocampal gyrus, superior frontal gyrus, middle frontal gyrus, and inferior frontal gyrus (p'slearning and memory performance. Prefrontal cortical atrophy is associated with stress-related deficits in verbal learning and memory in HIV-infected women. The time course of these volume losses in relation to memory deficits has yet to be elucidated, but the magnitude of the volumetric differences between women with higher versus lower stress suggests a prolonged vulnerability due to chronic stress and/or early life trauma.

  16. Critical Role of Endoplasmic Reticulum Stress in Chronic Intermittent Hypoxia-Induced Deficits in Synaptic Plasticity and Long-Term Memory.

    Science.gov (United States)

    Xu, Lin-Hao; Xie, Hui; Shi, Zhi-Hui; Du, Li-Da; Wing, Yun-Kwok; Li, Albert M; Ke, Ya; Yung, Wing-Ho

    2015-09-20

    This study examined the role of endoplasmic reticulum (ER) stress in mediating chronic intermittent hypoxia (IH)-induced neurocognitive deficits. We designed experiments to demonstrate that ER stress is initiated in the hippocampus under chronic IH and determined its role in apoptotic cell death, impaired synaptic structure and plasticity, and memory deficits. Two weeks of IH disrupted ER fine structure and upregulated ER stress markers, glucose-regulated protein 78, caspase-12, and C/EBP homologous protein, in the hippocampus, which could be suppressed by ER stress inhibitors, tauroursodeoxycholic acid (TUDCA) and 4-phenylbutyric acid. Meanwhile, ER stress induced apoptosis via decreased Bcl-2, promoted reactive oxygen species production, and increased malondialdehyde formation and protein carbonyl, as well as suppressed mitochondrial function. These effects were largely prevented by ER stress inhibitors. On the other hand, suppression of oxidative stress could reduce ER stress. In addition, the length of the synaptic active zone and number of mature spines were reduced by IH. Long-term recognition memory and spatial memory were also impaired, which was accompanied by reduced long-term potentiation in the Schaffer collateral pathway. These effects were prevented by coadministration of the TUDCA. These results show that ER stress plays a critical role in underlying memory deficits in obstructive sleep apnea (OSA)-associated IH. Attenuators of ER stress may serve as novel adjunct therapeutic agents for ameliorating OSA-induced neurocognitive impairment.

  17. Fetal oxidative stress mechanisms of neurodevelopmental deficits and exacerbation by ethanol and methamphetamine.

    Science.gov (United States)

    Wells, Peter G; Bhatia, Shama; Drake, Danielle M; Miller-Pinsler, Lutfiya

    2016-06-01

    In utero exposure of mouse progeny to alcohol (ethanol, EtOH) and methamphetamine (METH) causes substantial postnatal neurodevelopmental deficits. One emerging pathogenic mechanism underlying these deficits involves fetal brain production of reactive oxygen species (ROS) that alter signal transduction, and/or oxidatively damage cellular macromolecules like lipids, proteins, and DNA, the latter leading to altered gene expression, likely via non-mutagenic mechanisms. Even physiological levels of fetal ROS production can be pathogenic in biochemically predisposed progeny, and ROS formation can be enhanced by drugs like EtOH and METH, via activation/induction of ROS-producing NADPH oxidases (NOX), drug bioactivation to free radical intermediates by prostaglandin H synthases (PHS), and other mechanisms. Antioxidative enzymes, like catalase in the fetal brain, while low, provide critical protection. Oxidatively damaged DNA is normally rapidly repaired, and fetal deficiencies in several DNA repair proteins, including oxoguanine glycosylase 1 (OGG1) and breast cancer protein 1 (BRCA1), enhance the risk of drug-initiated postnatal neurodevelopmental deficits, and in some cases deficits in untreated progeny, the latter of which may be relevant to conditions like autism spectrum disorders (ASD). Risk is further regulated by fetal nuclear factor erythroid 2-related factor 2 (Nrf2), a ROS-sensing protein that upregulates an array of proteins, including antioxidative enzymes and DNA repair proteins. Imbalances between conceptal pathways for ROS formation, versus those for ROS detoxification and DNA repair, are important determinants of risk. Birth Defects Research (Part C) 108:108-130, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  18. Ultraviolet-B radiation and water deficit interact to alter flavonol and anthocyanin profiles in grapevine berries through transcriptomic regulation.

    Science.gov (United States)

    Martínez-Lüscher, Johann; Sánchez-Díaz, Manuel; Delrot, Serge; Aguirreolea, Jone; Pascual, Inmaculada; Gomès, Eric

    2014-11-01

    UV-B radiation and water deficit may trigger flavonol and anthocyanin biosynthesis in plant tissues. In addition, previous research has showed strong qualitative effects on grape berry skin flavonol and anthocyanin profiles in response to UV-B and water deficit. The aim of this study is to identify the mechanisms leading to quantitative and qualitative changes in flavonol and anthocyanin profiles, in response to separate and combined UV-B and water deficit. Grapevines (Vitis vinifera L. cv. Tempranillo) were exposed to three levels of UV-B radiation (0, 5.98 and 9.66 kJ m(-2) day(-1)) and subjected to two water regimes. A strong effect of UV-B on flavonol and anthocyanin biosynthesis was found, resulting in an increased anthocyanin concentration and a change in their profile. Concomitantly, two key biosynthetic genes (FLS1 and UFGT) were up-regulated by UV-B, leading to increased flavonol and anthocyanin skin concentration. Changes in flavonol and anthocyanin composition were explained to a large extend by transcript levels of F3'H, F3'5'H and OMT2. A significant interaction between UV-B and water deficit was found in the relative abundance of 3'4' and 3'4'5' substituted flavonols, but not in their anthocyanin homologues. The ratio between 3'4'5' and 3'4' substituted flavonols was linearly related to the ratios of F3'5'H and FLS1 transcription, two steps up-regulated independently by water deficit and UV-B radiation, respectively. Our results indicate that changes in flavonol profiles in response to environmental conditions are not only a consequence of changes in the expression of flavonoid hydroxylases; but also the result of the competition of FLS, F3'5'H and F3'H enzymes for the same flavonol substrates.

  19. Kaolin particle film and water deficit influence red winegrape color under high solar radiation in an arid climate

    Science.gov (United States)

    Main and interactive effects of a kaolin-based particle film and water deficit severity on vine and berry attributes were evaluated in the warm, semi-arid climate of southwestern Idaho over three growing seasons in the cultivars Cabernet Sauvignon and Malbec. Berry concentrations of total anthocyan...

  20. Potential foraging decisions by a desert ungulate to balance water and nutrient intake in a water-stressed environment

    Science.gov (United States)

    Gedir, Jay V.; Cain, James W.; Krausman, Paul R.; Allen, Jamison D.; Duff, Glenn C.; Morgart, John R.

    2016-01-01

    Arid climates have unpredictable precipitation patterns, and wildlife managers often provide supplemental water to help desert ungulates endure the hottest, driest periods. When surface water is unavailable, the only source of water for ungulates comes from the forage they consume, and they must make resourceful foraging decisions to meet their requirements. We compared two desert bighorn sheep (Ovis canadensis nelsoni) populations in Arizona, USA: a treatment population with supplemental water removed during treatment, and a control population. We examined whether sheep altered their seasonal diets without supplemental water. We calculated water and nutrient intake and metabolic water production from dry matter intake and forage moisture and nitrogen content, to determine whether sheep could meet their seasonal daily water and nutrient requirements solely from forage. Diets of sheep were higher in protein (all seasons) and moisture (autumn and winter) during treatment compared to pretreatment. During treatment, sheep diet composition was similar between the treatment and control populations, which suggests, under the climatic conditions of this study, water removal did not influence sheep diets. We estimated that under drought conditions, without any surface water available (although small ephemeral potholes would contain water after rains), female and male sheep would be unable to meet their daily water requirements in all seasons, except winter, when reproductive females had a nitrogen deficit. We determined that sheep could achieve water and nutrient balances in all seasons by shifting their total diet proportions by 8–55% from lower to higher moisture and nitrogen forage species. We elucidate how seasonal forage quality and foraging decisions by desert ungulates allow them to cope with their xeric and uncertain environment, and suggest that, with the forage conditions observed in our study area during this study period, providing supplemental water during

  1. Tualang Honey Attenuates Noise Stress-Induced Memory Deficits in Aged Rats.

    Science.gov (United States)

    Azman, Khairunnuur Fairuz; Zakaria, Rahimah; Abdul Aziz, Che Badariah; Othman, Zahiruddin

    2016-01-01

    Ageing and stress exposure may lead to memory impairment while oxidative stress is thought to be one of the underlying mechanisms involved. This study aimed to investigate the potential protective effects of Tualang honey supplementation on memory performance in aged rats exposed to noise stress. Tualang honey supplementation was given orally, 200 mg/kg body weight for 28 days. Rats in the stress group were subjected to loud noise, 100 dB(A), 4 hours daily for 14 days. All rats were subjected to novel object recognition test for evaluation of memory performance. It was observed that the rats subjected to noise stress exhibited significantly lower memory performance and higher oxidative stress as evident by elevated malondialdehyde and protein carbonyl levels and reduction of antioxidant enzymes activities compared to the nonstressed rats. Tualang honey supplementation was able to improve memory performance, decrease oxidative stress levels, increase brain-derived neurotrophic factor (BDNF) concentration, decrease acetylcholinesterase activity, and enhance neuronal proliferation in the medial prefrontal cortex (mPFC) and hippocampus. In conclusion, Tualang honey protects against memory decline due to stress exposure and/or ageing via enhancement of mPFC and hippocampal morphology possibly secondary to reduction in brain oxidative stress and/or upregulation of BDNF concentration and cholinergic system.

  2. Tualang Honey Attenuates Noise Stress-Induced Memory Deficits in Aged Rats

    Directory of Open Access Journals (Sweden)

    Khairunnuur Fairuz Azman

    2016-01-01

    Full Text Available Ageing and stress exposure may lead to memory impairment while oxidative stress is thought to be one of the underlying mechanisms involved. This study aimed to investigate the potential protective effects of Tualang honey supplementation on memory performance in aged rats exposed to noise stress. Tualang honey supplementation was given orally, 200 mg/kg body weight for 28 days. Rats in the stress group were subjected to loud noise, 100 dB(A, 4 hours daily for 14 days. All rats were subjected to novel object recognition test for evaluation of memory performance. It was observed that the rats subjected to noise stress exhibited significantly lower memory performance and higher oxidative stress as evident by elevated malondialdehyde and protein carbonyl levels and reduction of antioxidant enzymes activities compared to the nonstressed rats. Tualang honey supplementation was able to improve memory performance, decrease oxidative stress levels, increase brain-derived neurotrophic factor (BDNF concentration, decrease acetylcholinesterase activity, and enhance neuronal proliferation in the medial prefrontal cortex (mPFC and hippocampus. In conclusion, Tualang honey protects against memory decline due to stress exposure and/or ageing via enhancement of mPFC and hippocampal morphology possibly secondary to reduction in brain oxidative stress and/or upregulation of BDNF concentration and cholinergic system.

  3. Transcriptional differences in gene families of the ascorbate-glutathione cycle in wheat during mild water deficit.

    Science.gov (United States)

    Secenji, Maria; Hideg, Eva; Bebes, Attila; Györgyey, János

    2010-01-01

    When comparing the responses of two wheat (Triticum aestivum L.) genotypes, the drought-tolerant Plainsman V and the drought-sensitive Cappelle Desprez, to reduced amounts of irrigation water, we found differences in ascorbate metabolism: both ascorbate oxidation and transcription levels of enzymes processing ascorbate were changed. Relative transcript levels of ascorbate peroxidase (APX), monodehydroascorbate reductase (MDAR), dehydroascorbate reductase (DHAR) and glutathione reductase (GR) isoenzymes, predicted to localize in distinct subcellular organelles, showed different transcriptional changes in the two genotypes. Among APX coding mRNAs, expression levels of two cytosolic (cAPX I, II) and a thylakoid-bound (tAPX) variants increased significantly in Plainsman V while a cytosolic (cAPX I) and a stromal (sAPX II) APX coding transcripts were found to be higher in Cappelle Desprez after a 4-week-long water-deficit stress. Examining the MDARs, two cytosolic isoforms (cMDAR I, II) displayed significant up-regulation of mRNA levels in the sensitive genotype, whereas only one of them (cMDAR II) did in the tolerant cultivar. We found an up-regulated chloroplastic DHAR (chlDHAR) mRNA only in the sensitive Cappelle Desprez. However, increased expression levels of a cytosolic GR (cGR) and a chloroplastic GR (chlGR) were detected only in the tolerant Plainsman V. After 4 weeks of reduced irrigation, a significantly lower ascorbate/dehydroascorbate ratio was detected in leaves of the sensitive Cappelle Desprez than in the tolerant Plainsman V. Our results indicate that more robust transcription of ascorbate-based detoxification machinery may prevent an adverse shift of the cellular redox balance.

  4. Midazolam-ketamine dual therapy stops cholinergic status epilepticus and reduces Morris water maze deficits.

    Science.gov (United States)

    Niquet, Jerome; Baldwin, Roger; Norman, Keith; Suchomelova, Lucie; Lumley, Lucille; Wasterlain, Claude G

    2016-09-01

    Pharmacoresistance remains an unsolved therapeutic challenge in status epilepticus (SE) and in cholinergic SE induced by nerve agent intoxication. SE triggers a rapid internalization of synaptic γ-aminobutyric acid A (GABAA ) receptors and externalization of N-methyl-d-aspartate (NMDA) receptors that may explain the loss of potency of standard antiepileptic drugs (AEDs). We hypothesized that a drug combination aimed at correcting the consequences of receptor trafficking would reduce SE severity and its long-term consequences. A severe model of SE was induced in adult Sprague-Dawley rats with a high dose of lithium and pilocarpine. The GABAA receptor agonist midazolam, the NMDA receptor antagonist ketamine, and/or the AED valproate were injected 40 min after SE onset in combination or as monotherapy. Measures of SE severity were the primary outcome. Secondary outcomes were acute neuronal injury, spontaneous recurrent seizures (SRS), and Morris water maze (MWM) deficits. Midazolam-ketamine dual therapy was more efficient than double-dose midazolam or ketamine monotherapy or than valproate-midazolam or valproate-ketamine dual therapy in reducing several parameters of SE severity, suggesting a synergistic mechanism. In addition, midazolam-ketamine dual therapy reduced SE-induced acute neuronal injury, epileptogenesis, and MWM deficits. This study showed that a treatment aimed at correcting maladaptive GABAA receptor and NMDA receptor trafficking can stop SE and reduce its long-term consequences. Early midazolam-ketamine dual therapy may be superior to monotherapy in the treatment of benzodiazepine-refractory SE. Published 2016. This article is a U.S. Government work and is in the public domain in the USA.

  5. How plants cope with water stress in the field. Photosynthesis and growth.

    Science.gov (United States)

    Chaves, M M; Pereira, J S; Maroco, J; Rodrigues, M L; Ricardo, C P P; Osório, M L; Carvalho, I; Faria, T; Pinheiro, C

    2002-06-01

    Plants are often subjected to periods of soil and atmospheric water deficit during their life cycle. The frequency of such phenomena is likely to increase in the future even outside today's arid/semi-arid regions. Plant responses to water scarcity are complex, involving deleterious and/or adaptive changes, and under field conditions these responses can be synergistically or antagonistically modified by the superimposition of other stresses. This complexity is illustrated using examples of woody and herbaceous species mostly from Mediterranean-type ecosystems, with strategies ranging from drought-avoidance, as in winter/spring annuals or in deep-rooted perennials, to the stress resistance of sclerophylls. Differences among species that can be traced to different capacities for water acquisition, rather than to differences in metabolism at a given water status, are described. Changes in the root : shoot ratio or the temporary accumulation of reserves in the stem are accompanied by alterations in nitrogen and carbon metabolism, the fine regulation of which is still largely unknown. At the leaf level, the dissipation of excitation energy through processes other than photosynthetic C-metabolism is an important defence mechanism under conditions of water stress and is accompanied by down-regulation of photochemistry and, in the longer term, of carbon metabolism.

  6. Dealing with water deficit in Atta ant colonies: large ants scout for water while small ants transport it

    Directory of Open Access Journals (Sweden)

    Antonio Carlos Da-Silva

    2012-07-01

    Leafcutter ants (Atta sexdens rubropilosa (Forel 1908 have an elaborate social organization, complete with caste divisions. Activities carried out by specialist groups contribute to the overall success and survival of the colony when it is confronted with environmental challenges such as dehydration. Ants detect variations in humidity inside the nest and react by activating several types of behavior that enhance water uptake and decrease water loss, but it is not clear whether or not a single caste collects water regardless of the cost of bringing this resource back to the colony. Accordingly, we investigated water collection activities in three colonies of Atta sexdens rubropilosa experimentally exposed to water stress. Specifically, we analyzed whether or not the same ant caste foraged for water, regardless of the absolute energetic cost (distance of transporting this resource back to the colony. Our experimental design offered water sources at 0 m, 1 m and 10 m from the nest. We studied the body size of ants near the water sources from the initial offer of water (time  =  0 to 120 min, and tested for specialization. We observed a reduction in the average size and variance of ants that corroborated the specialization hypothesis. Although the temporal course of specialization changed with distance, the final outcome was similar among distances. Thus, we conclude that, for this species, a specialist (our use of the word “specialist” does not mean exclusive task force is responsible for collecting water, regardless of the cost of transporting water back to the colony.

  7. Experienced stress produces inhibitory deficits in old adults' Flanker task performance: First evidence for lifetime stress effects beyond memory.

    Science.gov (United States)

    Marshall, Amanda C; Cooper, Nicholas R; Geeraert, Nicolas

    2016-01-01

    Studies regarding aged individuals' performance on the Flanker task differ with respect to reporting impaired or intact executive control. Past work has explained this discrepancy by hypothesising that elderly individuals use increased top-down control mechanisms advantageous to Flanker performance. This study investigated this mechanism, focussing on cumulative experienced stress as a factor that may impact on its execution, thereby leading to impaired performance. Thirty elderly and thirty young participants completed a version of the Flanker task paired with electroencephalographic recordings of the alpha frequency, whose increased synchronisation indexes inhibitory processes. Among high stress elderly individuals, findings revealed a general slowing of reaction times for congruent and incongruent stimuli, which correlated with alpha desynchronisation for both stimulus categories. Results found high performing (low stress) elderly revealed neither a behavioural nor electrophysiological difference compared to young participants. Therefore, rather than impacting on top-down compensatory mechanisms, findings indicate that stress may affect elderly participants' inhibitory control in attentional and sensorimotor domains.

