RNA-sequencing reveals differentially expressed rice genes functionally associated with defense against brown planthopper in NILs pyramiding BPH14 and BPH15
Brown planthopper (BPH) is one of the most destructive pests in rice production. The pyramiding application of BPH-resistance genes BPH14 and BPH15 can effectively improve rice resistance to BPH, however, the molecular mechanisms underlying BPH14/BPH15 pyramiding lines are poorly understood. Here, a mRNA expression profiling analysis was performed on the near isogenic lines (NILs) containing the BPH14, BPH15 or BPH14/BPH15 and their recurrent parent (RP) Wushansimiao. A total of 14492 differentially expressed mRNAs (DEGs) were identified from 12 mRNA profiles of resistant NILs and RP at different feeding stages. In the transcriptome analysis, 531 DEGs appeared to be common among the resistant NILs compared to RP before and after BPH feeding, which were enriched in defense response, phosphorylation and salt stress response. In addition, 258 DEGs shared only in resistant NILs were obtained among the different feeding stages, which were enriched in oxidative stress response, karrikin response and chloroplast organization. 21 DEGs were further selected as candidates for BPH resistance. OsPOX8.1, a potential candidate DEG related to BPH resistance, increased reactive oxygen species levels in rice protoplast. Our results provide valuable information to further explore the defense mechanism of insect-resistant gene pyramiding lines and develop robust strategies for insect control. Overall design: JL, AY and LH conceived and designed research.