Iron status modulates cadmium tolerance: mechanistic insights from MsbHLH60-mediated regulation of the FIT/IRT1 module in alfalfa

Introduction Basic helix-loop-helix (bHLH) transcription factors play pivotal roles in plant adaptation to metallic elements, yet the mechanisms by which leguminous bHLHs regulate iron (Fe) homeostasis and cadmium (Cd) stress adaptation remain inadequately understood. Methods MsbHLH60 and its promoter was cloned from alfalfa. The expression of MsbHLH60 under iron deficiency (–Fe), Cd, and Cd accompanied by Fe deficiency (Cd(–Fe)) was analyzed by qRT-PCR and GUS assay. MsbHLH60 was subcellular lo