Protein-protein interactions reveal key genes in rice response to salt stress: a meta-analysis

The salt-tolerant genes (STGs) play important roles in protecting plants against salt stress. Although various types of STGs have been systematically characterized in plant species, the key genes (KGs) regulating salt stress tolerance in rice (Oryza sativa L.) remain elusive. This study focused on the identification and characterization of the members of STGs in rice through integrated bioinformatic and molecular approaches, including chromosomal location, physicochemical characteristics, protein-protein interaction, and expression profiles of the identified genes. A total of 164 differentially expressed genes (DEGs) were systematically identified as responsive to salt tolerance and sorted out potential 12 kg (OsHSP20.2, OsGFP2, OsBBTI2, OsEN20.6, OsUBC17, OsACD5, OsPEAB5, OsDP11, OsDFP5, OsWD40.7, OsEP11.1, and OsGRAM12) through the CytoHubba algorithms analysis. Physicochemical characterization indicated substantial variation among KGs, including genomic sequences (824-4051 bp), amino acid length (148-659 aa), molecular weight (16.39-71.35 kDa), and isoelectric point (4.66-10.37). Protein-protein interaction (PPI) network prediction indicated intricate functional associations among key STGs. Gene Ontology (GO) enrichment analysis revealed that the KGs are involved in numerous biological processes and molecular functions. Moreover, gene homology results revealed that KGs have multiple relationships with other plant species. Co-expression network analysis revealed that 12 kg are potentially involved in the regulatory mechanisms underlying the biological process. Relative gene expression through the comparative threshold (ΔΔCT) of qRT-PCR revealed that the KGs are salt-induced and may play crucial roles in rice responses to salt stress. Tissue-specific expression patterns revealed that the KGs significantly altered expression levels across different tissues and under stress. This systematic investigation demonstrated that the 12 identified genes may play roles in the development of salt-tolerant rice varieties.