利用基因工程改良杨木材性并提高造纸中纤维素利用效率的研究进展

Research Advances in Genetic Improvement of Wood Properties on Promoting the Utilization Efficiency of Cellulose in Poplar Pulping

木质纤维素是地球上数量最大的可再生资源,由木质素、半纤维素及纤维素三者紧密结合产生的抗降解屏障作用是纤维素能源利用的主要障碍。通过调控木质素生物合成途径关键基因的表达来降低杨树木质素含量或改变木质素成分,是提高杨木纤维素转化效率并降低转化成本的有效途径。通过选定木质素合成基因作为调控目标,运用RNAi抑制技术调整木质素的生物合成,转化获得转基因植株是一条可行的途径。同时建立并开发更合理的木质素提取方法,得到纯度得率更高的木质素,结合多维核磁共振等分析手段对转基因杨树组分的成分结构变化进行深入地解析,追踪基因工程对杨木材性的改良效果,进一步为木质纤维素高效利用以及生物质能源杨树的遗传育种研究开拓新思路。

Lignocelluloses are the largest renewable resource.The “biomass recalcitrance” created by tight binding of lignin,hemicelluloses and cellulose,which is also the major obstacle for cellulose-based ethanol.Moreover,the lignin within cell wall is a major contributor to pollution of paper production and high cost of cellulosic ethanol.Lignin content can be reduced and lignin components components can be altered by inhibiting the expression of critical genes in lignin biosynthetic pathway,thus improving the conversion efficiency of cellulose-based ethanol and lowering its conversion costs.After cloned the gene encoding enzymes involved in lignin biosynthesis,and constructed it into RNAi vectors,the transgenic plants were obtained.At the same time,establish a better method of lignin extraction and get higher purity and extraction rate of lignin,and analysis the component structure change of the transgenic poplar by NMR,in order to track the improving effect of genetic engineering on poplar wood properties.In short,it will provide theoretical guidance for the verification and improvement of lignin biosynthesis pathway of lignocellulosic biomass,efficient deconstruction of lignin and their value-added applications.It will also pave a new way for wood properties improvement and the genetic breeding of biomass energy type poplar.