中文摘要：

器官形状和大小的控制是一个基本的发育生物学过程,受细胞分裂和细胞扩展的影响。到目前为止,人们对植物器官形状和大小的调控机制知之甚少。本实验室前期研究发现了一个种子和器官大小的调控基因DA1,其编码一个泛素受体。在拟南芥（Arabidopsis thaliana）中,DA1通过抑制细胞的分裂来限制种子和器官的大小。本研究通过激活标签的方法在da1-1突变体背景下筛选到一个叶子形状发生改变的半显性突变体（yuan1-1D）。yuan1-1D形成短而圆的叶片和短的叶柄,细胞学分析显示,叶片和叶柄变短的主要原因是细胞的长向扩展降低导致的。YUAN1编码一个含有PHD锌指结构域的蛋白。GFP-YUAN1融合蛋白定位在细胞核内。过量表达YUAN1基因导致叶片和叶柄变短。遗传学分析显示,YUAN1和DA1、ROT3以及ROT4在控制叶片形状和大小方面作用于不同的遗传途径中。因此,本研究鉴定了一个新的控制器官形状和大小的基因YUAN1,为阐明植物器官形状和大小调控的分子机制提供了重要线索。

英文摘要：

Control of organ shape and size by cell proliferationandcell expansion is a fimdamental process in plant development. However, little is known about the molecular mechanisms that set the shape and size of determinate organs in plants. We have previously demonstrated that the Arabidopsis gene DA1 controls the final size of organs by restricting cell proliferation. Through an activation tagging screen for modifiers of dal-1, we have identified a semi-dominant mutant （yuanl-1D） with altered leaf shape and size. The yuanl-1D mutation results in reduced plant height, short and round leaves and short petioles due to defects in cell elongation. YUAN1 encodes a PHD zinc finger domain-containing protein. The GFP-YUAN1 fusion protein is localized to the nucleus. Overexpression of YUAN1 leads to round leaves and short petioles. Genetic analyses show that YUAN1 acts independently of DA1, ROTUNDIFOLIA 3 （ROT3） and ROTUNDIFOLIA4 （ROT4） to influence leaf shape and size. Collectively, our findings show that Arabidopsis YUAN1, a P/-ID zinc finger domain-containing protein, controls organ shape and size by restricting cell elongation, and give insight into how plants con-rol their organ shape and size.