结球白菜和拟南芥防御素基因的鉴定与比较分析

 植物防御素是一类富含半胱氨酸的小分子蛋白,在抗病反应中起着重要作用。本研究以结球白菜和拟南芥基因组序列为材料,利用生物信息学手段进行基因鉴定、染色体定位和进化分析。结果表明,结球白菜有11个防御素基因成员,数量少于拟南芥(15个),基因组DNA全长183~637 bp,开放阅读框全长183~363 bp;除结球白菜Bra029208序列外,其余防御素基因均有1个内含子;基因定位结果表明,一些基因成簇分布,推测由串联重复所致,拟南芥的3号、结球白菜的1、4、5和10号染色体均没有防御素基因的分布;进化分析结果表明,26个防御素成员可分为三大类,Ⅰ类有10条序列,Ⅱ类13条,Ⅲ类最少,仅3条。

Genome-wide identification and comparative analysis of defensin genes from Chinese cabbage and Arabidopsis thaliana

Plant defensins are low-molecular-weight cysteine-rich proteins, and play important roles in disease resistance response. Defensin gene identification, chromosomal location and evolution analysis were performed by bioinformatics methods taking genome sequences of Chinese cabbage and Arabidopsis thaliana as materials. The results revealed 11 defensin gene members in Chinese cabbage, less than those in A. thaliana (15). The full genomic DNA was 183-637 bp in length with open reading frames varying from 183-363 bp. All defensin genes contained an intron except Bra029208 from Chinese cabbage. Chromosomal location results showed few sets of genes clustered on chromosomes, and this phenomenon was speculated to be caused by tandem repeat. Evolutionary analysis indicated that the 26 defensin members could be divided into 3 types. There were 10 and 13 members in type Ⅰ and type Ⅱ defensin, respectively. However, only 3 members were found in type Ⅲ defensin.