H2S promotes flowering in <i>Brassica rapa</i> ssp. <i>pekinensis</i> by persulfidation of the splicing factor BraATO2

Hydrogen sulfide (H₂S) is a newly identified gasotransmitter that plays an irreplaceable physiological role in plant growth, development, and environmental responses through persulfidation of cysteine (Cys) residues (RSSH). However, reports on the direct RSSH targets of H₂S in plants remain limited. The flowering regulation mechanisms of <i>Brassica rapa</i> ssp. <i>pekinensis</i> are a significant scientific issue in the crop production industry; however, they remain poorly understood. BraATO2 is an important splicing factor in genetic alternative splicing (AS). Our study demonstrated that H₂S regulated BraATO2 function by persulfidating the Cys residue at position 416. In turn, this influenced the AS patterns of multiple genes in <i>B. rapa</i>, specifically the flowering regulator <i>BraAGL31</i>/<i>MAF2</i> within the <i>FLOWERING LOCUS C</i>-like (<i>FLC</i>-like) gene family, causing accelerated flowering. This study identified a new direct target of H₂S and uncovered a novel pathway influencing flowering in <i>B. rapa.</i> Furthermore, the study findings provide fresh insights into the development of innovative flowering regulators for plants.