In cultivated soybean, the stepwise selection of genes controlling flowering time and maturity has been crucial for latitudinal adaptation and yield potential. Although the early flowering alleles of tof12 and tof11 are sequentially selected during domestication, they are insufficient to fully explain the genetic basis of adaptation to high-latitude environments. Here, we identify a locus, Dgt1 (Downstream Gene of Tof11 and Tof12), that regulates flowering time and latitude adaptation in soybean. We demonstrate that Dgt1 encodes a homolog of REVEILLE1 (GmRVE1). Mechanistically, Tof11 and Tof12 directly suppress GmRVE1 expression, which represses flowering dependent on the E1 gene. Population genetic analyses reveal that the stepwise selection of Tof12, Tof11, and GmRVE1 promotes early flowering and enables the expansion of soybean cultivation from its domestication center to high-latitude regions. Our study provides a genetic resource for breeding ultra-early maturing and high-yielding soybean varieties.
Cheng et al. (Sat,) studied this question.