Functional divergences of natural variations of TaNAM-A1 in controlling leaf senescence during wheat grain filling  

作　　者：Longxi Zhou Guowei Chang Chuncai Shen Wan Teng Xue He Xueqiang Zhao Yanfu Jing Zhixiong Huang Yiping Tong 

机构地区：[1]Key Laboratory of Seed Innovation,Institute of Genetics and Developmental Sciences,Chinese Academy of Sciences,Beijing 100101,China [2]University of Chinese Academy of Sciences,Beijing 100049,China [3]The Innovative Academy of Seed Design,Chinese Academy of Sciences,Beijing 100101,China

出　　处：《Journal of Integrative Plant Biology》2024年第6期1242-1260,共19页植物学报（英文版）

基　　金：supported by the Strategic Priority Research Program of Chinese Academy of Sciences(Grant No.XDA24010202);the National Natural Sciences Foundation of China(U22A6009)。

摘　　要：Leaf senescence is an essential physiological process related to grain yield potential and nutritional quality.Green leaf duration(GLD)after anthesis directly reflects the leaf senescence process and exhibits large genotypic differences in common wheat;however,the underlying gene regulatory mechanism is still lacking.Here,we identified TaNAM-A1 as the causal gene of the major loci q GLD-6A for GLD during grain filling by map-based cloning.Transgenic assays and TILLING mutant analyses demonstrated that TaNAM-A1 played a critical role in regulating leaf senescence,and also affected spike length and grain size.Furthermore,the functional divergences among the three haplotypes of TaNAM-A1 were systematically evaluated.Wheat varieties with TaNAM-A1d(containing two mutations in the coding DNA sequence of TaNAM-A1)exhibited a longer GLD and superior yield-related traits compared to those with the wild type TaNAM-A1a.All three haplotypes were functional in activating the expression of genes involved in macromolecule degradation and mineral nutrient remobilization,with TaNAM-A1a showing the strongest activity and TaNAM-A1d the weakest.TaNAM-A1 also modulated the expression of the senescencerelated transcription factors TaNAC-S-7A and TaNAC016-3A.TaNAC016-3A enhanced the transcriptional activation ability of TaNAM-A1a by protein–protein interaction,thereby promoting the senescence process.Our study offers new insights into the fine-tuning of the leaf functional period and grain yield formation for wheat breeding under various geographical climatic conditions.

关 键 词：allelic variation leaf senescence map-based cloning TaNAM-A1 transcription factor Triticum aestivum 

分 类 号：S512.1[农业科学—作物学]