  8. WATER STRESS RESPONSE ON THE ENZYMATIC ACTIVITY IN COWPEA NODULES

    Directory of Open Access Journals (Sweden)

    Figueiredo Márcia do Vale B.

    2001-01-01

    Full Text Available A greenhouse experiment was carried out aiming to study the effect of water stress on metabolic activity of cowpea nodules at different plant development stages. Cowpea plants were grown in pots with yellow latosol soil under three different matric potentials treatments: -7.0 (control-S1, -70.0 (S2 and <-85.0 KPa (S3. The experimental design was randomized blocks with sub-divided plots, each plot containing a different degree of water stress, divided in sub-plots for the four different developmental stages: E1 (0-15, E2 (15-30, E3 (20-35 and E4 (30-45 days after emmergence. Water stress treatments were applied by monitoring soil water potential using a set of porous cups. The effect of water stress was most harmful to cowpea when it was applied at E2 than at other symbiotic process stages. Shoot/root ratio decreased from 2.61 to 2.14 when matric potential treatment was <-85.0 and -70.0 KPa respectively. There was a reduction in the glutamine synthetase activity and phosphoenolpyruvate carboxilase activity with increased stress, while glutamine synthase activity was the enzyme most sensitive to water stress. Glutamate dehydrogenase activity increased in more negative matric potential, indicating that this enzyme is sufficiently activitye under water stress.

  9. Morphological responses of pulse (Vigna spp. crops to soil water deficit

    Directory of Open Access Journals (Sweden)

    Baroowa Bhaswatee

    2012-01-01

    Full Text Available The present experiment was conducted with two common pulse crops namely black gram (Vigna mungo L. and green gram (Vigna radiata L. with the objective to study the morpho-physiological changes that took place in response to low moisture stress. Parameters such as plant height, leaf number, leaf area and pod number were studied under moisture stress condition as well as subsequent recovery stages. At harvest, yields of these two crops were recorded and various yield indexes like drought susceptibility index, drought tolerance index, mean and productivity rate were calculated. The study revealed that moisture stress has a significant impact on all these parameters in both crops. The effect was more significant in green gram compared to black gram. From the findings it is observed that moisture stress during flowering stage is detrimental for yield of the pulse crops and re-watering does not have a significant impact on yield improvement. Black gram variety T9 and green gram variety Pratap were identified as drought-tolerant varieties.

  10. Assessing maize foliar water stress levels under field conditions ...

    African Journals Online (AJOL)

    Assessing maize foliar water stress levels under field conditions using in-situ ... is non-destructive to the crops as opposed to other traditional ground-based methods. ... water indices that could monitor the water status at leaf level on maize (Zea ... about AJOL · AJOL's Partners · Contact AJOL · Terms and Conditions of Use.

  11. An Integrated Analysis of Changes in Water Stress in Europe

    DEFF Research Database (Denmark)

    Henrichs, T.; Lehner, B.; Alcamo, J.

    2002-01-01

    Future changes in water availability with climate change and changes in water use due to socio-economic development are to occur in parallel. In an integrated analysis we bring together these aspects of global change in a consistent manner, and analyse the water stress situation in Europe. We find...

  12. Rice leaf growth and water potential are resilient to evaporative demand and soil water deficit once the effects of root system are neutralized.

    Science.gov (United States)

    Parent, Boris; Suard, Benoît; Serraj, Rachid; Tardieu, François

    2010-08-01

    Rice is known to be sensitive to soil water deficit and evaporative demand, with a greatest sensitivity of lowland-adapted genotypes. We have analysed the responses of plant water relations and of leaf elongation rate (LER) to soil water status and evaporative demand in seven rice genotypes belonging to different species, subspecies, either upland- or lowland-adapted. In the considered range of soil water potential (0 to -0.6 MPa), stomatal conductance was controlled in such a way that the daytime leaf water potential was similar in well-watered, droughted or flooded conditions (isohydric behaviour). A low sensitivity of LER to evaporative demand was observed in the same three conditions, with small differences between genotypes and lower sensitivity than in maize. The sensitivity of LER to soil water deficit was similar to that of maize. A tendency towards lower sensitivities was observed in upland than lowland genotypes but with smaller differences than expected. We conclude that leaf water status and leaf elongation of rice are not particularly sensitive to water deficit. The main origin of drought sensitivity in rice may be its poor root system, whose effect was alleviated in the study presented here by growing plants in pots whose soil was entirely colonized by roots of all genotypes.

  13. Response to water deficit and high temperature of transgenic peas (Pisum sativum L.) containing a seed-specific alpha-amylase inhibitor and the subsequent effects on pea weevil (Bruchus pisorum L.) survival.

    Science.gov (United States)

    Sousa-Majer, Maria José de; Turner, Neil C; Hardie, Darryl C; Morton, Roger L; Lamont, Byron; Higgins, Thomas J V

    2004-02-01

    The effects of water deficit and high temperature on the production of alpha-amylase inhibitor 1 (alpha-AI-1) were studied in transgenic peas (Pisum sativum L.) that were developed to control the seed-feeding pea weevil (Bruchus pisorum L., Coleoptera: Bruchidae). Transgenic and non-transgenic plants were subjected to water-deficit and high-temperature treatments under controlled conditions in the glasshouse and growth cabinet, beginning 1 week after the first pods were formed. In the water-deficit treatments, the peas were either adequately watered (control) or water was withheld after first pod formation. The high-temperature experiments were performed in two growth cabinets, one maintained at 27/22 degrees C (control) and one at 32/27 degrees C day/night temperatures, with the vapour pressure deficit maintained at 1.3 kPa. The plants exposure to high temperatures and water deficit produced 27% and 79% fewer seeds, respectively, than the controls. In the transgenic peas the level of alpha-AI-1 as a percentage of total protein was not influenced by water stress, but was reduced on average by 36.3% (the range in two experiments was 11-50%) in the high-temperature treatment. Transgenic and non-transgenic pods of plants grown at 27/22 degrees C and 32/27 degrees C were inoculated with pea weevil eggs to evaluate whether the reduction in level of alpha-AI-1 in the transgenic pea seeds affected pea weevil development and survival. At the higher temperatures, 39% of adult pea weevil emerged, compared to 1.2% in the transgenic peas grown at the lower temperatures, indicating that high temperature reduced the protective capacity of the transgenic peas.

  14. Public participation and rural management of Brazilian waters: an alternative to the deficit model (Portuguese original version

    Directory of Open Access Journals (Sweden)

    Alessandro Luís Piolli

    2008-12-01

    Full Text Available The knowledge deficit model with regard to the public has been severely criticized in the sociology of the public perception of science. However, when dealing with public decisions regarding scientific matters, political and scientific institutions insist on defending the deficit model. The idea that only certified experts, or those with vast experience, should have the right to participate in decisions can bring about problems for the future of democracies. Through a type of "topography of ideas", in which some concepts from the social studies of science are used in order to think about these problems, and through the case study of public participation in the elaboration of the proposal of discounts in the fees charged for rural water use in Brazil, we will try to point out an alternative to the deficit model. This alternative includes a "minimum comprehension" of the scientific matters involved in the decision on the part of the participants, using criteria judged by the public itself.

  15. P2X7 Receptor Antagonism Attenuates the Intermittent Hypoxia-induced Spatial Deficits in a Murine Model of Sleep Apnea Via Inhibiting Neuroinflammation and Oxidative Stress

    Institute of Scientific and Technical Information of China (English)

    Yan Deng; Xue-Ling Guo; Xiao Yuan; Jin Shang; Die Zhu; Hui-Guo Liu

    2015-01-01

    Background:The mechanism of the neural injury caused by chronic intermittent hypoxia (CIH) that characterizes obstructive sleep apnea syndrome (OSAS) is not clearly known.The purpose of this study was to investigate whether P2X7 receptor (P2X7R) is responsible for the CIH-induced neural injury and the possible pathway it involves.Methods:Eight-week-old male C57BL/6 mice were used.For each exposure time point,eight mice divided in room air (RA) and IH group were assigned to the study of P2X7R expression.Whereas in the 21 days-Brilliant Blue G (BBG,a selective P2X7R antagonist) study,48 mice were randomly divided into CIH group,BBG-treated CIH group,RA group and BBG-treated RA group.The hippocampus P2X7R expression was determined by Western blotting and real-time polymerase chain reaction (PCR).The spatial learning was analyzed by Morris water maze.The nuclear factor kappa B (NFκB) and NADPH oxidase 2 (NOX2) expressions were analyzed by Westem blotting.The expressions of tumor necrosis factor α,interleukin 1 β (IL-β),IL-18,and IL-6 were measured by real-time PCR.The malondialdehyde and superoxide dismutase levels were detected by colorimetric method.Cell damage was evaluated by Hematoxylin and Eosin staining and Terminal Transferase dUTP Nick-end Labeling method.Results:The P2X7R mRNA was elevated and sustained after 3-day IH exposure and the P2X7R protein was elevated and sustained after 7-day IH exposure.In the BBG study,the CIH mice showed severer neuronal cell damage and poorer performance in the behavior test.The increased NFκB and NOX2 expressions along with the inflammation injury and oxidative stress were also observed in the CIH group.BBG alleviated CIH-induced neural injury and consequent functional deficits.Conclusions:The P2X7R antagonism attenuates the CIH-induced neuroinflammation,oxidative stress,and spatial deficits,demonstrating that the P2X7R is an important therapeutic target in the cognition deficits accompanied OSAS.

  16. Detecting Plant Photoprotective Response to Water Stress Through Variation In PAR Reflectance

    Science.gov (United States)

    Zygielbaum, A. I.; Arkebauer, T. J.; Walter-Shea, E.

    2012-12-01

    Published papers over several decades have shown increasing leaf-level optical reflectance with decreasing leaf water content. Our experimental results using maize and sorghum showed this increase consistently, caused by variation in optical absorption, in the visible (photosynthetically active radiation - PAR) and middle infrared (MIR) spectral regions. Relatively smaller response, driven by variation in optical scatter, was observed in near infrared (NIR). The concomitant increasing reflectance in the PAR and MIR regions is perplexing. PAR reflectance is dominated by chlorophyll absorption while MIR reflectance is dominated by water molecule absorption. However, changes in chlorophyll concentration, determined by chemical extraction, were too small to account for the variation in PAR reflectance. PAR and MIR reflectances were also influenced by the strength of incident light. Hence PAR reflectance appears to be modulated not only by pigment concentration, the classical description, but also by the strength of incident light and the severity of water deficit. We previously reported that these findings were consistent with chloroplast avoidance movement, a plant photoprotective response, which limits light absorption by pigments. We report here our continuing investigation of this phenomenon. In addition to reflectance measurements, time-lapse microscope images of leaves under increasing water deficit conditions were obtained. These show a brightening between veins which strongly supports our assertion that changes in PAR reflectance accompanying water deficit are caused primarily by chloroplast avoidance movement. Our results suggest that leaf, and possibly canopy, reflectance can therefore be used to detect and measure plant stress. These results also indicate that chloroplast avoidance movement may cause poor estimates of leaf chlorophyll content using techniques based on fluoresced, reflected or transmitted light.

  17. Water aging reverses residual stresses in hydrophilic dental composites.

    Science.gov (United States)

    Park, J W; Ferracane, J L

    2014-02-01

    Dental composites develop residual stresses during polymerization due to shrinkage. These stresses may change with time because of relaxation and water sorption in the oral environment. This phenomenon is likely dependent on the composition of the materials, specifically their hydrophilic characteristics, and could result in deleterious stresses on restorative materials and tooth structure. The purpose of this experiment was to use the thin ring-slitting method to compare the residual stress generated within composite materials of varying hydrophilicity when aged in wet and dry conditions after polymerization. Water sorption, solubility, elastic modulus, and residual stresses were measured in 6 commercial composites/cements aged in water and dry conditions. The self-adhesive resin cement showed the highest water sorption and solubility. All composites showed initial residual contraction stresses, which were maintained when aged dry. Residual stresses in 2 of the self-adhesive cements and the polyacid-modified composite aged in wet conditions resulted in a net expansion. This experiment verified that residual shrinkage stresses in dental composites can be reversed during aging in water, resulting in a net expansion, with the effect directly related to their hydrophilic properties.

  18. Forest Mortality in High-Elevation Pine Forests of Eastern California, USA; Influence of Climatic Water Deficit

    Science.gov (United States)

    Millar, C. I.; Westfall, R. D.; Flint, A. L.; Flint, L. E.; Bokach, M. J.; Delany, D. L.

    2011-12-01

    Widespread mortality in high-elevation forests has been increasing across western North American mountains in recent years, with climate, insects, and disease the primary causes. Subalpine forests in the eastern Sierra Nevada, by contrast, have experienced far less mortality than other ranges, and mortality events have been patchy and episodic. This situation, and lack of significant effect of non-native white-pine blister rust, enable investigation of fine-scale response of two subalpine Sierran species, whitebark pine (Pinus albicaulis, PiAl) and limber pine (P. flexilis, PiFl), to climate variability, in particular, climatic water deficit (CWD). We report similarities and differences between the two major mortality events in these pines in the last 150 years: 1988-1992 for PiFl and 2006-ongoing for PiAl. The ultimate cause of tree death was mountain pine beetle (Dendroctonus ponderosae), with climatic factors pre-conditioning stress in both species. Our studies include intensive ecology-plot analyses (both species) and region-wide air-survey forest-mortality detection mapping (PiAl only). We used climatic data from historic weather station data; for CWD, we modeled values from PRISM regional climate projections downscaled to 270 m and applied these to a regional water-balance model. The strongest correlations of ring-width (a measure of tree growth) in both species to climatic variables were to CWD: PiFl, -0.29 and -0.54 for live and dead trees, respectively; PiAl ,-0.19 for both live and dead trees. Correlations of ring-widths to 2-year lagged CWD were higher than to current-year means: PiFl, -0.34 and -0.44 for live and dead trees, respectively; PiAl, -0.43 and -0.46, live and dead trees, respectively. Mean annual CWD values of the mortality plots in the intensive study were 181 mm (PiAl) and 289 mm (PiFl); air surveys showed significantly higher CWD values for PiAl mortality stands than live forests (387 mm and 307 mm, respectively). Correlations of growth to

  19. Identification of resilient individuals and those at risk for performance deficits under stress

    National Research Council Canada - National Science Library

    Winslow, Brent D; Carroll, Meredith B; Martin, Jonathan W; Surpris, Glenn; Chadderdon, George L

    2015-01-01

    .... The ability to measure the physiological response to stressors and correlate that to task performance could be used to identify resilient individuals or those at risk for stress-related performance decrements...

  20. Physical activity attenuates intermittent hypoxia-induced spatial learning deficits and oxidative stress

    National Research Council Canada - National Science Library

    Gozal, David; Nair, Deepti; Goldbart, Aviv D

    2010-01-01

    Exposure to intermittent hypoxia (IH), such as occurs in sleep-disordered breathing, is associated with substantial cognitive impairments, oxidative stress and inflammation, and increased neuronal cell losses in brain regions underlying...

  1. Increasing water stress negatively affects pear fruit growth by reducing first its xylem and then its phloem inflow.

    Science.gov (United States)

    Morandi, Brunella; Losciale, Pasquale; Manfrini, Luigi; Zibordi, Marco; Anconelli, Stefano; Galli, Fabio; Pierpaoli, Emanuele; Corelli Grappadelli, Luca

    2014-10-15

    Drought stress negatively affects many physiological parameters and determines lower yields and fruit size. This paper investigates on the effects of prolonged water restriction on leaf gas exchanges, water relations and fruit growth on a 24-h time-scale in order to understand how different physiological processes interact to each other to face increasing drought stress and affect pear productive performances during the season. The diurnal patterns of tree water relations, leaf gas exchanges, fruit growth, fruit vascular and transpiration flows were monitored at about 50, 95 and 145 days after full bloom (DAFB) on pear trees of the cv. Abbé Fétel, subjected to two irrigation regimes, corresponding to a water restitution of 100% and 25% of the estimated Etc, respectively. Drought stress progressively increased during the season due to lower soil tensions and higher daily vapour pressure deficits (VPDs). Stem water potential was the first parameter to be negatively affected by stress and determined the simultaneous reduction of fruit xylem flow, which at 95 DAFB was reflected by a decrease in fruit daily growth. Leaf photosynthesis was reduced only from 95 DAFB on, but was not immediately reflected by a decrease in fruit phloem flow, which instead was reduced only at 145 DAFB. This work shows how water stress negatively affects pear fruit growth by reducing first its xylem and then its phloem inflow. This determines a progressive increase in the phloem relative contribution to growth, which lead to the typical higher dry matter percentages of stressed fruit.

  2. Water stress as a trigger of demand change: exploring the implications for drought planning

    Science.gov (United States)

    Garcia, M. E.; Islam, S.; Portney, K. E.

    2015-12-01

    Drought in the Anthropocene is a function of both supply and demand. Despite its importance, demand is typically incorporated into planning models exogenously using a single scenario of demand change over time. Alternatively, demand is incorporated endogenously in hydro-economic models based on the assumption of rationality. However, actors are constrained by limited information and information processing capabilities, casting doubt on the rationality assumption. Though the risk of water shortage changes incrementally with demand growth and hydrologic change, significant shifts in management are punctuated and often linked to periods of stress. The observation of lasting decreases in per capita demands in a number of cities during periods of water stress prompts an alternate hypothesis: the occurrence of water stress increases the tendency of cities to promote and enforce efficient technologies and behaviors and the tendency of users to adopt them. We show the relevance of this hypothesis by building a model of a hypothetical surface water system to answer the following question: what is the impact of reservoir operation policy on the reliability of water supply for a growing city? The model links the rate of demand decreases to the past reliability to compare standard operating policy (SOP) with hedging policy (HP). Under SOP, demand is fulfilled unless available supply drops below demand; under HP, water releases are reduced in anticipation of a deficit to decrease the risk of a large shortfall. The model shows that reservoir storage acts both as a buffer for variability and as a delay triggering oscillations around a sustainable level of demand. HP reduces the threshold for action thereby decreasing the delay and the oscillation effect. As a result per capita demand decrease during periods of water stress are more frequent but less drastic and the additive effect of small adjustments decreases the tendency of the system to overshoot available supplies.

  3. Assessing canopy PRI from airborne imagery to map water stress in maize

    Science.gov (United States)

    Rossini, M.; Fava, F.; Cogliati, S.; Meroni, M.; Marchesi, A.; Panigada, C.; Giardino, C.; Busetto, L.; Migliavacca, M.; Amaducci, S.; Colombo, R.

