拟南芥转录因子RWL1通过与TCP转录因子相互作用来调控叶片发育

叶片是自然界中多样性非常丰富的器官，对植物生存和人类粮食安全都非常重要，研究叶片发育的分子机制对农业生产具有重要意义，但植物如何根据内源信号和外部环境形成特定的叶片形态和大小的分子机制仍不十分清楚。本项目通过T-DNA插入激活突变体的筛选，获得2个叶片变圆变小且不平整的突变体，称为rwl1-1D (round and wavy leaves 1-1Dominant)和rwl1-2D，研究发现T-DNA分别插入在同一个RWL1基因的启动子上游基因间区和3'-端下游基因间区，均造成RWL1基因的过量表达。RWL1是一个转录因子，可与叶片发育的关键因子TCP转录因子相互作用。本项目拟深入研究rwl1-1D、rwl1-2D以及rwl1和其同源基因的功能敲除突变体，RWL1家族的表达模式和亚细胞定位，确定其如何调控TCP以及其下游基因，最终阐明RWL1如何根据内外环境调控叶片发育的分子机制。

Leaves are organs with high diversity in nature. Leaves are important not only for plant survival but also for food security. The understanding of plant leaf development has a practical meaning for food production. However, the molecular mechanisms by which plants form various leaf sizes and shapes in response to internal and environmental cues is still elusive. In this project, we screened a T-DNA activation tagging mutant collection for leaf defective mutants and obtained two mutant alleles named rwl1-1D (round and wavy leaves 1-1Dominant) and rwl1-2D which both produced small, round leaves with wavy margins. T-DNA insertion was located in the intergenic region upstream of RWL1 promoter in rwl1-1D, and was found in the intergenic region downstream of RWL1 3'-end. RWL1 encodes a transcription factor and yeast two hybrid assays showed that RWL1 interacted with TCP transcription factors which are key for leaf development. We will further identify the leaf phenotypes of rwl1-1D and rwl1-2D mutants, and also analyze the leaf defects of the mutants disrupting either RWL1 or its four homologs. We will investigate the expression pattern of RWL1 gene family and determine the subcellular localization of RWL1 protein family. We will also confirm the interactions between of RWL1 and TCP transcription factors and find out the downstream genes regulated by RWL1. The molecular mechanisms by which RWL1 regulates leaf development will be finally demonstrated.