木材细胞壁加厚的遗传调控研究

Wood material is an accumulation of the cell walls in the tree secondary vascular tissue. Wood formation is derived from the vascular cambium division inward to generate xylem cells which differentiate into wall-thickened wood. The feature of xylem cells such as cell wall thickness, cell wall ratio, and cell size determine the wood property and utilization. This proposal aims to dissect the genetic mechanism underlying the wood formation and cell wall thickening. Our previous study reveals that cell wall thickening can be regulated by oligosaccharide function and several receptor-like kinases are involved in wood formation process. Here we propose 1) to isolate, purify and analyze the oligosaccharides, which will be characterized for their structure and biological activity; 2) to analyze the signal transduction pathway mediated by an identified receptor-like kinase (Pt351) which has shown a role in regulating cell wall thickening. Completion of the proposed study would generate new insights into understanding of the molecular mechanism of wood formation and aid in establishment of new technology for wood property improvement.

木材是树木次生维管组织的细胞壁物质，是通过维管形成层干细胞向内分裂并分化成加厚的木质部细胞形成的。不同材性和用途的木材具有不同的木质部细胞壁厚度、胞壁率和细胞大小等。本研究将聚焦于解析木材细胞壁分化和加厚调控的遗传因子，阐明木材材性决定的分子机制。前期研究表明木质部细胞增大与加厚受到寡糖分子信号调控，同时还发现多个类受体激酶参与了该过程。本研究１）将对寡糖分子进行纯化、分离和鉴定，确定寡糖分子在调控细胞壁加厚中的作用，解析活性寡糖分子的结构和功能。２）对木质部细胞壁加厚调控过程中信号传导途径进行研究，解析已鉴定的类受体激酶基因（Pt351）在木质部细胞壁合成启动与加厚过程中所介导的信号接收、传导和调控功能的分子机理，为优质木材的培育提供新的分子技术支持。

林木将光合作用产物转化产生木材，为人类社会提供必需的可再生材料和生物质资源。木材形成过程中细胞壁的加厚是决定木材性状的关键，受到一系列内在发育和外部环境信号的调控。本研究项目利用分子遗传和功能基因组手段，对木质部细胞壁加厚过程中的信号及其传导通路进行了系统的解析，研究结果发现和鉴定了新的寡糖和小肽分子作为信号调控木质部分化和细胞壁的加厚，发现和解析了新的类受体激酶在木材形成与细胞壁加厚过程的功能，阐释了环境信号调控木材形成与细胞壁加厚的分子机制，并在此基础上，探索了木材性状改良的新的分子技术，为培育具有理想性状的林木提供了新的技术方案。