Understanding rice responses to the combination of Bacterial Panicle Blight and High Nighttime temperatures

ABSTRACT: The disease Bacterial Panicle Blight (BPB) caused by the bacterium Burkholderia glumae is one major constraint in rice production worldwide that has become more prevalent in years experiencing unusually high night temperatures (HNT). These observations suggest that BPB will be more devastating in the future with the increase in global temperatures; however, the relationship between BPB and HNT has not been investigated. This work sought to understand the interplay between BPB and HNT, by initially evaluating the phenotypic responses of 20 rice accessions from diverse geographic origins to B. glumae inoculation at two nighttime temperatures: normal nighttime temperature (NNT) (22oC) or high nighttime temperature (HNT) (28oC). The results revealed temperature-dependent and temperature-independent responses ranging from enhanced susceptibility to moderate resistance. To dissect the genetic basis of these differential responses, we used RNA-sequencing for comparative transcriptional profiling on two selected temperature-independent accessions with contrasting resistance (R) and susceptible (S) responses. Comparisons among accessions (R and S), treatments: Mock (M) and pathogen (P) and temperatures: NNT and HNT resulted in 6,346 differentially expressed genes (DEGs). Weighted gene co-expression network analysis of DEGs uncovered three modules showing contrasting expression patterns between the resistant and the susceptible accessions and MAPMAN analysis further identified 86 genes related to biotic stress. Those 86 genes were mapped to multiple functional categories and were evenly divided into upregulated in the resistant accession or upregulated in the susceptible accession after single stress (HNT or P) and combined stresses (HNT and P). We found enrichment in several functional categories including proteolysis, defense signaling, secondary metabolism and hormone regulation highlighting a complex transcriptional reprogramming involving multiple pathways. The results highlight the complex transcriptional reprogramming underlying stress responses and revealed that the genes responding to either HNT or P or the combination HNT/P are the same responses operating metabolism, proteolysis and secondary metabolites. The results from this research will enable deeper understanding of rice differential responses to BPB when combined with high night temperatures while providing key candidate genes to develop rice varieties resilient to the combination biotic and abiotic stresses such as BPB and HNT.

ORGANISM(S): Oryza sativa

PROVIDER: GSE307245 | GEO | 2026/07/15

REPOSITORIES: GEO