The MYB transcription factor Baymax1 plays a critical role in rice male fertility.
The MYB transcription factor Baymax1 plays a critical role in rice male fertility.
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MYB转录因子Baymax1在水稻雄性生育力中发挥着关键作用。
DOI：
10.1007/s00122-020-03706-w
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发表时间：
2021
影响因子：
5.4
通讯作者：
Cao Li-Yong
中科院分区：
文献类型：
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作者：
Xiang Xiao-Jiao;Sun Lian-Ping;Yu Ping;Yang Zheng-Fu;Zhang Pei-Pei;Zhang Ying-Xin;Wu Wei-Xun;Chen Dai-Bo;Zhan Xiao-Deng;Khan Riaz-Muhammad;Abbas Adil;Cheng Shi-Hua;Cao Li-Yong
关键信息通过图位克隆分离得到的水稻雄性育性基因eBaymax1，编码MYB转录因子，对水稻绒毡层和小孢子发育至关重要。摘要雄性育性基因的挖掘和表征将为未来水稻生产提供理论和物质基础。在拟南芥中，雄性器官（即花药）的发育通常涉及MYB（v-myb禽类成髓细胞瘤病毒癌基因同源物）和bHLH（碱性螺旋-环-螺旋）成员之间的协调。然而，MYB 蛋白在水稻花药发育中的作用仍知之甚少。在本研究中，我们分离并鉴定了编码 MYB 蛋白的 Baymax1 (BM1) 雄性不育突变体（具有正常营养生长）。 bm1突变体表现出减数分裂稍微滞后、绒毡层向分泌型转变失败、绒毡层过早退化和花粉外壁形成异常，导致成熟的白色花药中最终缺乏可见的花粉。利用CRISPR/Cas9技术进行图位克隆、互补和定点突变，证明突变的LOC_Os04g39470是bm1的致病基因。BM1在水稻第5期至第10期花药中优先表达。系统发育分析表明，水稻BM1及其在小米、玉米、油菜、卷心菜和木豆中的同源物在进化上是保守的。 BM1 可以分别与 bHLH 蛋白 TIP2、EAT1 和 PHD（植物同源结构域）-指成员 TIP3 发生物理相互作用。此外，BM1影响与绒毡层和小孢子发育相关的几个已知基因的表达。总的来说，我们的结果表明BM1是水稻雄性育性的关键调节因子之一，并且可以作为水稻雄性不育系育种和杂交种子生产的潜在目标。
Key messageRice male fertility geneBaymax1, isolated through map-based cloning, encodes a MYB transcription factor and is essential for rice tapetum and microspore development.AbstractThe mining and characterization of male fertility gene will provide theoretical and material basis for future rice production. InArabidopsis, the development of male organ (namely anther), usually involves the coordination between MYB (v-myb avian myeloblastosis viral oncogene homolog) and bHLH (basic helix-loop-helix) members. However, the role of MYB proteins in rice anther development remains poorly understood. In this study, we isolated and characterized a male sterile mutant (with normal vegetative growth) ofBaymax1(BM1), which encodes a MYB protein. Thebm1mutant exhibited slightly lagging meiosis, aborted transition of the tapetum to a secretory type, premature tapetal degeneration, and abnormal pollen exine formation, leading to ultimately lacks of visible pollens in the mature white anthers. Map-based cloning, complementation and targeted mutagenesis using CRISPR/Cas9 technology demonstrated that the mutatedLOC_Os04g39470is the causal gene inbm1.BM1is preferentially expressed in rice anthers from stage 5 to stage 10. Phylogenetic analysis indicated that rice BM1 and its homologs in millet, maize, rape, cabbage, and pigeonpea are evolutionarily conserved. BM1 can physically interacts with bHLH protein TIP2, EAT1, and PHD (plant homeodomain)-finger member TIP3, respectively. Moreover,BM1affects the expression of several known genes related to tapetum and microspore development. Collectively, our results suggest thatBM1is one of key regulators for rice male fertility and may serve as a potential target for rice male-sterile line breeding and hybrid seed production.