玉米褐色叶中脉突变体bm-like1的基因克隆与转录组分析  

Gene Isolation and Transcriptome Analysis of a Maize Brown Midrid Mutant bm-like1

作　　者：何田利 杨悦 张红伟[2] 杨宗莹 卢雨晴 李润植[1] 郑军[2] HE Tian-li;YANG Yue;ZHANG Hong-wei;YANG Zong-ying;LU Yu-qing;LI Run-zhi;ZHENG Jun(College of Agriculture,Shanxi Agricultural University,Jinzhong 030801;Institute of Crop Sciences,Chinese Academy of Agricultural Sciences,Beijing 100081)

机构地区：[1]山西农业大学农学院,晋中030801 [2]中国农业科学院作物科学研究所,北京100081

出　　处：《植物遗传资源学报》2021年第5期1375-1382,共8页Journal of Plant Genetic Resources

基　　金：中国农业科学院创新工程专项经费资助~~。

摘　　要：本研究在田间发现了一个自然突变的玉米褐色叶中脉突变体,并命名为bm-like1。多代自交后发现bm-like1的褐色叶中脉性状能够稳定遗传。通过突变体bm-like1和自交系B73杂交构建了F2群体,遗传分析发现,bm-like1的褐色叶中脉表型由隐性单基因BM3控制。利用BSA-Seq和精细定位方法,对有褐色叶中脉表型的F2植株进行定位,将目标区段定位在玉米第4号染色体32~36 Mb之间。通过玉米数据库检索发现,该定位区间内存在一个已报道的BM3基因。BM3基因编码咖啡酸-O-甲基转移酶,是玉米木质素生物合成途径中一个重要的酶。利用纯合突变体bm-like1与bm3突变体做杂交进行等位测验,发现杂交后代表现出褐色叶中脉的表型。经序列分析发现突变体bm-like1中BM3基因在起始密码子ATG上游144 bp处有一个1439 bp的h AT转座子插入,而bm3突变体在BM3基因第2外显子上有一个5452 bp的序列插入。利用实时荧光定量PCR实验和转录组分析发现,突变体bm-like1中BM3基因的表达量显著低于自交系B73,突变体bm-like1与自交系B73之间的差异表达基因主要集中在次生代谢物的合成和代谢途径。This study reported bm-like1,a naturally-occurring brown midrib mutant in maize.Segregation analysis in the F2 population derived from the homozygous bm-like1 mutant crossing with B73 inbred line indicated that the brown midrib phenotype in bm-like1 was controlled by a single recessive gene that named BM3.Using BSA-seq and fine mapping,the target region was mapped to the interval of 32-36 Mb on maize chromosome 4,where the BM3 gene was resided.BM3 encodes a caffeic acid o-methyltransferase,which is an important enzyme in lignin biosynthesis.By crossing bm-like1 with the bm3 mutant,the F1 plants were observed with a brown midrib,indicating that BM3 was the causal gene for bm-like1 mutant.Genomic sequence analysis revealed a 1439 bp h AT transposon at 144 bp upstream of transcription start site of BM3 in bm-like1,whereas the bm3 mutant represented a 5452 bp insertion in the second exon of BM3 gene.Real-time quantitative PCR and transcriptomic analysis approved a reduction on the expression of BM3 gene in bm-like1 to the wild type.Moreover,the differentially expressed genes between bm-like1 and wild type were mainly enriched in the secondary metabolites biosynthesis and metabolic pathway.

关 键 词：玉米 褐色叶中脉 木质素 BM3 BSA-Seq 

分 类 号：S513[农业科学—作物学] S548