Zhang Juntao, Zhou Ziwen, Liu Xiaobei, Zhang Yongjun, Zhang Tiantao
State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China.
Insects. 2025 May 18;16(5):532. doi: 10.3390/insects16050532.
(Bt) is an efficacious biocontrol bacterium known for producing various toxins, such as crystal toxins, which disrupt the midgut epithelium of pest larvae, leading to larval mortality. However, the development of resistance to in pests poses a significant threat to the widespread application of Bt corn. Consequently, we employed high-throughput sequencing of the midgut bacterial 16S ribosomal RNA to characterize the midgut bacteria in four Bt-resistant strains. Specifically, Bt-resistant strains (ACB-FR and ACB-AcR) exhibited lower bacterial diversity compared to ACB-AbR and ACB-IeR. Multivariate analyses and statistical evaluations further demonstrated that the microbiota communities in Bt-resistant pests (AbR, AcR, IeR, and FR) were distinct from those in Bt-susceptible strains. Notably, the genus predominated in BtS, whereas was the genus with peak enrichment in AbR, AcR, IeR, and FR. Bioassays subsequently revealed that enhances the Cry1Ab resistance of ACB larvae. Our investigations indicate that treatment with Bt protein alters the midgut microbiota community of , and these microbiota differences may potentially modulate the Bt-induced lethality mechanism.
苏云金芽孢杆菌（Bt）是一种有效的生防细菌，以产生多种毒素而闻名，如晶体毒素，这些毒素会破坏害虫幼虫的中肠上皮，导致幼虫死亡。然而，害虫对Bt产生抗性对Bt玉米的广泛应用构成了重大威胁。因此，我们采用中肠细菌16S核糖体RNA的高通量测序来表征四种Bt抗性品系的中肠细菌。具体而言，与ACB-AbR和ACB-IeR相比，Bt抗性品系（ACB-FR和ACB-AcR）的细菌多样性较低。多变量分析和统计评估进一步表明，Bt抗性害虫（AbR、AcR、IeR和FR）中的微生物群落与Bt敏感品系中的不同。值得注意的是，某属在Bt敏感品系中占主导地位，而另一属在AbR、AcR、IeR和FR中富集峰值最高。生物测定随后表明，该属增强了ACB幼虫对Cry1Ab的抗性。我们的研究表明，用Bt蛋白处理会改变ACB的中肠微生物群落，这些微生物群落差异可能会调节Bt诱导的致死机制。
