Ku80- and DNA ligase IV-deficient plants are sensitive to ionizing radiation and defective in T-DNA integration
Ku80- and DNA ligase IV-deficient plants are sensitive to ionizing radiation and defective in T-DNA integration
复制标题
DOI：
10.1046/j.1365-313x.2003.01738.x
复制
发表时间：
2003-05-01
期刊：
影响因子：
7.2
通讯作者：
Britt, AB
中科院分区：
文献类型：
--
作者：
Friesner, J;Britt, AB
双链断裂（DSB）修复途径催化断裂染色体的重新连接和转化DNA的整合。这些过程在细菌、真菌和动物中得到了很好的表征。植物通常被认为主要利用非同源末端连接（NHEJ）途径来修复DSB并整合转基因，因为与染色体具有大片段同源性的转化DNA被随机整合。为了验证NHEJ是植物DSB修复的重要途径这一假设，我们分离了Ku 80和DNA连接酶IV基因的拟南芥同源物中的T-DNA插入突变，这两个基因分别是NHEJ启动和完成所需的。这两种突变体都对γ射线的细胞生长抑制作用过敏，表明NHEJ确实是修复DSB的关键途径。突变体的T-DNA插入率也降低，表明Ku 80和DNA连接酶IV在拟南芥T-DNA整合的机制或调控中起重要作用。
Double-strand break (DSB) repair pathways catalyze the rejoining of broken chromosomes and the integration of transforming DNAs. These processes have been well characterized in bacteria, fungi, and animals. Plants are generally thought primarily to utilize a non-homologous end joining (NHEJ) pathway to repair DSBs and integrate transgenes, as transforming DNAs with large tracts of homology to the chromosome are integrated at random. In order to test the hypothesis that NHEJ is an important pathway for the repair of DSBs in plants, we isolated T-DNA insertion mutations in the Arabidopsis homologs of the Ku80 and DNA ligase IV genes, required for the initiation and completion, respectively, of NHEJ. Both mutants were hypersensitive to the cytostatic effects of gamma radiation, suggesting that NHEJ is indeed a critical pathway for the repair of DSBs. T-DNA insertion rates were also decreased in the mutants, indicating that Ku80 and DNA ligase IV play an important role in either the mechanism or the regulation of T-DNA integration in Arabidopsis .