    2013-12-01

    This paper presents a method for mapping water stress in a maize field using hyperspectral remote sensing imagery. An airborne survey using AISA (Specim, Finland) was performed in July 2008 over an experimental farm in Italy. Hyperspectral data were acquired over a maize field with three different irrigation regimes. An intensive field campaign was also conducted concurrently with imagery acquisition to measure relative leaf water content (RWC), active chlorophyll fluorescence (ΔF/Fm‧), leaf temperature (Tl) and Leaf Area Index (LAI). The analysis of the field data showed that at the time of the airborne overpass the maize plots with irrigation deficits were experiencing a moderate water stress, affecting the plant physiological status (ΔF/Fm‧, difference between Tl and air temperature (Tair), and RWC) but not the canopy structure (LAI). Among the different Vegetation Indices (VIs) computed from the airborne imagery the Photochemical Reflectance Index computed using the reflectance at 570 nm as the reference band (PRI570) showed the strongest relationships with ΔF/Fm‧ (r2 = 0.76), Tl - Tair (r2 = 0.82) and RWC (r2 = 0.64) and the red-edge Chlorophyll Index (CIred-edge) with LAI (r2 = 0.64). Thus PRI has been proven to be related to water stress at early stages, before structural changes occurred.

  4. Sweet corn water productivity under several deficit irrigation regimes applied during vegetative growth stage using treated wastewater as water irrigation source

    DEFF Research Database (Denmark)

    Hirich, A.; Rami, A.; Laajaj, K.

    2012-01-01

    .4% in terms of dry grain yield, 10.5% in terms of number of ears per plant, 11.5% for the 1000 grains weight and 19% in terms of crop water productivity compared with fully irrigated treatment. While those parameters in addition to root, shoot and plant height has been affected by deficit irrigation during......Yield and Crop Water Productivity are crucial issues in sustainable agriculture, especially in high-demand resource crops such as sweet corn. This study was conducted to investigate agronomic responses such as plant growth, yield and soil parameters (EC and Nitrate accumulation) to several deficit...... irrigation treatments (100, 75, 50, 25 and 0% of ETm) applied during vegetative growth stage, rainfed treatment was also tested. The finding of this research indicates that under deficit irrigation during vegetative growth stage applying 75% of ETm lead to increasing of 19.4% in terms of fresh ear yield, 9...

  5. Transient water stress in a vegetation canopy - Simulations and measurements

    Science.gov (United States)

    Carlson, Toby N.; Belles, James E.; Gillies, Robert R.

    1991-01-01

    Consideration is given to observational and modeling evidence of transient water stress, the effects of the transpiration plateau on the canopy radiometric temperature, and the factors responsible for the onset of the transpiration plateau, such as soil moisture. Attention is also given to the point at which the transient stress can be detected by remote measurement of surface temperature.

  6. Impacts of water stress, environment and rootstock on the diurnal behaviour of stem water potential and leaf conductance in pistachio (Pistacia vera L.

    Directory of Open Access Journals (Sweden)

    Houssem Memmi

    2016-06-01

    Full Text Available Little information is available on the diurnal behaviour of water potential and leaf conductance on pistachio trees despite their relevance to fine tune irrigation strategies. Mature pistachio trees were subject to simultaneous measurements of stem water potential (Ψx and leaf conductance (gl during the day, at three important periods of the irrigation season. Trees were grown on three different rootstocks and water regimes. An initial baseline relating Ψx to air vapor pressure deficit (VPD is presented for irrigation scheduling in pistachio. Ψx was closely correlated with VPD but with a different fit according to the degree of water stress. No evidence of the variation of Ψx in relation to the phenology of the tree was observed. Furthermore, midday Ψx showed more accuracy to indicate a situation of water stress than predawn water potential. Under well irrigated conditions, gl was positively correlated with VPD during stage II of growth reaching its peak when VPD reached its maximum value (around 4 kPa. This behaviour changed during stage III of fruit growth suggesting a reliance of stomatal behaviour to the phenological stage independently to the tree water status. The levels of water stress reached were translated in a slow recovery of tree water status and leaf conductance (more than 40 days. Regarding rootstocks, P. integerrima showed little adaptation to water shortage compared to the two other rootstocks under the studied conditions.

  7. Impacts of water stress, environment and rootstock on the diurnal behaviour of stem water potential and leaf conductance in pistachio (Pistacia vera L.)

    Energy Technology Data Exchange (ETDEWEB)

    Memmi, H.; Couceiro, J.F.; Gijón, C.; Pérez-López, D.

    2016-11-01

    Little information is available on the diurnal behaviour of water potential and leaf conductance on pistachio trees despite their relevance to fine tune irrigation strategies. Mature pistachio trees were subject to simultaneous measurements of stem water potential (Ψx) and leaf conductance (gl) during the day, at three important periods of the irrigation season. Trees were grown on three different rootstocks and water regimes. An initial baseline relating Ψx to air vapor pressure deficit (VPD) is presented for irrigation scheduling in pistachio. Ψx was closely correlated with VPD but with a different fit according to the degree of water stress. No evidence of the variation of Ψx in relation to the phenology of the tree was observed. Furthermore, midday Ψx showed more accuracy to indicate a situation of water stress than predawn water potential. Under well irrigated conditions, gl was positively correlated with VPD during stage II of growth reaching its peak when VPD reached its maximum value (around 4 kPa). This behaviour changed during stage III of fruit growth suggesting a reliance of stomatal behaviour to the phenological stage independently to the tree water status. The levels of water stress reached were translated in a slow recovery of tree water status and leaf conductance (more than 40 days). Regarding rootstocks, P. integerrima showed little adaptation to water shortage compared to the two other rootstocks under the studied conditions. (Author)

  8. Cytokinin Activity in Water-stressed Shoots 1

    Science.gov (United States)

    Itai, Chanan; Vaadia, Yoash

    1971-01-01

    Water stress applied to the plant shoot through enhanced evaporative demands reduced cytokinin activity in extracts of xylem exudate and leaves. This reduction resembled the changes in cytokinin activity caused by water stress applied to the root. Cytokinin activity in detached wilting leaves decreased rapidly. Recovery took place after several hours in a humid chamber. Experiments with 14C-kinetin indicated that the mechanism of the inactivation and its reversal involve a chemical transformation of the cytokinin molecule. PMID:16657585

  9. Sweet corn water productivity under several deficit irrigation regimes applied during vegetative growth stage using treated wastewater as water irrigation source

    DEFF Research Database (Denmark)

    Hirich, A.; Rami, A.; Laajaj, K.

    2012-01-01

    Yield and Crop Water Productivity are crucial issues in sustainable agriculture, especially in high-demand resource crops such as sweet corn. This study was conducted to investigate agronomic responses such as plant growth, yield and soil parameters (EC and Nitrate accumulation) to several deficit...

  10. THE REFERENCE EVAPOTRANSPIRATION AND THE CLIMATIC WATER DEFICIT IN THE WESTERN PLAIN OF ROMANIA, NORTH OF THE MUREŞ RIVER

    Directory of Open Access Journals (Sweden)

    EUGENIA ŞERBAN

    2013-04-01

    Full Text Available The Reference Evapotranspiration and the Climatic Water Deficit in the Western Plain of Romania, North of the Mureş River. In the present paper, reference evapotranspiration (ET0 was calculated by the method proposed by C.W. Thornthwaite. The climatic water deficit, as the difference between atmospheric precipitation and ET0, has also been calculated and analyzed. In this respect, monthly and annual air temperature and precipitation data from 10 weather stations were used. The analysis period was 1961-2002. The result was that the annual average reference evapotranspiration varies, throughout the Western Plain of Romania, North of the Mureş River territory, between 665 and 700 mm. It decreases from south to north and also from west to east, depending on the territorial distribution of the air temperature. The plain territory reveals an annual climatic water deficit between 63 mm in the north of the plain and 171 mm in its south. Therefore, the predominantly agricultural territory of the plain needs a water surplus from irrigation. Only in the east of the plain, at Holod, there is a surplus of moisture.

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

    Directory of Open Access Journals (Sweden)

    Krzysztof Klamkowski

    2006-12-01

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

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

    Directory of Open Access Journals (Sweden)

    Krzysztof Klamkowski

    2006-01-01

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

  13. Plasticity of Sorghum Stem Biomass Accumulation in Response to Water Deficit: A Multiscale Analysis from Internode Tissue to Plant Level.

    Science.gov (United States)

    Perrier, Lisa; Rouan, Lauriane; Jaffuel, Sylvie; Clément-Vidal, Anne; Roques, Sandrine; Soutiras, Armelle; Baptiste, Christelle; Bastianelli, Denis; Fabre, Denis; Dubois, Cécile; Pot, David; Luquet, Delphine

    2017-01-01

    Sorghum is increasingly used as a biomass crop worldwide. Its genetic diversity provides a large range of stem biochemical composition suitable for various end-uses as bioenergy or forage. Its drought tolerance enables it to reasonably sustain biomass production under water limited conditions. However, drought effect on the accumulation of sorghum stem biomass remains poorly understood which limits progress in crop improvement and management. This study aimed at identifying the morphological, biochemical and histological traits underlying biomass accumulation in the sorghum stem and its plasticity in response to water deficit. Two hybrids (G1, G4) different in stem biochemical composition (G4, more lignified, less sweet) were evaluated during 2 years in the field in Southern France, under two water treatments differentiated during stem elongation (irrigated; 1 month dry-down until an average soil water deficit of -8.85 bars). Plant phenology was observed weekly. At the end of the water treatment and at final harvest, plant height, stem and leaf dry-weight and the size, biochemical composition and tissue histology of internodes at 2-4 positions along the stem were measured. Stem biomass accumulation was significantly reduced by drought (in average 42% at the end of the dry-down). This was due to the reduction of the length, but not diameter, of the internodes expanded during water deficit. These internodes had more soluble sugar but lower lignin and cellulose contents. This was associated with a decrease of the areal proportion of lignified cell wall in internode outer zone whereas the areal proportion of this zone was not affected. All internodes for a given genotype and environment followed a common histochemical dynamics. Hemicellulose content and the areal proportion of inner vs. outer internode tissues were set up early during internode growth and were not drought responsive. G4 exhibited a higher drought sensitivity than G1 for plant height only. At final

  14. Chronic early postnatal scream sound stress induces learning deficits and NMDA receptor changes in the hippocampus of adult mice.

    Science.gov (United States)

    Hu, Lili; Han, Bo; Zhao, Xiaoge; Mi, Lihua; Song, Qiang; Wang, Jue; Song, Tusheng; Huang, Chen

    2016-04-13

    Chronic scream sounds during adulthood affect spatial learning and memory, both of which are sexually dimorphic. The long-term effects of chronic early postnatal scream sound stress (SSS) during postnatal days 1-21 (P1-P21) on spatial learning and memory in adult mice as well as whether or not these effects are sexually dimorphic are unknown. Therefore, the present study examines the performance of adult male and female mice in the Morris water maze following exposure to chronic early postnatal SSS. Hippocampal NR2A and NR2B levels as well as NR2A/NR2B subunit ratios were tested using immunohistochemistry. In the Morris water maze, stress males showed greater impairment in spatial learning and memory than background males; by contrast, stress and background females performed equally well. NR2B levels in CA1 and CA3 were upregulated, whereas NR2A/NR2B ratios were downregulated in stressed males, but not in females. These data suggest that chronic early postnatal SSS influences spatial learning and memory ability, levels of hippocampal NR2B, and NR2A/NR2B ratios in adult males. Moreover, chronic early stress-induced alterations exert long-lasting effects and appear to affect performance in a sex-specific manner.

  15. Thermal infrared as a tool to detect tree water stress in a coniferous forest

    Science.gov (United States)

    Nourtier, M.; Chanzy, A.; Bes, B.; Davi, H.; Hanocq, J. F.; Mariotte, N.; Sappe, G.

    2009-04-01

    In the context of climatic change, species area may move and so, a study of forest species vulnerability is on interest. In Mediterranean regions, trees can suffer of water stress due to drought during summer. Responses to environmental constraints are delayed in forest so it is necessary to anticipate risks in order to adapt management. It would be therefore interesting to localize areas where trees might be vulnerable to water stress. To detect such areas, the idea developed in this study is to map the severity of water stress, which may be linked to soil. Because vegetation surface temperature is linked to transpiration and so to water stress, the relevance of thermal infrared as a tool to detect water stress was explored. Past studies about surface temperature of forests at the planting scale did not lead to conclusive results. At this scale, important spatial and temporal variations of surface temperature, with a magnitude of about 10°C, can be registered but there is possibly a sizeable contribution of the undergrowth (Duchemin, 1998a, 1998b). In the other hand, important stress are not detectable, probably due to meteorological conditions (Pierce et al., 1990). During spring and summer 2008, an experimentation was carried out on the silver fir (Abies alba) forest of Mont Ventoux (south of France) to evaluate temporal variations at tree scale of the surface temperature in relation to water stress and climatic conditions. Two sites and three trees were chosen for measurements of surface temperature with a view to have different levels of water stress. Transpiration deficit is characterised by the ratio of actual transpiration to potential transpiration which is computed by the ISBA model (Noilhan et al., 1989) implemented by climatic observations made at the top of tree canopy. Sap flow measurements needed to calculate this ratio were completed on different trees of the sites. Climatic datas also allows building reference temperature and then surface

  16. Planting Patterns and Deficit Irrigation Strategies to Improve Wheat Production and Water Use Efficiency under Simulated Rainfall Conditions.

    Science.gov (United States)

    Ali, Shahzad; Xu, Yueyue; Ma, Xiangcheng; Ahmad, Irshad; Kamran, Muhammad; Dong, Zhaoyun; Cai, Tie; Jia, Qianmin; Ren, Xiaolong; Zhang, Peng; Jia, Zhikuan

    2017-01-01

    The ridge furrow (RF) rainwater harvesting system is an efficient way to enhance rainwater accessibility for crops and increase winter wheat productivity in semi-arid regions. However, the RF system has not been promoted widely in the semi-arid regions, which primarily exist in remote hilly areas. To exploit its efficiency on a large-scale, the RF system needs to be tested at different amounts of simulated precipitation combined with deficit irrigation. Therefore, in during the 2015-16 and 2016-17 winter wheat growing seasons, we examined the effects of two planting patterns: (1) the RF system and (2) traditional flat planting (TF) with three deficit irrigation levels (150, 75, 0 mm) under three simulated rainfall intensity (1: 275, 2: 200, 3: 125 mm), and determined soil water storage profile, evapotranspiration rate, grain filling rate, biomass, grain yield, and net economic return. Over the two study years, the RF treatment with 200 mm simulated rainfall and 150 mm deficit irrigation (RF2150) significantly (P RF2150 treatment thus achieved a higher WUE (76%) and RIWP (21%) compared to TF. Grain-filling rates, grain weight of superior and inferior grains, and net economic profit of winter wheat responded positively to simulated rainfall and deficit irrigation under both planting patterns. The 200 mm simulated rainfall amount was more economical than other precipitation amounts, and led to slight increases in soil water storage, total dry matter per plant, and grain yield; there were no significant differences when the simulated rainfall was increased beyond 200 mm. The highest (12,593 Yuan ha(-1)) net income profit was attained using the RF system at 200 mm rainfall and 150 mm deficit irrigation, which also led to significantly higher grain yield, WUE, and RIWP than all other treatments. Thus, we recommend the RF2150 treatment for higher productivity, income profit, and improve WUE in the dry-land farming system of China.

  17. How do membrane proteins sense water stress?

    NARCIS (Netherlands)

    Poolman, Bert; Blount, Paul; Folgering, Joost H.A.; Friesen, Robert H.E.; Moe, Paul C.; Heide, Tiemen van der

    2002-01-01

    Maintenance of cell turgor is a prerequisite for almost any form of life as it provides a mechanical force for the expansion of the cell envelope. As changes in extracellular osmolality will have similar physicochemical effects on cells from all biological kingdoms, the responses to osmotic stress m

  18. How do membrane proteins sense water stress?

    NARCIS (Netherlands)

    Poolman, Bert; Blount, Paul; Folgering, Joost H.A.; Friesen, Robert H.E.; Moe, Paul C.; Heide, Tiemen van der

    2002-01-01

    Maintenance of cell turgor is a prerequisite for almost any form of life as it provides a mechanical force for the expansion of the cell envelope. As changes in extracellular osmolality will have similar physicochemical effects on cells from all biological kingdoms, the responses to osmotic stress

  19. Spectral reflectance relationships to leaf water stress

    Science.gov (United States)

    Ripple, William J.

    1986-01-01

    Spectral reflectance data were collected from detached snapbean leaves in the laboratory with a multiband radiometer. Four experiments were designed to study the spectral response resulting from changes in leaf cover, relative water content of leaves, and leaf water potential. Spectral regions included in the analysis were red (630-690 nm), NIR (760-900 nm), and mid-IR (2.08-2.35 microns). The red and mid-IR bands showed sensitivity to changes in both leaf cover and relative water content of leaves. The NIR was only highly sensitive to changes in leaf cover. Results provided evidence that mid-IR reflectance was governed primarily by leaf moisture content, although soil reflectance was an important factor when leaf cover was less than 100 percent. High correlations between leaf water potentials and reflectance were attributed to covariances with relative water content of leaves and leaf cover.

  20. Influence of arbuscular mycorrhizae on photosynthesis and water status of maize plants under salt stress.

    Science.gov (United States)

    Sheng, Min; Tang, Ming; Chen, Hui; Yang, Baowei; Zhang, Fengfeng; Huang, Yanhui

    2008-09-01

    The influence of arbuscular mycorrhizal (AM) fungus Glomus mosseae on characteristics of the growth, water status, chlorophyll concentration, gas exchange, and chlorophyll fluorescence of maize plants under salt stress was studied in the greenhouse. Maize plants were grown in sand and soil mixture with five NaCl levels (0, 0.5, 1.0, 1.5, and 2.0 g/kg dry substrate) for 55 days, following 15 days of non-saline pretreatment. Under salt stress, mycorrhizal maize plants had higher dry weight of shoot and root, higher relative chlorophyll content, better water status (decreased water saturation deficit, increased water use efficiency, and relative water content), higher gas exchange capacity (increased photosynthetic rate, stomatal conductance and transpiration rate, and decreased intercellular CO(2) concentration), higher non-photochemistry efficiency [increased non-photochemical quenching values (NPQ)], and higher photochemistry efficiency [increased the maximum quantum yield in the dark-adapted state (Fv/Fm), the maximum quantum yield in the light-adapted sate (Fv'/Fm'), the actual quantum yield in the light-adapted steady state (phiPSII) and the photochemical quenching values (qP)], compared with non-mycorrhizal maize plants. In addition, AM symbiosis could trigger the regulation of the energy biturcation between photochemical and non-photochemical events reflected in the deexcitation rate constants (kN, kN', kP, and kP'). All the results show that G. mosseae alleviates the deleterious effect of salt stress on plant growth, through improving plant water status, chlorophyll concentration, and photosynthetic capacity, while the influence of AM symbiosis on photosynthetic capacity of maize plants can be indirectly affected by soil salinity and mycorrhizae-mediated enhancement of water status, but not by the mycorrhizae-mediated enhancement of chlorophyll concentration and plant biomass.

