Laboratory of Plant Stress Responses, Faculty of Agriculture, Kagawa University, Ikenobe 2393, Miki-Cho, Kita Gun, Kagawa 761-0795, Japan.
Biomolecules. 2021 Apr 16;11(4):587. doi: 10.3390/biom11040587.
Salt stress greatly disturbs the growth, morpho-physiological, and biochemical performance of plants. However, different physiological processes and acclimation mechanisms can be induced under stress, while some of them can be modulated by the appropriate chemical stimulus. The objective of this study was to evaluate the impact of exogenous pretreatment with 10 mM l-glutamic acid (l-Glu) on the physiological and biochemical parameters of lentil ( Medik.) under 110 mM NaCl stress. Salt stress inhibited the growth and reduced the photosynthetic pigment (chlorophylls and carotenoids) level, water content, and survival of lentil seedlings during recovery from the stress. Salt stress also induced oxidative damage, as indicated by higher hydrogen peroxide and malonaldehyde contents and electrolyte leakage, by interrupting the antioxidant defense system and promoting the accumulation of toxic levels of Na. However, l-Glu pretreatment mitigated the salt-induced damage in lentil seedlings by reducing the accumulation of Na, maintaining ion homeostasis, and increasing the activities of antioxidant enzymes (catalase and ascorbate peroxidase). As a result, salt-induced oxidative damage was reduced, seedling growth and photosynthetic pigment contents were enhanced, and the survival rate of the lentil seedlings was improved in response to salt stress, indicating an ameliorative role for l-Glu in lentil seedling growth under salt stress.
盐胁迫极大地扰乱了植物的生长、形态生理和生化性能。然而，在胁迫下可以诱导不同的生理过程和适应机制，其中一些可以通过适当的化学刺激来调节。本研究的目的是评估 10 mM l-谷氨酸（l-Glu）外源预处理对 110 mM NaCl 胁迫下小扁豆（Medik.）生理生化参数的影响。盐胁迫抑制了小扁豆幼苗的生长，降低了其在胁迫后恢复过程中的光合色素（叶绿素和类胡萝卜素）水平、含水量和存活率。盐胁迫还通过中断抗氧化防御系统和促进有毒水平的 Na 积累，诱导氧化损伤，表现为过氧化氢和丙二醛含量以及电解质泄漏增加。然而，l-Glu 预处理通过减少 Na 的积累、维持离子平衡以及增加抗氧化酶（过氧化氢酶和抗坏血酸过氧化物酶）的活性，减轻了盐对小扁豆幼苗的损伤。因此，盐诱导的氧化损伤减少，幼苗生长和光合色素含量提高，小扁豆幼苗的存活率提高，表明 l-Glu 在盐胁迫下对小扁豆幼苗生长具有改善作用。
