杨树CLE1多肽通过PXY受体蛋白参与维管发育的功能和调控机理研究

木材形成源自于木本植物维管形成层的分裂与分化。项目组前期研究中发现杨树CLE1多肽能够促进维管形成层的分裂活性，该促进作用依赖于PXY受体基因，并且受到PXY同源基因PXL3和PXL4的调控。本项目主要研究内容包括（1）通过杨树PtCLE1的过量表达、异位表达和利用CRISPR-Cas9构建基因敲除突变体，解析PtCLE1在维管发育中的功能；（2）构建ptpxy突变体进行其功能验证，通过PtPXY在拟南芥pxy突变体中的互补，以及互补植株多肽体外处理的转录组分析，研究CLE1多肽影响维管发育的分子机理；（3）通过酵母双杂交、Co-IP、BIFC和ITC等方法研究CLE1多肽与PtPXY及其同源受体间的物理互作；（4）综合酵母双杂交和转录组分析的结果挖掘CLE1-PtPXY信号途径下游新成员。本项目的实施有助于维管组织中“多肽信号-受体-转录因子”调控网络的构建和木材形成机理的进一步剖析。

Wood is derived from cell division and cell differentiation of vascular cambium in woody plants. In our previous study, a poplar CLE1 peptide was identified with activity in promoting cell division of vascular cambium. The activity was dependent on PXY, an LRR-RLK gene; and it could be regulated by PXL3 and PXL4, two analogous genes of PXY. This proposal includes the following studies: （1） To understand the function of PtCLE1 in vascular development by its overexpression, ectopic expression, CRISPR-Cas9 mediated gene knock-out analysis; （2） To analysis molecular mechanism of CLE1 peptide in vascular development by characterization of ptpxy knockout lines, by complementation of Arabidopsis pxy mutant with PtPXY gene, and by transcriptomic analysis of the complemented lines treated with CLE1 peptide in an Arabidopsis in vitro peptide application system; （3） To find out the physical interactions between CLE1 peptide and LRR-RLK receptors by Yeast-2-Hybrid analysis, Co-IP, BIFC and ITC technologies;（4） To search for new members in the downstream of the CLE1-PtPXY signaling pathway by combining the abovementioned Yeast-2-Hybrid analysis and transcriptomic analysis. These studies will help us to build up a regulatory network of “peptide ligand- receptor-transcriptional factor” in vascular development, and will be helpful in understanding the mechanism of wood formation.