Genome-wide analysis of the PRT gene family in rice reveals that OsPRT7 plays a significant role in heat stress response.

PRTase plays vital roles in plant development and abiotic stress responses by maintaining the balance between plant growth and stress adaptation.The evolutionary conservation of the OsPRT gene family was elucidated by integrating phylogenetic tree construction, synteny assessments, and Ka/Ks ratio calculations. To identify prospective thermotolerant candidates, a comprehensive screening strategy was employed; this encompassed tissue-specific expression profiling, expression profiling under heat stress conditions, haplotype association analysis across 620 rice accessions, amino acid variant examination, and subsequent RT-qPCR verification. The promoter regions of OsPRT genes harbor multiple cis-acting elements related to stress responses. Notably, a single intra-species collinear paralogous pair was identified within the OsPRTs, with Ka/Ks evaluations strongly suggesting that this gene family has been subjected to rigorous purifying selection. Expression analysis indicated that most OsPRT genes have tissue-specific expression patterns. Haplotype analysis revealed significant differences among OsPRT5, OsPRT6, and OsPRT7. RT-qPCR results showed that the expression level of OsPRT7 exhibited a downward trend under high-temperature treatment. Collectively, our results suggest that OsPRTs have potential functions in rice heat stress tolerance, providing new insights into the molecular mechanisms underlying the environmental adaptation and adaptive evolution of OsPRT genes in rice.