Sorghum SbGhd7 is a major regulator of floral transition and directly represses genes crucial for flowering activation

Sorghum is multipurpose crop worldwide serving as food, feed, and feedstock for biofuels, whose floral transition and vegetative growth heavily depend on photoperiod. Although multiple sorghum maturity loci (Ma1-Ma6) have been associated with photoperiod sensitivity in previous QTL studies, the underlying molecular mechanisms remain poorly understood. By functional characterizing sorghum SbGhd7 (Ma6) and integrating RNA-seq analysis of Ghd7 overexpression sorghum, ChIP-seq analysis of SbGhd7 binding sites in protoplasts and molecular studies, we discovered that SbEhd1 and SbFT10 are the direct targets of SbGhd7. SbGhd7 is a transcriptional repressor and inhibits florigen-induced floral transition by repressing SbEhd1 and SbFT10 expression. Comparative gene expression profiling analysis of RNA-seq data for leaf tissues from 4-week-old empty vector control and SbGhd7 overexpression (SbGhd7 OE) sorghum plants.