Plant Physiology and Biochemistry Section, Department of Botany, Faculty of Life Sciences, Aligarh Muslim University, Aligarh, 202002, India.
Plant Physiology and Biochemistry Section, Department of Botany, Faculty of Life Sciences, Aligarh Muslim University, Aligarh, 202002, India.
Chemosphere. 2020 Aug;252:126486. doi: 10.1016/j.chemosphere.2020.126486. Epub 2020 Mar 14.
Hydrogen peroxide (HO) acts as a significant regulatory component interrelated with signal transduction in plants. The positive role of HO in plants subjected to myriad of abiotic factors has led us to comprehend that it is not only a free radical, generated as a product of oxidative stress, but also helpful in the maintenance of cellular homeostasis in crop plants. Studies over the last two centuries has indicated that HO is a key molecule which regulate photosynthesis, stomatal movement, pollen growth, fruit and flower development and leaf senescence. Exogenously-sourced HO at nanomolar levels functions as a signalling molecule, facilitates seed germination, chlorophyll content, stomatal opening, and delays senescence, while at elevated levels, it triggers oxidative burst to organic molecules, which could lead to cell death. Furthermore, HO is also known to interplay synergistically or antagonistically with other plant growth regulators such as auxins, gibberellins, cytokinins, abscisic acid, jasmonic acid, ethylene and salicylic acid, nitric oxide and Ca (as signalling molecules), and brassinosteroids (steroidal PGRs) under myriad of environmental stresses and thus, mediate plant growth and development and reactions to abiotic factors. The purpose of this review is to specify accessible knowledge on the role and dynamic mechanisms of HO in mediating growth responses and plant resilience to HM stresses, and its crosstalk with other significant PGRs in controlling various processes. More recently, signal transduction by mitogen activated protein kinases and other transcription factors which attenuate HM stresses in plants have also been dissected.
过氧化氢 (HO) 作为一种与植物信号转导相关的重要调节成分。HO 在植物受到多种非生物因素的影响时发挥积极作用，这使我们认识到它不仅是一种自由基，是氧化应激的产物，而且有助于维持作物细胞的内稳态。过去两个世纪的研究表明，HO 是一种关键分子，可调节光合作用、气孔运动、花粉生长、果实和花发育以及叶片衰老。外源 HO 在纳摩尔水平作为信号分子发挥作用，促进种子萌发、叶绿素含量、气孔开放，并延缓衰老，而在较高水平时，它会引发氧化爆发，对有机分子造成损害，从而导致细胞死亡。此外，HO 还与其他植物生长调节剂如生长素、赤霉素、细胞分裂素、脱落酸、茉莉酸、乙烯和水杨酸、一氧化氮和 Ca（作为信号分子）以及油菜素内酯（甾体 PGRs）协同或拮抗作用，在多种环境胁迫下，调节植物生长和发育以及对非生物因素的反应。本综述的目的是阐明 HO 在介导生长反应和植物对重金属胁迫的抗性方面的作用和动态机制，以及它与其他重要 PGR 之间的相互作用，以控制各种过程。最近，还分析了 mitogen activated protein kinases 和其他转录因子通过信号转导减轻植物中重金属胁迫的作用。
