Post Graduate Department of Botany, Berhampur University, Bhanja Bihar, Berhampur, 760007, India.
Mol Biol Rep. 2024 Apr 20;51(1):543. doi: 10.1007/s11033-024-09507-4.
Heavy metal stress is a major problem in present scenario and the consequences are well known. The agroecosystems are heavily affected by the heavy metal stress and the question arises on the sustainability of the agricultural products. Heavy metals inhibit the process to influence the reactive oxygen species production. When abundantly present copper metal ion has toxic effects which is mitigated by the exogenous application of Si. The role of silicon is to enhance physical parameters as well as gas exchange parameters. Si is likely to increase antioxidant enzymes in response to copper stress which can relocate toxic metals at subcellular level and remove heavy metals from the cell. Silicon regulates phytohormones when excess copper is present. Rate of photosynthesis and mineral absorption is increased in response to metal stress. Silicon manages enzymatic and non-enzymatic activities to balance metal stress condition. Cu transport by the plasma membrane is controlled by a family of proteins called copper transporter present at cell surface. Plants maintain balance in absorption, use and storage for proper copper ion homeostasis. Copper chaperones play vital role in copper ion movement within cells. Prior to that metallochaperones control Cu levels. The genes responsible in copper stress mitigation are discovered in various plant species and their function are decoded. However, detailed molecular mechanism is yet to be studied. This review discusses about the crucial mechanisms of Si-mediated alleviation of copper stress, the role of copper binding proteins in copper homeostasis. Moreover, it also provides a brief information on the genes, their function and regulation of their expression in relevance to Cu abundance in different plant species which will be beneficial for further understanding of the role of silicon in stabilization of copper stress.
重金属胁迫是当前面临的一个主要问题，其后果众所周知。农业生态系统受到重金属胁迫的严重影响，这就引发了关于农产品可持续性的问题。重金属会抑制反应氧物种的产生过程。当大量存在的铜金属离子具有毒性时，可以通过外源施加硅来减轻这种毒性。硅的作用是增强物理参数和气体交换参数。硅可能会增加抗氧化酶，以应对铜胁迫，从而将有毒金属重新定位到亚细胞水平，并将重金属从细胞中去除。当存在过量的铜时，硅会调节植物激素。光合作用和矿物质吸收的速度会因金属胁迫而增加。硅通过管理酶和非酶活性来平衡金属胁迫条件。质膜对铜的运输由存在于细胞表面的称为铜转运蛋白的蛋白质家族控制。植物维持吸收、利用和储存的平衡，以保持适当的铜离子内稳态。铜伴侣蛋白在铜离子在细胞内的运动中起着至关重要的作用。在此之前，金属伴侣蛋白控制 Cu 水平。在各种植物物种中发现了负责减轻铜胁迫的基因，并对其功能进行了解码。然而，详细的分子机制仍有待研究。本综述讨论了硅介导缓解铜胁迫的关键机制，以及铜结合蛋白在铜稳态中的作用。此外，还简要介绍了与不同植物物种中 Cu 丰度相关的基因、它们的功能及其表达调控的信息，这将有助于进一步了解硅在稳定铜胁迫中的作用。
