Ri质粒T-DNA对6年生转基因三倍体毛白杨生长和生理性状的影响

为探索外源基因在成年树木中的表达及稳定性,以转Ri质粒6年生三倍体毛白杨成年树木为材料,以同时种植的未转基因三倍体毛白杨为对照植株,对21个转基因株系和对照植株进行外源基因检测和生长、生理特性测定。PCR检测结果证明,Ri质粒T-DNA上的tms、rolC基因在各转基因株系基因组中稳定存在。转基因株系生长受到不同程度影响,各转基因株系的叶柄长、叶片长、叶片宽度和叶面积均小于对照植株,叶片长宽比大于对照植株;71%的转基因株系树高低于对照植株;81%的转基因株系胸径低于对照植株。转基因株系叶绿素a和叶绿素a+b含量、Fv/Fm值、PI值均低于对照植株。81%的转基因株系叶片内源GA3含量及所有株系叶片的内源IAA含量和IAA/ABA比值均高于对照植株,而86%转基因株系叶片的内源ABA含量低于对照植株。T-DNA能够在三倍体毛白杨成年树木中稳定表达,使植物体内内源IAA和GA3含量提高,生长受到抑制,但不同株系存在较大差异。本研究结果为进一步研究外源基因在植物体内的表达调控机制提供了参考依据。

Effect of Ri Plasmid T-DNA on Growth and Physiological Traits in 6-year-old Transgenic Triploid Populus tomentosa

In order to study the expression and stability of exogenous genes in adult trees,6-years-old triploid Populustomentosa contained Ri plasmid were used as the studied materials to test the exogenous genes,the triploid Populustomentosa grown at same time was used as the control,the characteristics of growth and physiology of 21 transgenic lines and the control were studied.PCR results confirmed the tms and rolC genes of the Ri plasmid T-DNA were stable in the genome of the transgenic lines.The growth of transgenic lines was affected at different level:petiole length,leaf length,leaf width and leaf area was lower and the ratio of leaf length to width was higher than that of control.71％ transgenic lines were shorter than the control in the height;the diameter at breast height of 81％ transgenic lines were lower than control.The content of chlorophyll a,chlorophyll a + b,the value of Fv/Fm and PI were all less than the control content of endogenous GA3 in the leaves of 81％ transgenic lines were higher than control,meanwhile the content of endogenous IAA and IAA/ABA ratio in all of the transgenic lines were higher than control.But there were less content of endogenous ABA in 86％ transgenic lines than the control.T-DNA expressed stably in adult triploid Populustomentosa,and increased the content of endogenous auxin and the gibberellin,so the growth was inhibited,but there were big differences among different lines.The result in the present study will provide a theoretical and practical basis for further study of the regulation mechanism of exogenous gene expression in plants.