拟南芥雄性不育突变体pmi1的遗传与定位

Identification of arabidopsis male sterile mutant pmi1

通过甲基磺酸乙酯(简称EMS)诱变拟南芥Col-0种子获得一株隐形雄性不育突变体pollen mitosis 1,pmi1.遗传分析结果显示突变体为配子体遗传.细胞学观察发现突变体花粉粒发育出现异常:细胞塌陷,细胞核在单核靠边期后和花粉第一次有丝分裂(简称PMI)前的时间段发生降解.通过图位克隆方法将该基因定位在分子标记T19L18和T1D16之间,物理距离55Kb.测序分析证明这55Kb区间中的ERECTA基因的编码区在3067bp的位置发生单碱基替换,C/G变为A/T.由此说明ERECTA基因在拟南芥从单核小孢子到二细胞花粉的发育过程中起着重要作用.

An Arabidopsis male sterile mutant pollen mitosis 1 ,pmil was obtained through ethyl methane sulfonate （EMS） muta- genesis on wild type accession Col -0. Genetic analysis indicated that the male sterility phenotype of the mutant was inherent through gametophyte. Cytological observation suggested that the development of mutant pollen was abnormal, and its nucleus degraded before it entered into pollen mitosis I stage （PMI）. Map-based cloning using F2 population from the crossing between the pmil and wild type Ler had localized the impaired gene P1MI to the chromosomal region between two molecular markers,T19L18 and T1D16 which are 55Kb apart. A single base substitution was found at the 3067bp locus of ERECTA open reading frame in this 55Kb region. Taken together, our results suggested the ERECTA gene might play an important role in the development progress from uninucleate microspore to binucleate pollen in Arabidopsis.