Ullah Abd, Ali Iftikhar, Noor Javaria, Zeng Fanjiang, Bawazeer Sami, Eldin Sayed M, Asghar Muhammad Ahsan, Javed Hafiz Hassan, Saleem Khansa, Ullah Sami, Ali Haider
Xinjiang Key Laboratory of Desert Plant Root Ecology and Vegetation Restoration, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi, China.
Cele National Station of Observation and Research for Desert-Grassland Ecosystems, Cele, China.
Front Plant Sci. 2023 Jan 18;13:1081188. doi: 10.3389/fpls.2022.1081188. eCollection 2022.
Increasing soil salinization has a detrimental effect on agricultural productivity.Therefore, strategies are needed to induce salinity-tolerance in crop species for sustainable foodproduction. γ-aminobutyric acid (GABA) plays a key role in regulating plant salinity stresstolerance. However, it remains largely unknown how mungbean plants (Vigna radiata L.) respondto exogenous GABA under salinity stress.
Thus, we evaluated the effect of exogenous GABA (1.5 mM) on the growth and physiobiochemicalresponse mechanism of mungbean plants to saline stress (0-, 50-, and 100 mM [NaCland Na2SO4, at a 1:1 molar ratio]).
Increased saline stress adversely affected mungbean plants' growth and metabolism. Forinstance, leaf-stem-root biomass (34- and 56%, 31- and 53%, and 27- and 56% under 50- and 100mM, respectively]) and chlorophyll concentrations declined. The carotenoid level increased (10%)at 50 mM and remained unaffected at 100 mM. Hydrogen peroxide (H2O2), malondialdehyde(MDA), osmolytes (soluble sugars, soluble proteins, proline), total phenolic content, andenzymatic activities of superoxide dismutase (SOD), ascorbate peroxidase (APX), peroxidase(POD), glutathione reductase (GTR), and polyphenol oxidation (PPO) were significantlyincreased. In leaves, salinity caused a significant increase in Na+ concentration but a decrease inK+ concentration, resulting in a low K+/Na+ concentration (51- and 71% under 50- and 100- mMstress). Additionally, nitrogen concentration and the activities of nitrate reductase (NR) andglutamine synthetase (GS) decreased significantly. The reduction in glutamate synthase (GOGAT)activity was only significant (65%) at 100 mM stress. Exogenous GABA decreased Na+, H2O2,and MDA concentrations but enhanced photosynthetic pigments, K+ and K+/Na+ ratio, Nmetabolism, osmolytes, and enzymatic antioxidant activities, thus reducing salinity-associatedstress damages, resulting in improved growth and biomass.
Exogenous GABA may have improved the salinity tolerance of mungbean plants by maintaining their morpho-physiological responses and reducing the accumulation of harmfulsubstances under salinity. Future molecular studies can contribute to a better understanding of themolecular mechanisms by which GABA regulates mungbean salinity tolerance.
土壤盐渍化加剧对农业生产力产生不利影响。因此，需要采取策略来诱导作物品种的耐盐性，以实现可持续粮食生产。γ-氨基丁酸（GABA）在调节植物耐盐胁迫中起关键作用。然而，绿豆植株（Vigna radiata L.）在盐胁迫下如何对外源GABA作出反应仍 largely未知。
因此，我们评估了外源GABA（1.5 mM）对绿豆植株在盐胁迫（0、50和100 mM [NaCl和Na2SO4，摩尔比为1:1]）下生长和生理生化反应机制的影响。
盐胁迫加剧对绿豆植株的生长和代谢产生不利影响。例如，叶-茎-根生物量（50 mM和100 mM下分别下降34%和56%、31%和53%、27%和56%）和叶绿素浓度降低。类胡萝卜素水平在50 mM时增加（10%），在100 mM时未受影响。过氧化氢（H2O2）、丙二醛（MDA）、渗透溶质（可溶性糖、可溶性蛋白质、脯氨酸）、总酚含量以及超氧化物歧化酶（SOD）、抗坏血酸过氧化物酶（APX）、过氧化物酶（POD）、谷胱甘肽还原酶（GTR）和多酚氧化酶（PPO）的酶活性显著增加。在叶片中，盐胁迫导致Na+浓度显著增加，但K+浓度降低，导致低钾/钠浓度（50 mM和100 mM胁迫下分别降低51%和71%）。此外，氮浓度以及硝酸还原酶（NR）和谷氨酰胺合成酶（GS）的活性显著降低。谷氨酸合酶（GOGAT）活性仅在100 mM胁迫下显著降低（65%）。外源GABA降低了Na+、H2O2和MDA浓度，但提高了光合色素、K+和钾/钠比值、氮代谢、渗透溶质和酶抗氧化活性，从而减少了与盐胁迫相关的损伤，导致生长和生物量增加。
外源GABA可能通过维持绿豆植株的形态生理反应并减少盐胁迫下有害物质的积累，提高了其耐盐性。未来的分子研究有助于更好地理解GABA调节绿豆耐盐性的分子机制。
