Application Of Glycinebetaine Research Articles

Mitigation of Salinity Stress Effects on Growth, Physio-Chemical Parameters and Yield of Snapbean (<i>Phaseolus vulgaris</i> L.) by Exogenous Application of Glycine Betaine

Pots experiment was carried out during season 2017 at greenhouse of the Agric. Bot. Dep., Fac. of Agric., Zagazig Univ., Egypt to evaluate the effect of glycine betaine (GB) application under salinity stress (50 and100 mM NaCl) on growth, physio-chemical analysis and yield of snap bean cv. Bronco. A complete randomized blocks design was used in this search with three replications. Growth parameters, chlorophyll content and green pod yield were significantly decreased with subjecting plants to NaCl. However foliar application of GB detoxified the stress generated by NaCl and significantly improved the above mention parameters. Salinity stress increased the electrolyte leakage (EL) and decreased membrane stability index (MSI) and relative water content (RWC). While foliar application of GB was improved MSI and RWC and minimized EL. Proline content and antioxidant enzymes significantly increased in the response to NaCl stress as well as GB application.

Mitigation of Salinity Stress Effects on Growth, Physio-Chemical Parameters and Yield of Snapbean (<i>Phaseolus vulgaris</i> L.) by Exogenous Application of Glycine Betaine

Pots experiment was carried out during season 2017 at greenhouse of the Agric. Bot. Dep., Fac. of Agric., Zagazig Univ., Egypt to evaluate the effect of glycine betaine (GB) application under salinity stress (50 and100 mM NaCl) on growth, physio-chemical analysis and yield of snap bean cv. Bronco. A complete randomized blocks design was used in this search with three replications. Growth parameters, chlorophyll content and green pod yield were significantly decreased with subjecting plants to NaCl. However foliar application of GB detoxified the stress generated by NaCl and significantly improved the above mention parameters. Salinity stress increased the electrolyte leakage (EL) and decreased membrane stability index (MSI) and relative water content (RWC). While foliar application of GB was improved MSI and RWC and minimized EL. Proline content and antioxidant enzymes significantly increased in the response to NaCl stress as well as GB application.

How glycine betaine induces tolerance of cucumber plants to salinity stress?

The mechanism of osmoprotectant action on photosynthesis process is still not well known, especially under salt stress. The objective of this study was to evaluate and explain the effect of glycine betaine (GB) on photosynthetic efficiency and other physiological parameters of cucumber plants grown under salinity stress. Our results indicated that salinity decreased chlorophyll and carotenoids content, Ca2+ and K+ concentrations, and quantum yield parameters, such as probability that a trapped exciton moves an electron in to the electron transport chain beyond QA, quantum yield of electron transport from QA to QB in PSII, quantum yield of reduction of end electron acceptors in PSI, performance index for the photochemical activity, total performance index for the photochemical activity, trapping per reaction centers, and other parameters related to primary photochemical reactions of PSII. However, the exogenously applied GB increased most of tested parameters including the total soluble carbohydrate, proline and GB content, and Ca2+ and K+ concentrations, under salt stress. We suggest that GB can play an essential role as regulator to improve photosynthetic efficiency and thus yield of cucumber plants under salt stress conditions. At the level of photosynthesis process, the application of exogenous GB indirectly enhanced the performance of the photosynthetic machinery of cucumber plant due to the reduction of the dissipated light energy, as heat, and the increase of primary reactions of photosynthesis efficiency.

Regulation of Reactive Oxygen Species Metabolism and Glyoxalase Systems by Exogenous Osmolytes Confers Thermotolerance in Brassica napus

