Council of Scientific and Industrial Research - National Botanical Research Institute (CSIR-NBRI), Rana Pratap Marg, Lucknow, 226001, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India.
Council of Scientific and Industrial Research - National Botanical Research Institute (CSIR-NBRI), Rana Pratap Marg, Lucknow, 226001, India.
Environ Pollut. 2022 Mar 15;297:118694. doi: 10.1016/j.envpol.2021.118694. Epub 2021 Dec 21.
Rice is a staple crop, and food chain contamination of arsenic in rice grain possesses a serious health risk to billions of population. Arsenic stress negatively affects the rice growth, yield and quality of the grains. Nitric oxide (NO) is a major signaling molecule that may trigger various cellular responses in plants. The protective role of NO during arsenite (AsIII) stress and its relationship with plant physiological and metabolic responses is not explored in detail. Exogenous NO, supplemented through the roots in the form of sodium nitroprusside, has been shown to provide protection vis-à-vis AsIII toxicity. The NO-mediated variation in physiological traits such as stomatal density, size, chlorophyll content and photosynthetic rate maintained the growth of the rice plant during AsIII stress. Besides, NO exposure also enhanced the lignin content in the root, decreased total arsenic content and maintained the activities of antioxidant isoenzymes to reduce the ROS level essential for protecting from AsIII mediated oxidative damage in rice plants. Further, NO supplementation enhanced the GSH/GSSG ratio and PC/As molar ratio by modulating PC content to reduce arsenic toxicity. Further, NO-mediated modulation of the level of GA, IAA, SA, JA, amino acids and phenolic metabolites during AsIII stress appears to play a central role to cope up with AsIII toxicity. The study highlighted the role of NO in AsIII stress tolerance involving modulation of metalloid detoxification and physiological pathways in rice plants.
大米是一种主食作物，而食物链中大米砷污染对数十亿人口的健康构成了严重威胁。砷胁迫会对水稻生长、产量和品质产生负面影响。一氧化氮（NO）是一种主要的信号分子，它可能在植物中引发各种细胞反应。NO 在亚砷酸盐（AsIII）胁迫下的保护作用及其与植物生理和代谢反应的关系尚未得到详细研究。通过根系以硝普酸钠的形式补充外源 NO 已被证明可以提供对 AsIII 毒性的保护。NO 介导的生理特征变化，如气孔密度、大小、叶绿素含量和光合速率，在 AsIII 胁迫期间维持了水稻植株的生长。此外，NO 暴露还增加了根中的木质素含量，降低了总砷含量，并维持了抗氧化酶同工酶的活性，以降低保护水稻免受 AsIII 介导的氧化损伤所需的 ROS 水平。此外，NO 补充通过调节 PC 含量来提高 GSH/GSSG 比和 PC/As 摩尔比，从而降低砷毒性。此外，NO 介导的 GA、IAA、SA、JA、氨基酸和酚类代谢物水平在 AsIII 胁迫下的调节似乎在应对 AsIII 毒性方面发挥了核心作用。该研究强调了 NO 在砷胁迫耐受中的作用，涉及到对水稻植物中金属解毒和生理途径的调节。
