Walking through crossroads-rice responses to heat and biotic stress interactions.

Abstract

Rice, the most important source of calories for humans is prone to severe yield loss due to changing climate including heat stress. Additionally, rice encounters biotic stresses in conjunction with heat stress, which exacerbates the adverse effects, and exponentially increase such losses. Several investigations have identified biotic and heat stress-related quantitative trait loci (QTLs) that may contribute to improved tolerance to these stresses. However, a significant knowledge gap exists in identifying the genomic regions imparting tolerance against combined biotic and heat stress. Hereby, we are presenting a conceptual meta-analysis identifying genomic regions that may be promising candidates for enhancing combined biotic and heat stress tolerance in rice. Fourteen common genomic regions were identified along chromosomes 1, 2, 3, 4, 6, 10 and 12, which harbored 1265 genes related to heat stress and defense responses in rice. Further, the meta expression analysis revealed 24 differentially expressed genes (DEGs) involved in calcium-mediated stress signaling including transcription factors Myb, bHLH, ROS signaling, molecular chaperones HSP110 and pathogenesis related proteins. Additionally, we also proposed a hypothetical model based on GO and MapMan analysis representing the pathways intersecting heat and biotic stresses. These DEGs can be potential candidate genes for improving tolerance to combined biotic and heat stress in rice. We present a framework highlighting plausible connecting links (QTLs/genes) between rice response to heat stress and different biotic factors associated with yield, that can be extended to other crops.