In the current study, the beneficial role of proline (Pro) and glycinebetaine (GB) in alleviating high temperature (HT) stress was investigated in Brassica napus L. (rapeseed) seedlings. Ten-d-old rapeseed seedlings were treated with and/or without 2 mM Pro and 2 mM GB and exposed to 38/28 °C day/night (16 and 8 h) temperature for 24 and 48 h. Heat stress induced high amount of hydrogen peroxide (H2O2), lipoxygenase (LOX) and malondialdehyde (MDA) level. Exogenous Pro and GB addition in HT-affected plants increased the levels of ascorbate (AsA) and reduced glutathione (GSH) and their redox pool. Exogenous Pro and GB increased functions of AsA-GSH pathways enzymes along with catalase (CAT), glutathione S-transferase (GST) and glutathione peroxidase (GPX) in HT exposed plants. The enhanced antioxidant defense system by supplementation of Pro and GB helped to reduce oxidative stress and photosynthetic pigments damage caused by HT-induced stress. High methylglyoxal (MG) content decreased upon exogenous Pro and GB application along with enhanced activities of glyoxalase I (Gly I) and Gly II enzymes in HT-stressed plants. Applied Pro and GB under HT stress enhanced endogenous Pro level further to prevent excess water loss and also improved relative water content. Thus, Pro- and/or GB-induced regulatory interactions between ROS and MG detoxification systems may be a useful approach for the reversal of HT-induced oxidative stress.

Glisin Betain Uygulamalarının Tuz Stresi Altında Domatesin Bazı Büyüme ve Fizyolojik Özellikleri Üzerine Etkisi

The effects of the exogenous foliar application of glycine betaine (GB) with different doses (0, 5, 10 and 20 mM) on plant growth, chlorophyll content, stomatal conductance, phenolic and proline contents in tomato grown under salt stress were evaluated. Tomato plants ( Lycopersicon esculentum Mill.) were imposed to salinity stress for 2 months with 75 mM NaCl. Salt stress reduced the growth, chlorophyll reading values and stomatal conductance in tomato. GB application decreased the inhibation of salt stress on tomato plant growth, and increased stomatal conductivity and chlorophyll content. The effective dose of GB was 10 mM to increase tolerance against salt stress. Plant height significantly increased in 5, 10 and 20 mM GB treatments by 2.2, 13.1 and 18.9%, respectively compared to the control. 5 and 10 mM GB treatments significantly increased chlorophyll reading values (51.18 and 53.44, respectively) compared with control (48.92). 10 mM GB exhibited a rapid increase in stomatal conductivity by 11.3% compared with control. Moreover, 10 mM GB showed an increase in proline content by 53.4% compared with control. According to results of our study, it can be suggested that exogenous GB treatments could mitigate the deleterious effects of salt stress in tomato.

The effects of glycine betaine and L-arginine on biochemical properties of pot marigold (calendula officinalis L.) under water stress

Pot marigold (Calendula officinalis L.) is widely used due to its various biological activities to treat diseases as an analgesic, anti-diabetic, anti-ulcer and anti-inflammatory agent. To ameliorate the adverse effects of water stress on this medicinal plant, foliar application of glycine betaine (GB) and L-arginine (LA) was used. For this purpose, water stress was applied at three levels (100%, 70% , and 40% field capacity (FC)), and foliar application was used at five levels (control, 50 mM GB, 100 mM GB, 1.5 mM LA, and 3 mM LA) as factorial based on completely randomized design. We measured phenol and flavonoid content, DPPH radical scavenging activity, superoxide dismutase (SOD) and phenylalanine ammonia-lyase (PAL) activity, and essential oil (EO) content and yield. Total phenol content in the interaction of 40% FC and GB 100 mM was higher than the other treatments. The highest and lowest total flavonoid content and DPPH radical scavenging activity were observed in the interaction of 40% FC and 100% FC, respectively. These variables at GB 100 mM were greater than the others. The highest SOD and PAL activity was found in the interaction of 40% FC and LA 3 mM/GB 100 mM. The content and yield of EO in the interaction of 70% FC and 100 mM GB were greater than other treatments. In sum, 70% of water stress did not significantly change the biochemical properties of C. officinalis, but 40% FC dramatically influenced the quality of the plant. GB 100 mM could stimulate the plant to activate its antioxidant systems under water stress and obtain the highest EO.