  1. Water deficit affects primary metabolism differently in two Lolium multiflorum/Festuca arundinacea introgression forms with a distinct capacity for photosynthesis and membrane regeneration.

    Directory of Open Access Journals (Sweden)

    Dawid Perlikowski

    2016-07-01

    Full Text Available Understanding how plants respond to drought at different levels of cell metabolism is an important aspect of research on the mechanisms involved in stress tolerance. Furthermore, a dissection of drought tolerance into its crucial components by the use of plant introgression forms facilitates to analyze this trait more deeply. The important components of plant drought tolerance are the capacity for photosynthesis under drought conditions, and the ability of cellular membrane regeneration after stress cessation. Two closely related introgression forms of Lolium multiflorum/Festuca arundinacea, differing in the level of photosynthetic capacity during stress, and in the ability to regenerate their cellular membranes after stress cessation, were used as forage grass models in a primary metabolome profiling and in an evaluation of chloroplast 1,6-bisphosphate aldolase accumulation level and activity, during 11 days of water deficit, followed by 10 days of rehydration. It was revealed here that the introgression form, characterized by the ability to regenerate membranes after rehydration, contained higher amounts of proline, melibiose, galactaric acid, myo-inositol and myo-inositol-1-phosphate involved in osmoprotection and stress signaling under drought. Moreover, during the rehydration period, this form also maintained elevated accumulation levels of most the primary metabolites, analyzed here. The other introgression form, characterized by the higher capacity for photosynthesis, revealed a higher accumulation level and activity of chloroplast aldolase under drought conditions, and higher accumulation levels of most photosynthetic products during control and drought periods. The potential impact of the observed metabolic alterations on cellular membrane recovery after stress cessation, and on a photosynthetic capacity under drought conditions in grasses, are discussed.

  2. Amino acid fingerprint in the rhizosphere of Pisum sativum in response to water stress

    Science.gov (United States)

    Bobille, Hélène; Fustec, Joëlle; Robins, Richard J.; Cukier, Caroline; Limami, Anis M.

    2017-04-01

    In cropping systems, legumes release substantial amounts of nitrogen (N) into the soil, via rhizodeposition, and constitute a sustainable source of N, instead of synthetic N fertilisers (Fustec et al. 2010). More frequent or/and intense droughts and floodings, due to climate change and intensification of agriculture, may affect N rhizodeposition (Preece & Peñuelas 2016). However, the effects of water stress on this process are poorly documented. A part of N derived from root exudates, mainly in amino acids (AAs) form, is suspected shape and regulate rhizosphere microbial community, thus playing a potential role in maintaining plant health in case of abiotic stress (Moe 2013). We hypothesized that root AA exudation could change significantly, according to water availability, and would help to understand N metabolism changes in plant-rhizosphere interactions. Because studying exudation from plant grown in unsterilized soil is challenging (Oburger et al. 2013), we have measured the rhizosphere AA fingerprint (RAAF), as the result of interactions between AA exudation and rhizospheric environment. In addition, plants were stem-labeled (cotton-wick) with 15N-urea for 72 h to provide direct evidence of a link between root AA and exudation in the soil. The RAAF was measured in Pisum sativum rhizosphere, under either a water deficit or a water excess for 72 h. Water deficit decreases biomass accumulation in shoots but not in roots. Then, water deficit had no significant effect on total AAs released into the rhizosphere but, it significantly modified the composition of RAAF, with a preferential increase of proline, alanine and glutamate and a rise in isotopic enrichment of AAs derived from oxaloacetate in tricarboxylic acidic cycle (asparagine, aspartate, threonine and isoleucine). These results support the idea that, under the early stages of water deficit, recently assimilated N is rapidly translocated to the roots, and part of it is exudated in AAs. Most of the exudated

  3. Crop water stress maps for an entire growing season from visible and thermal UAV imagery

    Science.gov (United States)

    Hoffmann, Helene; Jensen, Rasmus; Thomsen, Anton; Nieto, Hector; Rasmussen, Jesper; Friborg, Thomas

    2016-12-01

    This study investigates whether a water deficit index (WDI) based on imagery from unmanned aerial vehicles (UAVs) can provide accurate crop water stress maps at different growth stages of barley and in differing weather situations. Data from both the early and late growing season are included to investigate whether the WDI has the unique potential to be applicable both when the land surface is partly composed of bare soil and when crops on the land surface are senescing. The WDI differs from the more commonly applied crop water stress index (CWSI) in that it uses both a spectral vegetation index (VI), to determine the degree of surface greenness, and the composite land surface temperature (LST) (not solely canopy temperature).Lightweight thermal and RGB (red-green-blue) cameras were mounted on a UAV on three occasions during the growing season 2014, and provided composite LST and color images, respectively. From the LST, maps of surface-air temperature differences were computed. From the color images, the normalized green-red difference index (NGRDI), constituting the indicator of surface greenness, was computed. Advantages of the WDI as an irrigation map, as compared with simpler maps of the surface-air temperature difference, are discussed, and the suitability of the NGRDI is assessed. Final WDI maps had a spatial resolution of 0.25 m.It was found that the UAV-based WDI is in agreement with measured stress values from an eddy covariance system. Further, the WDI is especially valuable in the late growing season because at this stage the remote sensing data represent crop water availability to a greater extent than they do in the early growing season, and because the WDI accounts for areas of ripe crops that no longer have the same need for irrigation. WDI maps can potentially serve as water stress maps, showing the farmer where irrigation is needed to ensure healthy growing plants, during entire growing season.

  4. Larval Survival and Growth of Emerald Ash Borer (Coleoptera: Buprestidae) on White Ash and White Fringetree Saplings Under Well-Watered and Water-Deficit Conditions.

    Science.gov (United States)

    Rutledge, Claire E; Arango-Velez, Adriana

    2017-04-01

    Emerald ash borer (Agrilus planipennis Fairmaire) was recently found on a novel host in North America, white fringetree (Chionanthus virginicus L.) (Oleaceae). In this study, we artificially infested 4-yr-old, naïve white fringetree and white ash (Fraxinus americana L.) saplings under well-watered and water-deficit conditions with emerald ash borer eggs. We used physiological and phenotypical approaches to investigate both plant response to emerald ash borer and insect development at 21, 36, and 61 d postinfestation. Photosynthesis was reduced in both tree species by larval feeding, but not by water deficits. Emerald ash borer larvae established and survived successfully on white ash. Both establishment and survival were lower on white fringetree than on white ash. Larvae were larger, and had reached higher instars at all three time points on white ash than on white fringetrees. Larvae grew faster in white ash under water-deficit conditions; however, water-deficit conditions negatively impacted survival of larvae at 61 d postinfestation in white fringetrees, although head size did not differ among surviving larvae. White ash showed higher callus formation in well-watered trees, but no impact on larval survival was observed. In white fringetree, callus formation was not affected by water treatment, and was inversely related to larval survival. The higher rate of mortality and slow growth rate of larvae in white fringetree as compared to white ash suggest that populations of emerald ash borer may be sustained by white fringetree, but may grow more slowly than in white ash. © The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  5. Study the Effect of Different Phosphorus Fertilizers on Physiological Characteristic of Photosynthetic Pigments and Soluble Sugars of Safflower under Water Deficit Condition

    Directory of Open Access Journals (Sweden)

    S Heshmati

    2016-10-01

    Full Text Available Introduction Drought stress is one of the most important and effective factors in agricultural practices in arid and semi-arid regions of the world. The arid and semi-arid regions comprise more than 70% of the total area of Iran. Reduction in chlorophyll concentrations has been attributed to the increase in chlorophyll degradation in water deficit conditions and impairment in the enzymes activity responsible for the synthesis of photosynthetic pigments. Under drought stress, maintenance of photosynthetic capacities and leaf chlorophyll are physiological parameters which influence drought stress tolerant of crop. Phosphorus is one the most essential elements for plant growth after nitrogen. However, the availability of this nutrient for plants is limited by different chemical reactions especially in arid and semi-arid soils. Plant growth-promoting bacteria (PGPB are soil and rhizosphere bacteria that can benefit plant growth by different mechanisms. Given the negative environmental impact of chemical fertilizers and their increasing costs, the use of PGPB as natural fertilizers is advantageous for the development of sustainable agriculture. Inoculation of plants with native beneficial microorganisms may increase drought tolerance of plants growing in arid or semi-arid areas. Materials and Methods In order to study the effect of biologic and chemical phosphorous fertilizer on photosynthetic pigments of safflower cultivar (IL111, under water deficit condition, an experiment was conducted in 2012 at the Research Field of the Faculty of Agriculture, Shahed University. The experimental design was split-factorial arrangement in randomized complete block design with three replicates. The main factors were the three levels of irrigation treatment: full irrigation (irrigation up to 50% soil moisture depletion relative to field capacity, water stress in the vegetative and flowering stages (irrigation up to 75% soil moisture depletion relative to field

  6. A Three-Dimensional Index for Characterizing Crop Water Stress

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    Jessica A. Torrion

    2014-05-01

    Full Text Available The application of remotely sensed estimates of canopy minus air temperature (Tc-Ta for detecting crop water stress can be limited in semi-arid regions, because of the lack of full ground cover (GC at water-critical crop stages. Thus, soil background may restrict water stress interpretation by thermal remote sensing. For partial GC, the combination of plant canopy temperature and surrounding soil temperature in an image pixel is expressed as surface temperature (Ts. Soil brightness (SB for an image scene varies with surface soil moisture. This study evaluates SB, GC and Ts-Ta and determines a fusion approach to assess crop water stress. The study was conducted (2007 and 2008 on a commercial scale, center pivot irrigated research site in the Texas High Plains. High-resolution aircraft-based imagery (red, near-infrared and thermal was acquired on clear days. The GC and SB were derived using the Perpendicular Vegetation Index approach. The Ts-Ta was derived using an array of ground Ts sensors, thermal imagery and weather station air temperature. The Ts-Ta, GC and SB were fused using the hue, saturation, intensity method, respectively. Results showed that this method can be used to assess water stress in reference to the differential irrigation plots and corresponding yield without the use of additional energy balance calculation for water stress in partial GC conditions.

  7. Dynamic changes of anti-oxidative enzymes of 10 wheat genotypes at soil water deficits.

    Science.gov (United States)

    Shao, Hong Bo; Liang, Zong Suo; Shao, Ming An; Sun, Qun

    2005-05-25

    -oxidative enzymes were stronger, MDA lower; (5) these results demonstrated that different wheat genotypes have different physiological mechanisms to adapt themselves to changing drought stress, whose molecular basis is discrete gene expression profiling (transcriptom); (6) our results also showed that the concept and method accepted and adopted by most researchers--that 75% FC is a proper supply for higher plants--was doubted because this level could not reflect the true suitable level of different wheat genotypes; (7) our research can provide insights into physiological mechanisms of crop anti-drought and direct practical materials for wheat anti-drought breeding; (8) POD, SOD and CAT activities of different wheat genotypes had quite different changing trend at different stages and under different soil water stress conditions, which was linked with their origin of cultivation and individual soil water stress threshold; (9) our primary results also firstly displayed that the changing trend for wheat adapting to environmental stress during life circle was an S-shaped curve, which is, by chance, consistent with Plant Growth Grand Periodicity Curve.

  8. A rat model of post-traumatic stress disorder reproduces the hippocampal deficits seen in the human syndrome

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    Sonal eGoswami

    2012-06-01

    Full Text Available Despite recent progress, the causes and pathophysiology of post-traumatic stress disorder (PTSD remain poorly understood, partly because of ethical limitations inherent to human studies. One approach to circumvent this obstacle is to study PTSD in a valid animal model of the human syndrome. In one such model, extreme and long-lasting behavioral manifestations of anxiety develop in a subset of Lewis rats after exposure to an intense predatory threat that mimics the type of life-and-death situation known to precipitate PTSD in humans. This study aimed to assess whether the hippocampus-associated deficits observed in the human syndrome are reproduced in this rodent model. Prior to predatory threat, different groups of rats were each tested on one of three object recognition memory tasks that varied in the types of contextual clues (i.e. that require the hippocampus or not the rats could use to identify novel items. After task completion, the rats were subjected to predatory threat and, one week later, tested on the elevated plus maze. Based on their exploratory behavior in the plus maze, rats were then classified as resilient or PTSD-like and their performance on the pre-threat object recognition tasks compared. The performance of PTSD-like rats was inferior to that of resilient rats but only when subjects relied on an allocentric frame of reference to identify novel items, a process thought to be critically dependent on the hippocampus. Therefore, these results suggest that even prior to trauma, PTSD-like rats show a deficit in hippocampal-dependent functions, as reported in twin studies of human PTSD.

  9. Assessing water resource system vulnerability to unprecedented hydrological drought using copulas to characterize drought duration and deficit

    Science.gov (United States)

    Borgomeo, Edoardo; Pflug, Georg; Hall, Jim W.; Hochrainer-Stigler, Stefan

    2015-11-01

    Global climate models suggest an increase in evapotranspiration, changing storm tracks, and moisture delivery in many parts of the world, which are likely to cause more prolonged and severe drought, yet the weakness of climate models in modeling persistence of hydroclimatic variables and the uncertainties associated with regional climate projections mean that impact assessments based on climate model output may underestimate the risk of multiyear droughts. In this paper, we propose a vulnerability-based approach to test water resource system response to drought. We generate a large number of synthetic streamflow series with different drought durations and deficits and use them as input to a water resource system model. Marginal distributions of the streamflow for each month are generated by bootstrapping the historical data, while the joint probability distributions of consecutive months are constructed using a copula-based method. Droughts with longer durations and larger deficits than the observed record are generated by perturbing the copula parameter and by adopting an importance sampling strategy for low flows. In this way, potential climate-induced changes in monthly hydrological persistence are factored into the vulnerability analysis. The method is applied to the London water system (England) to investigate under which drought conditions severe water use restrictions would need to be imposed. Results indicate that the water system is vulnerable to drought conditions outside the range of historical events. The vulnerability assessment results were coupled with climate model information to compare alternative water management options with respect to their vulnerability to increasingly long and severe drought.

  10. [Sleep disturbances and spatial memory deficits in post-traumatic stress disorder: the case of L'Aquila (Central Italy)].

    Science.gov (United States)

    Ferrara, Michele; Mazza, Monica; Curcio, Giuseppe; Iaria, Giuseppe; De Gennaro, Luigi; Tempesta, Daniela

    2016-01-01

    Altered sleep is a common and central symptom of post-traumatic stress disorder (PTSD). In fact, sleep disturbances are included in the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) diagnostic criteria for PTSD. However, it has been hypothesized that sleep disturbances are crucially involved in the aetiology of PTSD, rather than being solely a symptom arising secondarily from this disorder. Therefore, knowing the long-term effects of a trauma can be essential to establish the need of specific interventions for the prevention and treatment of mental disorders that may persist years after a traumatic experience. In one study we showed, for the first time, that even after a period of two years people exposed to a catastrophic disaster such as the L'Aquila earthquake continue to suffer from a reduced sleep quality. Moreover, we observed that sleep quality scores decreased as a function of the proximity to the epicentre, suggesting that the psychological effects of an earthquake may be pervasive and long-lasting. It has been widely shown that disruption of sleep by acute stress may lead to deterioration in memory processing. In fact, in a recent study we observed alterations in spatial memory in PTSD subjects. Our findings indicated that PTSD is accompanied by an impressive deficit in forming a cognitive map of the environment, as well as in sleep-dependent memory consolidation. The fact that this deterioration was correlated to the subjective sleep disturbances in our PTSD group demonstrates the existence of an intimate relationship between sleep, memory consolidation, and stress.

  11. The Effect of Water Stress and Polymer on Water Use Efficiency, Yield and several Morphological Traits of Sunflower under Greenhouse Condition

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    Hossein NAZARLI

    2010-12-01

    Full Text Available In many part of Iran, the reproductive growth stages of sunflower (Helianthus annuus L. are exposed to water deficit stress. Therefore, the investigation of irrigation management in the farm conditions is a necessary element for increasing irrigation efficiency and decreasing water losses. The objective of present study was to investigate the effect of different rates of super absorbent polymer and levels of water stress on water use efficiency (WUE, yield and some morphological traits of sunflower (cultivar Master. Factorial experiment was carried out in completely randomized design with 3 replications. Factors were water stress in three levels (irrigation in 0.75; 0.50 and 0.25% of field capacity and super absorbent polymer in five levels (0; 0.75; 0.150; 2.25; 3 g/kg of soil. Super absorbent polymer was added in eight leaves stage of sunflower to pots in deepness of roots development. Water stress treatment was also applied in this growth stage of sunflower. For stress application, pots were weighted every day and irrigated when soil water received to 0.75; 0.50 and 0.25 of field capacity, respectively. The results of ANOVA indicated that the effect of different rates of super absorbent polymer and different rates of consumed water in all traits were significant. ANOVA also revealed that the interactive effects of two mentioned factors were significant except for seed yield trait. Polynomial model based on the ANOVA results was fitted for each trait. The results indicated that water stress significantly convert in decreasing the number of leaves per plant, chlorophyll content, 100 weight of seeds, seed yield and WUE in sunflower, whereas the application of super absorbent polymer moderated the negative effect of deficit irrigation, especially in high rates of polymer (2.25 and 3 g/kg of soil. The above mentioned rates of polymer have the best effect to all characteristics of sunflower in all levels of water stress treatment. The findings

  12. Screening for drought tolerance: comparison of maize hybrids under water deficit condition

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    Qurban Ali

    2016-02-01

    Full Text Available Background: Maize is an important cereal crop, grown throughout the globe for human food and livestock feed, but biotic and abiotic factors had shown adverse effects on biomass and grain yield. Changing climatic conditions have imposed drought (water scarcity as a major problem to combat with yield losses and biomass in maize and other cereals. Methods: The prescribed study was conducted to evaluate F1 hybrids at seedling subject to 45% moisture level. The data was recorded and subjected to multivariate analysis to find the significant variation attributed by various traits under stress conditions for efficient root/shoot development. Results: Significant differences were found in F1 hybrids for all studied traits. Higher heritability was found for root length, shoot length and fresh shoot weight, while fresh shoot weight, dry shoot weight and dry root weight showed higher genetic advance. Significant correlation was found for dry root weight to fresh shoot length and fresh root length, fresh root weight to fresh root/shoot weight ratio and fresh shoot weight. The hybrids Sh-139×B-316, Raka-poshi×B-316, B-327×B-316, Sh-139×EV-340, EV-1097Q×EV-347, EV-1097Q×EV-340, EV-1097Q×Pop/209 and B-327×EV-340 showed higher and positive heterosis and heterobeltiosis for most of the studied traits. To assess the overall variation on dependent structure, we used multivariate analysis, an important tool in breeding program, for efficient selection. Conclusions: EV-1097Q×Pop/209 and Sh-139×EV-340 showed significant results for root and shoot development under various water stress regimes at seedling stage, thus further studies should be carried out to find out the known and un-known loci regarding root and shoot development traits in high yielding maize cultivars under arid/semi-arid regions.

