The present study was conducted in order to determine the effect of GABA on 2 rice cultivars, i.e., CSR 43 (tolerant) and Pusa 44 (susceptible) at seedling stage under 200 mM saline–alkaline stress (SAS) (molar ratio of 1:9:9:1 of NaCl/Na2SO4/Na2CO3/Na2HCO3) with and without GABA (1.5 mM) supplementation. Exogenous GABA application enhanced the protein content along with the activities of glutamate decarboxylase (GAD) and diamine oxidase (DAO) in cultivar CSR 43. Under SAS, the activities of GAD, DAO and contents of protein were found higher in CSR 43 as compared to Pusa 44 while reverse was observed under GABA + SAS. As compared to sole application of GABA/SAS, CSR 43 possessed higher proline content under GABA + SAS. Endogenous GABA contents were found to increase under SAS in both cultivars, whereas the levels remained higher in CSR 43. Thus, it is elucidated that the increased endogenous GABA by exogenous GABA treatment could improve stress tolerance of rice seedlings associated with GABA regulation in improving DAO activity along with proline content.

中文翻译：

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γ-氨基丁酸在缓解水稻盐碱胁迫条件中的作用

本研究旨在确定 GABA 对 2 个水稻品种，即 CSR 43（耐受）和 Pusa 44（易感）在 200 mM 盐碱胁迫 (SAS)（摩尔比为 1: 9:9:1 的 NaCl/Na2SO4/Na2CO3/Na2HCO3)，添加和不添加 GABA (1.5 mM) 补充剂。外源 GABA 应用提高了品种 CSR 43 的蛋白质含量以及谷氨酸脱羧酶 (GAD) 和二胺氧化酶 (DAO) 的活性。在 SAS 下，与 CSR 43 相比，发现 GAD、DAO 的活性和蛋白质含量在 CSR 43 中更高在 GABA + SAS 下观察到相反的 Pusa 44。与单独应用 GABA/SAS 相比，CSR 43 在 GABA + SAS 下具有更高的脯氨酸含量。发现在 SAS 下两个品种的内源 GABA 含量增加，而 CSR 43 中的水平仍然较高。因此，