植物种子和器官大小是重要的产量性状，大小调控也是一个重要的发育生物学问题和新兴研究领域，但其调控的分子机理仍不清楚。申请人长期从事植物种子和器官大小调控的分子机理研究。克隆了DA1、DA2、SOD2、SOD9、 EOD3、EOD8和SMG1等调控种子和器官大小的关键基因，建立了种子和器官大小调控的分子遗传网络，并在其作用的分子机理研究方面取得了原创性成果。近年来，申请人领导的实验室在Genes & Development, Plant Cell, Development, Plant Journal，Plant Physiology和New Phytologist等国际期刊上发表论文11篇，已成为该新兴研究领域中开拓性的研究工作。申请人拟开展的“DA3调控种子和器官大小的分子机理研究”是在前期研究工作的基础上，阐明DA3调控种子和器官大小的分子机制，为高产育种提供理论基础和基因资源。

The size of seeds and organs is an important agronomic trait, and control of seed and organ size is also a fundamental question in developmental biology. However, the genetic and molecular mechanisms that set final seed and organ size are largely unknown despite their central importance. My lab is working on how plants control their final seed and organ size. We have isolated a set of mutants with altered seed and/or organ size. Several genes (e.g.DA1, DA2, SOD2, SOD9, EOD3, EOD8 and SMG1) have been identified as important factors of seed and organ size control. We have built up a genetic and molecular framework for control of seed and organ size in plants. Our findings give insight into molecular mechanisms that set final seed and organ size in plants. Our results have been published in Genes & Development, Plant Cell, Development, Plant Journal, Plant Physiology and New Phytologist. In this proposal, we plan to study molecular mechanisms of DA3 in seed and organ size control. A combination of genetic, molecular, and biochemical approaches will be used to characterize the roles of DA3 in seed and organ size control and identify novel components in the DA3 pathway. Our aims are to understand the molecular mechanisms of DA3 action and discover novel genes for engineering high crop yield.