水稻Os09g24220基因插入突变体的分子鉴定与农艺性状分析  

Molecular characterization and agronomic trait analysis of rice Os09g24220 gene insertion mutants

作　　者：袁兵[1] 崔海瑞[1] 富昊伟[2] 蒋萌[1] 李瑞清[1] 赵海军[1] 舒庆尧[1] 

机构地区：[1]浙江大学原子核农业科学研究所,杭州310029 [2]浙江省嘉兴市农业科学研究院,浙江嘉兴314016

出　　处：《浙江大学学报（农业与生命科学版）》2014年第4期456-462,共7页Journal of Zhejiang University:Agriculture and Life Sciences

基　　金：国家自然科学基金资助项目(1175154);IAEA协调研究项目(CPR15655);农业公益性行业科研专项(201103007)

摘　　要：通过同源搜索从水稻Tos17插入突变体库中获得单拷贝Os09g24220基因的突变体,利用3引物PCR和RT-PCR对该基因的3个插入突变体NF9010,NF7784和ND6011进行分子鉴定,并对其农艺性状进行分析.3引物PCR结果证实了Tos17的插入,而且它们都是纯合的插入突变体.RT-PCR分析显示,在突变体NF9010和NF7784的幼苗中,利用扩增片段位于插入位点前的引物可检测到Os09g24220 mRNA转录片段,而利用跨越插入位点或位于插入位点之后的引物则检测不到转录产物,说明尽管这2个突变体中具有截短的转录产物,但缺乏全长和有功能的Os09g24220 mRNA;而在突变体ND6011中,利用所有位于功能区上游、中部和下游的引物均能检测到Os09g24220转录产物,利用跨越插入位点的引物则检测不到转录产物,表明ND6011具有功能性Os09g24220mRNA,但不是全长mRNA.对3个插入突变体的株高、有效分蘖数、穗长、结实率和千粒质量等农艺性状进行考察,并与其野生型进行比较.结果显示,每个突变体至少有1个性状发生了显著改变.突变体ND6011仅结实率显著降低(P<0.05),而NF7784和NF9010的穗长和结实率均极显著下降(P<0.01),而且NF9010的株高也显著降低.总之,Os09g24220基因的Tos17插入突变体具有突变表型,部分农艺性状发生了显著改变,而且不同突变体具有不同的突变表型,与Tos17插入不同位置对Os09g24220基因功能的影响有关.这为进一步研究该基因在水稻DNA修复中的功能和探讨这类突变体在水稻诱变育种中的应用奠定了基础.Summary The mismatch repair （ MMR） is a major pathway in DNA repair system ,which is critical for maintaining genome stability and DNA replication fidelity ,as it is responsible for the recognizing and repairing erroneous insertions , deletions and mismatch of bases newly arising during DNA replication and genetic recombination , as well as during the repair of some forms of DNA damage . The major components in the MMR system include MutS , MutH , and MutL in Escherichia coli . In eukaryotes , homologues of MutS and MutL havebeen found ,but not of MutH . Based on homology , several MutS homologues have also been identified and cloned from A rabidopsis thaliana . Amongst these homlogues MSH2 complexes with MSH6 , MSH3 or MSH7 form M utSα, M utSβ and M utSγ heterodimers to recognize different types of mutations , respectively . M utation or disruption of MMR gene causes significantly increased frequencies of point mutations and microsatellite instability , thus to enhance genetic diversity for plant breeding . Rice is an important food crop and a prominent molecular model species for monocotyledonous plants. Some MMR genes have been annotated in Rice Annotation Project Database, one of which is OsO9924220, a homologue to Msh6 （At4g02070） in the MMR system of A. thaliana. However, no information is available for the OsO9924220 gene function and its mutator phenotype in rice. We reasoned that, if the disrupted Os09924220 gene can enhance genetic diversity, offspring exhibiting mutations in agronomic traits could be generated using this approach. Herein, we mainly conducted molecular characterization of Tos17 insertion mutants of the OsO9924220 gene and analyzed their agronomic traits, to provide a foundation for the function studies of the Os09g24220 gene and exploitation of the mutant in rice mutation breeding. Three insertion mutants, NF9010, NF7784 and ND6011 with the Tos17 insertion at the 1st, 8th exons and 3＇- UTR （untranslated region）, respectively, were characterized by triple-primer PCR and

关 键 词：水稻 Os09g24220基因 插入突变体 分子鉴定 农艺性状 

分 类 号：Q754[生物学—分子生物学]