毛白杨阿魏酸-5-羟基化酶对烟草木质素的影响

Lignin biosynthesis in tobacco with regulated expression of poplar ferulate 5-hydroxylase

为了研究阿魏酸-5-羟基化酶(F5H)在木质素合成途径中的调控作用,采用CTAB法提取毛白杨RNA,反转录得到c DNA并克隆出毛白杨F5H基因,将其以正义、反义、干涉的基因形式,使用农杆菌侵染法导入烟草基因组中。将得到的转基因植株茎段进行解剖分析,并测定其木质素细胞壁化学组成。转基因植株的木质素、纤维素总量和木质部解剖分析结果与野生型相比均为未表现出明显差异,植株正常生长。F5H的过量表达和基因沉默均不影响植株木质化和生长,可以说明它是木质素合成途径可供选择的一个很好的调控点。

Ferulate 5-hydroxylase （F5H）is a key enzyme in the lignin biosynthesis pathway, which is one of the most important regulated sites. FSH gene was cloned with the template of cDNA from Populus tomentosa and three expressed vectors with sense, antisense and RNAi were constructed in Nicotiana tabacum, respectively. We also observed the transverse anatomy of stem and analyzed the total lignin content. In lignin modification, FSH had no significant effect on both anatomic structure and total lignin content in xylem. In conclusion, overexpression and silence of FSH gene had no effect on the growth and lignification. The results provide an important basis for further study in resulation of lisnin biosynthesis.