OsPCR1基因参与水稻籽粒Cd积累的调控机理研究

Heavy metal has become one of the major issues of farmland ecosystem pollution in China, which brings serious risks to the safety of food production and the people’s health. The Safety of rice production has now becoming extremely urgent, while rice is one of the most important cereal crops in China. The project will use the grain-low-Cd rice (xiushui 11) and the transgenic lines of OsPCR1 gene (overexpression, interference expression and promoter-GFP expression) as study materials, to study the gene expression relationship between the OsPCR1 gene which was found be related to low-Cd accumulation of rice grain in the early experiments and the related metal ion transporter genes, the different temporal and spatial expression patterns of OsPCR1 gene and OsPCR1 protein, the characteristic of Cd uptake, transport and accumulation at different growth stages of rice, to clarify the regulation mechanism of OsPCR1 gene in the process of Cd transport and accumulation in rice grain. Aims to provide a theoretical basis for revealing the molecular mechanism of low-Cd accumulation in rice grain, and also provide a new way to breed new rice varieties with low-Cd accumulation in rice grain.

重金属已成为我国农田生态系统污染的重大问题之一，给我国粮食生产安全和人民健康带来了严重的危害。水稻是我国最重要的粮食作物之一，确保水稻的安全生产迫在眉睫。本项目将利用籽粒Cd低积累的水稻秀水11和获得的OsPCR1过表达、干扰表达及OsPCR1 promoter-GFP表达的转基因株系为研究材料，研究前期获知的与水稻籽粒Cd低积累相关的镉抗性基因（rice plant cadmium resistance gene 1，OsPCR1，Os02g0579800）与相关金属离子转运基因的表达关系，OsPCR1基因及其蛋白的时空表达特异性，水稻在不同生育时期对Cd吸收、转运及积累的特征，以阐明OsPCR1基因在水稻籽粒Cd转运、积累过程的调控机理。为揭示水稻籽粒Cd低积累的分子机制提供理论基础，也为在生产上培育出籽粒Cd低积累的水稻新品种提供一条新途径。

重金属已成为我国农田生态系统污染的重大问题之一，给我国粮食生产安全和人民健康带来了严重的危害。水稻是我国最重要的粮食作物之一，确保水稻的安全生产迫在眉睫。本项目明确了籽粒Cd高积累水稻（秀水110）与籽粒Cd低积累水稻（秀水11）Cd积累模式的差异，表明Cd胁迫对秀水110农艺性状的影响比秀水11更明显，秀水110在不同生长时期不同部位中的Cd含量均高于秀水11。且秀水110在韧皮部中的Cd含量显著高于秀水11，木质部汁液中的Cd含量显著低于秀水11。明确了水稻籽粒Cd积累是一个多基因调控过程，验证了一些Cd积累和转运相关基因（OsHMA2、OsHMA3、OsLCD、OsMTP1与OsNRAMP5等）的时空表达特性，表明除OsNRAMP5外其余均在秀水110与秀水11的Cd积累过程上发挥了作用；生物信息学预测了9个OsPCRs功能基因，并对表达量较大的OsPCR1与OsPCR3进行了水稻中的转基因试验，结果表明OsPCR1与OsPCR3的表达与水稻Cd耐性相关，且参与调控水稻体内Cd的积累，预测OsPCR1与OsPCR3主要调控水稻根从外界吸收Cd的过程，关键作用部位是根。该结果为进一步揭示水稻籽粒Cd积累的分子机制提供了理论基础。