Drought is the most catastrophic abiotic stress that affect plant growth and development. Plant initiates alterations at physiological, biochemical and molecular levels to combat deleterious effects of drought in which abscisic acid, play a pivotal role. The present investigation was conducted to investigate how abscisic acid modulates different biochemical traits under osmotic stress. Twenty-one days old seedlings were exposed to osmotic stress, exogenously applied abscisic acid and the combination of both osmotic stress and abscisic acid to study the influence of abscisic acid on biochemical traits under moisture stress. The results reveals that abscisic acid has no influence on leaf water potential, however, it has active role in increasing osmolytes like proline. Δ1-pyrroline-5-carboxylate reductase and proline dehydrogenase remained unresponsiveness to ABA that indicates ABA-independent regulation of these two enzymes but the activity of Δ1-pyrroline-5-carboxylate synthesase and Ornithine-δ-aminotransferase was enhanced (3 fold) in response to abscisic acid. Antioxidative enzymes increased (catalase-2.5 fold; peroxidase- 3 fold and SOD- 6 fold) in response to abscisic acid and osmotic stress, gave an insight of the regulation of these traits under the influence of abscisic acid. Aldehyde oxidase remained unresponsive to abscisic acid but showed enhanced expression when both abscisic acid and osmotic stress was applied suggest its ABA-independent regulation. The information provided here has significance in understanding the regulation of different catabolite that play important role in drought tolerance and can be implemented for the development of drought-tolerant varieties.

中文翻译：

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外源ABA诱导渗透胁迫下选定水稻品种生理生化特性的变化。

干旱是影响植物生长发育的最严重的非生物胁迫。植物在生理，生化和分子水平上引发变化，以抵抗干旱的破坏作用，其中脱落酸起关键作用。进行本研究以调查脱落酸如何在渗透胁迫下调节不同的生化特性。将21天大的幼苗暴露于渗透胁迫下，外源施用脱落酸并结合渗透胁迫和脱落酸，研究脱落酸对水分胁迫下生化性状的影响。结果表明，脱落酸对叶水势没有影响，但是，它在增加渗透液（如脯氨酸）方面具有积极作用。Δ1-吡咯啉-5-羧酸还原酶和脯氨酸脱氢酶仍然对ABA无反应，表明这两种酶的ABA依赖性调节，但Δ1-吡咯啉-5-羧酸合成酶和鸟氨酸-δ-氨基转移酶的活性增强（3倍）。对脱落酸的反应。响应于脱落酸和渗透胁迫，抗氧化酶增加（过氧化氢酶-2.5倍；过氧化物酶-3倍和SOD-6倍），从而在脱落酸的影响下对这些性状的调节有了深入的了解。醛氧化酶仍然对脱落酸无反应，但是当同时施用脱落酸和渗透胁迫时显示出增强的表达，表明其ABA依赖性调节。