scholarly journals Growth-Promoting Effect of Rhizobacterium (Bacillus subtilis IB22) in Salt-Stressed Barley Depends on Abscisic Acid Accumulation in the Roots

2021 ◽  
Vol 22 (19) ◽  
pp. 10680
Author(s):  
Zarina Akhtyamova ◽  
Tatiana Arkhipova ◽  
Elena Martynenko ◽  
Tatyana Nuzhnaya ◽  
Ludmila Kuzmina ◽  
...  
Keyword(s):  
Bacillus Subtilis ◽  
Abscisic Acid ◽  
Salt Stress ◽  
Transcript Abundance ◽  
Promoting Effect ◽  
Mutant Transcript ◽  
Relative Water ◽  
Probable Outcome ◽  
Leaf Relative Water Content ◽  
Stress Accumulation

An ABA-deficient barley mutant (Az34) and its parental cultivar (Steptoe) were compared. Plants of salt-stressed Az34 (100 mmol m−3 NaCl for 10 days) grown in sand were 40% smaller than those of “Steptoe”, exhibited a lower leaf relative water content and lower ABA concentrations. Rhizosphere inoculation with IB22 increased plant growth of both genotypes. IB22 inoculation raised ABA in roots of salt-stressed plants by supplying ABA exogenously and by up-regulating ABA synthesis gene HvNCED2 and down-regulating ABA catabolic gene HvCYP707A1. Inoculation partially compensated for the inherent ABA deficiency of the mutant. Transcript abundance of HvNCED2 and related HvNCED1 in the absence of inoculation was 10 times higher in roots than in shoots of both mutant and parent, indicating that ABA was mainly synthesized in roots. Under salt stress, accumulation of ABA in the roots of bacteria-treated plants was accompanied by a decline in shoot ABA suggesting bacterial inhibition of ABA transport from roots to shoots. ABA accumulation in the roots of bacteria-treated Az34 was accompanied by increased leaf hydration, the probable outcome of increased root hydraulic conductance. Thereby, we tested the hypothesis that the ability of rhizobacterium (Bacillus subtilis IB22) to modify responses of plants to salt stress depends on abscisic acid (ABA) accumulating in roots.

scholarly journals Changes in plant growth, leaf relative water content and physiological traits in response to salt stress in peanut (Arachis hypogaea L.) varieties

2021 ◽  
Vol 49 (1) ◽  
pp. 12049
Author(s):  
Tekam L. MEGUEKAM ◽  
Dany P. MOUALEU ◽  
Victor D. TAFFOUO ◽  
Hartmut STÜTZEL
Keyword(s):  
Salt Stress ◽  
Plant Growth ◽  
Water Content ◽  
Arachis Hypogaea ◽  
Relative Water Content ◽  
Physiological Traits ◽  
Salt Tolerant ◽  
Arachis Hypogaea L ◽  
Relative Water ◽  
Leaf Relative Water Content

Salinity is the main environmental factor accountable for decreasing crop productivity worldwide. The effects of NaCl salinity on plant growth (leaf relative water content (RWC), leaf dry weight (LDW), shoot length (SL), number of leaves (NL), number of branches (NB) and total leaf area (TLA) and physiological characteristics (stomatal conductance (gs), transpiration rate (TR), net photosynthetic (Pn), yield of photosystem II (ΦPsII) and the intercellular CO2 concentration (CO2int) in peanut (Arachis hypogaea L.) varieties (‘Vanda’, ‘P244601’ and ‘Pl184948’, widely used in Cameroon, Tanzania and Ghana, respectively, were investigated under hydroponic condition. Plants were subjected to four levels of NaCl (0, 40, 80 and 120 mM) at early seedling growth stage of plant development. Application of NaCl treatment led to a significant decrease in LDW, SL, NL, TLA, Pn, gs, TR and CO2int concentration of ‘Vanda’ and ‘P244601’ compared to untreated plants while the plant growth inhibition was notably noted at 120 mM NaCl in ‘P1184948’ for LDW, SL and NB. The highest depressive effect was detected in gs of salt-sensitive ‘Vanda’ while the lowest were recorded in gs of salt-tolerant ‘P1184948’ at high salinity level. Enhanced NaCl concentrations led to a significant increase in ΦPSII of ‘P1184948’ compared to ‘Vanda’, ‘P244601’ and untreated plants. Leaf CHL content was significantly increased in moderately-tolerant ‘‘P244601’ and salt-tolerant ‘P1184948’ at 80 mM NaCl compared to salt sensitive ‘Vanda’ and untreated plants. The depressive effect of salt on RWC was recorded at 120 mM NaCl in peanut leaves of all varieties. Under salt stress ‘P1184948’ was observed to have relatively higher tolerance on average of all growth and physiological traits than ‘Vanda’ and P244601’ suggesting that it could be grown in salt-affected soils.

