Natural variation in GmRVE4d facilitates soybean latitudinal adaptation by regulating GmPRR5a-dependent flowering and maturity.

Timely flowering and maturity are crucial for plant reproduction and environmental adaptation. Light-dark cycle-associated regulatory networks integrate photoperiodic cues with intrinsic developmental programs and play pivotal roles in flowering, maturity and environmental adaptation. Soybean is a short-day crop with strong photoperiod responsiveness; however, the molecular mechanisms by which these networks mediate soybean adaptation to diverse environments remain largely elusive. Here, we combine genome-wide association analysis with deep learning-based assessment of soybean maturity variation and identify GmRVE4d, a homolog of the Arabidopsis clock-associated REVEILLE, as a maturity-associated locus across both field environments. Genetic analysis reveals evidence of domestication-related artificial selection at GmRVE4d and identifies the late-maturing haplotype GmRVE4dH3. Functional analyses further demonstrate that the GmRVE4d protein directly binds to the promoter of GmPRR5a, a soybean homolog of the Arabidopsis clock-associated component PSEUDO-RESPONSE REGULATOR 5, and represses its transcription, thereby delaying soybean flowering and maturity. Taken together, our findings suggest that GmRVE4d is a negative regulator of soybean flowering and maturity that functions by directly repressing GmPRR5a expression and represents a promising molecular target for expanding cultivation latitudes through molecular breeding.