A natural variation in the promoter of <i>TaGDSL</i>‐<i>7D</i> contributes to grain weight and yield in wheat

Abstract

Summary Grain weight (GW) is a critical agronomic trait that greatly impacts wheat yield, yet the underlying genetic factors remain largely unknown. Here, we identify and characterize a candidate gene TaGDSL‐7D controlling GW in wheat through map‐based cloning, which encodes an ER‐located GDSL‐family protein. Natural variations within the promoter of the GW‐enhancing TaGDSL‐7D HS2 allele result in a differential transcriptional response by promoting the binding of the TaGT1 transcription factor, a positive GW regulator. Additionally, TaGT1 directly interacts with TaBZR1 to enhance TaGDSL‐7D activation. Haplotype analysis revealed that TaGDSL‐7D HS2 is a superior haplotype, improving both GW and yield. Taken together, these findings highlight the pivotal role of TaGDSL‐7D in deciphering the genetic basis of GW in wheat and provide valuable natural allelic variation for GW improvement in high‐yield breeding programmes.