  13. Changes in carbon and nitrogen allocation, growth and grain yield induced by arbuscular mycorrhizal fungi in wheat (Triticum aestivum L.) subjected to a period of water deficit

    DEFF Research Database (Denmark)

    Zhou, Qin; Ravnskov, Sabine; Jiang, Dong

    2015-01-01

    Drought is a major abiotic factor limiting agricultural crop production. One of the effective ways to increase drought resistance in plants could be to optimize the exploitation of symbiosis with arbuscular mycorrhizal fungi (AMF). Hypothesizing that alleviation of water deficits by AMF in wheat...... will help maintain photosynthetic carbon-use, we studied the role of AMF on gas-exchange, light-use efficiencies, carbon/nitrogen ratios and growth and yield parameters in the contrasting wheat (Triticum aestivum L.) cultivars ‘Vinjett’ and ‘1110’ grown with/without AMF symbiosis. Water deficits applied...... increased plant height in both cultivars. AMF also increased biomass and grain yield in ‘1110’ but not in ‘Vinjett’. The results showed that the improvements in growth and yield were the results of AMF-mediated increases in photosynthesis during drought stress and that the alleviating effect of AMF depended...

  14. Growth, physiology and yield of durum wheat (Triticum durum) treated with sewage sludge under water stress conditions.

    Science.gov (United States)

    Boudjabi, Sonia; Kribaa, Mohammed; Chenchouni, Haroun

    2015-01-01

    In arid and semi-arid areas, low soil fertility and water deficit considerably limit crop production. The use of sewage sludge as an organic amendment could contribute to the improvement of soil fertility and hence the agronomic production. The study aims to highlight the behaviour of durum wheat to the application of sewage sludge associated with water stress. The assessment focused on morphophysiological parameters of the wheat plant and yield. Under greenhouse conditions, the variety Mohamed Ben Bachir was treated by four water stress levels (100 %, 80 %, 50 % and 30 %). Each stress level comprised five fertilizer treatments: 20, 50 and 100 t/ha of dry sludge, 35 kg/ha of urea, and a control with no fertilization. Results revealed a significant loss in water content and chlorophyll a in leaves. Water stress negatively affected the development of wheat plants by reducing significantly seed yield, leaf area and biomass produced. Plant's responses to water stress manifested by an accumulation of proline and a decrease in total phosphorus. However, the increasing doses of sewage sludge limited the effect of water stress. Our findings showed an increase in the amount of chlorophyll pigments, leaf area, total phosphorus, biomass and yield. In addition, excessive accumulation of proline (1.11 ± 1.03 µg/g DM) was recorded as a result of the high concentration of sludge (100 t/ha DM). The application of sewage sludge is beneficial for the wheat crop, but the high accumulation of proline in plants treated with high dose of sludge suggests to properly consider this fact. The application of sludge should be used with caution in soils where water is limited. Because the combined effect of these two factors could result in a fatal osmotic stress to crop development.

  15. Infrared Thermometry to Estimate Crop Water Stress Index and Water Use of Irrigated Maize in Northeastern Colorado

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    Neil C. Hansen

    2012-11-01

    Full Text Available With an increasing demand of fresh water resources in arid/semi-arid parts of the world, researchers and practitioners are relying more than ever on remote sensing techniques for monitoring and evaluating crop water status and for estimating crop water use or crop actual evapotranspiration (ETa. In this present study, infrared thermometry was used in conjunction with a few weather parameters to develop non-water-stressed and non-transpiring baselines for irrigated maize in a semi-arid region of Colorado in the western USA. A remote sensing-based Crop Water Stress Index (CWSI was then estimated for four hourly periods each day during 5 August to 2 September 2011 (29 days. The estimated CWSI was smallest during the 10:00–11:00 a.m. and largest during the 12:00–13:00 p.m. hours. Plotting volumetric water content of the topsoil vs. CWSI revealed that there is a high correlation between the two parameters during the analyzed period. CWSI values were also used to estimate maize actual transpiration (Ta. Ta estimates were more influenced by crop biomass rather than irrigation depths alone, mainly due to the fact that the effects of deficit irrigation were largely masked by the significant precipitation during the growing season. During the study period, applying an independent remotely sensed energy balance model showed that maize ETa was 159 mm, 30% larger than CWSI-Ta (122 mm and 9% smaller than standard-condition maize ET (174 mm.

  16. Photosynthetic efficiency of Pedunculate oak seedlings under simulated water stress

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    Popović Zorica

    2010-01-01

    Full Text Available Photosynthetic performance of seedlings of Quercus robur exposed to short-term water stress in the laboratory conditions was assessed through the method of induced fluorometry. The substrate for seedlings was clayey loam, with the dominant texture fraction made of silt, followed by clay and fine sand, with total porosity 68.2%. Seedlings were separated in two groups: control (C (soil water regime in pots was maintained at the level of field water capacity and treated (water-stressed, WS (soil water regime was maintained in the range of wilting point and lentocapillary capacity. The photosynthetic efficiency was 0.642±0.25 and 0.522±0.024 (WS and C, respectively, which was mostly due to transplantation disturbances and sporadic leaf chlorosis. During the experiment Fv/Fm decreased in both groups (0.551±0.0100 and 0.427±0.018 in C and WS, respectively. Our results showed significant differences between stressed and control group, in regard to both observed parameters (Fv/Fm and T½. Photosynthetic efficiency of pedunculate oak seedlings was significantly affected by short-term water stress, but to a lesser extent than by sufficient watering.

  17. Identification of Water Stress in Citrus Leaves Using Sensing Technologies

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    Reza Ehsani

    2013-11-01

    Full Text Available Water stress is a serious concern in the citrus industry due to its effect on citrus quality and yield. A sensor system for early detection will allow rapid implementation of control measures and management decisions to reduce any adverse effects. Laser-induced breakdown spectroscopy (LIBS presents a potentially suitable technique for early stress detection through elemental profile analysis of the citrus leaves. It is anticipated that the physiological change in plants due to stress will induce changes in the element profile. The major goal of this study was to evaluate the performance of laser-induced breakdown spectroscopy as a method of water stress detection for potential use in the citrus industry. In this work, two levels of water stress were applied to Cleopatra (Cleo mandarin, Carrizo citrange, and Shekwasha seedlings under the controlled conditions of a greenhouse. Leaves collected from the healthy and stressed plants were analyzed using LIBS, as well as with a spectroradiometer (visible-near infrared spectroscopy and a thermal camera (thermal infrared. Statistical classification of healthy and stressed samples revealed that the LIBS data could be classified with an overall accuracy of 80% using a Naïve-Bayes and bagged decision tree-based classifiers. These accuracies were lower than the classification accuracies acquired from visible-near infrared spectra. An accuracy of 93% and higher was achieved using a bagged decision tree with visible-near infrared spectral reflectance data.

  18. Alleviation of Water Stress Effects on MR220 Rice by Application of Periodical Water Stress and Potassium Fertilization

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    Nurul Amalina Mohd Zain

    2014-02-01

    Full Text Available The use of periodical water stress and potassium fertilization may enhance rice tolerance to drought stress and improve the crop’s instantaneous water use efficiency without much yield reduction. This study was conducted to assess the effects of different periodical water stress combined with potassium fertilization regimes on growth, yield, leaf gas exchanges and biochemical changes in rice grown in pots and compare them with standard local rice grower practices. Five treatments including (1 standard local grower’s practice (control, 80CF = 80 kg K2O/ha + control flooding; (2 120PW15 = 120 kg K2O/ha + periodical water stress for 15 days; (3 120DS15V = 120 kg K2O/ha + drought stress for 15 days during the vegetative stage; (4 120DS25V = 120 kg K2O/ha + drought stress for 25 days and (5 120DS15R = 120 kg K2O/ha + drought stress for 15 days during the reproductive stage, were evaluated in this experiment. Control and 120PW15 treatments were stopped at 100 DAS, and continuously saturated conditions were applied until harvest. It was found that rice under 120PW15 treatment showed tolerance to drought stress evidenced by increased water use efficiency, peroxidase (POX, catalase (CAT and proline levels, maximum efficiency of photosystem II (fv/fm and lower minimal fluorescence (fo, compared to other treatments. Path coefficient analysis revealed that most of parameters contribute directly rather than indirectly to rice yield. In this experiment, there were four factors that are directly involved with rice yield: grain soluble sugar, photosynthesis, water use efficiency and total chlorophyll content. The residual factors affecting rice yield are observed to be quite low in the experiment (0.350, confirming that rice yield was mostly influenced by the parameters measured during the study.

  19. Water deficits and heat shock effects on photosynthesis of a transgenic Arabidopsis thaliana constitutively expressing ABP9, a bZIP transcription factor

    DEFF Research Database (Denmark)

    Zhang, Xia; Wollenweber, Bernd; Jiang, Dong

    2008-01-01

    The effects of water deficits (WD), heat shock (HS), and both (HSWD) on photosynthetic carbon- and light-use efficiencies together with leaf ABA content, pigment composition and expressions of stress- and light harvesting-responsive genes were investigated in ABP9 [ABA-responsive-element (ABRE......, altered expression of stress-regulated or light harvesting-responsive genes was observed. Collectively, our results indicate that constitutive expression of ABP9 improves the photosynthetic capacity of plants under stress by adjusting photosynthetic pigment composition, dissipating excess light energy......) binding protein 9] transgenic Arabidopsis (5P2). WD, HS, and HSWD significantly decreased photosynthetic rate (A) and stomatal conductance (gs) in wild-type plants (WT). A and gs of 5P2 transgenic plants were slightly reduced by a single stress and were hardly modified by HSWD. Although A and electron...

  20. Crop modeling: Studying the effect of water stress on the driving forces governing plant water potential

    Science.gov (United States)

    van Emmerik, T. H. M.; Mirfenderesgi, G.; Bohrer, G.; Steele-Dunne, S. C.; Van De Giesen, N.

    2015-12-01

    Water stress is one of the most important environmental factors that influence plant water dynamics. To prevent excessive water loss and physiological damage, plants can regulate transpiration by adjusting the stomatal aperture. This enhances survival, but also reduced photosynthesis and productivity. During periods of low water availability, stomatal regulation is a trade-off between optimization of either survival or production. Water stress defence mechanisms lead to significant changes in plant dynamics, e.g. leaf and stem water content. Recent research has shown that water content in a corn canopy can change up to 30% diurnally as a result of water stress, which has a considerable influence on radar backscatter from a corn canopy [1]. This highlighted the potential of water stress detection using radar. To fully explore the potential of water stress monitoring using radar, we need to understand the driving forces governing plant water potential. For this study, the recently developed the Finite-Element Tree-Crown Hydrodynamic model version 2 (FETCH2) model is applied to a corn canopy. FETCH2 is developed to resolve the hydrodynamic processes within a plant using the porous media analogy, allowing investigation of the influence of environmental stress factors on plant dynamics such as transpiration, photosynthesis, stomatal conductance, and leaf and stem water content. The model is parameterized and evaluated using a detailed dataset obtained during a three-month field experiment in Flevoland, the Netherlands, on a corn canopy. [1] van Emmerik, T., S. Steele-Dunne, J. Judge and N. van de Giesen: "Impact of Diurnal Variation in Vegetation Water Content on Radar Backscatter of Maize During Water Stress", Geosciences and Remote Sensing, IEEE Transactions on, vol. 52, issue 7, doi: 10.1109/TGRS.2014.2386142, 2015.

  1. Effect of phytoliths for mitigating water stress in durum wheat.

    Science.gov (United States)

    Meunier, Jean Dominique; Barboni, Doris; Anwar-Ul-Haq, Muhammad; Levard, Clément; Chaurand, Perrine; Vidal, Vladimir; Grauby, Olivier; Huc, Roland; Laffont-Schwob, Isabelle; Rabier, Jacques; Keller, Catherine

    2017-07-01

    The role of silicon (Si) in alleviating biotic and abiotic stresses in crops is well evidenced by empirical studies; however, the mechanisms by which it works are still poorly known. The aim of this study is to determine whether or not phytolith composition and distribution in wheat are affected by drought and, if so, why. Durum wheat was grown using hydroponics in the presence of polyethylene glycol (PEG)-6000 to perform a water-stress simulation. We developed an original method for in situ analysis of phytoliths in leaves via X-ray imaging. PEG was efficient in inhibiting water uptake by roots and creating stress, and prevented a small fraction of Si from being accumulated in the shoots. The application of Si with PEG maintained shoot and root fresh weights (FW) and relative water content at higher values than for plants without Si, especially at PEG 12%. Our data show that, under water stress in the presence of Si, accumulation of phytoliths over the veins provides better support to the leaf, thus allowing for a better development of the whole plant than in the absence of Si. The development of silicified trichomes in durum wheat depends primarily on the availability of Si in soil and is not an adaptation to water stress. © 2017 The Authors. New Phytologist © 2017 New Phytologist Trust.

  2. Comparative studies using the Morris water maze to assess spatial memory deficits in two transgenic mouse models of Alzheimer's disease.

    Science.gov (United States)

    Edwards, Stephen R; Hamlin, Adam S; Marks, Nicola; Coulson, Elizabeth J; Smith, Maree T

    2014-10-01

    Evaluation of the efficacy of novel therapeutics for potential treatment of Alzheimer's disease (AD) requires an animal model that develops age-related cognitive deficits reproducibly between independent groups of investigators. Herein we assessed comparative temporal changes in spatial memory function in two commercially available transgenic mouse models of AD using the Morris water maze (MWM), incorporating both visible and hidden platform training. Individual cohorts of cDNA-based 'line 85'-derived double-transgenic mice coexpressing the 'Swedish' mutation of amyloid precursor protein (APPSwe) and the presenillin 1 (PS1) 'dE9' mutation were assessed in the MWM at mean ages of 3.6, 9.3 and 14.8 months. We found significant deficits in spatial memory retention in APPSwe/PS1dE9 mice aged 3.6 months and robust deficits in spatial memory acquisition and retention in APPSwe/PS1dE9 mice aged 9.3 months, with a further significant decline by age 14.8 months. β-Amyloid deposits were present in brain sections by 7.25 months of age. In contrast, MWM studies with individual cohorts (aged 4-21 months) of single-transgenic genomic-based APPSwe mice expressing APPSwe on a yeast artificial chromosomal (YAC) construct showed no significant deficits in spatial memory acquisition until 21 months of age. There were no significant deficits in spatial memory retention up to 21 months of age and β-amyloid deposits were not present in brain sections up to 24 months of age. These data, generated using comprehensive study designs, show that APPSwe/PS1dE9 but not APPSwe YAC mice appear to provide a suitably robust model of AD for efficacy assessment of novel AD treatments in development.

  3. Rhizosphere: a leverage for tolerance to water deficits of soil microflora ?

    Science.gov (United States)

    Bérard, Annette; Ruy, Stéphane; Coronel, Anaïs; Toussaint, Bruce; Czarnes, Sonia; Legendre, Laurent; Doussan, Claude

    2015-04-01

    Microbial soil communities play a fundamental role in soil organic matter mineralization, which is a key process for plant nutrition, growth and production in agro-ecosystems. A number of these microbial processes take place in the rhizosphere: the soil zone influenced by plant roots activity, which is a "hotspot " of biological and physico-chemical activity, transfers and biomass production. The knowledge of rhizosphere processes is however still scanty, especially regarding the interactions between physico-chemical processes occurring there and soil microorganisms. The rhizosphere is a place where soil aggregates are more stable, and where bulk density, porosity, water and nutrients transfer are modified with respect to the bulk soil (e.g. because of production of mucilage, of which exo-polysaccharides (EPS) produced by roots and microorganisms. During a maize field experiment, rhizospheric soil (i.e. soil strongly adhering to maize roots) and bulk soil were sampled twice in spring and summer. These soil samples were characterized for physicochemical parameters (water retention curves and analysis of exopolysaccarides) and microflora (microbial biomass, catabolic capacities of the microbial communities assessed with the MicroRespTM technique, stability of soil microbial respiration faced to a heat-drought disturbance). We observed differences between rhizospheric and bulk soils for all parameters studied: Rhizospheric soils showed higher microbial biomasses, higher quantities of exopolysaccarides and a higher water retention capacity compared to bulk soil measurements. Moreover, microbial soil respiration showed a higher stability confronted to heat-drought stress in the rhizospheric soils compared to bulk soils. Results were more pronounced during summer compared to spring. Globally these data obtained from field suggest that in a changing climate conditions, the specific physico-biological conditions in the rhizosphere partially linked to exopolysaccarides

  4. Physiological and molecular responses of the isoprenoid biosynthetic pathway in a drought-resistant Mediterranean shrub, Cistus creticus exposed to water deficit.

    Science.gov (United States)

    Munné-Bosch, Sergi; Falara, Vasiliki; Pateraki, Irene; López-Carbonell, Marta; Cela, Jana; Kanellis, Angelos K

    2009-01-30

    The goal of the present research was to obtain new insights into the mechanisms underlying drought stress resistance in plants. Specifically, we evaluated changes in the expression of genes encoding enzymes involved in isoprenoid biosynthesis, together with the levels of the corresponding metabolites (chlorophylls, carotenoids, tocopherols and abscisic acid), in a drought-resistant Mediterranean shrub, Cistus creticus grown under Mediterranean field conditions. Summer drought led to reductions in the relative leaf water content (RWC) by 25%, but did not alter the maximum efficiency of PSII, indicating the absence of damage to the photosynthetic apparatus. While the expression of genes encoding C. creticus chlorophyll a oxygenase/chlorophyll b synthase (CAO) and phytoene synthase (PSY) were not affected by water deficit, the genes encoding homogentisate phytyl-transferase (HPT) and 9-cis-epoxycarotenoid dioxygenase (NCED) were induced in water-stressed (WS) plants. Drought-induced changes in gene expression were observed at early stages of drought and were strongly correlated with levels of the corresponding metabolites, with simultaneous increases in abscisic acid and alpha-tocopherol levels of up to 4-fold and 62%, respectively. Furthermore, alpha-tocopherol levels were strongly positively correlated with abscisic acid contents, but not with the levels of jasmonic acid and salicylic acid. We conclude that the abscisic acid and tocopherol biosynthetic pathway may be regulated at the transcript level in WS C. creticus plants, and that the genes encoding HPT and NCED may play a key role in the drought stress resistance of this Mediterranean shrub by modulating abscisic acid and tocopherol biosynthesis.

