摘要
Flowering time is a critical determinant of regional adaptation for crops and has strong effects on crop yields. Here, we report that TaZIM-A1, an atypical GATAlike transcription factor, is a negative regulator of flowering in wheat. TaZIM-A1 possessed weak transcriptional repression activity, with its CCT domain functioning as the major inhibitory region. TaZIM-A1 expression exhibited a typical circadian oscillation pattern under various light regimes.Overexpression of TaZIM-A1 caused a delay in flowering time and a decrease in thousand-kernel weight(TKW) in wheat under long-day conditions. Moreover, TaZIM-A1 directly bound to the promoters of TaCO-1 and TaFT-1 and downregulated their expression. Sequence analysis of a collection of common wheat cultivars identified three and two haplotypes for TaZIM-A1 and TaZIM-B1, respectively. Association analysis revealed that TaZIM-A1-HapI/-HapIII and TaZIMB1-HapI have undergone strong positive selection during modern wheat breeding, likely due to their association with earlier heading and higher TKW. Diagnostic markers were developed for these haplotypes that can be used for wheat cultivar improvement, via marker-assisted breeding.
Flowering time is a critical determinant of regional adaptation for crops and has strong effects on crop yields. Here, we report that TaZIM-A1, an atypical GATAlike transcription factor, is a negative regulator of flowering in wheat. TaZIM-A1 possessed weak transcriptional repression activity, with its CCT domain functioning as the major inhibitory region. TaZIM-A1 expression exhibited a typical circadian oscillation pattern under various light regimes.Overexpression of TaZIM-A1 caused a delay in flowering time and a decrease in thousand-kernel weight(TKW) in wheat under long-day conditions. Moreover, TaZIM-A1 directly bound to the promoters of TaCO-1 and TaFT-1 and downregulated their expression. Sequence analysis of a collection of common wheat cultivars identified three and two haplotypes for TaZIM-A1 and TaZIM-B1, respectively. Association analysis revealed that TaZIM-A1-HapI/-HapIII and TaZIMB1-HapI have undergone strong positive selection during modern wheat breeding, likely due to their association with earlier heading and higher TKW. Diagnostic markers were developed for these haplotypes that can be used for wheat cultivar improvement, via marker-assisted breeding.
基金
supported by grants from the National Key Research and Development Program of China(2016YFD0100302)
the China Natural Science Foundation(31671687)
the National Transgenic Animals and Plants Research Project(2016ZX08009001-001-003)
the CAAS-Innovation Team Project
