叶桉COMT和CCoAOMT基因定向调控木质素单体合成的烟草转化研究*

利用烟草遗传转化体系,研究叶桉(Eucalyptus urophylla)咖啡酸氧甲基转移酶基因(EuCOMT)和咖啡酰CoA氧甲基转移酶基因(EuCCoAOMT)对木质素单体合成的定向调控效果。

Directional Regulation of Lignin Monomer Synthesis in Tobacco by Using COMT Gene and CCoAOMT Gene of Eucalyptus urophylla

Directional regulation effect of Eucalyptus urophylla COMT gene and CCoAOMT gene on lignin monomer synthesis were studied by tobacco transformation system. Transgenic plants C-S(contain sense EuCOMT fragment), CR(contain full-length RNAi fragment of EuCCoAOMT), C-CR(contain EuCOM and EuCCoAOMT dual-gene) were obtained, and the expression of sense EuCOMT fragment was detected in transgenic tobacco, while the RNAi fragment of EuCCoAOMT caused strong inhibition on tobacco CCoAOMT gene. The growth morphology, lignin content, fiber content and anatomical structure of transgenic tobacco were not significantly different from those of wild type. The results of lignin monomer detection showed the G lignin content increased 17.72% and S/G ratio decreased 17.99% in transgenic plant C-S, meanwhile the S/G ratio increased 61.62% in CR. In C-CR, G lignin content decreased 57.38%, and S/G ratio increased 114.94%. The result showed that the inhibition of CCoAOMT had a significant inhibitory effect on lignin synthesis in G, and the dual-gene transformation of EuCOMT and EuCCoAOMT showing the best directional regulation effect.