Genome-Wide Identification and Expression Profile Analysis of the NADPH Oxidase Gene Family in Avena sativa L

The plant respiratory burst oxidase homologs (RBOHs) are crucial enzymes responsible for the production of reactive oxygen species (ROS) in plants, playing a pivotal role in regulating various aspects of plant growth, development, and stress responses. While RBOH family members have been identified across a wide range of plant species, the functions and characteristics of the RBOH gene family in oats remain poorly understood. In this study, 35 members of the RBOH gene family in the oat genome were identified using bioinformatics approaches. Conserved motif and gene structure analyses revealed that most AsRBOH genes contain Motif4 and Motif5. Phylogenetic tree analysis demonstrated that the AsRBOHs can be classified into five distinct subfamilies. Synteny analysis indicated that AsRBOHs share the highest number of syntenic gene pairs with wheat. Additionally, cis-regulatory element analysis identified several elements associated with drought and hypoxia-specific responses in AsRBOHs. Expression analysis using qRT-PCR showed that 28 AsRBOH genes were upregulated under drought stress, while 18 were downregulated under salt stress. Notably, the genes 7DG1382190 and 7AG1225850 were found to be involved in both drought and salt stress responses. In conclusion, these findings provide a valuable foundation for future functional studies of the AsRBOH gene family in oats, offering insights that could contribute to the improvement and innovation of oat varieties and germplasm.