Ecotoxicogenomics Lab, Department of Biotechnology, Jamia Millia Islamia, New Delhi, 110025, India.
Ecotoxicogenomics Lab, Department of Biotechnology, Jamia Millia Islamia, New Delhi, 110025, India.
Nitric Oxide. 2019 Aug 1;89:81-92. doi: 10.1016/j.niox.2019.05.005. Epub 2019 May 13.
The present study was designed to see the effect of exogenous nitric oxide (NO) and abscisic acid (ABA) and their interaction on physiological and biochemical activities in leaves and roots of two Indian mustard (Brassica juncea) cultivars [cv. Pusa Jagannath (PJN) and Varuna (VAR)] exposed to polyethylene glycol (PEG)-induced drought stress. Seven days old hydroponically grown seedlings were treated with PEG (10%), sodium nitroprusside, a NO donor [NO (100 μM)] and abscisic acid [ABA (10 μM)], using different combinations as: Control, ABA, NO, PEG, PEG + ABA, PEG + NO, and PEG + NO + ABA. Results revealed that in response to PEG-induced drought stress leaf relative water content, chlorophyll, carotenoid and protein content decreased with increased production of O, MDA, HO, cysteine content and non-enzymatic antioxidants (including proline, flavonoid, phenolic, anthocyanin, and ascorbic acid), whereas, the enzymatic antioxidants (including SOD, CAT, APX, GR) showed the response range from no effect to increase or decrease in certain enzymes in both Brassica cultivars. The application of NO or/and ABA in PEG-stressed cultivars showed that both enzymatic and non-enzymatic antioxidants responded differently to attenuate oxidative stress in leaves and roots of both cultivars. Overall, PJN had the antioxidant protection mainly through the accumulation of non-enzymatic antioxidants, whereas VAR showed tolerance by the enhancement of both enzymatic and non-enzymatic antioxidant activities. Altogether, the study concluded that the independent NO and its interaction with ABA (PEG + NO and PEG + NO + ABA) were much effective than independent ABA (PEG + ABA) in lowering PEG-drought stress in Brassica cultivars.
本研究旨在观察外源一氧化氮（NO）和脱落酸（ABA）及其相互作用对PEG 诱导干旱胁迫下两种印度芥菜（Brassica juncea）品种[cv. Pusa Jagannath（PJN）和 Varuna（VAR）]叶片和根系生理生化活性的影响。7 天龄水培幼苗用 PEG（10%）、硝普钠（NO 供体，100μM）和脱落酸（10μM）处理，采用不同组合：对照、ABA、NO、PEG、PEG+ABA、PEG+NO 和 PEG+NO+ABA。结果表明，在 PEG 诱导的干旱胁迫下，叶片相对含水量、叶绿素、类胡萝卜素和蛋白质含量下降，而 O、MDA、HO、半胱氨酸含量和非酶抗氧化剂（包括脯氨酸、类黄酮、酚类、花青素和抗坏血酸）的产生增加，而 SOD、CAT、APX、GR 等酶抗氧化剂的响应范围从无影响到某些酶的增加或减少。在 PEG 胁迫的品种中应用 NO 或/和 ABA 表明，两种酶和非酶抗氧化剂对减轻两个品种叶片和根系的氧化应激有不同的反应。总的来说，PJN 主要通过积累非酶抗氧化剂来保护抗氧化剂，而 VAR 则通过增强酶和非酶抗氧化剂的活性来表现出耐受性。综上所述，本研究表明，独立的 NO 及其与 ABA 的相互作用（PEG+NO 和 PEG+NO+ABA）比独立的 ABA（PEG+ABA）更能有效降低 Brassica 品种的 PEG 干旱胁迫。
