Characterization of Xanthomonas citri pv.citri from China based on spoligotyping  

作　　者：Wenting Li Zhenxi Li Jiaquan Huang Meirong Xu Zheng Zheng Xiaoling Deng 

机构地区：[1]Guangdong Province Key Laboratory of Microbial Signals and Disease Control,College of Plant Protection,South China Agricultural University,Guangzhou 510642,China

出　　处：《Horticultural Plant Journal》2022年第6期727-736,共10页园艺学报（英文版）

基　　金：supported by Chinese Modern Agricultural Technology Systems (Grant No.CARS-26)。

摘　　要：Xanthomonas citri pv.citri(Xcc),a gram-negative bacterium,is the causal agent of citrus canker,one of the most devastating diseases threatening the citrus industry worldwide.Understanding the diversity and population structure of Xcc is a prerequisite for disease epidemiological monitoring and effective disease management.Recent characterization of the clustered regularly interspaced short palindromic repeats(CRISPR)/cas(CRISPR-associated proteins genes)system with a highly variable repeat number among species provides a new molecular typing method for bacterial genetic analysis.In this study,we performed systematic in silico analyses of 28 Xcc genomes and identified a credible CRISPR/cas in Xcc strains.Further analysis of CRISPR polymorphisms(repeat number and spacer types)in 129 Xcc A strains collected from six provinces in China identified 15 types of CRISPR arrays with 25 spacers.Phylogenetic analysis of Xcc strains based on the CRISPR locus produced a more reliable and accurate typing result compared to the commonly used loci.In addition,seven associated cas genes—cas1,cas2,cas3,cas4,cas5,cas7(csd2),and cas8(csd1)—were found located adjacent to the CRISPR array.BLAST results showed>99%similarity of seven cas genes among Xcc strains.Homology analysis of spacer sequences showed that six spacers had possible phage/prophage origin.The characterization of the CRISPR/cas system among Xcc strains provided an updated strain typing method for Xcc diversity analysis and yielded a panoramic view of CRISPR evolution for further studies of Xcc-phage interactions.

关 键 词：Xanthomonas citri pv.citri CRISPR Diversity SPACERS Typing method 

分 类 号：S436.66[农业科学—农业昆虫与害虫防治]