Gene Participates in Regulating Autophagy and Fission of Mitochondria in the Brown Planthopper, .

Autophagy plays multiple roles in regulating various physiological processes in cells. However, we currently lack a systematic analysis of autophagy and the autophagy-related gene 1 in the brown planthopper (BPH, ), one of the most destructive of the insect pests of rice. In this study, the full-length cDNA of an autophagy-related gene, , was cloned from BPH. Real-time qPCR (RT-qPCR) revealed that this gene was expressed differently across developmental stages, at higher levels in nymphs but lower levels in adults. RNA interference with dsNlATG1 significantly decreased the mRNA level of the target gene to 14.6% at day 4 compared with that of the dsGFP control group. The survival of the dsNlATG1-treated group decreased significantly from day 4 onward, dropping to 48.3% on day 8. Examination using transmission electron microscopy (TEM) showed that epithelial cells of the BPH's midgut in the dsNlATG1-treated group had less autophagic vacuoles than did the dsGFP control, and knockdown of clearly inhibited the starvation-induced autophagy response in this insect. RNA interference of upregulated the gene involved in mitochondrial fission, leading to reductions in mitochondrial width and area. Furthermore, knockdown of also decreased the ATP content and accumulation of glycogen. Together, these results demonstrate that the gene participates in regulating autophagy and fission of mitochondria in the brown planthopper, making it a potentially promising target for pest control given its key role in autophagy, including maintaining the normal structure and function of mitochondria.