Genome-Wide Characterization of Nuclear Factor Y (NF-Y) Transcription Factors in Allohexaploid Oat

Nuclear factor Y (NF-Y) constitutes a pivotal transcription factor family that modulates plant growth and development as well as abiotic stress responses. Oat (Avena sativa L.) is an economically vital cereal crop and a major livestock forage globally. Nevertheless, the NF-Y gene family has not yet been systematically characterized in the oat genome. Here, we identified 36 AsNF-Y genes in the oat genome and categorized them into three distinct subfamilies (NF-YA, NF-YB, and NF-YC). Phylogeny, gene structure, duplication, collinearity, and conserved motif analyses revealed high evolutionary conservation of this gene family. Additionally, the identification of diverse cis-acting regulatory elements in the promoters of AsNF-Y genes, combined with their differential expression profiles under multiple abiotic stress conditions, indicated that AsNF-Ys serve as crucial regulators in modulating oat abiotic stress tolerance. Furthermore, preliminary functional validation via the TRV-VIGS system confirmed that two candidate genes, AsNF-YC02 and AsNF-YC06, may positively regulate salt tolerance in oat. Collectively, our findings deepen the understanding of NF-Y genes in gramineous crops and supply promising candidates for the genetic improvement of oat stress tolerance and molecular breeding.