转基因植物中T-DNA整合的分子特征及表达

植物中不同转基因方法转化外源基因的T-DNA整合特征既具有共性,又具有特性,使得转基因的遗传在各独立转化体间呈现多样性,另外多种遗传因子和限制因素使受体植物中外源基因的表达存在下降,甚至出现基因沉默等复杂现象。本文主要对农杆菌介导及裸露DNA直接转化转基因植物中T-DNA的分子特征和转基因表达的影响因子进行了介绍和概述。转化体中转基因的遗传稳定性和表达主要取决于转基因在植物基因组中的整合位置、拷贝数及组成结构。因而,通过对具有表达水平各异的转化体进行深入的遗传分析和分子生物学研究以及转化体之间进行的比较研究,将对转基因技术自身的完善、定点整合以及更有效的利用转基因技术都具有十分重要的意义。

Molecule Characterization and Expression of T-DNA Integration in Trans-formed Plants

The characterization of T-DNA integration of different transgenic methods transfering genes in plants has common characteristics, as well as specific characteristics, which makes the hereditary of transgene present-ing diversity in different independence transformed plants. In addition, the expression of foreign genes in recep-tor plants represents down-regulated, even some complicated phenomenon are found, such as gene silencing un-der multi-genetic factors and limitation factor. In this article, we chiefly introduced and summarized the molecule characterization of T-DNA in transgenic plants by Agrobacterium-mediated transformation and exposed DNA directly transformated and the factors affecting the expression of transgene. The hereditary stability and ex-pression of transgene mainly depends on the integration sites, copy number and its structure of plant genome from transgene. Therefore, it would take on substantially significance for perfecting the transgene technique it-self, site-specific integration and more efficiently utilizing transgene technique via deep genetic analysis and molecular biology investigation of transformations with differently expression patterns, as well as the compara-tive research of transformations.