scholarly journals Regulatory networks of gene expression in maize (Zea mays) under drought stress and re-watering

2018 ◽  
Author(s):  
Liru Cao ◽  
Xiaomin Lu ◽  
Pengyu Zhang ◽  
Lixia Ku ◽  
Guorui Wang ◽  
...  
Keyword(s):  
Gene Expression ◽  
Superoxide Dismutase ◽  
Abscisic Acid ◽  
Drought Stress ◽  
Stomatal Conductance ◽  
Expression Profiles ◽  
Gene Expression Profiles ◽  
Proline Content ◽  
Relative Water ◽  
Leaf Relative Water Content

AbstractDrought can severely limit plant growth and production. However, few studies have investigated gene expression profiles in maize during drought/re-watering. We compared drought-treated and water-sufficient maize plants by measuring their leaf relative water content, superoxide dismutase and peroxidase activities, proline content, and leaf gas exchange parameters (photosynthetic rates, stomatal conductance, and transpiration rates). We conducted RNA sequencing analyses to elucidate gene expression profiles and identify miRNAs that might be related to drought resistance. A GO enrichment analysis showed that the common DEGs (differently expressed genes) between drought-treated and control plants were involved in response to stimulus, cellular process, metabolic process, cell part, and binding and catalytic activity. Analyses of gene expression profiles revealed that 26 of the DEGs under drought encoded 10 enzymes involved in proline synthesis, suggesting that increased proline synthesis was a key part of the drought response. We also investigated cell wall-related genes and transcription factors regulating abscisic acid-dependent and -independent pathways. The expression profiles of the miRNAs miR6214-3p, miR5072-3p, zma-miR529-5p, zma-miR167e-5p, zma-miR167f-5p, and zma-miR167j-5p and their relevant targets under drought conditions were analyzed. These results provide new insights into the molecular mechanisms of drought tolerance, and may identify new targets for breeding drought-tolerant maize lines.Abbreviationsleaf relative water content: RWC, superoxide dismutase activity: SOD, peroxidase activity: POD, proline content: Pro, photosynthetic rates: Pn, stomatal conductance: Cond, transpiration rates: Tr.; quantitative real-time polymerase chain reaction: qPCR; abscisic acid; ABA; polyethylene glycol :PEG; Principal component analysis :PCA; polyacrylamide gel electrophoresis :PAGEHighlightThe study of physiology and molecular mechanism of maize laid a theoretical foundation for drought resistance breeding under drought stress and re-watering.

scholarly journals Complex Analysis of Antioxidant Activity, Abscisic Acid Level, and Accumulation of Osmotica in Apple and Cherry In Vitro Cultures under Osmotic Stress

2021 ◽  
Vol 22 (15) ◽  
pp. 7922
Author(s):  
Petra Jiroutova ◽  
Zuzana Kovalikova ◽  
Jakub Toman ◽  
Dominika Dobrovolna ◽  
Rudolf Andrys
Keyword(s):  
Antioxidant Activity ◽  
Abscisic Acid ◽  
Osmotic Stress ◽  
Complex Analysis ◽  
Biochemical Processes ◽  
Wide Range ◽  
Relative Water ◽  
Leaf Relative Water Content ◽  
Abscisic Acid Level

