浮萍GST基因调控重金属镉超富集的分子机制

水体重金属镉(Cd)污染是最严重的生态环境问题之一，利用超富集植物进行重金属污染水体修复已逐渐成为研究热点。然而，相较于超富集陆生植物而言，有关Cd在水生植物体内富集机制的研究尚浅。本研究以战略性能源植物浮萍为实验材料，前期通过分析超富集和非超富集浮萍生态型Cd胁迫处理转录组，发现谷胱甘肽代谢途径在整个富集过程中具有重要作用，其关键酶谷胱甘肽转硫酶(Glutathione S-transferase, GST)的表达受到强烈诱导。本项目拟综合运用金属组分与形态分析、高通量测序、基因编辑等实验技术，研究Cd胁迫对浮萍GST基因表达量和GST酶活的影响，解析GST基因协助浮萍Cd转运和钝化的机制，同时借助遗传转化验证浮萍GST基因参与Cd富集的生物学功能。本项目可为浮萍种质资源改良提供思路和基因资源，也为深入揭示水生植物超富集重金属的生理生化与分子机制奠定理论基础。

Cadmium (Cd) pollution in waters is one of the most serious ecological and environmental problems. The use of hyperaccumulators for heavy metal polluted waters restoring has gradually become a research focus. However, compared with the study on terrestrial hyperaccumulators, the research on the molecular mechanism of Cd enrichment in aquatic plants is still shallow. In this study, the strategic energy plant duckweed was used as experimental material. Previous study about transcriptomes of hyperaccumulating and non-hyperaccumulating ecotypes showed that the glutathione metabolic pathway plays important roles in the Cd enrichment process. And the expression of glutathione S-transferase (GST) was strongly induced, which is the key enzyme of glutathione metabolism pathway. This project intends to study the effects of Cd stress on the expression of GST gene and GST enzyme activity in duckweed, analyze how the GST gene regulate Cd transport and inactivation, and verify the biological function of GST gene involved in Cd enrichment. To address these questions, metal composition and morphology analysis, high-throughput sequencing, and gene editing were comprehensively applied. This project will provide ideas and gene resources for the improvement of duckweed germplasm resources, and lay theoretical foundations for revealing mechanisms of heavy metal hyperaccumulation in aquatic plants.