Construction of a multicontrol sterility system for a maize male‐sterile line and hybrid seed production based on the ZmMs7 gene encoding a PHD‐finger transcription factor

• Published in: Plant biotechnology journal Vol. 16; no. 2; pp. 459 - 471
• Main Authors: Zhang, Danfeng, Wu, Suowei, An, Xueli, Xie, Ke, Dong, Zhenying, Zhou, Yan, Xu, Liwen, Fang, Wen, Liu, Shensi, Liu, Shuangshuang, Zhu, Taotao, Li, Jinping, Rao, Liqun, Zhao, Jiuran, Wan, Xiangyuan
• Format: Journal Article
• Language: English
• Published: England John Wiley & Sons, Inc 01.02.2018; John Wiley and Sons Inc
• Subjects: Adenine; Arabidopsis thaliana; Biotechnology; Cloning; Color; Corn; Cross-pollination; Deoxyribonucleic acid; DNA; Fertility; Fluorescence; Food; Genetic aspects; Genetic engineering; genetic male sterility; Genetically engineered foods; Genetically modified crops; Herbicide resistance; hybrid seed production; Hybridization, Genetic - genetics; Hybridization, Genetic - physiology; maize; Male sterility; Methylase; nontransgenic progeny; Plant Infertility - physiology; Plant reproduction; Plants, Genetically Modified - genetics; Plants, Genetically Modified - metabolism; Plants, Genetically Modified - physiology; Pollen; Pollination; Production methods; Propagation; Seed industry; Seeds; Seeds - genetics; Seeds - metabolism; Seeds - physiology; Site-specific DNA methyltransferase (adenine-specific); Transcription factors; Transcription Factors - genetics; Transcription Factors - metabolism; transgenic maintainer line; Transgenic plants; Zea mays; Zea mays - genetics; Zea mays - metabolism; Zea mays - physiology; ZmMs7; α-Amylase; ZmMs7; genetic male sterility; nontransgenic progeny; transgenic maintainer line; maize; hybrid seed production
• ISSN: 1467-7644; 1467-7652
• DOI: 10.1111/pbi.12786

Summary Although hundreds of genetic male sterility (GMS) mutants have been identified in maize, few are commercially used due to a lack of effective methods to produce large quantities of pure male‐sterile seeds. Here, we develop a multicontrol sterility (MCS) system based on the maize male sterility 7 (ms7) mutant and its wild‐type Zea mays Male sterility 7 (ZmMs7) gene via a transgenic strategy, leading to the utilization of GMS in hybrid seed production. ZmMs7 is isolated by a map‐based cloning approach and encodes a PHD‐finger transcription factor orthologous to rice PTC1 and Arabidopsis MS1. The MCS transgenic maintainer lines are developed based on the ms7‐6007 mutant transformed with MCS constructs containing the (i) ZmMs7 gene to restore fertility, (ii) α‐amylase gene ZmAA and/or (iii) DNA adenine methylase gene Dam to devitalize transgenic pollen, (iv) red fluorescence protein gene DsRed2 or mCherry to mark transgenic seeds and (v) herbicide‐resistant gene Bar for transgenic seed selection. Self‐pollination of the MCS transgenic maintainer line produces transgenic red fluorescent seeds and nontransgenic normal colour seeds at a 1:1 ratio. Among them, all the fluorescent seeds are male fertile, but the seeds with a normal colour are male sterile. Cross‐pollination of the transgenic plants to male‐sterile plants propagates male‐sterile seeds with high purity. Moreover, the transgene transmission rate through pollen of transgenic plants harbouring two pollen‐disrupted genes is lower than that containing one pollen‐disrupted gene. The MCS system has great potential to enhance the efficiency of maize male‐sterile line propagation and commercial hybrid seed production.