Plant response to osmotic stress is a complex issue and includes a wide range of physiological and biochemical processes. Extensive studies of known cultivars and their reaction to drought or salinity stress are very important for future breeding of new and tolerant cultivars. Our study focused on the antioxidant activity, accumulations of osmotica, and the content of abscisic acid in apple (cv. “Malinové holovouské”, “Fragrance”, “Rubinstep”, “Idared”, “Car Alexander”) and cherry (cv. “Regina”, “Napoleonova”, “Kaštánka”, “Sunburst”, “P-HL-C”) cultivated in vitro on media containing different levels of polyethylene glycol PEG-6000. Our results indicated that the studied genotypes responded differently to osmotic stress manifested as reduction in the leaf relative water content (RWC) and increment in the activities of antioxidant enzymes, proline, sugars, and abscisic acid content. Overall, cherry cultivars showed a smaller decrease in percentage RWC and enzymatic activities, but enhanced proline content compared to the apple plants cultivars. Cultivars “Rubinstep”, “Napoleonova”, and “Kaštánka” exhibited higher antioxidant capacity and accumulation of osmoprotectants like proline and sorbitol that can be associated with the drought-tolerance system.

scholarly journals Influence of Bacillus subtilis strain on abscisic acid content in ABA-deficient barley mutant and its wild type

2021 ◽  
Vol 2(26) ◽  
pp. 28-40
Author(s):  
Z.A. Akhtyamova ◽  
◽  
T.N. Arkhipova ◽  
E.V. Martynenko ◽  
T.V. Nuzhnaya ◽  
...  
Keyword(s):  
Bacillus Subtilis ◽  
Abscisic Acid ◽  
Leaf Area ◽  
Photochemical Quenching ◽  
Bacterial Suspension ◽  
Subtilis Strain ◽  
Deficient Mutant ◽  
Wild Type ◽  
Promoting Effect ◽  
Shoot Mass

The ability to produce phytohormones and influence their metabolism in plants is an important property of rhizosphere bacteria that determines their plant growth promoting effect. Since abscisic acid (ABA) reduces stomatal conductance and increases the ability of tissues to conduct water, maintenance of water balance in lettuce plants on the background of activation of their growth was associated with the accumulation of ABA under the influence of bacteria. The aim of the study is to test the hypothesis that the growth-stimulating effect of bacteria on plants depends on their ability to synthesize the hormone ABA. The plants were grown on a light platform; seedlings were treated with a bacterial suspension simultaneously with planting. The ABA content, the relative water content, the chlorophyll content, the level of non-photochemical quenching, the leaf area and the weight of the shoots were measured. The level of transcripts of the HvNCED1, HvNCED2, and HvCYP707A1 genes responsible for ABA metabolism in barley was assessed using real-time PCR. Comparison of the ABA-deficient mutant of barley and plants of its wild type revealed the stimulation of the growth of plants of both genotypes upon bacterial treatment. The shoot mass and leaf area of the untreated mutant with bacteria were about 30 % less compared to Steptoe. The stimulating effect of bacteria was manifested in an increase in leaf area by 15 % in Steptoe and by 35 % in Az 34; shoot mass – by 18 % and 41 %, respectively. As a result, the phenotype difference between plants of two genotypes decreased. In the deficient mutant, the ABA level increased under the influence of Bacillus subtilis IB-22 more than twice. It was due to the ability of bacteria to produce ABA and reduce the activity of ABA degradation in barley plants. The results obtained in this study indicate that certain bacterial strains are able to increase the level of ABA in plants, compensating for the genetically determined deficiency of this hormone.

scholarly journals Responses of leaf gas exchange attributes, photosynthetic pigments and antioxidant enzymes in NaCl-stressed cotton (Gossypium hirsutum L.) seedlings to exogenous glycine betaine and salicylic acid

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Abdoul Kader Mounkaila Hamani ◽  
Guangshuai Wang ◽  
Mukesh Kumar Soothar ◽  
Xiaojun Shen ◽  
Yang Gao ◽  
...  
Keyword(s):  
Enzyme Activity ◽  
Salt Stress ◽  
Gas Exchange ◽  
Antioxidant Enzyme ◽  
Foliar Application ◽  
Leaf Gas Exchange ◽  
Foliar Spray ◽  
Antioxidant Enzyme Activity ◽  
Relative Water ◽  
Leaf Relative Water Content

