Modified photoperiod response of CsFT promotes day neutrality and early flowering in cultivated cucumber.

segregating populations, which span a ~ 970 kb region and contain 60 predicted genes. RNA-seq analysis showed that the critical photoperiod pathway gene FLOWERING LOCUS T (CsFT) within the ps-1 locus exhibits differential expression between 9930 and Hardwickii, which was confirmed by qRT-PCR detection. CsFT in Hardwickii was sensitive to day length and could be significantly induced by SD conditions, whereas CsFT was highly expressed in 9930 and was insensitive to day length. Moreover, the role of CsFT in promoting flowering was verified by overexpression of CsFT in Arabidopsis. We also identified the genetic variations existing in the promoter of CsFT among the different geographic cucumbers and suggest they have possible roles in photoperiod domestication. The results of this study suggest that a variation in photoperiod sensitivity of CsFT is associated with day neutrality and early flowering in cultivated cucumber and could contribute to cucumber cultivation in diverse regions throughout the world.