Evolutionary Analysis of Six Gene Families Part of the Reactive Oxygen Species (ROS) Gene Network in Three Species.

Climate change is expected to intensify the occurrence of abiotic stress in plants, such as hypoxia and salt stresses, leading to the production of reactive oxygen species (ROS), which need to be effectively managed by various oxido-reductases encoded by the so-called ROS gene network. Here, we studied six oxido-reductases families in three species, as well as and , which are adapted to hypoxia and salt stress, respectively. Using available and new genomic data, we performed a phylogenomic analysis and compared RNA-seq data to study genomic and transcriptomic adaptations. This comprehensive approach allowed for the gaining of insights into the impact of the adaptation to saline or hypoxia conditions on genome organization (gene gains and losses) and transcriptional regulation. Notably, the comparison of the and genomes to that of highlighted changes in the distribution of ohnologs and homologs, particularly affecting class III peroxidase genes (). These changes were specific to each gene, to gene families subjected to duplication events and to each species, suggesting distinct evolutionary responses. The analysis of transcriptomic data has allowed for the identification of genes related to stress responses in , and, conversely, to adaptation in and .