Abstract Background Application of exogenous glycine betaine (GB) and exogenous salicylic acid (SA) mitigates the adverse effects of salinity. Foliar spraying with exogenous GB or SA alleviates salt stress in plants by increasing leaf gas exchange and stimulating antioxidant enzyme activity. The effects of foliar application of exogenous GB and SA on the physiology and biochemistry of cotton seedlings subjected to salt stress remain unclear. Results Results showed that salt stress of 150 mM NaCl significantly reduced leaf gas exchange and chlorophyll fluorescence and decreased photosynthetic pigment quantities and leaf relative water content. Foliar spray concentrations of 5.0 mM exogenous GB and 1.0 mM exogenous SA promoted gas exchange and fluorescence in cotton seedlings, increased quantities of chlorophyll pigments, and stimulated the antioxidant enzyme activity. The foliar spray also increased leaf relative water content and endogenous GB and SA content in comparison with the salt-stressed only control. Despite the salt-induced increase in antioxidant enzyme content, exogenous GB and SA in experimental concentrations significantly increased the activity of glutathione reductase, ascorbate peroxidase, superoxide dismutase, catalase and peroxidase, and decreased malondialdehyde content under salt stress. Across all experimental foliar spray GB and SA concentrations, the photochemical efficiency of photosystem II (FV/FM) reached a peak at a concentration of 5.0 mM GB. The net photosynthetic rate (Pn) and FV/FM were positively correlated with chlorophyll a and chlorophyll b content in response to foliar spraying of exogenous GB and SA under salt stress. Conclusions We concluded, from our results, that concentrations of 5.0 mM GB or 1.0 mM SA are optimal choices for mitigating NaCl-induced damage in cotton seedlings because they promote leaf photosynthesis, increase quantities of photosynthetic pigments, and stimulate antioxidant enzyme activity. Among, 5.0 mM GB and 1.0 mM SA, the best performance in enhancing endogenous GB and SA concentrations was obtained with the foliar application of 1.0 mM SA under salt stress.

Physiological, biochemical and mineral dimensions of green beangenotypes depending on Zn priming and salinity

2016 ◽  
Author(s):  
Nurdilek Gulmezoglu ◽  
Cigdem Aydogan ◽  
Ece Turhan
Keyword(s):  
Salt Stress ◽  
Growth And Development ◽  
Dry Weight ◽  
Green Bean ◽  
Salt Tolerant ◽  
Leaf Emergence ◽  
Inhibition Of Growth ◽  
Relative Water ◽  
Leaf Relative Water Content ◽  
K Concentration

The effects of salinity and zinc (Zn) priming on the physical and mineral composition of green bean genotypes were investigated on two green bean genotypes (‘ªeker Fasulye’ and ‘Local Genotype’) by soaking seeds in 0.05% Zn (ZnSO4.7H2O) solution and by exposing to salt stress by applying 50, 100 and 150 mM NaCl after first true leaf emergence. Plants not exposed to salt stress were treated as control. The effects of Zn priming on the salt tolerance of genotypes, fresh and dry weight of plant leaf relative water content (RWC), loss of turgidity (LOT), Na, K, Ca and Zn concentrations in the leaves, stem and root portions of plants were evaluated. The NaCl concentrations led to significant variations in the examined parameters. The highest concentration of salt (150 mM) caused fading in leaves and led to inhibition of growth and development. Salt application generally reduced the fresh and dry weights of plants of both genotypes where Zn priming showed an amendatory effect. Leaf RWC decreased with salt applications while LOT increased but Zn priming had no amendatory effect on these parameters. ‘ªeker Fasulye’ genotype was found to be relatively more salt tolerant than ‘Local Genotype’ on the basis of the investigated parameters. Zinc priming decreased the Na and Ca concentrations in plant organs; however, a decrease in K concentration was observed due to increase in NaCl.