Indole-3-acetic-acid and ACC deaminase producing Leclercia adecarboxylata MO1 improves Solanum lycopersicum L. growth and salinity stress tolerance by endogenous secondary metabolites regulation

BackgroundThe utilization of plant growth-promoting microbes is an environment friendly strategy to counteract stressful condition and encourage plants tolerance. In this regards, the current study was designed to isolate ACC deaminase and indole-3-acetic acid (IAA) producing halotolerant bacteria to promote tomato (Solanum lycopersicum L.) growth and tolerance against salinity stress.ResultsThe selected bacterial isolate MO1 was identified as Leclercia adecarboxylata and IAA quantification results revealed that MO1 produced significant amount of IAA (9.815 ± 0.6293 μg mL− 1). The MO1 showed the presence of ACC (1-Aminocyclopropane-1-Carboxylate) deaminase responsible acdS gene and tolerance against salinity stress. A plant microbe interaction experiment using tomato (Solanum lycopersicum L.) with glycine betaine (GB) as a positive control was carried out to investigate the positive role MO1 in improving plant growth and stress tolerance. The results indicated that MO1 inoculation and GB application significantly increased growth attributes under normal as well as saline condition (120 mM NaCl). The MO1 inoculation and GB treatment approach conferred good protection against salinity stress by significantly improving glucose by 17.57 and 18.76%, sucrose by 34.2 and 12.49%, fructose by 19.9 and 10.9%, citric acid by 47.48 and 34.57%, malic acid by 52.19 and 28.38%, serine by 43.78 and 69.42%, glycine by 14.48 and 22.76%, methionine by 100 and 124.99%, threonine by 70 and 63.08%, and proline by 36.92 and 48.38%, respectively, while under normal conditions MO1 inoculation and GB treatment also enhanced glucose by 19.83 and 13.19%, sucrose by 23.43 and 15.75%, fructose by 15.79 and 8.18%, citric acid by 43.26 and 33.14%, malic acid by 36.18 and 14.48%, serine by 46.5 and 48.55%, glycine by 19.85 and 29.77%, methionine by 22.22 and 38.89%, threonine by 21.95 and 17.07%, and proline by 29.61 and 34.68% compared to levels in non-treated plants, respectively. In addition, the endogenous abscisic acid (ABA) level was noticeably lower in MO1-inoculated (30.28 and 30.04%) and GB-treated plants (45 and 35.35%) compared to their corresponding control plants under normal condition as well as salinity stress, respectively.ConclusionThe current findings suggest that the IAA- and ACC-deaminase-producing abilities MO1 can improve plants tolerance to salinity stress.

Exogenous application of glycine betaine improved water use efficiency in winter wheat (Triticum aestivum L.) via modulating photosynthetic efficiency and antioxidative capacity under conventional and limited irrigation conditions

Improving water use efficiency (WUE) is an important subject in agricultural irrigation for alleviating the scarcity of water resources in semiarid regions of the North China Plain. Moreover, glycine betaine (GB) is one of the most effective compatible solutes synthesized naturally in plants for enhancing stress tolerance under abiotic stress, but little information is available on the involvement of GB in regulating crop WUE under field conditions. This study was conducted to explore the role of exogenously applied GB in improving WUE and plant physiological and biochemical responses in winter wheat subjected to conventional or limited irrigation during the 2015–2016 and 2016–2017 growing seasons. Exogenous application of GB significantly enhanced antioxidant enzyme activities and reduced the accumulation of malondialdehyde and hydrogen peroxide under limited irrigation conditions. Furthermore, GB-treated plants maintained higher leaf relative water content and membrane stability, which led to higher chlorophyll content and gas exchange attributes for better intrinsic and instantaneous water use efficiencies compared to control plants under limited irrigation conditions. GB-treated plants had higher indole-acetic acid and zeatin riboside levels but lower ABA levels compared to control plants under conventional and limited irrigation conditions. Additionally, GB enhanced the grain filling rate and duration, grain number per spike, and final grain weight, which resulted in higher grain yield compared to the control. Interestingly, GB significantly improved the integrative and photosynthetic WUE under conventional and limited irrigation conditions, although GB treatment did not markedly affect total water consumption. These results suggest the involvement of GB in improving WUEs in winter wheat by modulating hormonal balance, membrane stability, photosynthetic performance and antioxidant systems to maintain higher grain yield under conventional and limited irrigation conditions.