  5. Comparative Metabolome Profile between Tobacco and Soybean Grown under Water-Stressed Conditions.

    Science.gov (United States)

    Rabara, Roel C; Tripathi, Prateek; Rushton, Paul J

    2017-01-01

    Understanding how plants respond to water deficit is important in order to develop crops tolerant to drought. In this study, we compare two large metabolomics datasets where we employed a nontargeted metabolomics approach to elucidate metabolic pathways perturbed by progressive dehydration in tobacco and soybean plants. The two datasets were created using the same strategy to create water deficit conditions and an identical metabolomics pipeline. Comparisons between the two datasets therefore reveal common responses between the two species, responses specific to one of the species, responses that occur in both root and leaf tissues, and responses that are specific to one tissue. Stomatal closure is the immediate response of the plant and this did not coincide with accumulation of abscisic acid. A total of 116 and 140 metabolites were observed in tobacco leaves and roots, respectively, while 241 and 207 were observed in soybean leaves and roots, respectively. Accumulation of metabolites is significantly correlated with the extent of dehydration in both species. Among the metabolites that show increases that are restricted to just one plant, 4-hydroxy-2-oxoglutaric acid (KHG) in tobacco roots and coumestrol in soybean roots show the highest tissue-specific accumulation. The comparisons of these two large nontargeted metabolomics datasets provide novel information and suggest that KHG will be a useful marker for drought stress for some members of Solanaceae and coumestrol for some legume species.

  6. Comparative Metabolome Profile between Tobacco and Soybean Grown under Water-Stressed Conditions

    Directory of Open Access Journals (Sweden)

    Roel C. Rabara

    2017-01-01

    Full Text Available Understanding how plants respond to water deficit is important in order to develop crops tolerant to drought. In this study, we compare two large metabolomics datasets where we employed a nontargeted metabolomics approach to elucidate metabolic pathways perturbed by progressive dehydration in tobacco and soybean plants. The two datasets were created using the same strategy to create water deficit conditions and an identical metabolomics pipeline. Comparisons between the two datasets therefore reveal common responses between the two species, responses specific to one of the species, responses that occur in both root and leaf tissues, and responses that are specific to one tissue. Stomatal closure is the immediate response of the plant and this did not coincide with accumulation of abscisic acid. A total of 116 and 140 metabolites were observed in tobacco leaves and roots, respectively, while 241 and 207 were observed in soybean leaves and roots, respectively. Accumulation of metabolites is significantly correlated with the extent of dehydration in both species. Among the metabolites that show increases that are restricted to just one plant, 4-hydroxy-2-oxoglutaric acid (KHG in tobacco roots and coumestrol in soybean roots show the highest tissue-specific accumulation. The comparisons of these two large nontargeted metabolomics datasets provide novel information and suggest that KHG will be a useful marker for drought stress for some members of Solanaceae and coumestrol for some legume species.

  7. Water stress before harvest of pepper-rosmarin

    Directory of Open Access Journals (Sweden)

    Ivan Caldeira Almeida Alvarenga

    2011-07-01

    Full Text Available The objective of this work was to assess the effect of different periods of water stress before harvest of pepper-rosmarin (Lippia sidoides on the contents of essential oil and flavonoids. The experiment was carried out during 270 days of cultivation, with drainage lysimeters, in a completely randomized block design with five treatments: 0, 2, 4, 6, and 8 days of water suppression before harvest, with four replicates. Fresh and dry matter yield, essential oil content, total flavonoids content, and water potential and temperature of leaves were determined. There was a decrease of approximately 50% in oil content and of 60% in total flavonoid content with the reduction of leaf water potential in 0.3 MPa. Essential oil is more sensitive to water stress than total flavonoids.

  8. Chlorine stress mediates microbial surface attachment in drinking water systems.

    Science.gov (United States)

    Liu, Li; Le, Yang; Jin, Juliang; Zhou, Yuliang; Chen, Guowei

    2015-03-01

    Microbial attachment to drinking water pipe surfaces facilitates pathogen survival and deteriorates disinfection performance, directly threatening the safety of drinking water. Notwithstanding that the formation of biofilm has been studied for decades, the underlying mechanisms for the origins of microbial surface attachment in biofilm development in drinking water pipelines remain largely elusive. We combined experimental and mathematical methods to investigate the role of environmental stress-mediated cell motility on microbial surface attachment in chlorination-stressed drinking water distribution systems. Results show that at low levels of disinfectant (0.0-1.0 mg/L), the presence of chlorine promotes initiation of microbial surface attachment, while higher amounts of disinfectant (>1.0 mg/L) inhibit microbial attachment. The proposed mathematical model further demonstrates that chlorination stress (0.0-5.0 mg/L)-mediated microbial cell motility regulates the frequency of cell-wall collision and thereby controls initial microbial surface attachment. The results reveal that transport processes and decay patterns of chlorine in drinking water pipelines regulate microbial cell motility and, thus, control initial surface cell attachment. It provides a mechanistic understanding of microbial attachment shaped by environmental disinfection stress and leads to new insights into microbial safety protocols in water distribution systems.

  9. Alleviation of osmotic stress of water and salt in germination and ...

    African Journals Online (AJOL)

    STORAGESEVER

    2008-07-04

    Jul 4, 2008 ... Generally, salt stress causes both osmotic stress and ionic stress ... environmental stress conditions, such as drought, chilling, and high light ..... chickpea seeds on seedling growth and carbohydrate metabolism under water ...

  10. Water Stress & Biomass Monitoring and SWAP Modeling of Irrigated Crops in Saratov Region of Russia

    Science.gov (United States)

    Zeyliger, Anatoly; Ermolaeva, Olga

    2016-04-01

    results of analyzing water stress during growing season of 2012 and yielded biomass of crops three types of crops alfalfa, corn and soya irrigated by sprinkling machines at left bank of Volga River at Saratov Region of Russia are presented and analyzed. For that a combination of data received from satellite, local meteorological station and farmers as well as SWAP model was used. Analyze of data sets of monitored water deficit of each crop averaged for irrigation period was done by linear regression with yielded biomass values. Following analyze of effectiveness of irrigation water application was done by SWAP agrohydrological model.

  11. Planting Patterns and Deficit Irrigation Strategies to Improve Wheat Production and Water Use Efficiency under Simulated Rainfall Conditions

    Science.gov (United States)

    Ali, Shahzad; Xu, Yueyue; Ma, Xiangcheng; Ahmad, Irshad; Kamran, Muhammad; Dong, Zhaoyun; Cai, Tie; Jia, Qianmin; Ren, Xiaolong; Zhang, Peng; Jia, Zhikuan

    2017-01-01

    The ridge furrow (RF) rainwater harvesting system is an efficient way to enhance rainwater accessibility for crops and increase winter wheat productivity in semi-arid regions. However, the RF system has not been promoted widely in the semi-arid regions, which primarily exist in remote hilly areas. To exploit its efficiency on a large-scale, the RF system needs to be tested at different amounts of simulated precipitation combined with deficit irrigation. Therefore, in during the 2015–16 and 2016–17 winter wheat growing seasons, we examined the effects of two planting patterns: (1) the RF system and (2) traditional flat planting (TF) with three deficit irrigation levels (150, 75, 0 mm) under three simulated rainfall intensity (1: 275, 2: 200, 3: 125 mm), and determined soil water storage profile, evapotranspiration rate, grain filling rate, biomass, grain yield, and net economic return. Over the two study years, the RF treatment with 200 mm simulated rainfall and 150 mm deficit irrigation (RF2150) significantly (P irrigation under both planting patterns. The 200 mm simulated rainfall amount was more economical than other precipitation amounts, and led to slight increases in soil water storage, total dry matter per plant, and grain yield; there were no significant differences when the simulated rainfall was increased beyond 200 mm. The highest (12,593 Yuan ha−1) net income profit was attained using the RF system at 200 mm rainfall and 150 mm deficit irrigation, which also led to significantly higher grain yield, WUE, and RIWP than all other treatments. Thus, we recommend the RF2150 treatment for higher productivity, income profit, and improve WUE in the dry-land farming system of China. PMID:28878787

  12. Airborne thermography for crop water stress assessment

    Science.gov (United States)

    Millard, J. P.; Idso, S. B.; Reginato, R. J.; Jackson, R. D.; Ehrler, W. L.; Goettelman, R. C.

    1977-01-01

    Aircraft overflights to obtain canopy temperatures of six differentially irrigated plots of durum wheat were made at Phoenix, Arizona on 1 and 29 April 1976. The data were acquired by a Texas Instruments model RS-25 infrared line scanner operating in the 8 to 14 micrometer bandpass region. Concurrently, plant water tension was measured on the ground with the Scholander pressure bomb technique. The results indicated that canopy temperatures acquired by aircraft about an hour and a half past solar noon correlated well with presunrise plant water tension - a parameter directly related to plant growth and development. The aircraft data also showed significant within-field canopy temperature variability, indicating the superiority of the synoptic view provided by aircraft over the more spotty view obtained by ground-operated infrared thermometers.

  13. An improved approach for remotely sensing water stress impacts on forest C uptake.

    Science.gov (United States)

    Sims, Daniel A; Brzostek, Edward R; Rahman, Abdullah F; Dragoni, Danilo; Phillips, Richard P

    2014-09-01

    Given that forests represent the primary terrestrial sink for atmospheric CO2 , projections of future carbon (C) storage hinge on forest responses to climate variation. Models of gross primary production (GPP) responses to water stress are commonly based on remotely sensed changes in canopy 'greenness' (e.g., normalized difference vegetation index; NDVI). However, many forests have low spectral sensitivity to water stress (SSWS) - defined here as drought-induced decline in GPP without a change in greenness. Current satellite-derived estimates of GPP use a vapor pressure deficit (VPD) scalar to account for the low SWSS of forests, but fail to capture their responses to water stress. Our objectives were to characterize differences in SSWS among forested and nonforested ecosystems, and to develop an improved framework for predicting the impacts of water stress on GPP in forests with low SSWS. First, we paired two independent drought indices with NDVI data for the conterminous US from 2000 to 2011, and examined the relationship between water stress and NDVI. We found that forests had lower SSWS than nonforests regardless of drought index or duration. We then compared satellite-derived estimates of GPP with eddy-covariance observations of GPP in two deciduous broadleaf forests with low SSWS: the Missouri Ozark (MO) and Morgan Monroe State Forest (MMSF) AmeriFlux sites. Model estimates of GPP that used VPD scalars were poorly correlated with observations of GPP at MO (r(2) = 0.09) and MMSF (r(2) = 0.38). When we included the NDVI responses to water stress of adjacent ecosystems with high SSWS into a model based solely on temperature and greenness, we substantially improved predictions of GPP at MO (r(2) = 0.83) and for a severe drought year at the MMSF (r(2) = 0.82). Collectively, our results suggest that large-scale estimates of GPP that capture variation in SSWS among ecosystems could improve predictions of C uptake by forests under drought. © 2014 John Wiley & Sons

  14. Increased protein content of chickpea (Cicer arietinum L.) inoculated with arbuscular mycorrhizal fungi and nitrogen-fixing bacteria under water deficit conditions.

    Science.gov (United States)

    Oliveira, Rui S; Carvalho, Patrícia; Marques, Guilhermina; Ferreira, Luís; Nunes, Mafalda; Rocha, Inês; Ma, Ying; Carvalho, Maria F; Vosátka, Miroslav; Freitas, Helena

    2017-10-01

    Chickpea (Cicer arietinum L.) is a widely cropped pulse and an important source of proteins for humans. In Mediterranean regions it is predicted that drought will reduce soil moisture and become a major issue in agricultural practice. Nitrogen (N)-fixing bacteria and arbuscular mycorrhizal (AM) fungi have the potential to improve plant growth and drought tolerance. The aim of the study was to assess the effects of N-fixing bacteria and AM fungi on the growth, grain yield and protein content of chickpea under water deficit. Plants inoculated with Mesorhizobium mediterraneum or Rhizophagus irregularis without water deficit and inoculated with M. mediterraneum under moderate water deficit had significant increases in biomass. Inoculation with microbial symbionts brought no benefits to chickpea under severe water deficit. However, under moderate water deficit grain crude protein was increased by 13%, 17% and 22% in plants inoculated with M. mediterraneum, R. irregularis and M. mediterraneum + R. irregularis, respectively. Inoculation with N-fixing bacteria and AM fungi has the potential to benefit agricultural production of chickpea under water deficit conditions and to contribute to increased grain protein content. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  15. Uncovering latent deficits due to mild traumatic brain injury (mTBI by using normobaric hypoxia stress

    Directory of Open Access Journals (Sweden)

    Leonard eTemme

    2013-04-01

    Full Text Available Memory deficits and other cognitive symptoms frequently associated with mTBI are commonly thought to resolve within 7 to 10 days. This generalization is based principally on observations made in individuals who are in the unstressed environmental conditions typical to a clinic and so does not consider the impact of physiologic, environmental or psychological stress. Normobaric Hypoxia (NH stress can be generated by mixing normal mean sea level air (MSL containing 21% oxygen (O2 with nitrogen, which is biologically inert, so that the resultant mixed gas has a partial pressure of O2 approximating that of specified altitudes. This technique was used to generate NH equivalents of 8,000, 12,000 and 14,000 feet above MSL in a group of 36 volunteers with an mTBI history and an equal number of controls matched on the basis of age, gender, weight, etc. Short term visual memory was tested using Matching to Sample (M2S subtest of the BrainCheckers analogue of the Automated Neuropsychological Assessment Metrics (ANAM. Although there were no significant differences in M2S performance between the two groups of subjects at MSL, with increased altitude, performance deteriorated in the mTBI group as predicted to be significantly worse than that of the controls. When the subjects were returned to MSL, the difference disappeared. This finding suggests that the hypoxic challenge paradigm developed here has potential clinical utility for assessing the effects of mTBI in individuals who appear asymptomatic under normal conditions.

  16. Behavioral Deficits in Juveniles Mediated by Maternal Stress Hormones in Mice

    Directory of Open Access Journals (Sweden)

    Jamie Maguire

    2016-01-01

    Full Text Available Maternal depression has been shown to negatively impact offspring development. Investigation into the impact of maternal depression and offspring behavior has relied on correlative studies in humans. Further investigation into the underlying mechanisms has been hindered by the lack of useful animal models. We previously characterized a mouse model which exhibits depression-like behaviors restricted to the postpartum period and abnormal/fragmented maternal care (Gabrd−/− mice. Here we utilized this unique mouse model to investigate the mechanism(s through which maternal depression-like behaviors adversely impact offspring development. Cross-fostering experiments reveal increased anxiety-like and depression-like behaviors in mice reared by Gabrd−/− mothers. Wild type and Gabrd−/− mice subjected to unpredictable stress during late pregnancy exhibit decreased pup survival and depression-like behavior in the postpartum period. Exogenous corticosterone treatment in wild type mice during late pregnancy is sufficient to decrease pup survival and induce anxiety-like and depression-like behaviors in the offspring. Further, the abnormal behaviors in juvenile mice reared by Gabrd−/− mice are alleviated by treatment of the mothers with the corticotropin-releasing hormone (CRH antagonist, Antalarmin. These studies suggest that hyperresponsiveness of the HPA axis is associated with postpartum depression and may mediate the adverse effects of maternal depression on offspring behavior.

  17. Root water uptake under non-uniform transient salinity and water stress

    NARCIS (Netherlands)

    Homaee, M.

    1999-01-01

    The study described in this thesis focuses on the quantitative understanding of water uptake by roots under separate and combined salinity and water stresses. The major difficulty in solving Richards' equation stems from the lack of a sink term function that adequately describes root water uptake. F

  18. Evaluation of tolerance to water stress in beans

    Directory of Open Access Journals (Sweden)

    Mauricio Marini Köop

    2012-09-01

    Full Text Available The goal of this study was to evaluate the genotypes of beans, and to sort them into groups that are tolerant and sensitive to water stress, by assessing their morphological characteristics for use in blocks of crosses and the study of gene expression. We evaluated nine bean genotypes: IAPAR 14, IAPAR 81, Pérola, IPR Colibri, IPR Juriti, IPR Chopim, IPR Gralha, and IPR Tiziu IPR Uirapuru. The genotypes were subjected to two irrigation conditions: i irrigation water as needed throughout the culture cycle and ii irrigation water as needed until the appearance of the first bud, followed by no irrigation water for 15 days. The experimental design was in randomized blocks with three replications. The characteristics evaluated were: i plant height; ii stem diameter, iii number of pods per plant, iv number of grains per pod, v root length and vi root dry mass. Stem diameter should not be used to determine if bean genotypes are tolerant or susceptible to water shortages. The results for the Pérola genotype were the highest for most of the characteristics evaluated, and, for this reason, it was classified as tolerant to water stress during flowering. The genotypes IAPAR and 81 IPR Juriti had the lowest results for the most features and were classified as susceptible to water stress during flowering.

