Investigation of Gut Bacterial Communities of Asian Citrus Psyllid (Diaphorina citri) Reared on Different Host Plants

SIMPLE SUMMARY: Diaphorina citri is a crucial natural vector of the Huanglongbing pathogen, which has devastated the citrus industry. The host plant is a critical factor that affects insect biology and its symbiont abundance. However, little is known about how host plants affect the bacterial community located in D. citri. In this work, the guts of five different host-plant-feeding populations (i.e., Citrus reticulata cv. Shatangju, Citrus poonensis cv. Ponkan, Murraya paniculata (orange jasmine), Citrus limon (lemon), and Citrus sinensis (navel orange)) were analyzed for bacterial communities by next-generation sequencing. The dominant phylum was Proteobacteria. The most common and abundant bacterial genera in D. citri were Wolbachia, Escherichia-Shigella, and Candidatus Profftella, but their relative abundance varied among the different host plant groups. There were obvious differences in the gut microbiota among the different hosts, and the gut microbe diversity was the highest in the ponkan-feeding population, while the lowest was in the Shatangju-feeding population. Overall, our findings indicate that the host plant can significantly affect the gut microbial community of D. citri. This result can provide new insights into the co-adaptation of D. citri and its symbionts. ABSTRACT: Diaphorina citri Kuwayama (Hemiptera: Liviidae) can cause severe damage to citrus plants, as it transmits Candidatus Liberibacter spp., a causative agent of Huanglongbing disease. Symbiotic bacteria play vital roles in the ecology and biology of herbivore hosts, thereby affecting host growth and adaptation. In our research, the effects of Rutaceous plants (i.e., Citrus reticulata cv. Shatangju, Citrus poonensis cv. Ponkan, Murraya paniculata (orange jasmine), Citrus limon (lemon), and Citrus sinensis (navel orange)) on the gut microbiota (GM) and microbial diversity of D. citri adults were investigated by 16S rRNA high-throughput sequencing. It was found that Proteobacteria dominated the GM communities. The gut microbe diversity was the highest in the ponkan-feeding population, and the lowest in the Shatangju-feeding population. The NMDS analysis revealed that there were obvious differences in the GM communities among the different hosts. PICRUSt function prediction indicated significant differences in host function, and those pathways were crucial for maintaining population reproduction, growth, development, and adaptation to environmental stress in D. citri. Our study sheds new light on the interactions between symbionts, herbivores, and host plants and expands our knowledge on host adaptation related to GM in D. citri.