赤霉素合成基因GA20ox过表达对杨树木材组分结构影响的研究

Gibberellin regulates plant growth and development by affecting cell division, including stem elongation and wood formation. However, the current research is lack of exploring the fact that how the synthesis pathway of gibberellin affects wood formation and wood properties. In our preliminary work, it was found that adjusting the expression level of the key factor GA20ox in gibberellin biosynthesis could promote the growth of poplar. It can be expected to change the structure of wood, as well as to discover new ways of solving the problem of low utilization of fiber in production. This project will reveal the mechanism of promoting tree growth through hormone determination and transcriptome analysis of transgenic poplar, in which GA20ox is specifically overexpressed in xylem. Simultaneously, we will use infrared spectroscopy, multidimensional Nuclear Magnetic Resonance (NMR) and Gel Permeation Chromatography (GPC) to analyze wood properties. These techniques are helpful for us to analyze structural changes of lignin, cellulose and Lignin-Carbohydrate Complex (LCC) in transgenic poplar trees comprehensively. In addition, the correlation between the regulation changes of gibberellin synthesis and wood properties will be explored, and the role GA20ox in xylem growth and wood formation will be investigated. These results will provide the feasibility of modifying wood properties and structures in poplar via regulating GA20ox expression. It will pave a new way for wood properties improvement and the genetic breeding of biomass energy type poplar.

赤霉素通过影响细胞分裂来调控植物生长和发育，包括茎伸长和木材形成等，然而目前关于赤霉素的合成途径如何影响木材形成及材性的研究比较欠缺。我们前期工作发现通过调节赤霉素合成中的一个关键因子GA20ox表达水平可促进杨树生长，以期改变木材结构，为解决生产中纤维利用率低的难题开发新途径。本项目将在杨树木质部中特异性地过量表达GA20ox，通过对转基因杨树激素测定和转录组分析，来揭示促进树木生长的机制。同时材性上采用红外光谱，多维核磁共振（NMR），凝胶色谱测定分子量（GPC )等技术，对转基因杨树木质素、纤维素及木素-碳水化合物复合体（LCC）等各组分的结构变化进行全面深入地解析，探究赤霉素合成调控变化与材性的相关性，解析赤霉素合成特异基因GA20ox在木质部生长、木材形成中的作用。明确通过调控GA20ox表达改造杨树材性与结构的可行性，为林木材性改良以及生物质能源型杨树的遗传育种研究开拓新思路。

赤霉素通过影响细胞分裂来调控植物生长和发育，包括茎伸长和木材形成等，然而目前关于赤霉素的合成途径如何影响木材形成及材性的研究比较欠缺。本项目在杨树木质部中特异性地过量表达GA20ox，通过对转基因杨树激素测定和转录组分析，揭示了促进树木生长的机制。同时材性上采用红外光谱，多维核磁共振（NMR），凝胶色谱测定分子量（GPC)等技术，对转基因杨树木质素、纤维素及木素-碳水化合物复合体（LCC）等各组分的结构变化进行全面深入地解析，探究赤霉素合成调控变化与材性的相关性，解析赤霉素合成特异基因GA20ox在木质部生长、木材形成中的作用。明确通过调控GA20ox表达改造杨树材性与结构的可行性，为林木材性改良以及生物质能源型杨树的遗传育种研究开拓新思路。本项目执行期内，共发表SCI论文3篇，中文科技核心论文3篇，获优秀论文奖2项，申请发明专利4件，授权1件，实用新型专利授权4件。