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

ABSTRACT 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 Cd 2+ flux in roots and whole‐plant Cd accumulation, whereas AtNF‐YA3 knockout enhanced Cd 2+ 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 Cd 2+ 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.