Lang Jing, Fu Yuxin, Zhou Yong, Cheng Mengping, Deng Min, Li Maolian, Zhu Tingting, Yang Jian, Guo Xiaojiang, Gui Lixuan, Li Linchuan, Chen Zhongxu, Yi Yingjin, Zhang Lianquan, Hao Ming, Huang Lin, Tan Chao, Chen Guoyue, Jiang Qiantao, Qi Pengfei, Pu Zhien, Ma Jian, Liu Zehou, Liu Yujiao, Luo Ming-Cheng, Wei Yuming, Zheng Youliang, Wu Yongrui, Liu Dengcai, Wang JiRui
Triticeae Research Institute, Sichuan Agricultural University, Chengdu, 611130, China.
CAS Center for Excellence in Molecular Plant Science, Chinese Academy of Sciences, Shanghai, 210027, China.
New Phytol. 2021 Jun;230(5):1940-1952. doi: 10.1111/nph.17312. Epub 2021 Mar 30.
Pre-harvest sprouting (PHS), the germination of grain before harvest, is a serious problem resulting in wheat yield and quality losses. Here, we mapped the PHS resistance gene PHS-3D from synthetic hexaploid wheat to a 2.4 Mb presence-absence variation (PAV) region and found that its resistance effect was attributed to the pleiotropic Myb10-D by integrated omics and functional analyses. Three haplotypes were detected in this PAV region among 262 worldwide wheat lines and 16 Aegilops tauschii, and the germination percentages of wheat lines containing Myb10-D was approximately 40% lower than that of the other lines. Transcriptome and metabolome profiling indicated that Myb10-D affected the transcription of genes in both the flavonoid and abscisic acid (ABA) biosynthesis pathways, which resulted in increases in flavonoids and ABA in transgenic wheat lines. Myb10-D activates 9-cis-epoxycarotenoid dioxygenase (NCED) by biding the secondary wall MYB-responsive element (SMRE) to promote ABA biosynthesis in early wheat seed development stages. We revealed that the newly discovered function of Myb10-D confers PHS resistance by enhancing ABA biosynthesis to delay germination in wheat. The PAV harboring Myb10-D associated with grain color and PHS will be useful for understanding and selecting white grained PHS resistant wheat cultivars.
收获前发芽（PHS）是指谷物在收获前发芽的现象，这是一个严重的问题，会导致小麦产量和品质下降。在此，我们将人工合成六倍体小麦中的PHS抗性基因PHS-3D定位到一个2.4兆碱基的存在-缺失变异（PAV）区域，并通过综合组学和功能分析发现其抗性效应归因于多效性的Myb10-D。在262份全球小麦品系和16份节节麦中，该PAV区域检测到三种单倍型，含有Myb10-D的小麦品系的发芽率比其他品系低约40%。转录组和代谢组分析表明，Myb10-D影响类黄酮和脱落酸（ABA）生物合成途径中基因的转录，导致转基因小麦品系中类黄酮和ABA含量增加。Myb10-D通过结合次生壁MYB响应元件（SMRE）激活9-顺式环氧类胡萝卜素双加氧酶（NCED），以促进小麦种子发育早期的ABA生物合成。我们揭示，新发现的Myb10-D功能通过增强ABA生物合成来延迟小麦发芽，从而赋予PHS抗性。含有与籽粒颜色和PHS相关的Myb10-D的PAV将有助于理解和选择白色籽粒抗PHS的小麦品种。
