高圣风 徐毕爽 陆大倩 刘爱勤 苟亚峰 孙世伟 王政 孟倩倩

摘  要：生防菌株Bacillus velezensis Z对胡椒瘟病等多种植物病害具有良好的生防效果;全基因组测序能够为其分子机理研究和开发应用提供信息基础。本研究开展该菌株全基因组测序，并进行比较基因组学和抑菌次生代谢产物合成基因簇预测研究。结果表明：B. velezensis Z菌株的基因组中含有1条4 054 780 bp大小的环形染色体DNA和1个17 122 bp大小的环形质粒，总基因组的GC含量为46.24%，共编码基因4173个;包含27个rRNA，86个tRNA基因，34个sRNA;含有串联重复序列179个，其中13个微卫星DNA，138个小卫星DNA;通过比较基因组学分析，结果发现该菌株与贝莱斯芽孢杆菌模式菌株FZB42同源性极高，与枯草芽孢杆菌模式菌株168之间具有一定的遗传距离;同时发现B. velezensis Z基因组中共编码次生代谢产物合成基因簇13个，其中8个与表面活性素（surfactin）、泛革素（fengycin）、溶杆菌素（bacilysin）、macrolactin H、bacillaene、difficidin、plantazolicin、amylocyclicin等已知基因簇完全相似或高度相似，其他5个基因簇皆功能未知。总之，本研究揭示了B. velezensis Z的全基因组遗传信息，明确其与贝莱斯芽孢杆菌和枯草芽孢杆菌的比较基因组学关系，预测了抑菌产物合成编码基因簇，为该生防菌株及其抑菌产物的机理研究和开发应用奠定基础。

关键词：贝莱斯芽孢杆菌;全基因组测序;比较基因组学;次生代谢产物;抑菌

中图分类号：S435.73      文献标识码：A

Abstract： Bio-control strain Bacillus velezensis Z shows good effects on the control of various diseases， especially good for the black pepper Phytophtora foot rot disease. The whole genome sequencing is an important basis to further study the molecular mechanism. In this study， the whole genome of the strain was completely sequenced using both Illumina HiSeq 4000 and PacBio RS II， and the gene function annotation， analyses of comparative genomics and secondary metabolite biosynthetic gene clusters were performed using blast alignment tools. The complete genome sequence of B. velezensis Z was consisted of a circular 4 054 780 bp chromosome and a 17 122 bp plasmid with GC content of 46.24%， 4173 identified genes， 27 rRNA， 86 tRNA， 34 sRNA， 179 tandem repeat regions including 138 minisatellite DNA and 13 microsatellite DNA. The genome showed highly homologous with the model strain B. velezensis Z FZB42 by the analyses of core/pan gene and gene family. B. velezensis Z harbored 13 secondary metabolite biosynthetic gene clusters， including 8 clusters involved in the synthesis of surfactin， plantazolicin， macrolactin H， bacilysin， fengycin， difficidin， amylocyclicin， bacillaene， and others functionally unknown. In conclusion， the genetic information， comparative genomics and antibiotics synthesis gene clusters of the B. velezensis Z were revealed in this study， and it would be useful for further research and utilization of the strain.

Keywords： Bacillus velezensis; whole genome sequencing; comparative genomics; secondary metabolite; antibiotic

DOI： 10.3969/j.issn.1000-2561.2021.05.003

根際促生细菌（plant growth-promoting rhi-zobacteria，PGPR）天然生存于植物根际，具有拮抗病原菌、促进植株生长、诱导植株抗病、修复根际环境等多种功效，是当前实施“减肥、减药”的有效支撑手段[1-2]。芽孢杆菌（Bacillus spp.）具有广普高效、容易培养、耐逆境、耐储藏等特点，是国内外研究和应用最多的生防菌类群。……