基于比较基因组学分析苏云金芽胞杆菌防治蛴螬的相关功能基因

为挖掘对地下害虫蛴螬高效的苏云金芽胞杆菌（Bacillus thuringiensis，简称Bt）菌株在杀虫及环境适应方面的关键功能基因，本研究对蛴螬高效的菌株261-1、Fcd114、1126-1、HBF-18和78-2以及对鳞翅目害虫高效菌株WBt-2、G03进行了基因组测序，并与对鳞翅目害虫高效菌株HD1、HD12、HD73和对蛴螬高毒力菌株Bt185等基因组进行了比较分析，重点分析比较了杀虫基因、多糖代谢相关基因、与其他微生物竞争和适应性相关的酰基高丝氨酸内酯水解酶（N-Acylhomoserine lactones hydrolase，aiiA）、突破和克服靶标昆虫免疫系统的免疫抑制因子A（Immune Inhibitor A，InhA）、具有抗病并能增效杀虫的双效菌素（Zwittermicin A，ZwA）等五大类基因和基因簇。研究发现，这些菌株按照其所含有的杀虫基因特异性可分为3个类型：对鳞翅目害虫有效的菌株（类型1）、对鞘翅目害虫有效的菌株（类型2）以及同时含有两种害虫有效基因的菌株（类型3）。对地下害虫蛴螬特异（类型2）的Bt菌株除了在杀虫基因上具有特异性之外，所含有的aiiA、InhA基因也有显著特点。相关研究为进一步对地下害虫蛴螬高效Bt菌株的改良提供了新思路。

Analysis of Functional Genes of Bacillus thuringiensis Isolates against White Grubs by Comparative Genomics

In order to discover the key functional genes of insecticidal activity and environmental adaptation from the high toxicity Bacillus thuringiensis (Bt) strains against underground pests, Bt strains 261-1, Fcd114, 1126-1, HBF-18 and 78-2 with high insecticidal activities against Coleoptera were sequenced, as well as lepidoptera-toxic strains WBt-2 and G03. The published genomes of lepidoptera-toxic HD1, HD12, HD73 and Bt185 strains-toxic to white grubs were included in the comparison. Five kind genes and clusters involved in insecticidal, related to the synthesis and degradation of polysaccharide, microbial competition and adaptation, such as aiiA gene (N-Acylhomoserine lactones hydrolase, aiiA), inhA (Immune inhibitor A, inhA) acting on the immune systems of target insects and Zwittermicin A (ZwA), were analyzed and compared respectively. The results indicated that these strains could be divided into three types based on the specific insecticidal genes, they contained:type 1, lepidoptera-specific; type 2, coleoptera-specific; and type 3, both lepidoptera and coleoptera-toxic. Type 2 strains specific to subterranean pests, had specific toxicity-related genes, which were involved in aiiA, and inhA. The results provided a new vision for further improvement of highly effective Bt strains to control underground pests.