水稻穗顶部退化基因OsPAA1的克隆与作用机制研究

水稻穗顶部退化现象在生产中较为普遍，往往会造成无法预期的产量损失。穗顶部退化现象极易受环境条件影响，因此基因克隆工作非常困难，到目前为止，尚没有控制该现象的基因被成功克隆。我们从粳稻品种Kitaake组织培养后代中发现了一个穗顶部退化突变体paa1。通过对其精细定位、测序分析以及遗传互补实验，发现了控制该性状的基因并命名为OsPAA1。OsPAA1编码一个类ALMT(Al-activated malate transporter)蛋白的功能未知基因。本项目拟在前期工作基础上，对OsPAA1的表达模式以及OsPAA1的亚细胞定位进行分析。通过对野生型和paa1突变体细胞内苹果酸和过氧化氢含量的检测，初步确定穗顶部退化表型产生的原因，并利用生物化学的方法确定OsPAA1蛋白参与的蛋白调控网络，进而深入了解穗部退化表型发生的分子机理，为在育种上避免穗部退化提供理论基础。

Panicle apical abortion is a common phenotype appeared frequently in rice breeding populations, which tends to cause unexpected yield loss. Panicle apical abortion is vulnerable to environment, so no gene related to panicle apical abortion was successfully cloned. In the study, we found a mutant paa1 (panicle apical abortion 1) from the tissue culture of Kitaake (Japonica). By map-based cloning, sequencing, and complementation assays, we found the gene named OsPAA1 which regulated this phenotype. OsPAA1 encodes a ALMT-like protein, which is an unknown function protein. In this program, we plan to analysis the expression pattern of OsPAA1 and the subcellular localization of OsPAA1. Confirm the reason of panicle apical abortion by detecting the content of malate and hydrogen peroxide in wide type and paa1 mutant，and find the interacting-proteins of OsPAA1 to study the molecular mechanism of the panicle apical abortion in the mutant of paa1.