Tripathi Durgesh Kumar, Rai Padmaja, Kandhol Nidhi, Kumar Alok, Sahi Shivendra, Corpas Francisco J, Sharma Shivesh, Singh Vijay Pratap
Crop Nanobiology and Molecular Stress Physiology Lab, Amity Institute of Organic Agriculture, Amity University Uttar Pradesh, Sector-125, Noida 201313, India.
Department of Biotechnology, Motilal Nehru National Institute of Technology Allahabad, Prayagraj, UP 211004, India.
Plant Cell Physiol. 2023 Jan 30;63(12):1943-1953. doi: 10.1093/pcp/pcac150.
Along with the rapidly increasing environmental contamination by heavy metals, the exposure of plants to chromium has also magnified, resulting in a declined productivity. Hexavalent chromium [Cr(VI)], the most toxic form of Cr, brings about changes in plant processes at morpho-physiological and biochemical levels. However, silicon (Si) is known to mitigate the impact of abiotic stresses in plants. Here, we demonstrate Si-mediated alleviation of Cr(VI) toxicity and its effects on root hair formation in rice seedlings. Reduced glutathione (GSH) and indole-3 acetic acid (IAA, an important auxin) were assessed for their involvement in root hair formation after the application of Si to Cr(VI)-stressed plants, and our results confirmed their crucial significance in such developmental processes. The expression analysis of genes involved in GSH biosynthesis (OsGS2) and regeneration (OsGR1), and auxin biosynthesis (OsTAA1 and OsYUCCA1) and transport (OsAUX1 and OsPIN1) corroborated their positive role in Si-mediated root hair formation in Cr(VI)-stressed rice seedlings. Moreover, the results indicated that nitric oxide (NO) seems a probable but not fundamental component in Si-mediated formation of roots in rice during exposure to Cr(VI) stress. In this study, the indispensable role of GSH and IAA, redox homeostasis of GSH and IAA biosynthesis and transport are discussed with regard to Si-mediated formation of root hairs in rice under Cr(VI) stress. The results of the study suggest that Si is a protective agent against Cr(VI) stress in rice, and the findings can be used to develop Cr(VI) stress-tolerant varieties of rice with enhanced productivity.
随着环境中重金属污染的迅速增加，植物接触铬的情况也日益严重，导致生产力下降。六价铬[Cr(VI)]是铬毒性最强的形式，会在形态生理和生化水平上改变植物的生理过程。然而，已知硅（Si）可减轻植物非生物胁迫的影响。在此，我们证明了硅介导的对Cr(VI)毒性的缓解作用及其对水稻幼苗根毛形成的影响。在向受Cr(VI)胁迫的植物施用硅后，评估了还原型谷胱甘肽（GSH）和吲哚-3-乙酸（IAA，一种重要的生长素）在根毛形成中的作用，我们的结果证实了它们在这种发育过程中的关键意义。对参与GSH生物合成（OsGS2）和再生（OsGR1）以及生长素生物合成（OsTAA1和OsYUCCA1）和运输（OsAUX1和OsPIN1）的基因进行表达分析，证实了它们在硅介导的受Cr(VI)胁迫的水稻幼苗根毛形成中的积极作用。此外，结果表明一氧化氮（NO）似乎是水稻在Cr(VI)胁迫下硅介导的根形成过程中的一个可能但非基本成分。在本研究中，讨论了GSH和IAA的不可或缺作用以及GSH的氧化还原稳态和IAA生物合成与运输在Cr(VI)胁迫下硅介导的水稻根毛形成中的作用。研究结果表明，硅是水稻抵御Cr(VI)胁迫的保护剂，这些发现可用于培育具有更高生产力的耐Cr(VI)胁迫水稻品种。
