大麦稃壳白化突变性状的遗传解析  

Genetic dissection of the albino hull mutations in barley(Hordeum vulgare L.)

作　　者：孙曼 安朝丹 高广奇 郭杰 杨平 蒋枞璁 SUN Man;AN Chao-Dan;GAO Guang-Qi;GUO Jie;YANG Ping;JIANG Cong-Cong(College of Agriculture,Shanxi Agricultural University,Jinzhong 030801,Shanxi,China;Key Laboratory of Grain Crop Genetic Resources Evaluation and Utilization,Ministry of Agriculture and Rural Affairs/Institute of Crop Sciences,Chinese Academy of Agricultural Sciences,Beijing 100081,China)

机构地区：[1]山西农业大学农学院,山西晋中030801 [2]农业农村部粮食作物基因资源评价利用重点实验室/中国农业科学院作物科学研究所,北京100081

出　　处：《作物学报》2024年第12期3046-3054,共9页Acta Agronomica Sinica

基　　金：中国农业科学院科技创新工程项目(农科英才计划-杨平)资助。

摘　　要：大麦(Hordeum vulgare L.)稃壳是在小穗上包裹种子的花器官,包括内稃和外稃。大麦稃壳具有光合作用能力,为籽粒发育提供部分营养物质。通过EMS诱变获得的大麦稃壳白化突变体,其稃壳明显呈白色,叶枕、茎节和茎基部均呈白化变异,但叶片和芒均为绿色。本研究对稃壳白化突变性状进行鉴定和遗传分析,发现该突变性状由单个隐性基因控制;通过候选基因测序及竞争性等位基因特异性PCR(KASP)共分离检测,证实该白化突变是由基因HvGLK2的功能缺失所致;并在HvGLK2基因上鉴定到3个独立突变事件,均与已发表的大麦alm1和ebu-a等白化变异不同。HvGLK2基因编码一个Golden 2-like(GLK)转录因子,为MYB基因家族GARP亚家族成员,在多数的单、双子叶植物中均存在另一个同源基因GLK1。通过公共数据库检索HvGLK2基因的表达谱数据,发现HvGLK2在大麦衰老叶片、外稃及穗轴中高丰度表达。本研究明确了HvGLK2基因对大麦稃壳和茎节等组织叶绿素合成的关键作用,相关的稃壳白化突变体为稃壳光合作用对产量形成的机制研究提供了理想材料。Lemma and palea are the outermost organs on each floret of barley(Hordeum vulgare L.),where the majority of spike photosynthesis occurs,supplying carbohydrates to the developing grains.The barley albino hull(alh)mutants,obtained from EMS mutagenesis,showed albinistic lemma and palea,as well as albinistic pulvini,stem nodes,and stem bases,while the leaves and awns remain green.In this study,multiple allelic alh mutants were identified,and segregating populations were generated accordingly.Genetic analysis indicated that a single recessive gene is responsible for the alh phenotype.Through re-sequencing of the candidate gene in multiple alh mutants,and co-segregation tests using competitive allele-specific PCR(KASP)markers,loss-of-function mutations in the gene HvGLK2 were shown to account for the alh phenotype.Each of the three independent mutations identified in this study is distinct from previously reported albino lemma variants such as alm1 or ebu-a.HvGLK2 encodes a Golden 2-like(GLK2)transcription factor,belonging to the GARP subfamily of MYB transcription factors,and has a paralog designated GLK1 in most monocot and dicot species.The temporal and spatial expression patterns showed that HvGLK2 is abundantly transcribed in senescent leaves,lemmas,and rachises.This study highlights the importance of HvGLK2 in chlorophyll synthesis in various organs,including lemma,palea,and stem nodes of barley plants.Moreover,it provides valuable materials for further studies aimed at evaluating the contribution of spike photosynthesis to the eventual grain yield.

关 键 词：大麦 稃壳 白化突变体 HvGLK2 功能缺失 

分 类 号：S512.3[农业科学—作物学]