遗传

• 研究报告 •    

水稻窄长粒突变体nlg1的筛选及候选基因鉴定

郭念1,王辰杰1,李钊1,韩囡囡1,周晨1,王凯迎1,黄科2,潘咏清2,3,李英洁2,李云海2   

  1. 1. 海南大学南繁学院(三亚南繁研究院),三亚 572025

    2. 中国科学院遗传与发育生物学研究所,种子创新重点实验室, 北京100101

    3. 中国科学院大学,北京 100039
  • 收稿日期:2024-11-14 修回日期:2024-12-29 出版日期:2025-02-21 发布日期:2025-02-21
  • 基金资助:
    国家重点研发项目(编号:2021YFF1000202,2022YFF1002903)资助

Genetic analysis and identification of candidate genes for a narrow and long grain mutant (nlg1) in rice

Nian Guo1, Chenjie Wang1, Zhao Li1, Nannan Han1, Chen Zhou1, Kaiying Wang1, Ke Huang2, Yongqing Pan2,3, Yingjie Li2, Yunhai Li2   

  1. 1. School of Breeding and Multiplication (Sanya Institute of Breeding and Multiplication), Hainan University, Sanya 572025, China

    2. Key Laboratory of Seed Innovation, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China

    3. University of Chinese Academy of Sciences, Beijing 100039, China
  • Received:2024-11-14 Revised:2024-12-29 Published:2025-02-21 Online:2025-02-21

摘要: 籽粒大小是水稻产量的关键决定因素之一,挖掘调控水稻籽粒大小的基因并解析其分子机制,对水稻精准育种具有重要意义。本研究通过EMS诱变粳稻品种ZH11,获得一个籽粒变窄变长的突变体nlg1 (narrow and long grain 1)。扫描电镜观察发现nlg1成熟颖壳外表皮纵向细胞数目增加,横向细胞数目减少且细胞宽度变窄,表明NLG1基因可能通过调控颖壳细胞的增殖和扩展影响籽粒大小。结合基因组重测序和MutMap分析,将候选基因定位为LOC_Os09g27590 (即已报道的GS9),该基因编码一个结构域功能未知的蛋白。在nlg1突变体中,GS9基因第一个外显子插入一个碱基C,导致移码突变和蛋白翻译提前终止。遗传互补实验证实NLG1基因能够恢复nlg1突变体的表型。因此,本研究鉴定了一个新的GS9等位突变,为深入解析GS9调控籽粒大小的分子机制提供了新线索,同时为水稻分子设计育种提供了重要的基因资源和理论依据。

关键词: 水稻, 籽粒大小, MutMap, GS9

Abstract: Grain size is one of the components that determine the rice yield. Exploring more key genes that regulating grain size and analyzing their molecular mechanisms are of great importance for precision breeding of rice. In this study, we screened a mutant nlg1 (narrow and long grain 1) with narrow and long grains by mutagenizing the japonica rice variety ZH11 with EMS. Observation and statistical analysis of the outer surface of the mature glume of nlg1 by scanning electron microscopy revealed an increased number of longitudinal cells and a decreased number of transverse cells, along with a reduction in the width of transverse cells. These findings suggest that NLG1 may regulate grain size by simultaneously influencing the proliferation and expansion of lemma cells. The candidate gene was cloned by genome resequencing combined with MutMap analysis method. The results showed that the candidate gene of LOC_Os09g27590 was the previous reported gene, GS9, which encodes a protein with unknown domains. In the nlg1 mutant, a base C was inserted in the first exon of the candidate gene of LOC_Os09g27590, causing a frameshift mutation that leads to premature termination of protein translation. Further genetic complementation experiments showed that NLG1 rescued the phenotype of the nlg1 mutant. Therefore, this study identifies a novel GS9 allele mutation, and further dissection of its molecular regulatory networks in grain size control can provides a theoretical support and genetic resources for precise rice breeding.

Key words: rice, grain size, MutMap, GS9