Exogenously applied glycinebetaine induced alteration in some key physio-biochemical attributes and plant anatomical features in water stressed oat (Avena sativa L.) plants

Although exogenous application of glycinebetaine (GB) is widely reported to regulate a myriad of physio-biochemical attributes in plants under stressful environments including drought stress, there is little information available in the literature on how and up to what extent GB can induce changes in anatomical features in water starved plants. Thus, the present research work was conducted to assess the GB-induced changes in growth, physio-biochemical, and anatomical characteristics in two cultivars (CK-1 and F-411) of oat (Avena sativa L.) under limited water supply. After exposure to water stress, a considerable reduction was observed in plant growth in terms of lengths and weights of shoot and roots, leaf mesophyll thickness, leaf midrib thickness, root cortex thickness, root diameter, stem diameter, stem phloem area, and stem vascular bundle area in both oat cultivars. However, water stress resulted in a significant increase in leaf total phenolics, hydrogen peroxide (H2O2), ascorbic acid (AsA), GB contents, activities of enzymes (CAT, SOD and POD), total soluble proteins, leaf epidermis (abaxial and adaxial) thickness, bulliform cell area, sclerenchyma thickness, root endodermis and epidermis thickness, root metaxylem area, stem metaxylem area and stem sclerenchyma thickness in both oat cultivars. Foliar-applied 100 mM GB suppressed H2O2 contents, while improved growth attributes, free proline and GB contents, activity of SOD enzyme, leaf abaxial epidermis thickness, leaf bulliform cell area, leaf midrib thickness, leaf sclerenchyma thickness, root cortex thickness, root endodermis, epidermis thickness, root stele diameter, stem diameter, stem epidermis thickness, stem metaxylem area, and stem phloem and vascular bundle area in both oat cultivars. For both oat cultivars, CK-1 was superior to F-411 in leaf abaxial epidermis thickness, leaf mesophyll, leaf sclerenchyma, root metaxylem area, stem diameter, stem epidermis, sclerenchyma thickness, stem metaxylem area, and stem vascular bundle area. Overall, both oat cultivars showed inconsistent behavior to water stress and foliar-applied GB in terms of different physio-biochemical attributes, however, CK-1 was superior to F-411 in a number of anatomical features of leaf, root, and stem.

Exogenous Glycinebetaine Reduces Cadmium Uptake and Mitigates Cadmium Toxicity in Two Tobacco Genotypes Differing in Cadmium Tolerance.

Greenhouse hydroponic experiments were conducted using Cd-sensitive (cv. Guiyan1) and Cd-tolerant (cv. Yunyan2) tobacco cultivars to study the ameliorative effects of exogenous glycinebetaine (GB) upon 5 μM Cd stress. The foliar spray of GB markedly reduced Cd concentrations in plants and alleviated Cd-induced soil plant analysis development (SPAD) value, plant height and root length inhibition, with the mitigation effect being more obvious in Yunyan2. External GB markedly reduced Cd-induced malondialdehyde (MDA) accumulation, induced stomatal closure, ameliorated Cd-induced damages on leaf/root ultrastructure, and increased the chlorophyll content and fluorescence parameters of Fo, Fm, and Fv/Fm in both cultivars and Pn in Yunyan2. Exogenous GB counteracted Cd-induced alterations of certain antioxidant enzymes and nutrients uptake, e.g., the depressed Cd-induced increase of superoxide dismutase (SOD) and peroxidase (POD) activities, but significantly elevated the depressed catalase (CAT) and ascorbate peroxidase (APX) activities. The results indicate that alleviated Cd toxicity by GB application is related to the reduced Cd uptake and MDA accumulation, balanced nutrients and antioxidant enzyme activities, improved PSII, and integrated ultrastructure in tobacco plants.

