Genome-Wide Identification and Expression Analysis of LOX Gene Family in Rice (Oryza sativa L.) Under Abiotic Stress Conditions

Background Lipoxygenases ( LOX s) are enzymes that facilitate the oxygenation of polyunsaturated fatty acids (PUFAs) to create oxylipins through hydroperoxides that are involved in methyl jasmonate (MeJA) signaling pathway and are essential for seed germination, growth and development, defense mechanisms, and responses to stress. This study was designed for systematic analysis and exploration of expression patterns of the LOX gene family of rice. Results Twelve LOX genes were identified, and phylogenetic and structural analyses grouped them into 9-LOXs, Type I 13-LOXs, and Type II 13-LOXs subfamilies with conserved lipoxygenase domains, motif and gene structure patterns. These genes were dispersed unevenly across seven chromosomes. Analysis of gene duplication found four tandem and segmental duplication events predominantly driving their moderate expansion, with Ka/Ks ratios suggesting purifying selection. Syntenic analysis across three genomes indicated relatively conserved roles of orthologous gene pairs of this family. The cis-acting regulatory elements revealed 46 CRE motifs responsive to light, cellular development, hormones and stress. Notably, 151 putative miRNAs were identified as potential post-transcriptional regulators. PPI analysis highlighted 10 key nodes with high interaction degrees. GO enrichment classified the functions of OsLOX s into biological, metabolic and cellular processes. RNA-seq expression profiling demonstrated OsLOX s expression across diverse tissues, developmental stages and stress. RT-qPCR data analysis further validated that OsLOX genes exhibited temporally variable differential expression under multiple abiotic stress conditions including drought, salinity, saline-alkalinity, heat and cold, and in response to IAA hormonal treatment. Conclusion In conclusions, drought and cold stress significantly upregulated certain OsLOX s, enabling rice plants to confront these adverse conditions. This study will underscore the path for forthcoming in-vivo analyses to uncover the molecular processes of LOX genes involved in tolerance to stress in rice.