溴氰虫酰胺对小菜蛾肠道微生物群落及其代谢功能的影响

Effects of Cyantraniliprole on Intestinal Microbial Community and Metabolic Function of Plutella xylostella(Linnaeus)

溴氰虫酰胺是防治鳞翅目害虫的第二代鱼尼丁受体抑制剂类杀虫剂,为明确其对小菜蛾幼虫肠道微生物群落结构及代谢功能的影响,采用分离培养法和高通量测序技术研究1 mg/L溴氰虫酰胺浸叶饲喂后小菜蛾肠道微生物的群落结构,采用Biolog-ECO碳源代谢表型技术研究1 mg/L溴氰虫酰胺浸叶饲喂以及0.1、1、10、100 mg/L溴氰虫酰胺直接作用后小菜蛾肠道微生物群落的代谢功能变化。结果表明,小菜蛾肠道可培养优势细菌主要为蒙氏肠球菌(Enterococcus mundtii)和血杆菌(Sanguibacter sp.),经1 mg/L溴氰虫酰胺浸叶饲喂处理和未经处理的小菜蛾(对照)肠道可培养细菌分别约为2.4×10^(6)cfu/g和4.5×10^(6)cfu/g。高通量测序结果显示,小菜蛾肠道优势细菌门为厚壁菌门(Firmicutes)、蓝细菌门(Cyanobacteria)、变形菌门(Proteobacteria),其在溴氰虫酰胺处理和对照中的相对丰度分别为74.0%和94.0%、8.6%和3.4%、13.4%和0.8%;优势菌属为肠球菌属(Enterococcus)、血杆菌属(Sanguibacter),其在溴氰虫酰胺处理和对照中的相对丰度分别为74.0%和94.0%、2.5%和0.5%。1 mg/L溴氰虫酰胺浸叶饲喂后,小菜蛾肠道中厚壁菌门和肠球菌属相对丰度均显著降低,而蓝细菌门和血杆菌属相对丰度均显著增加;小菜蛾肠道细菌群落多样性、均匀度和丰富度整体较对照增加,且多样性和丰富度增幅显著。1 mg/L溴氰虫酰胺浸叶饲喂以及0.1、1 mg/L溴氰虫酰胺直接作用对小菜蛾肠道微生物的碳源代谢能力均无显著影响,而10、100 mg/L溴氰虫酰胺直接作用于肠道可降低肠道微生物的碳源代谢能力。综上,1 mg/L溴氰虫酰胺浸叶饲喂可降低小菜蛾肠道可培养细菌数量,显著增加肠道微生物群落丰富度与多样性,高质量浓度溴氰虫酰胺直接作用可抑制肠道菌群的代谢能力。

Cyantraniliprole is a second generation of ryanodine receptors inhibitor insecticide to control Lepidoptera pests.To understand the effects of cyantraniliprole on the intestinal microbial community structure and metabolic function of Plutella xylostella larvae,culture‑dependent method and high‑throughput sequencing were used to investigate the intestinal microbial community structure of P.xylostella fed with 1 mg/L cyantraniliprole soaked leaves.The changes in intestinal microbial community metabolic function of P.xylostella fed with 1 mg/L cyantraniliprole soaked leaves and the changes in intestinal microbial community metabolic function when the intestinal suspension was mixed with 0.1,1,10,100 mg/L cyantraniliprole were investigated using the Biolog‑ECO carbon source metabolic phenotype technology.The results showed that the dominant culturable bacteria in the intestine of P.xylostella were Enterococcus mundtii and Sanguibacter sp.The numbers of intestinal culturable bacteria of P.xylostella fed with 1 mg/L cyantraniliprole soaked leaves and clean leaves(as the control)were 2.4×10^(6)cfu/g and 4.5×10^(6)cfu/g,respectively.The results of high‑throughput sequencing showed that the dominant phyla in the intestine of P.xylostella were Firmicutes,Cyanobacteria and Proteobacteria,and their relative abundance in treatment/control group was 74.0%/94.0%,8.6%/3.4%and 13.4%/0.8%,respectively.The dominant genera in the intestine of P.xylostella were Enterococcus and Sanguibacter,and their relative abundance in treatment/control group was 74.0%/94.0%and 2.5%/0.5%,respectively.After feeding with 1 mg/L cyantraniliprole soaked leaves,the relative abundance of Firmicutes and Enterococcus in the intestine of P.xylostella decreased significantly,while the relative abundance of Cyanobacteria and Sanguibacter increased significantly.Compared to the control group,the diversity,evenness and richness of intestinal bacterial community of P.xylostella were increased,with a significant increase in diversity and richness.The carbon source metabolic capacity of intestinal microorganisms was not significantly affected under 0.1,1 mg/L cyantraniliprole stress and feeding with 1 mg/L cyantraniliprole soaked leaves,while decreased under 10,100 mg/L cyantraniliprole stress.In summary,feeding with 1 mg/L cyantraniliprole soaked leaves can reduce the number of culturable bacteria in the intestine of P.xylostella,and significantly increase the richness and diversity of intestinal microbial community.Under the pressure of high concentration of cyantraniliprole,the intestinal microbial metabolic capacity of P.xylostella decreased.