水稻矮化多蘖突变体mtd2/htd1-1的鉴定与图位克隆  

Identification and Map-based Cloning of Multi-tillering Dwarf Mutant mtd2/htd1-1 in Rice(Oryza sativa L.)

作　　者：王晓雯[1] 王媛媛 冯蓓祺 雷松翰 范骏扬 杨晶晶 仝瑞建 田维江 桑贤春[1] WANG Xiaowen;WANG Yuanyuan;FENG Beiqi;LEI Songhan;FAN Junyang;YANG Jingjing;TONG Ruijian;TIAN Weijiang;SANG Xianchun(College of Agronomy and Biotechnology,Southwest University,Chongqing 400715,China;College of Agriculture and Biological Engineering of Heze University,Heze Shandong 274000,China)

机构地区：[1]西南大学农学与生物科技学院,重庆400715 [2]菏泽学院农业与生物工程学院,山东菏泽274000

出　　处：《西南大学学报（自然科学版）》2024年第2期1-12,共12页Journal of Southwest University(Natural Science Edition)

基　　金：重庆市现代农业产业技术体系创新团队项目(CQMAITS202301);国家重点研发计划子课题(2022YFD1201600);重庆市大学生创新创业训练计划项目(S202310635031,S202310635071)。

摘　　要：株高是株型构成的重要因子,分蘖则是有效穗形成的基础,二者均是水稻重要的农艺性状.为研究株高和分蘖发育的分子机理,用甲基磺酸乙酯(EMS)诱变保持系西大1B,从中鉴定到1个矮化多蘖突变体,命名为mtd2(more tiller and dwarfism 2).与野生型西大1B相比,mtd2的分蘖数(70.00个)是野生型的6.25倍,株高(49.12 cm)则为野生型的59.4%,同时还表现出小穗、短叶等特征.遗传分析表明:mtd2分蘖增多和植株矮化的突变表型呈共分离现象且受单隐性核基因调控.利用mtd2和缙恢10号杂交组合的F2隐性群体,最终将MTD2基因精细定位于第4染色体分子标记C04-2和C04-3之间157 kb的物理范围内,该区间内含1个已克隆的多蘖矮秆基因LOC_Os04g46470-HTD1.对定位区间内的HTD1进行DNA测序,发现其编码区有11个碱基缺失,导致移码突变.构建互补载体,转化突变体mtd2,其矮化多蘖表型恢复正常,表明mtd2是htd1的一个新等位突变体.细胞学分析发现:mtd2分蘖数增多是由于分蘖芽发育较快所致;qRT-PCR分析表明:MTD2可能参与独脚金内酯(SLs)相关的分蘖芽发育调控网络,这为进一步鉴定MTD2/HTD1基因的功能奠定了基础.Plant height is an important factor of plant architecture,and tillering is the basis for the formation of effective panicle.Both of them are important agronomic traits of rice.To study the molecular mechanism of plant height and tiller development,we used EMS to mutate the maintainer line Xida 1B,and identified a multi-tillering and dwarf mutant named mtd2.Compared with wild-type(WT)Xida 1B,mtd2 had 6.25 times more tillers than WT,and plant height was 49.12 cm,only 59.4%of WT.In addition,mtd2 had smaller panicles and shorter leaves.Genetic analysis showed that mutant phenotypes of mtd2 with increased tillers and plant dwarf was co-segregated and regulated by single recessive nuclear genes.Using the F2 recessive population of mtd2 and Jinhui 10 crossing,the MTD2 gene was finally finepositioned within a physical distance of 157 kb on chromosome 4 between molecular markers C04-2 and C04-3.Bioinformatics analysis revealed that the mapping interval contained a cloned gene LOC_Os04g46470-HTD1(HTD1).DNA sequencing revealed an 11-base deletion in the HTD1 coding region,which caused a frameshift mutation.The complementary vector was constructed and transformed into mutant mtd2.The dwarf and multi tiller phenotype of mtd2 returned to normal,proving that mtd2 is a new allelic mutant of htd1.Cytological analysis showed that the increase of tiller number in mtd2 was due to the rapid development of tiller buds,which led to more tiller buds.In addition,the qRT-PCR results indicated that MTD2 may be involved in the regulatory network of tillering bud development related to strigolactones(SLs),which laid the foundation for further identification of the function of MTD2/HTD1 genes.

关 键 词：水稻 多蘖矮秆基因(MTD2/HTD1) 图位克隆 激素 独脚金内酯 

分 类 号：S326[农业科学—作物遗传育种]