Synergistic Response Mechanisms in Rice Seedlings Exposed to Brown Planthopper Infestation and High-Temperature Stress

Recently, rice yield has been severely affected by both brown planthopper (BPH, <i>Nilaparvata lugens</i>) infestation and high-temperature stress. Numerous previous studies have identified genes conferring resistance to BPH and high-temperature tolerance in rice, respectively. However, it remains unclear how rice synergistically responds to these two stress factors. In the present study, we found that pre-treatment with high temperature can enhance rice seeding resistance to BPH, while BPH feeding did not alter the high-temperature tolerance of rice. This result can be elucidated by the subsequent transcriptome analysis. Differentially expressed genes (DEGs) following high-temperature treatment were enriched in metabolic processes and phenylpropanoid biosynthesis pathways, thereby enhancing rice resistance to BPH. Further weighted gene co-expression network analysis (WGCNA) indicated that genes in the magenta and black modules were predominantly associated with the protein folding and transmembrane transport biological processes. And several candidate genes, including <i>Loc_Os01g02170</i> and <i>Loc_Os01g59870</i>, were identified that may play crucial roles in simultaneously regulating rice resistance to BPH and high-temperature stress. This research will provide new gene resources for cultivating rice with compound traits and provide ideas for the mechanism analysis of rice response to multiple stresses.