Molecular Crosstalk Between <i>AtNF‐YA3</i> and <i>AtWRKY41</i> in Regulating <i>Arabidopsis</i> Immunity in Response to Cadmium Toxicity

Cadmium toxicity severely restricts plant growth and development. Nuclear transcription factor-YA (NF-YA) plays a critical role in regulating abiotic stress tolerance, but its role in Cd stress remains unknown. We identified AtNF-YA3 transcription factor as a crucial player in Arabidopsis thaliana Cd stress tolerance. AtNF-YA3 overexpression significantly enhances tolerance to Cd stress, while AtNF-YA3 knockout causes heightened sensitivity. Overexpression significantly reduced Cd²⁺ flux in roots and whole-plant Cd accumulation, whereas AtNF-YA3 knockout enhanced Cd²⁺ flux, and Cd and ROS accumulation. Transcriptome analysis revealed that Cd stress disrupted immune responsive pathways in the knockout line relative to wild-type. Moreover, AtWRKY41 transcription factor expression levels decreased by approximately two-fold in the knockout line relative to wild-type. Yeast two-hybrid and luciferase assays demonstrated a direct interaction between AtNF-YA3 and AtWRKY41; yeast one-hybrid and dual-luciferase assays confirmed that AtWRKY41 directly binds to the AtNF-YA3 promoter. Arabidopsis AtWRKY41 knockout lines exhibited significantly increased sensitivity to Cd stress, and increased Cd²⁺ flux rates and Cd and ROS accumulation. Genetic analysis indicated that AtWRKY41 acts upstream of AtNF-YA3 to increase Cd stress tolerance. Together, these findings suggest that AtNF-YA3 is a key regulator of Cd tolerance and a potential target for plant heavy metal phytoremediation research.