In silico analysis and expression profiling reveal the presence of abiotic stress and developmental stage specific Aconitase genes in rice (Oryza sativa L.)

The growth and yield of crops have been significantly affected by abiotic stresses. Although respiratory metabolism is integral to plants, its understanding within the context of stress adaptation remains limited. While the rice genome contains three Aconitase genes, their specific roles in abiotic stress tolerance and plant development remain largely unexplored. This study aimed to characterize the Aconitase gene family in rice, shedding light on the evolution of Aconitase and its involvement in diverse developmental processes, as well as its response under various abiotic stress conditions. Phylogenetic analysis indicated the evolutionary relationship between rice Aconitase genes and those of other plant species. The prediction of promoter cis-elements revealed the presence of diverse cis-acting elements associated with the response to abiotic stress within the Aconitase gene family. In addition, an analysis of public RNA-seq data indicated the potential involvement of Aconitase genes in various developmental processes and mechanisms related to stress tolerance. Further, qRT-PCR confirmed the expression patterns of Aconitase genes. Expression analysis revealed differential expression of Aconitase genes under cold, drought, ABA, and salt stresses. Elevated levels of the OsAco1 transcript resulted in a phenotype that exhibited increased tolerance to salt stress. Biochemical analysis revealed higher Aconitase activity in the overexpressed line compared to the control plant. Furthermore, the overexpressed line exhibited improved growth and lower H₂O₂ levels than the control plant following a 2-hour exposure to 200 mM salt stress. These findings suggest a potential role of Aconitase in enhancing salt stress tolerance. Moreover, they lay the foundation for further exploration into the precise involvement of Aconitase in plant developmental processes under various stress conditions, with the ultimate aim of developing salt-tolerant rice cultivars.