玉米轴色突变体698-3R的遗传鉴定  

Genetic Identification of Color Mutant 698-3R in Maize Cob

作　　者：余学杰[1,2] 李开兵 张玉 柯永培[1,2] 蔡林 石海春[1,2] YU Xuejie;LI Kaibing;ZHANG Yu;KE Yongpei;CAI Linx;SHI Haichun(College of Agronomy,Sichuan Agricultural University,Chengdu 611130,China;Sichuan Zhenghong Biology Co.,Ltd.,Chengdu 610213,China;Bijie Bureau of Agriculture and Rural Affairs,Bijie Guizhou 551700,China;Shandong Xinfeng Seed Co.,Ltd.,Liaocheng Shandong 252400,China)

机构地区：[1]四川农业大学农学院,成都611130 [2]四川农大正红生物技术有限责任公司,成都610213 [3]贵州毕节市农业农村局,贵州毕节551700 [4]山东鑫丰种业有限公司,山东聊城252400

出　　处：《西北农业学报》2020年第6期860-869,共10页Acta Agriculturae Boreali-occidentalis Sinica

基　　金：四川省科技支撑计划项目(2016NYZ0006,2011FZ0119);四川省重点研发项目(2019YFN0012)。

摘　　要：以辐射诱变获得的玉米红轴突变体698-3R为材料,通过遗传交配设计分析轴色的遗传规律,利用SSR-BSA法初步定位轴色基因,并对候选基因进行克隆和表达分析。结果表明:(1)突变体698-3R的红轴对白轴性状表现为显性遗传,受一对核基因控制,初步定位在第一染色体上的SSR标记phi095与umc1452之间,与phi095相距3.9cM,与umc1452相距7.1cM,将该基因暂定名为C(t);(2)以轴色基因 P1的cDNA为模板克隆C(t),发现698-3R有3个C(t)转录本,而野生型698-3中至少有2个;预测氨基酸序列比对发现,698-3R中3个C(t)蛋白的氨基酸序列与已知P1-wr蛋白一致,突变使其获得完整的MYB结构域和酸性激活域,而野生型698-3中698-3-P-1蛋白由于编码序列缺失导致移码突变,不具有该功能结构域;(3)对C(t)基因qRT-PCR分析发现,除25DAP外,其余4个时期在698-3R中表达水平均显著或极显著高于698-3;以 A1和 C2基因表达验证分析发现,C(t)与验证基因表达模式一致,说明C(t)可能具有 P1激活调控 A1和 C2基因表达的功能。推测该红轴基因C(t)可能为一个 P1-wr基因。In this study,698-3R mutant with red cob color derived from inbred line 698-3 by irradiation was selected for investigate the hereditary character of cob color by genetic analysis and the candidate gene mapping by SSR-BSA,candidate gene cloning and expression were also studied.The results showed:(1)the trait of red cob color was controlled by one single dominant gene,and the red cob gene,temporally named as C(t),was mapped on the chromosome 1S between two SSR markers of phi095 and umc1452 with genetic distance of 3.9 cM and 7.1 cM,respectively;(2)C(t)was cloned by the template of cDNA of P1 gene,and three transcripts of C(t)were identified in 698-3R while at least two in the wild type 698-3.Alignment of predicted amino acid sequences revealed that the amino acid sequence of three C(t)proteins in 698-3R were consistent with that in P1-wr protein.The complete MYB domain and acid-activating domain were obtained by mutation,while C(t)protein,698-3-P-1 protein from 698-3 were verified for lack of MYB domain;(3)The qRT-PCR analysis indicated that C(t)gene expression in 698-3R was significantly or extremely significantly up-regulated in four sampling periods except for 25 DAP compared with the wild type of 698-3.Gene expression patterns of A1 and C2 were consistent with that of C(t)gene,this suggests that C(t)would activate and regulate gene expression of A1 and C2 via P1 gene.Accordingly,we proposed that the red cob gene C(t)was a P1-wr allele.

关 键 词：玉米 辐射诱变 698-3R 轴色 遗传鉴定 基因定位 基因克隆 

分 类 号：S513[农业科学—作物学]