Exogenous Foliar Application of Glycine Betaine to Alleviate Water Deficit Tolerance in Two Indica Rice Genotypes under Greenhouse Conditions

The aim of this investigation was to enhance overall growth, yield attributes as well as physio-biochemical adaptive strategies by exogenous foliar application of glycine betaine (GlyBet) in two rice varieties against water deficit stress under greenhouse conditions. Rice crop cvs. RD43 (low amylose content) and SPR1 (high amylose content) grown in clay pots containing garden soil until booting stage were chosen as the test plant material, sprayed by 0 (control) or 100 mM GlyBet and subsequently subjected to: MWD (mild water deficit by 8 d water withholding; 24.80% SWC; Soil water content) or SWD (severe water deficit by 14 d water withholding; 13.63% SWC) or WW (well-watered conditions or control). Free proline content in cv. RD43 was rapidly increased in relation to the degree of water deficit and suppressed by exogenous GlyBet, while free proline in cv. SPR1 was lower than cv. RD43. Overall growth performances and yield traits in both cultivars under MWD were maintained by exogenous application of GlyBet; however, these parameters declined under SWD even after the GlyBet application. Degradation of photosynthetic pigments and chlorophyll fluorescence in pretreated GlyBet plants under SWD were prevented, resulting in elevated net photosynthetic rate (Pn). Interestingly, Pn was very sensitive parameter that sharply declined under SWD in both RD43 and SPR1 genotypes. Positive relationships between physio-morphological and biochemical changes in rice genotypes were demonstrated with high correlation co-efficiency. Based on the key results, it is concluded that foliar GlyBet application may play an important role in drought-tolerant enhancement in rice crops.

Spatial and Temporal Profile of Glycine Betaine Accumulation in Plants Under Abiotic Stresses.

Several halophytes and a few crop plants, including Poaceae, synthesize and accumulate glycine betaine (GB) in response to environmental constraints. GB plays an important role in osmoregulation, in fact, it is one of the main nitrogen-containing compatible osmolytes found in Poaceae. It can interplay with molecules and structures, preserving the activity of macromolecules, maintaining the integrity of membranes against stresses and scavenging ROS. Exogenous GB applications have been proven to induce the expression of genes involved in oxidative stress responses, with a restriction of ROS accumulation and lipid peroxidation in cultured tobacco cells under drought and salinity, and even stabilizing photosynthetic structures under stress. In the plant kingdom, GB is synthesized from choline by a two-step oxidation reaction. The first oxidation is catalyzed by choline monooxygenase (CMO) and the second oxidation is catalyzed by NAD+-dependent betaine aldehyde dehydrogenase. Moreover, in plants, the cytosolic enzyme, named N-methyltransferase, catalyzes the conversion of phosphoethanolamine to phosphocholine. However, changes in CMO expression genes under abiotic stresses have been observed. GB accumulation is ontogenetically controlled since it happens in young tissues during prolonged stress, while its degradation is generally not significant in plants. This ability of plants to accumulate high levels of GB in young tissues under abiotic stress, is independent of nitrogen (N) availability and supports the view that plant N allocation is dictated primarily to supply and protect the growing tissues, even under N limitation. Indeed, the contribution of GB to osmotic adjustment and ionic and oxidative stress defense in young tissues, is much higher than that in older ones. In this review, the biosynthesis and accumulation of GB in plants, under several abiotic stresses, were analyzed focusing on all possible roles this metabolite can play, particularly in young tissues.

Effects of foliar application of glycine betaine and chitosan on Puccinellia distans (Jacq.) Pari, subjected to salt stress.

Using brackish water for irrigation may expose turfgrasses to salinity stress. Employing the best treatments to maintain high-quality turfs under saline conditions is an important requirement for turfgrass management. We tested the response of a halophyte grass, Puccinellia distans, to irrigation with saline solutions and to foliar application of two osmoprotectants, such as glycine betaine (GB) or chitosan (CH). Plants were grown in pots under controlled conditions and irrigated with 200 mM or 600 mM of NaCl solutions. The response to salinity treatments and osmoprotectant application was evaluated after 90 days by measuring leaf firing, leaf density, shoot length and biomass, root length, and shoot water potential. Increasing salinity reduced shoot density, shoot and root length, shoot water potential, and increased leaf firing and shoot solute potential at 200 mM of NaCl. These effects were more pronounced at 600 mM of NaCl. Application of GB greatly increased shoot growth traits at 200 mM of NaCl and also showed beneficial effects on most traits at 600 mM. Application of CH showed positive effects only on leaf firing and leaf water potential at 600 mM. Our results show that P. distans can tolerate high levels of salt stress, which can be best alleviated by GB treatment.

