Abstract：
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.
摘要：
重金属应力是目前情况下的主要问题，其后果是众所周知的。农业生态系统受到重金属胁迫的严重影响，出现了农产品可持续性的问题。重金属抑制该过程影响活性氧的产生。当大量存在时,铜金属离子具有毒性作用,其通过外源施加Si来减轻。硅的作用是增强物理参数以及气体交换参数。Si可能会增加抗氧化酶，以响应铜胁迫，铜胁迫可以在亚细胞水平上重新定位有毒金属并从细胞中去除重金属。当存在过量的铜时,硅调节植物激素。光合作用和矿物质吸收速率响应于金属胁迫而增加。硅管理酶活性和非酶活性以平衡金属胁迫条件。质膜的Cu转运受细胞表面存在的称为铜转运蛋白的蛋白质家族控制。植物在吸收中保持平衡，使用和储存适当的铜离子稳态。铜伴侣在细胞内的铜离子运动中起着至关重要的作用。在此之前,金属伴侣控制Cu水平。在各种植物物种中发现了负责铜胁迫缓解的基因，并对其功能进行了解码。然而,详细的分子机理还有待研究。本文综述了硅介导的铜胁迫缓解的重要机制，铜结合蛋白在铜稳态中的作用。此外，它还提供了关于基因的简要信息，它们的功能和与不同植物物种中Cu丰度相关的表达调节，这将有助于进一步了解硅在稳定铜胁迫中的作用。