  19. Planting Patterns and Deficit Irrigation Strategies to Improve Wheat Production and Water Use Efficiency under Simulated Rainfall Conditions

    Directory of Open Access Journals (Sweden)

    Shahzad Ali

    2017-08-01

    Full Text Available The ridge furrow (RF rainwater harvesting system is an efficient way to enhance rainwater accessibility for crops and increase winter wheat productivity in semi-arid regions. However, the RF system has not been promoted widely in the semi-arid regions, which primarily exist in remote hilly areas. To exploit its efficiency on a large-scale, the RF system needs to be tested at different amounts of simulated precipitation combined with deficit irrigation. Therefore, in during the 2015–16 and 2016–17 winter wheat growing seasons, we examined the effects of two planting patterns: (1 the RF system and (2 traditional flat planting (TF with three deficit irrigation levels (150, 75, 0 mm under three simulated rainfall intensity (1: 275, 2: 200, 3: 125 mm, and determined soil water storage profile, evapotranspiration rate, grain filling rate, biomass, grain yield, and net economic return. Over the two study years, the RF treatment with 200 mm simulated rainfall and 150 mm deficit irrigation (RF2150 significantly (P < 0.05 increased soil water storage in the depth of (200 cm; reduced ET at the field scale by 33%; increased total dry matter accumulation per plant; increased the grain-filling rate; and improved biomass (11% and grain (19% yields. The RF2150 treatment thus achieved a higher WUE (76% and RIWP (21% compared to TF. Grain-filling rates, grain weight of superior and inferior grains, and net economic profit of winter wheat responded positively to simulated rainfall and deficit irrigation under both planting patterns. The 200 mm simulated rainfall amount was more economical than other precipitation amounts, and led to slight increases in soil water storage, total dry matter per plant, and grain yield; there were no significant differences when the simulated rainfall was increased beyond 200 mm. The highest (12,593 Yuan ha−1 net income profit was attained using the RF system at 200 mm rainfall and 150 mm deficit irrigation, which also led to

  20. Ganaxolone improves behavioral deficits in a mouse model of post-traumatic stress disorder

    Directory of Open Access Journals (Sweden)

    Graziano ePinna

    2014-09-01

    Full Text Available Allopregnanolone and its equipotent stereoisomer, pregnanolone (together termed ALLO, are neuroactive steroids that positively and allosterically modulate the action of gamma-amino-butyric acid (GABA at GABAA receptors. Levels of ALLO are reduced in the cerebrospinal fluid of female premenopausal patients with posttraumatic stress disorder (PTSD, a severe, neuropsychiatric condition that affects millions, yet is without a consistently effective therapy. This suggests that restoring downregulated brain ALLO levels in PTSD may be beneficial. ALLO biosynthesis is also decreased in association with the emergence of PTSD-like behaviors in socially isolated (SI mice. Similar to PTSD patients, SI mice also exhibit changes in the frontocortical and hippocampal expression of GABAA receptor subunits, resulting in resistance to benzodiazepine-mediated sedation and anxiolysis. ALLO acts at a larger spectrum of GABAA receptor subunits than benzodiazepines, and increasing corticolimbic ALLO levels in SI mice by injecting ALLO or stimulating ALLO biosynthesis with a selective brain steroidogenic stimulant, such as S-norfluoxetine, at doses far below those that block serotonin reuptake, reduces PTSD-like behavior in these mice. This suggests that synthetic analogs of ALLO, such as ganaxolone, may also improve anxiety, aggression, and other PTSD-like behaviors in the SI mouse model. Consistent with this hypothesis, ganaxolone (3.75-30 mg/kg, s.c. injected 60 minutes before testing of SI mice, induced a dose-dependent reduction in aggression toward a same-sex intrude and anxiety-like behavior in an elevated plus maze. The EC50 dose of ganaxolone used in these tests also normalized exaggerated contextual fear conditioning and, remarkably, enhanced fear extinction retention in SI mice. At these doses, ganaxolone failed to change locomotion in an open field test. Therefore, unlike benzodiazepines, ganaxolone at non-sedating concentrations appears to improve

  1. Modeling the response of peach fruit growth to water stress.

    Science.gov (United States)

    Génard, M; Huguet, J G

    1996-04-01

    We applied a semi-mechanistic model of fresh matter accumulation to peach fruit during the stage of rapid mesocarp development. The model, which is based on simple hypotheses of fluid flows into and out of the fruit, assumes that solution flow into the fruit increases with fruit weight and transpiration per unit weight, and decreases with the maximum daily shrinkage of the trunk, which was used as an indicator of water stress. Fruit transpiration was assumed to increase with fruit size and with radiation. Fruit respiration was considered to be related to fruit growth and to temperature. The model simulates variability in growth among fruits according to climatic conditions, degree of water stress and weight of the fruit at the beginning of the simulation. We used data obtained from well-watered and water-stressed trees grown in containers to estimate model parameters and to test the model. There was close agreement between the simulated and measured values. A sensitivity analysis showed that initial fruit weight partly determined the variation in growth among fruits. The analysis also indicated that there was an optimal irradiance for fruit growth and that the effect of high global radiation on growth varied according to the stage of fruit development. Water stress, which was the most important factor influencing fruit growth, rapidly depressed growth, particularly when applied late in the season.

  2. Cotinine reduces depressive-like behavior, working memory deficits, and synaptic loss associated with chronic stress in mice.

    Science.gov (United States)

    Grizzell, J Alex; Iarkov, Alexandre; Holmes, Rosalee; Mori, Takahashi; Echeverria, Valentina

    2014-07-15

    Chronic stress underlies and/or exacerbates many psychiatric conditions and often results in memory impairment as well as depressive symptoms. Such afflicted individuals use tobacco more than the general population and this has been suggested as a form of self-medication. Cotinine, the predominant metabolite of nicotine, may underlie such behavior as it has been shown to ameliorate anxiety and memory loss in animal models. In this study, we sought to investigate the effects of cotinine on working memory and depressive-like behavior in mice subjected to prolonged restraint. Cotinine-treated mice displayed better performance than vehicle-treated cohorts on the working memory task, the radial arm water maze test. In addition, with or without chronic stress exposure, cotinine-treated mice engaged in fewer depressive-like behaviors as assessed using the tail suspension and Porsolt's forced swim tests. These antidepressant and nootropic effects of cotinine were associated with an increase in the synaptophysin expression, a commonly used marker of synaptic density, in the hippocampus as well as the prefrontal and entorhinal cortices of restrained mice. The beneficial effects of cotinine in preventing various consequences of chronic stress were underscored by the inhibition of the glycogen synthase kinase 3 β in the hippocampus and prefrontal cortex. Taken together, our results show for the first time that cotinine reduces the negative effects of stress on mood, memory, and the synapse.

  3. Influence of water stress on Botryosphaeriaceae disease expression in grapevines

    Directory of Open Access Journals (Sweden)

    Jan VAN NIEKERK

    2011-12-01

    Full Text Available Several species in Botryosphaeriaceae have been associated with grapevine trunk diseases. To evaluate the effect of water stress on infection of grapevines by Botryosphaeriaceae spp., 1-year-old Shiraz/101-14 Mgt nursery grapevine plants were planted in plastic potting bags and placed outdoors under shade netting. Five weeks after planting, vines were pruned and the pruning wounds inoculated with spore suspensions of Neofusicoccum australe, Neofusicoccum parvum, Lasiodiplodia theobromae or Diplodia seriata. Control treatments consisted of applications of sterile water or a Trichoderma harzianum spore suspension. Stem inoculations were done by inserting a colonised or uncolonised agar plug into a wound made in each stem. Four different irrigation regimes were introduced 12 weeks after planting to simulate varying degrees of water stress. Measurements of stomatal conductance, photosynthetic rate and leaf spectrometry were made to monitor physiological stress. Eight months after inoculation, vines were uprooted and the root, shoot and plant mass of each vine determined. Lesions observed in the inoculated pruning wounds and stems were also measured. Vines subjected to the lowest irrigation regime were significantly smaller than optimally irrigated vines. Water stressed vines also had significantly lower photosynthetic rates and levels of stomatal conductance compared with vines receiving optimal irrigation, indicating that these plants experienced significantly higher levels of physiological stress. The mean lesion length was significantly longer in the pruning wounds and stems of plants subjected to the lowest irrigation regime, with lesion length declining linearly with increasing irrigation volume. These results clearly indicate that when a grapevine is exposed to water stress, colonisation and disease expression by Botryosphaeriaceae spp. are much more severe.

  4. Genome wide association study (GWAS) for grain yield in rice cultivated under water deficit.

    Science.gov (United States)

    Pantalião, Gabriel Feresin; Narciso, Marcelo; Guimarães, Cléber; Castro, Adriano; Colombari, José Manoel; Breseghello, Flavio; Rodrigues, Luana; Vianello, Rosana Pereira; Borba, Tereza Oliveira; Brondani, Claudio

    2016-12-01

    The identification of rice drought tolerant materials is crucial for the development of best performing cultivars for the upland cultivation system. This study aimed to identify markers and candidate genes associated with drought tolerance by Genome Wide Association Study analysis, in order to develop tools for use in rice breeding programs. This analysis was made with 175 upland rice accessions (Oryza sativa), evaluated in experiments with and without water restriction, and 150,325 SNPs. Thirteen SNP markers associated with yield under drought conditions were identified. Through stepwise regression analysis, eight SNP markers were selected and validated in silico, and when tested by PCR, two out of the eight SNP markers were able to identify a group of rice genotypes with higher productivity under drought. These results are encouraging for deriving markers for the routine analysis of marker assisted selection. From the drought experiment, including the genes inherited in linkage blocks, 50 genes were identified, from which 30 were annotated, and 10 were previously related to drought and/or abiotic stress tolerance, such as the transcription factors WRKY and Apetala2, and protein kinases.

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

    OpenAIRE

    Krzysztof Klamkowski; Waldemar Treder

    2006-01-01

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

  6. Honey prevents neurobehavioural deficit and oxidative stress induced by lead acetate exposure in male Wistar rats- a preliminary study.

    Science.gov (United States)

    Abdulmajeed, Wahab Imam; Sulieman, Habeeb Bolakale; Zubayr, Maymunah Oloruntosin; Imam, Aminu; Amin, Abdulbasit; Biliaminu, Sikiru Abayomi; Oyewole, Lukuman Aboyeji; Owoyele, Bamidele Victor

    2016-02-01

    This research sought to investigate the possible neuroprotective effects of honey against lead (Pb)-induced neurotoxicity. Twenty four male Wistar rats were divided into four groups: Control group that received 1 ml/kg distilled orally for 28 days; while groups II-IV received 0.2% lead in drinking water and 1 ml/kg of distilled water, 1 ml/kg of honey, 1.5 ml/kg of honey respectively for 28 days. Anxiety and exploratory activities were determined in the open field test. Memory function was determined using Morris water maze after which the animals were sacrificed. The brains were then excised, homogenized and Lipid peroxidation (MDA), Superoxide dismutase (SOD), Catalase, Glutathione (GSH) and Glutathione -S- Transferase (GST) activities were determined in the brains. Results showed that lead exposure causes decrease in locomotor and exploratory activities; increase anxiety, memory impairment, lipid peroxidation and decrease antioxidant activities. However, co-administration of honey with lead inhibited neurotoxicity as indicated by the improvement in memory function as evidenced by decreased latency period and increased in time spent in target quadrant in honey-fed rats compared to the lead-exposed animals. Furthermore, honey increased locomotion, exploration and decreased anxiety in lead-exposed rats as indicated by the frequency of rearing, freezing duration and the number of line crossed by animals. Also administration of honey improves antioxidant activities as shown by increased brain SOD, GST and GSH activities compared to the lead-treated groups but no significant effect on MDA level. It can be concluded that honey has neuroprotective effects against lead-induced cognitive deficit probably by enhancing antioxidant activities.

  7. Rapid changes in leaf elongation, ABA and water status during the recovery phase following application of water stress in two durum wheat varieties differing in drought tolerance.

    Science.gov (United States)

    Mahdid, Mohamed; Kameli, Abdelkrim; Ehlert, Christina; Simonneau, Thierry

    2011-10-01

    This study aims to investigate the role of Abscisic acid (ABA) in water potential and turgor variations as well as growth recovery during the first phase of a rapid water stress induced by PEG6000. Two wheat varieties (Triticum durum L.), MBB (more tolerant) and OZ (less productive under drought), were grown in aerated nutrient solutions. Leaf elongation kinetics of the growing leaf 3 was estimated using LVDT. Water potential was measured using a pressure chamber; osmotic potential was estimated from expressed sap of elongation zone, turgor pressure of the same zone of leaf three was estimated directly by pressure probe. Growth rapidly ceased for a period of about one hour after the addition of PEG, gradual recovery was then observed for about 2 h. A significant difference was found in the % recovery of Leaf Elongation Rate (LER) and ABA between the two varieties, leading to better water status in MBB compared to OZ. The results of this study showed the possible role of ABA on growth resumption by the increase of relative water content and turgor via osmotic adjustment during the stress period in the leaves, which indicates the importance of OA in the resumption of LER even in the short term under conditions of water deficit. Full recovery of turgor but not of LER at the end stress period suggested the possible effect on cell wall extensibility (hardening) even at short term resulting from the rapid accumulation of ABA.

  8. Implications of the mesophyll conductance to CO2 for photosynthesis and water-use efficiency during long-term water stress and recovery in two contrasting Eucalyptus species.

    Science.gov (United States)

    Cano, F Javier; López, Rosana; Warren, Charles R

    2014-11-01

    Water stress (WS) slows growth and photosynthesis (A(n)), but most knowledge comes from short-time studies that do not account for longer term acclimation processes that are especially relevant in tree species. Using two Eucalyptus species that contrast in drought tolerance, we induced moderate and severe water deficits by withholding water until stomatal conductance (g(sw)) decreased to two pre-defined values for 24 d, WS was maintained at the target g(sw) for 29 d and then plants were re-watered. Additionally, we developed new equations to simulate the effect on mesophyll conductance (g(m)) of accounting for the resistance to refixation of CO(2). The diffusive limitations to CO(2), dominated by the stomata, were the most important constraints to A(n). Full recovery of A(n) was reached after re-watering, characterized by quick recovery of gm and even higher biochemical capacity, in contrast to the slower recovery of g(sw). The acclimation to long-term WS led to decreased mesophyll and biochemical limitations, in contrast to studies in which stress was imposed more rapidly. Finally, we provide evidence that higher gm under WS contributes to higher intrinsic water-use efficiency (iWUE) and reduces the leaf oxidative stress, highlighting the importance of gm as a target for breeding/genetic engineering.

  9. Stress – an underestimated hazard in water sports

    Directory of Open Access Journals (Sweden)

    Remlein Małgorzata

    2015-12-01

    Full Text Available Strong wind, low temperature, intense current and poor visibility under water are the most common stress inducing factors in individuals practising water sports. Stress is a state of agitation, which can be caused both by external and internal factors. Its objective is to mobilise one’s physical and psychological capabilities, thus it is a favourable reaction especially in crisis situations when such full mobilisation enables one to cope. Psychological stress is usually evoked by the occurrence of an atypical situation, exceeding one’s handling capacity. It can be induced by seeing real or imagined danger in the surroundings, as well as by external pressure related to a task interpreted as too difficult or exceeding one’s capabilities. Internal pressure appears when a person feels insecure in a given situation, when they cannot solve a problem or they feel discomfort due to their inability to meet the expectations of others, for instance, to perform a particular dive, or because of the money spent on this purpose or the invested time. Physical stress is usually an organism’s response to the environmental impacts. This article presents and discusses factors which have an effect on stress intensification, as well as providing a characterisation of selected psychological and medical theories of stress.

  10. Chronic deficit in nitric oxide elicits oxidative stress and augments T-type calcium-channel contribution to vascular tone of rodent arteries and arterioles

    DEFF Research Database (Denmark)

    Howitt, Lauren; Kuo, Ivana Y; Ellis, Anthie;

    2013-01-01

    AIMS: As cardiovascular disease is characterized by reduced nitric oxide bioavailability, our aim was to determine the impact of this change on the mechanism underlying vascular tone of pressurized arteries in vitro and in vivo. METHODS AND RESULTS: We used pressurized cerebral and mesenteric......, by regulating the bioavailability of reactive oxygen species produced by NADPH oxidase. Our data provide evidence for a novel causal link between nitric oxide deficit, oxidative stress, and T-type calcium channel function....

  11. Effect of water deficit on the cell wall of the date palm (Phoenix dactylifera 'Deglet nour', Arecales) fruit during development.

    Science.gov (United States)

    Gribaa, Ali; Dardelle, Flavien; Lehner, Arnaud; Rihouey, Christophe; Burel, Carole; Ferchichi, Ali; Driouich, Azeddine; Mollet, Jean-Claude

    2013-05-01

    Date palm (Phoenix dactylifera) is an important crop providing a valuable nutrition source for people in many countries including the Middle East and North Africa. In recent years, the amount of rain in North Africa and especially in the Tunisian palm grove areas has dropped significantly. We investigated the growth and cell wall remodelling of fruits harvested at three key development stages from trees grown with or without water supply. During development, cell wall solubilization and remodelling was characterized by a decrease of the degree of methylesterification of pectin, an important loss of galactose content and a reduction of the branching of xylan by arabinose in irrigated condition. Water deficit had a profound effect on fruit size, pulp content, cell wall composition and remodelling. Loss of galactose content was not as important, arabinose content was significantly higher in the pectin-enriched extracts from non-irrigated condition, and the levels of methylesterification of pectin and O-acetylation of xyloglucan were lower than in irrigated condition. The lower levels of hydrophobic groups (methylester and O-acetyl) and the less intensive degradation of the hydrophilic galactan, arabinan and arabinogalactan in the cell wall may be implicated in maintaining the hydration status of the cells under water deficit.

  12. Water stress in global transboundary river basins : Significance of upstream water use on downstream stress

    NARCIS (Netherlands)

    Munia, H.; Guillaume, J. H A; Mirumachi, N.; Porkka, M.; Wada, Y.; Kummu, M.

    2016-01-01

    Growing population and water demand have increased pressure on water resources in various parts of the globe, including many transboundary river basins. While the impacts of upstream water use on downstream water availability have been analysed in many of these international river basins, this has n

  13. Water stress in global transboundary river basins : Significance of upstream water use on downstream stress

    NARCIS (Netherlands)

    Munia, H.; Guillaume, J. H A; Mirumachi, N.; Porkka, M.; Wada, Y.|info:eu-repo/dai/nl/341387819; Kummu, M.

    2016-01-01

    Growing population and water demand have increased pressure on water resources in various parts of the globe, including many transboundary river basins. While the impacts of upstream water use on downstream water availability have been analysed in many of these international river basins, this has

  14. Water stress strengthens mutualism among ants, trees, and scale insects.

    Directory of Open Access Journals (Sweden)

    Elizabeth G Pringle

    2013-11-01

    Full Text Available Abiotic environmental variables strongly affect the outcomes of species interactions. For example, mutualistic interactions between species are often stronger when resources are limited. The effect might be indirect: water stress on plants can lead to carbon stress, which could alter carbon-mediated plant mutualisms. In mutualistic ant-plant symbioses, plants host ant colonies that defend them against herbivores. Here we show that the partners' investments in a widespread ant-plant symbiosis increase with water stress across 26 sites along a Mesoamerican precipitation gradient. At lower precipitation levels, Cordia alliodora trees invest more carbon in Azteca ants via phloem-feeding scale insects that provide the ants with sugars, and the ants provide better defense of the carbon-producing leaves. Under water stress, the trees have smaller carbon pools. A model of the carbon trade-offs for the mutualistic partners shows that the observed strategies can arise from the carbon costs of rare but extreme events of herbivory in the rainy season. Thus, water limitation, together with the risk of herbivory, increases the strength of a carbon-based mutualism.

  15. Water stress strengthens mutualism among ants, trees, and scale insects.

    Science.gov (United States)

    Pringle, Elizabeth G; Akçay, Erol; Raab, Ted K; Dirzo, Rodolfo; Gordon, Deborah M

    2013-11-01

    Abiotic environmental variables strongly affect the outcomes of species interactions. For example, mutualistic interactions between species are often stronger when resources are limited. The effect might be indirect: water stress on plants can lead to carbon stress, which could alter carbon-mediated plant mutualisms. In mutualistic ant-plant symbioses, plants host ant colonies that defend them against herbivores. Here we show that the partners' investments in a widespread ant-plant symbiosis increase with water stress across 26 sites along a Mesoamerican precipitation gradient. At lower precipitation levels, Cordia alliodora trees invest more carbon in Azteca ants via phloem-feeding scale insects that provide the ants with sugars, and the ants provide better defense of the carbon-producing leaves. Under water stress, the trees have smaller carbon pools. A model of the carbon trade-offs for the mutualistic partners shows that the observed strategies can arise from the carbon costs of rare but extreme events of herbivory in the rainy season. Thus, water limitation, together with the risk of herbivory, increases the strength of a carbon-based mutualism.