Exogenous Application of Salicylic Acid and Glycine Betaine as Tools to Enhance Biomass and Tolerance of Potato Cultivars

This pot experiment was aimed at characterization of agro-physiological responses of potato to water deficit and exogenously application of salicylic acid (SA) and glycine betaine (GB). Four potato cultivars, Spirit, Born, Arinda and Banba, were exposed to two irrigation regimes (30 and 60% depletion of available soil water) and two levels of both SA (0.5 and 1.0 mM) and GB application (1.0 and 2.0 mM) in addition to the control (0.0 mM SA and GB). Activities of ascorbate peroxidase (APX), superoxide dismutase (SOD), total antioxidant capacity (TAC), ion leakage (IL), fluorescence chlorophyll (Fv/Fm), chlorophyll pigments, root dry mass (RDM) and plant dry mass (PDM) were measured. Water deficiency resulted in significant effects on all characteristics. Antioxidant enzymes and IL increased, but the other characteristics decreased significantly with water deficit. Tolerant cultivars (Spirit and Born) revealed higher activity of SOD enzyme, chlorophyll content, PDM and lower IL than non-tolerant cultivars (Arinda and Banba). This investigation has been able to provide evidence that SA and GB affected antioxidant enzymes and increased chlorophyll pigments and PDM. The range of the increases seemed greater when potato cultivars were grown under water deficit circumstances. PDM increased by increasing SA and GB levels. This led to the supposition that injurious effects on potato cultivars due to water deficit could be relieved by SA and GB.

Up-regulation of antioxidative defense systems by glycine betaine foliar application in onion plants confer tolerance to salinity stress

Abstract Plants face a lot of abiotic stresses, during their life cycle, including salinity that greatly influences their growth and entire metabolism. Osmoprotectants have to enable plant to beat such stress. Two-season field experiments were conducted consecutively in 2015/16 and 2016/17 to study the effect of glycine betaine (GB) foliar application at three levels (0; a control, 25 and 50 mM) on onion growth, physio-biochemical attributes and antioxidant defense system activity was investigated under 4.80 dS m−1 salt stress. Under saline soil conditions, GB treatment significantly increased growth indices (e.g., shoot length, leaves area of plant−1, shoot fresh and dry weights), bulb yields and water use efficiency (WUE), leaf chlorophylls contents and their efficiency, stomatal conductance and tissue health measured as relative water content and membrane stability index. Additionally, endogenous osmoprotectants (e.g., GB and choline) contents, non-enzymatic antioxidants (e.g., glutathione and ascorbic acid) contents and enzymatic antioxidants (e.g., catalase, superoxide dismutase, and ascorbate peroxidase) were significantly increased with exogenous GB application under salt stress. In contrast, glutathione reductase activity was reduced, while free proline and soluble sugars contents were not affected. A level of 50 mM GB was more effective to be the better treatment by which this study recommends to use for growing onion plants under moderate salt stress.

Foliar Application of Glycine Betaine Alters Sugar Metabolism of Wheat Leaves Under Prolonged Field Drought Stress

The present investigation was carried out to examine the alterations in contents of various sugars in a set of 19 wheat genotypes under drought stress. In addition, foliar application of glycine betaine (GB, 100 mM) was done to explore participation of this osmolyte in drought response mechanism. Drought stress caused a significant increase in total soluble sugars (TSS) and starch levels, at both maximum tillering and anthesis stages. Activities of sucrose phosphate synthase (Suc-P-syn) and sucrose synthase (Suc syn) were also increased in drought stressed plants at both the stages. Exogenous application of GB resulted in higher TSS under drought stress; however reduced levels of starch were observed at anthesis in GB treated plants. GB application caused a decline in activity of Suc-P-syn and Suc syn at both stages. The alterations in sugar levels of GB sprayed plants suggested that regulation of sugar metabolism could undergo modifications (upstream or downstream) in presence of osmolytes like GB. Genotype-specific response to GB spray resulted in yield benefits in selected genotypes under drought stress.