scholarly journals Mitigation of salt stress in strawberry by foliar K, Ca and Mg nutrient supply

2009 ◽  
Vol 55 (No. 5) ◽  
pp. 213-221 ◽  
Author(s):  
E. Yildirim ◽  
H. Karlidag ◽  
M. Turan
Keyword(s):  
Salt Stress ◽  
Salinity Stress ◽  
Plant Root ◽  
Dry Weight ◽  
Nutrient Supply ◽  
Stress Treatment ◽  
Shoot Dry Weight ◽  
Foliar Nutrient ◽  
Relative Water ◽  
Leaf Relative Water Content

Plant root and shoot dry weight, leaf relative water content (LRWC) and chlorophyll content were reduced by 30%, 21%, 15%, 34%, respectively, at 40mM NaCl as compared to non-salt stress conditions. However, membrane permeability (MP) of plant increased (85.0%) with increasing salinity. Foliar nutrient application (FNA) alleviated deleterious effects of salinity stress on growth and this effect was statistically significant. The highest alleviation effect of FNA at 40mM salinity stress was observed in the case of 10mM foliar KNO<sub>3</sub> and Ca(NO<sub>3</sub>)<sub>2</sub> application, resulting in increase in plant root dry weight (50%), shoot dry weight (50%), LRWC (8.2%) and MP decrease (27.4%) at 40mM NaCl. Phosphorus, Fe and Zn contents in shoots and roots of plants also increased with FNA treatments, but they were still much lower than those of non-salt stress treatment. Sulphur, P, Fe and Zn contents of shoots reached similar values as in non-salt stress treatment when KNO<sub>3</sub> was applied, whereas Fe, Mn, Zn, and Cu contents of roots reached the values of non-salt stress treatment when Ca(NO<sub>3</sub>)<sub>2</sub> was applied.

scholarly journals Under salt stress guard cells rewire ion transport and abscisic acid (ABA) signaling

2021 ◽  
Author(s):  
Sohail M. Karimi ◽  
Matthias Freund ◽  
Brittney M. Wager ◽  
Michael Knoblauch ◽  
Jörg Fromm ◽  
...  
Keyword(s):  
Abscisic Acid ◽  
Salt Stress ◽  
Ion Transport ◽  
Guard Cells ◽  
Aba Signaling

Relationships between physiological traits and productivity of sugarcane in response to water deficit

2012 ◽  
Vol 152 (1) ◽  
pp. 104-118 ◽  
Author(s):  
M. DE A. SILVA ◽  
J. L. JIFON ◽  
J. A. G. DA SILVA ◽  
C. M. DOS SANTOS ◽  
V. SHARMA
Keyword(s):  
Water Deficit ◽  
Field Studies ◽  
Water Deficit Stress ◽  
Chlorophyll Contents ◽  
Physiological Variables ◽  
Drought Tolerant ◽  
Relative Water ◽  
Leaf Relative Water Content ◽  
Sugarcane Productivity ◽  
Response To Water

SUMMARYThe relationships between physiological variables and sugarcane productivity under water deficit conditions were investigated in field studies during 2005 and 2006 in Weslaco, Texas, USA. A total of 78 genotypes and two commercial varieties were studied, one of which was drought-tolerant (TCP93-4245) and the other drought-sensitive (TCP87-3388). All genotypes were subjected to two irrigation regimes: a control well-watered treatment (wet) and a moderate water-deficit stress (dry) treatment for a period of 90 days. Maximum quantum efficiency of photosystem II (Fv/Fm), estimated chlorophyll content (SPAD index), leaf temperature (LT), leaf relative water content (RWC) and productivity were measured. The productivity of all genotypes was, on average, affected negatively; however, certain genotypes did not suffer significant reduction. Under water deficit, the productivity of the genotypes was positively and significantly correlated with Fv/Fm, SPAD index and RWC, while LT had a negative correlation. These findings suggest that genotypes exhibiting traits of high RWC values, high chlorophyll contents and high photosynthetic radiation use efficiency under low moisture availability should be targeted for selection and variety development in programmes aimed at improving sugarcane for drought prone environments.

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