  16. Exogenous Application of Growth Enhancers Mitigate Water Stress in Wheat by Antioxidant Elevation

    Directory of Open Access Journals (Sweden)

    Hamid eNawaz

    2016-05-01

    Full Text Available TThe present study was conducted to investigate the response of two wheat cultivars (AARI-11 and Millat-11 to a foliar application of four growth enhancers which include: {H2O (water, MLE30 (moringa leaf extract, KCl (potassium chloride and BAP (benzyl-amino purine}, within the six irrigation water-regimes which are applied at the various critical growth stages such as crown root initiation (CRI, tillering (T, booting (B and heading (H. Irrigation water-regimes include: CRI+T+B, CRI+T, CRI+B, T+B, T+H and control (CRI+T+B+H. The growth enhancers i.e. H2O, MLE30 (1:30, KCl (2% and BAP (50 mg L-1 were applied @ 500 L ha-1 at tillering and heading stages. The results demonstrated some increased quantities of both enzymatic (superoxide dismutase, peroxidase, catalase and non-enzymatic (ascorbic acid, phenol antioxidants in leaves of AARI-11 when MLE30 was applied under T+B and T+H irrigation water-regimes. Similar results were also observed in the case of leaf chlorophyll a & b and K+ contents in both cultivars under control, T+B and CRI+T+B irrigation water regimes. AARI-11 produced the highest biological and grain yield, due to the application of MLE30 and BAP under control, CRI+T+B, T+B and T+H irrigation water-regimes. However, KCl lagged behind among the treatments set for both cultivars under all the irrigation water-regimes. Foliar spray of MLE30 remained prominent growth enhancer and stresses mitigating agent under water deficit conditions particularly under T+B and T+H irrigation water-regimes. Moreover, economic analysis indicated that the foliar application of MLE30 is a cost effective and environment friendly strategy for the maximum yield and income.

  17. Exogenous Application of Growth Enhancers Mitigate Water Stress in Wheat by Antioxidant Elevation

    Science.gov (United States)

    Nawaz, Hamid; Yasmeen, Azra; Anjum, Muhammad A.; Hussain, Nazim

    2016-01-01

    The present study was conducted to investigate the response of two wheat cultivars (AARI-11 and Millat-11) to a foliar application of four growth enhancers which include: {H2O (water), MLE30 (moringa leaf extract), KCl (potassium chloride), and BAP (benzyl-amino purine)}, within the six irrigation water-regimes which are applied at the various critical growth stages such as crown root initiation (CRI), tillering (T), booting (B), and heading (H). Irrigation water-regimes include: CRI+T+B, CRI+T, CRI+B, T+B, T+H, and control (CRI+T+B+H). The growth enhancers i.e., H2O, MLE30 (1:30), KCl (2%), and BAP (50 mg L−1) were applied @ 500 L ha−1 at tillering and heading stages. The results demonstrated some increased quantities of both enzymatic (superoxide dismutase, peroxidase, catalase) and non-enzymatic (ascorbic acid, phenol) antioxidants in leaves of AARI-11 when MLE30 was applied under T+B and T+H irrigation water-regimes. Similar results were also observed in the case of leaf chlorophyll “a” and “b” and K+ contents in both cultivars under control, T+B and CRI+T+B irrigation water regimes. AARI-11 produced the highest biological and grain yield, due to the application of MLE30 and BAP under control, CRI+T+B, T+B, and T+H irrigation water-regimes. However, KCl lagged behind among the treatments set for both cultivars under all the irrigation water-regimes. Foliar spray of MLE30 remained prominent growth enhancer and stresses mitigating agent under water deficit conditions particularly under T+B and T+H irrigation water-regimes. Moreover, economic analysis indicated that the foliar application of MLE30 is a cost effective and environment friendly strategy for the maximum yield and income. PMID:27200065

  18. Back-casting global water stress: Reconstruction of past water demand and climate variability

    Science.gov (United States)

    Wada, Y.; van Beek, L. P.; Bierkens, M. F.

    2010-12-01

    Water scarcity, caused by an existing regional imbalance of water availability and water demand, poses a serious environmental issue to the global society. Since the late 1990s, several studies have quantified blue water stress at the global scale by using the global hydrological models to simulate blue water availability (i.e., surface freshwater in rivers, lakes and reservoirs) which is confronted against water demand to compute water stress. While these assessments have identified regions suffering from current water stress and vulnerable to future water scarcity due to the effects of the climate change and prone to frequent droughts (e.g., Australia, Central and West USA, India, North-East China, Pakistan), the development of past water stress with the influences of population and economic growth and expanding irrigated area has not yet been quantified, which might give an important implication for the future assessment of water stress. Here, we developed a method to reconstruct past water demand from agricultural (i.e., irrigation and livestock), industrial and domestic (i.e., households and municipalities) sector over the period 1960 to 2001, which was used to contrast transient effects in its development against climate variability in the severity of water stress. Agricultural water demand was estimated based on past extents of irrigated area and livestock densities. We developed a simple algorithm to approximate the past economic development based on GDP, energy and household consumption and electricity production, which was subsequently used together with population numbers to estimate industrial and domestic water demand. Desalinated water use and groundwater abstraction were additionally calculated over the same period, the latter being proportional to water demand. Various annual country statistics were used but resulted estimates were gridded at a spatial resolution of 0.5° and disaggregated into a monthly temporal scale as it can be expected that

  19. Physiological Traits Associated with Wheat Yield Potential and Performance under Water-Stress in a Mediterranean Environment

    Science.gov (United States)

    del Pozo, Alejandro; Yáñez, Alejandra; Matus, Iván A.; Tapia, Gerardo; Castillo, Dalma; Sanchez-Jardón, Laura; Araus, José L.

    2016-01-01

    Different physiological traits have been proposed as key traits associated with yield potential as well as performance under water stress. The aim of this paper is to examine the genotypic variability of leaf chlorophyll, stem water-soluble carbohydrate content and carbon isotope discrimination (Δ13C), and their relationship with grain yield (GY) and other agronomical traits, under contrasting water conditions in a Mediterranean environment. The study was performed on a large collection of 384 wheat genotypes grown under water stress (WS, rainfed), mild water stress (MWS, deficit irrigation), and full irrigation (FI). The average GY of two growing seasons was 2.4, 4.8, and 8.9 Mg ha−1 under WS, MWS, and FI, respectively. Chlorophyll content at anthesis was positively correlated with GY (except under FI in 2011) and the agronomical components kernels per spike (KS) and thousand kernel weight (TKW). The WSC content at anthesis (WSCCa) was negatively correlated with spikes per square meter (SM2), but positively correlated with KS and TKW under WS and FI conditions. As a consequence, the relationships between WSCCa with GY were low or not significant. Therefore, selecting for high stem WSC would not necessary lead to genotypes of GY potential. The relationship between Δ13C and GY was positive under FI and MWS but negative under severe WS (in 2011), indicating higher water use under yield potential and MWS conditions. PMID:27458470

  20. Effects of water stress and light intensity on chlorophyll fluorescence parameters and pigments of Aloe vera L.

    Science.gov (United States)

    Hazrati, Saeid; Tahmasebi-Sarvestani, Zeinolabedin; Modarres-Sanavy, Seyed Ali Mohammad; Mokhtassi-Bidgoli, Ali; Nicola, Silvana

    2016-09-01

    Aloe vera L. is one of the most important medicinal plants in the world. In order to determine the effects of light intensity and water deficit stress on chlorophyll (Chl) fluorescence and pigments of A. vera, a split-plot in time experiment was laid out in a randomized complete block design with four replications in a research greenhouse. The factorial combination of three light intensities (50, 75 and 100% of sunlight) and four irrigation regimes (irrigation after depleting 20, 40, 60 and 80% of soil water content) were considered as main factors. Sampling time was considered as sub factor. The first, second and third samplings were performed 90, 180 and 270 days after imposing the treatments, respectively. The results demonstrated that the highest light intensity and the severe water stress decreased maximum fluorescence (Fm), variable fluorescence (Fv)/Fm, quantum yield of PSII photochemistry (ФPSII), Chl and photochemical quenching (qP) but increased non-photochemical quenching (NPQ), minimum fluorescence (F0) and Anthocyanin (Anth). Additionally, the highest Fm, Fv/Fm, ФPSII and qP and the lowest NPQ and F0 were observed when 50% of sunlight was blocked and irrigation was done after 40% soil water depletion. Irradiance of full sunlight and water deficit stress let to the photoinhibition of photosynthesis, as indicated by a reduced quantum yield of PSII, ФPSII, and qP, as well as higher NPQ. Thus, chlorophyll florescence measurements provide valuable physiological data. Close to half of total solar radiation and irrigation after depleting 40% of soil water content were selected as the most efficient treatments.

  1. Prenatal stress induces spatial memory deficits and epigenetic changes in the hippocampus indicative of heterochromatin formation and reduced gene expression.

    Science.gov (United States)

    Benoit, Jamie D; Rakic, Pasko; Frick, Karyn M

    2015-03-15

    Stress during pregnancy has a wide variety of negative effects in both human [1] and animal offspring [2]. These effects are especially apparent in various forms of learning and memory such as object recognition [3] and spatial memory [4]. The cognitive effects of prenatal stress (PNS) may be mediated through epigenetic changes such as histone acetylation and DNA methylation [5]. As such, the present study investigated the effects of chronic unpredictable PNS on memory and epigenetic measures in adult offspring. Mice that underwent PNS exhibited impaired spatial memory in the Morris water maze, as well as sex-specific changes in levels of DNA methyltransferase (DNMT) 1 protein, and acetylated histone H3 (AcH3) in the hippocampus, and serum corticosterone. Male mice exposed to PNS exhibited decreased hippocampal AcH3, whereas female PNS mice displayed a further reduction in AcH3, as well as heightened hippocampal DNMT1 protein levels and corticosterone levels. These data suggest that PNS may epigenetically reduce transcription in the hippocampus, particularly in females in whom this effect may be related to increased baseline stress hormone levels, and which may underlie the sexual dimorphism in rates of mental illness in humans. Copyright © 2014 Elsevier B.V. All rights reserved.

  2. Ovary Apical Abortion under Water Deficit Is Caused by Changes in Sequential Development of Ovaries and in Silk Growth Rate in Maize.

    Science.gov (United States)

    Oury, Vincent; Tardieu, François; Turc, Olivier

    2016-06-01

    Grain abortion allows the production of at least a few viable seeds under water deficit but causes major yield loss. It is maximum for water deficits occurring during flowering in maize (Zea mays). We have tested the hypothesis that abortion is linked to the differential development of ovary cohorts along the ear and to the timing of silk emergence. Ovary volume and silk growth were followed over 25 to 30 d under four levels of water deficit and in four hybrids in two experiments. A position-time model allowed characterizing the development of ovary cohorts and their silk emergence. Silk growth rate decreased in water deficit and stopped 2 to 3 d after first silk emergence, simultaneously for all ovary cohorts, versus 7 to 8 d in well-watered plants. Abortion rate in different treatments and positions on the ear was not associated with ovary growth rate. It was accounted for by the superposition of (1) the sequential emergence of silks originating from ovaries of different cohorts along the ear with (2) one event occurring on a single day, the simultaneous silk growth arrest. Abortion occurred in the youngest ovaries whose silks did not emerge 2 d before silk arrest. This mechanism accounted for more than 90% of drought-related abortion in our experiments. It resembles the control of abortion in a large range of species and inflorescence architectures. This finding has large consequences for breeding drought-tolerant maize and for modeling grain yields in water deficit.

  3. Malbec grape (Vitis vinifera L.) responses to the environment: Berry phenolics as influenced by solar UV-B, water deficit and sprayed abscisic acid.

    Science.gov (United States)

    Alonso, Rodrigo; Berli, Federico J; Fontana, Ariel; Piccoli, Patricia; Bottini, Rubén

    2016-12-01

    High-altitude vineyards receive elevated solar ultraviolet-B (UV-B) levels so producing high quality berries for winemaking because of induction in the synthesis of phenolic compounds. Water deficit (D) after veraison, is a commonly used tool to regulate berry polyphenols concentration in red wine cultivars. Abscisic acid (ABA) plays a crucial role in the acclimation to environmental factors/signals (including UV-B and D). The aim of the present study was to evaluate independent and interactive effects of high-altitude solar UV-B, moderate water deficit and ABA applications on Vitis vinifera cv. Malbec berries. The experiment was conducted during two growing seasons with two treatments of UV-B (+UV-B and -UV-B), watering (+D and -D) and ABA (+ABA and -ABA), in a factorial design. Berry fresh weight, sugar content, fruit yield, phenolic compounds profile and antioxidant capacity (ORAC) were analyzed at harvest. Previous incidence of high UV-B prevented deleterious effects of water deficit, i.e. berry weight reduction and diminution of sugar accumulation. High UV-B increased total phenols (mainly astilbin, quercetin and kaempferol) and ORAC, irrespectively of the combination with other factors. Fruit yield was reduced by combining water deficit and high UV-B or water deficit and ABA. Two applications of ABA were enough to induced biochemical changes increasing total anthocyanins, especially those with higher antioxidant capacity. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  4. Dry Matter Accumulation and Remobilization in Grain Sorghum Genotypes (Sorghum bicolor L. Moench (underNormal and Water Stress Conditions

    Directory of Open Access Journals (Sweden)

    A Beheshti

    2011-02-01

    Full Text Available Abstract Production, remobilization and accumulation of assimilates in crops especially under water stress are essential factors for determination and studying the yield differences of species and cultivars. Field experiment was conducted using a split plot design based on a randomized complete block design with 3 replication s during 2007 growing season in agricultural research station (Khorasan Agricultural and Natural Resource Research Center, Mashhad-Iran. Main plots were consisted of 2 levels of water, water deficit after anthesis and normal condition (with out water stress and factorial arrangement of photosynthesis status (non desiccation and chemical desiccation with potassium iodide and 3 grain sorghum genotypes (Sepide, M5 and M2 promising lines were assigned to sub plots. Results of variance analysis showed, that the effects of water stress on dry matter accumulation, efficiency of remobilization (REE, percent of remobilization (REP, biologic yield were significant in (p≤0.01 (and grain yield (economic yield was significant in p≤0.05, respectively. Water deficit caused an increase of 10.08%, 24.45 % and 12.43% in dry matter accumulation, percent of remobilization and efficiency of remobilization, respectively as compared to normal conditions. This in turn was led to decrease in seed yield, biological yield and harvest index by 36.38%, 5.43% and 31.60%, respectively. The effect of disturbance in current photosynthesis was significant in all of traits and caused the increase of 15.58%, 17.5% and 36.62% in dry matter accumulation, efficiency of remobilization and percent of remobilization, respectively. The role of remobilization was crucial in sorghum genotypes. Interaction between factors showed that highest dry matter accumulation, percentage of remobilization and efficiency of remobilization was in drought stress and disturbance in current photosynthesis and was 16.62%, 62.54 and 24.60%, respectively and was significantly

  5. Phosphatidic acid, a versatile water-stress signal in roots

    Directory of Open Access Journals (Sweden)

    Fionn eMcLoughlin

    2013-12-01

    Full Text Available Adequate water supply is of utmost importance for growth and reproduction of plants. In order to cope with water deprivation, plants have to adapt their development and metabolism to ensure survival. To maximize water use efficiency, plants use a large array of signaling mediators such as hormones, protein kinases and phosphatases, Ca2+, reactive oxygen species and low abundant phospholipids that together form complex signaling cascades. Phosphatidic acid (PA is a signaling lipid that rapidly accumulates in response to a wide array of abiotic stress stimuli. PA formation provides the cell with spatial and transient information about the external environment by acting as a protein-docking site in cellular membranes. PA reportedly binds to a number of proteins that play a role during water limiting conditions, such as drought and salinity and has been shown to play an important role in maintaining root system architecture. Members of two osmotic stress-activated protein kinase families, sucrose non-fermenting 1-related protein kinase 2 (SnRK2 and mitogen activated protein kinases (MAPKs were recently shown bind PA and are also involved in the maintenance of root system architecture and salinity stress tolerance. In addition, PA regulates several proteins involved in abscisic acid (ABA-signaling. PA-dependent recruitment of glyceraldehyde-3-phosphate dehydrogenase (GAPDH under water limiting conditions indicates a role in regulating metabolic processes. Finally, a recent study also shows the PA recruits the clathrin heavy chain and a potassium channel subunit, hinting towards additional roles in cellular trafficking and potassium homeostasis. Taken together, the rapidly increasing number of proteins reported to interact with PA implies a broad role for this versatile signaling phospholipid in mediating salt and water stress responses.

  6. Manganese-exposed developing rats display motor deficits and striatal oxidative stress that are reversed by Trolox.

    Science.gov (United States)

    Cordova, Fabiano M; Aguiar, Aderbal S; Peres, Tanara V; Lopes, Mark W; Gonçalves, Filipe M; Pedro, Daniela Z; Lopes, Samantha C; Pilati, Célso; Prediger, Rui D S; Farina, Marcelo; Erikson, Keith M; Aschner, Michael; Leal, Rodrigo B

    2013-07-01

    While manganese (Mn) is essential for proper central nervous system (CNS) development, excessive Mn exposure may lead to neurotoxicity. Mn preferentially accumulates in the basal ganglia, and in adults it may cause Parkinson's disease-like disorder. Compared to adults, younger individuals accumulate greater Mn levels in the CNS and are more vulnerable to its toxicity. Moreover, the mechanisms mediating developmental Mn-induced neurotoxicity are not completely understood. The present study investigated the developmental neurotoxicity elicited by Mn exposure (5, 10 and 20 mg/kg; i.p.) from postnatal day 8 to PN27 in rats. Neurochemical analyses were carried out on PN29, with a particular focus on striatal alterations in intracellular signaling pathways (MAPKs, Akt and DARPP-32), oxidative stress generation and cell death. Motor alterations were evaluated later in life at 3, 4 or 5 weeks of age. Mn exposure (20 mg/kg) increased p38(MAPK) and Akt phosphorylation, but decreased DARPP-32-Thr-34 phosphorylation. Mn (10 and 20 mg/kg) increased caspase activity and F2-isoprostane production (a biological marker of lipid peroxidation). Paralleling the changes in striatal biochemical