Glycine betaine accumulation in Avicennia germinans propagules and seedlings as a function of abiotic stress

The black mangrove (Avicennia germinans) is native to the subtropical coasts of Florida and can tolerate moderate to high salinity environments. Propagules, germinated seeds that remain attached to the maternal plants until mature, are dispersed in shallow waters and transported through currents until washing ashore, and establishing roots on an appropriate substrate to initiate growth. Recently, the poleward expansion of A. germinans has been observed. The literature and findings in our laboratory suggest that A. germinans gains its salt and temperature tolerance in part by the modified amino acid, glycine betaine (GB). We sought to investigate the expression of GB in A. germinans as a function of abiotic stressors: high saline and low temperatures. The role of endogenous GB accumulation as a function of substrate condition and temperature was investigated in propagules. The accumulation of exogenous GB was measured in seedlings exposed to various saline and temperature environments. Propagules exposed to colder temperatures accumulated more GB (100–200 ug/umol) than moderate temperatures (50 ug/umol). Propagules exposed to 18 ppt saline accumulated more GB than those exposed to 36 ppt at 0°C. Propagules exposed to saline environments accumulated more GB at 0°C compared to sand and air samples. Significantly more propagules treated at 36 ppt developed into seedlings and demonstrated faster growth rates. Additionally, an exogenous application of 10 μM GB improved seedling survival after exposure to −2°C and high saline stress (60 ppt and 100 ppt). Preliminary findings demonstrate that APX and SOD enzymes are both present in the leaf samples after these stressors. These results further characterize the role GB contributes to the ability of A. germinans to acclimate following environmental stressors. Propagules express endogenous GB in response to abiotic stress, while exogenous application of GB may confer additional protection from continued stress. Subsequent investigations will further elucidate the roles APX and SOD may influence in the GB mechanism. The significance of these findings further characterize the mechanisms by which A. germinans survive high saline environments and colder temperatures.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Physiological adjustments of wheat to drought stress as influenced by osmoprotectants and cytokinins

Glycine betaine (GB), Trehalose (Tre) and proline function as compatible solutes and are up regulated in plants under drought stress. In physiological responses, these play an osmoprotective role enabling the plants to better tolerate the adverse conditions of growth. In the present study, the effect of exogenous application of GB and Tre along with cytokinins (Kn, BA) applied during vegetative and anthesis stages to wheat cultivars (HD2967, PBW660 and WH1105) has been investigated. Proline content significantly increased under drought stress in all the three cultivars. Application of Tre along with both Kn and BA reduced the accumulation of proline in leaves at vegetative and anthesis stage. Drought stress conditions favoured accumulation of GB and choline in leaves of wheat cultivars and percent increase was more in PBW660. GB and Tre further improved accumulation of endogenous glycine betaine and choline. This advantageous effect of the osmoprotectants in combination with cytokinins alleviated growth inhibition during drought and improved the number of productive tillers and grains.

Grain yield response of drought stressed wheat to foliar application of glycine betaine

A field experiment was conducted to investigate influence of exogenous application of glycine betaine (GB) on performance of wheat under prolonged drought conditions. A set of 19 wheat genotypes differing in stress sensitivity, were sprayed with 100mM GB at maximum tillering and anthesis stage. GB treatment significantly declined the phenological pace under drought stress by increasing days to anthesis. Foliar applied GB improved grains/ spike and thousand grain weight of selected wheat genotypes over stressed ones. The genotype specific response to GB application suggested some threshold optimum level to be necessary for yield improvement under drought stress in susceptible genotypes as compared with tolerant ones. In overall, GB alleviated negative effects of drought stress by a rise in harvest index of most genotypes suggesting its role in assimilate translocation.

Grain yield response of drought stressed wheat to foliar application of glycine betaine

<span>A field experiment was conducted to investigate influence of exogenous application of glycine betaine (GB) on performance of wheat under prolonged drought conditions. A set of 19 wheat genotypes differing in stress sensitivity, were sprayed with 100mM GB at maximum tillering and anthesis stage. GB treatment significantly declined the phenological pace under drought stress by increasing days to anthesis. Foliar applied GB improved grains/ spike and thousand grain weight of selected wheat genotypes over stressed ones. The genotype specific response to GB application suggested some threshold optimum level to be necessary for yield improvement under drought stress in susceptible genotypes as compared with tolerant ones. In overall, GB alleviated negative effects of drought stress by a rise in harvest index of most genotypes suggesting its role in assimilate translocation.</span>