TabHLH95-TaNF-YB1 module promotes grain starch synthesis in bread wheat  

作　　者：Yunchuan Liu Wei Xi Xiaolu Wang Huifang Li Hongxia Liu Tian Li Jian Hou Xu Liu Chenyang Hao Xueyong Zhang 

机构地区：[1]Key Laboratory of Crop Gene Resources and Germplasm Enhancement,Ministry of Agriculture and Rural Affairs/The National Key Facility for Crop Gene Resources and Genetic Improvement/Institute of Crop Sciences,Chinese Academy of Agricultural Sciences,Beijing 100081,China [2]State Key Laboratory of Aridland Crop Science(Gansu Agricultural University)/Gansu Provincial Key Laboratory of Crop Improvement&Germplasm Enhancement,Lanzhou,Gansu 730070,China [3]College of Agronomy,Gansu Agricultural University,Lanzhou,Gansu 730070,China

出　　处：《Journal of Genetics and Genomics》2023年第11期883-894,共12页遗传学报（英文版）

基　　金：supported by the National Natural Science Foundation of China(32201804);the China Postdoctoral Science Foundation(2022M723458).

摘　　要：Starch is the most abundant substance in wheat(Triticum aestivum L.)endosperm and provides the major carbohydrate energy for human daily life.Starch synthesis-related(SSR)genes are believed to be spatiotemporally specific,but their transcriptional regulation remains unclear in wheat.Here,we investigate the role of the basic helix-loop-helix(bHLH)transcription factor TabHLH95 in starch synthesis.TabHLH95 is preferentially expressed in the developing grains in wheat and encodes a nucleus localized protein without autoactivation activity.The Tabhlh95 knockout mutants display smaller grain size and less starch content than wild type,whereas overexpression of TabHLH95 enhances starch accumulation and significantly improves thousand grain weight.Transcriptome analysis reveals that the expression of multiple SSR genes is significantly reduced in the Tabhlh95 mutants.TabHLH95 binds to the promoters of ADP-glucose pyrophosphorylase large subunit 1(AGPL1-1D/-1B),AGPL2-5D,and isoamylase(ISA1-7D)and enhances their transcription.Intriguingly,TabHLH95 interacts with the nuclear factor Y(NF-Y)family transcription factor TaNF-YB1,thereby synergistically regulating starch synthesis.These results suggest that the TabHLH95-TaNF-YB1 complex positively modulates starch synthesis and grain weight by regulating the expression of a subset of SSR genes,thus providing a good potential approach for genetic improvement of grain productivity in wheat.

关 键 词：Starch synthesis TabHLH95-TaNF-YB1 module Synergistic regulation Grain weight Wheat 

分 类 号：S512.1[农业科学—作物学]