控制玉米株高基因PHR1的基因克隆  

Mapping and cloning of plant height gene PHR1 in maize

作　　者：杨晨曦 周文期 周香艳[1] 刘忠祥[2] 周玉乾[2] 刘芥杉 杨彦忠[2] 何海军[2] 王晓娟[2] 连晓荣[2] 李永生 YANG Chen-Xi;ZHOU Wen-Qi;ZHOU Xiang-Yan;LIU Zhong-Xiang;ZHOU Yu-Qian;LIU Jie-Shan;YANG Yan-Zhong;HE Hai-Jun;WANG Xiao-Juan;LIAN Xiao-Rong;LI Yong-Sheng(College of Life Science and Technology,Gansu Agricultural University,Gansu 730070,Lanzhou,China;Crop Research Institute,Gansu Academy of Agriculture Sciences,Gansu 730070,Lanzhou,China)

机构地区：[1]甘肃农业大学生命科学技术学院,甘肃兰州730070 [2]甘肃省农业科学院作物研究所,甘肃兰州730070

出　　处：《作物学报》2024年第1期55-66,共12页Acta Agronomica Sinica

基　　金：国家自然科学基金项目(32160490,31960443);甘肃省重大专项(21ZD11NA005,21ZD10NF003);甘肃省农业科学院生物育种专项(2022GAAS04);甘肃农业大学青年导师基金项目(GSAU-QDFC-2021-14);中国工程院战略研究与咨询项目:特色粮油作物优异基因精准鉴定及新种质创制(2021-DFZD-21-3)资助。

摘　　要：株高属于玉米理想株型育种的一个重要指标,不但影响玉米机械化收获,更与玉米的倒伏性和生物产量密切相关。本研究以低剂量快中子(4.19 Gy)辐照诱变玉米自交系KWS39获得的矮秆低穗位突变体为研究对象,该突变体命名为plant height reducing mutant-1(phr-1),开展了表型性状的田间调查分析,并利用phr-1×B73获得的F2分离群体,借助极端性状混池测序分析法(BSA-seq)及目标区段重组交换鉴定的方法,基于B73参考基因组对目标区段内的基因进行挖掘和功能注释,定位候选基因。研究结果表明,在1号染色体Bin1.06区间可能存在变异位点,进而利用大的分离群体结合目标区段多态性标记开发,将目标区段精细定位分子标记到Umc1122和Umc1583a两个标记之间约600 kb区间,该区段内存在一个控制株高的已知基因Brachytic2(BR2),BR2编码一个调控玉米茎秆中生长素极性运输的糖蛋白。候选基因测序结果表明,phr-1是BR2基因在第4个外显子处插入了165 bp的序列,导致第547位氨基酸变为终止子,蛋白翻译提前终止。phr-1的基因突变位点和变异方式与已报道的br2-1单个碱基发生变异位点完全不同,通过等位杂交实验证明了phr-1突变体就是br2-1的一个新等位突变体,候选基因就是BR2基因。本研究为玉米BR2基因在玉米株高遗传改良中提供了新的种质资源。Plant height is an important index for the ideal maize breeding,which not only affects the mechanical harvest of maize,but also closely relates to the lodging resistance and the biological yield of maize.In this study,a plant height reducing mutant-1(phr-1)was obtained by using low-dose fast neutron(4.19 Gy)irradiation to mutate the maize inbred line KWS39 at the low ear position.Phenotypic traits were investigated and analyzed in the field,and candidate genes were identified by mining and functional annotation of genes in the target region based on the B73 reference genome using the extreme trait pool sequencing analysis(BSA-seq)and the method of target region recombination exchange identification with F2 segregation population of phr-1×B73.These results indicated that there might be a variation site in Bin1.06 interval on chromosome 1,and the target region was precisely located between two markers,Umc1122 and Umc1583a,with a 600 kb interval by using the large segregation population and polymorphic markers.Brachytic2(BR2),encoding a sugar protein regulating the polar transport of auxin in maize stems,is a known gene controlling plant height in this region.The sequencing of candidate genes revealed that phr-1 was a new allelic mutation of br2-1,with a 165 bp insertion in the fourth exon of the BR2 gene resulting in the amino acid at position 547 changing to a stop codon and premature protein translation termination.The mutation site and variation mode of phr-1 were completely different from those of br2-1 single base mutation site.The allelic hybridization experiment confirmed that the PHR1 candidate gene is a new allelic mutation of the BR2 gene.This study provides new germplasm resources for maize BR2 gene in plant height genetic improvement.

关 键 词：玉米 株高 穗位高 BSA混池测序 基因定位 功能分析 

分 类 号：S513[农业科学—作物学]