拟南芥AtPDF2.5调控重金属镉定向分配和耐受分子机理

目前我国镉(Cd)污染土壤严重，由于人均耕地较少，镉污染土壤仍用于种植粮食作物，导致Cd大米事件多发，危害人类健康。因此，培育经济食用部位重金属安全而非经济食用部位重金属积累的修复型作物，是解决重金属污染的有效策略。为了达到这一目标，找到植物中不仅能定向调控Cd分配，还能显著增强Cd耐受的基因非常关键。为此，我们通过酵母遗传互补的方法发现：拟南芥植物防御素AtPDF2.5异源表达能显著增强酵母对Cd的抗性，并降低了酵母中Cd的含量。进一步研究表明该基因主要在维管组织表达，亚细胞定位于质外体。后期我们想通过原位荧光观察进一步确定候选基因的表达部位，利用生理生化方法，鉴定其突变体和过量表达株系Cd相关表型，阐明AtPDF2.5在调控重金属Cd分配和耐受中的作用机理。最终为生产实践提供理论基础。

Pollution by heavy metals limits the area of land available for cultivation of food crops. A potential solution to this problem might lie in the molecular breeding of food crops for phytoremediation that accumulate toxic metals in straw while producing safe and nutritious grains.In order to achieve this goal, it is crucial to find the genes that not only regulate Cd allocation but also significantly enhance the tolerance of Cd. To this end, we found that an Arabidopsis thaliana defensin gene AtPDF2.5 heterologous expression can significantly enhance the tolerance of Cd and decreased the content of Cd in yeast. Further study indicate that AtPDF2.5 is mainly expressed in vascular tissue, and the subcellular is located in the apoplast. Later we want to conform its cellar localization by confocal observation of situ fluorescence, through physiological and biochemical methods, identify the phenotype of AtPDF2.5mutant and overexpression lines, to clarify the mechanism of AtPDF2.5 in regulating Cd allocation and tolerance in Arabidopsis thaliana. Finally, it provides theoretical basis for production practice.