影响水稻镉低吸收的关键因素及育种研究进展

    Key Factors Affecting the Low Accumulation of Cadmium in Rice and the Progress of Breeding Research

    • 摘要: 水稻是我国重要粮食作物,其质量安全关系国家粮食安全和人民健康。近年来,稻米镉超标问题日益突出,已成为制约水稻可持续发展及威胁公众健康的关键因素。因此,深入探究水稻镉低吸收的分子机制与环境调控策略,培育低镉水稻品种,成为当前农业领域的重大研究方向。该文系统梳理影响水稻镉吸收与积累的关键环境因素,明确指出温度、水分及营养元素是核心调控因子。在遗传机制层面,该文重点阐述控制水稻镉低积累的数量性状位点(QTL)及影响低镉水稻的相关基因。目前利用较多的基因有OsNRAMP5OsHMA3OsLCT1OsIRT1OsHMA2等,将其系统归纳为转运与区隔化、调控与响应、解毒与螯合三大核心基因家族,并绘制这些基因在细胞质、液泡等细胞器中的作用示意图,直观呈现“吸收- 转运- 螯合- 区室化”的完整分子通路,为镉低积累基因挖掘提供参考。该文还概述各省份低镉水稻筛选工作的进度,并以广东省为例,详细介绍其“引进+本土化”的低镉品种培育策略,即成功引进国家审定的低镉品种‘西子3号’,同时大力推广示范本地优良品种‘粤禾丝苗’‘广红3号’‘泰丰优208’,逐步构建科学合理的低镉水稻品种体系。此外,该文系统综述现有低镉水稻的主要育种技术,涵盖传统常规育种、分子标记辅助选择及基因编辑等前沿手段,可为后续镉低积累基因挖掘及镉低积累新种质和品种培育提供参考。

       

      Abstract: Rice is an important food crop in China, and its quality and safety are closely related to national food securityand public health. In recent years, the problem of cadmium exceeding the standard in rice has become increasingly prominent, which has become a key factor restricting the sustainable development of rice and threatening public health. Therefore, indepth exploration of the molecular mechanism of low cadmium absorption in rice and environmental regulation strategies, aswell as the cultivation of low cadmium rice varieties, has become a major research direction in the agricultural field. This articlesystematically reviews the key environmental factors affecting cadmium absorption and accumulation in rice, clearly pointingout that temperature, water, and nutrient element are the core regulatory factors. At the genetic mechanism level, this articlefocuses on the quantitative trait loci (QTL) controlling low cadmium accumulation in rice and the related genes affecting lowcadmium rice. Currently, the genes that are widely used include OsNRAMP5, OsHMA3, OsLCT1, OsIRT1, OsHMA2, etc.These genes are systematically classified into three core gene families: transport and compartmentalization, regulation andresponse, and detoxification and chelation. A schematic diagram of the role of these low cadmium genes in organelles such asthe cytoplasm and vacuole is drawn, visually presenting the complete molecular pathway of "absorption - transport - chelation- compartmentalization", providing a reference for the mining of low cadmium genes. This article also summarizes the progressof low cadmium rice screening in various provinces, and takes Guangdong Province as an example to detail its "introduction +localization" strategy for low cadmium variety cultivation, that is successfully introducing the nationally approved low cadmiumvariety 'Xizi 3', while vigorously promoting and demonstrating local excellent varieties such as 'Yuehe Simiao', 'Guanghong3', and 'Taifeng You 208', gradually establishing a scientific and reasonable low cadmium rice variety system. In addition, thisarticle systematically reviews the main breeding techniques for existing low cadmium rice, covering traditional conventionalbreeding, molecular marker-assisted selection, and gene editing and other cutting-edge methods, which can provide a referencefor the subsequent mining of low cadmium genes and the cultivation of new low cadmium accumulation germplasm and varieties.