Qing Xiangyu, Li Jianrui, Lin Zhen, Wang Wei, Yi Fei, Chen Jian, Liu Qiujie, Song Weibin, Lai Jinsheng, Chen Baojian, Zhao Haiming, Yang Zhijia
State Key Laboratory of Maize Bio-breeding, Key Laboratory of Genome Editing Research and Application, Ministry of Agriculture and Rural Affairs, Department of Plant Genetics and Breeding, National Maize Improvement Center, College of Agronomy and Biotechnology, China Agricultural University, Beijing 100193, China.
State Key Laboratory of Crop Gene Resources and Breeding/Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
J Genet Genomics. 2025 Mar;52(3):411-421. doi: 10.1016/j.jgg.2025.01.011. Epub 2025 Jan 25.
Transcription factors play critical roles in the regulation of gene expression during maize kernel development. The maize endosperm, a large storage organ, accounting for nearly 90% of the dry weight of mature kernels, serves as the primary site for starch storage. In this study, we identify an endosperm-specific EREB gene, ZmEREB167, which encodes a nucleus-localized EREB protein. Knockout of ZmEREB167 significantly increases kernel size and weight, as well as starch and protein content, compared with the wild type. In situ hybridization experiments show that ZmEREB167 is highly expressed in the BETL as well as PED regions of maize kernels. Dual-luciferase assays show that ZmEREB167 exhibits transcriptionally repressor activity in maize protoplasts. Transcriptome analysis reveals that a large number of genes are up-regulated in the Zmereb167-C1 mutant compared with the wild type, including key genetic factors such as ZmMRP-1 and ZmMN1, as well as multiple transporters involved in maize endosperm development. Integration of RNA-seq and ChIP-seq results identify 68 target genes modulated by ZmEREB167. We find that ZmEREB167 directly targets OPAQUE2, ZmNRT1.1, ZmIAA12, ZmIAA19, and ZmbZIP20, repressing their expressions. Our study demonstrates that ZmEREB167 functions as a negative regulator in maize endosperm development and affects starch accumulation and kernel size.
转录因子在玉米籽粒发育过程中的基因表达调控中发挥着关键作用。玉米胚乳是一个大型的储存器官，占成熟籽粒干重的近90%，是淀粉储存的主要部位。在本研究中，我们鉴定出一个胚乳特异性的EREB基因ZmEREB167，它编码一种定位于细胞核的EREB蛋白。与野生型相比，敲除ZmEREB167显著增加了籽粒大小和重量，以及淀粉和蛋白质含量。原位杂交实验表明，ZmEREB167在玉米籽粒的BETL以及PED区域高度表达。双荧光素酶测定表明，ZmEREB167在玉米原生质体中表现出转录抑制活性。转录组分析显示，与野生型相比，Zmereb167-C1突变体中有大量基因上调，包括ZmMRP-1和ZmMN1等关键遗传因子，以及多个参与玉米胚乳发育的转运蛋白。RNA-seq和ChIP-seq结果的整合鉴定出68个受ZmEREB167调控的靶基因。我们发现ZmEREB167直接靶向Opaque2、ZmNRT1.1、ZmIAA12、ZmIAA19和ZmbZIP20，抑制它们的表达。我们的研究表明，ZmEREB167在玉米胚乳发育中起负调控作用，并影响淀粉积累和籽粒大小。
