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作 者 ：宋磊;杨仲南;吴世福;崔永兰

期 刊 ：武汉植物学研究 2008年 26卷 5期 页码：437-442

关键词：拟南芥；图位克隆；精细定位；透射电镜技术(TEM)；基因预测；

Keywords:Arabidopsis thaliana, Map-based cloning, Fine-mapping, TEM, Gene prediction,

摘 要 ：通过甲基磺酸乙酯(EMS)诱变与遗传分析,从拟南芥(Arabidopsis thaliana)中筛选到一株隐性单基因控制的网状突变体E-210。该突变体植株生长缓慢,叶脉呈绿色,叶肉呈黄色。通过透射电镜观察,发现野生型植株和突变植株在叶绿体结构上差异不大,猜测该突变体E-210基因与叶绿体的发育可能没有直接关系,而很可能同叶绿素或叶绿体的生物合成有关。通过图位克隆的方法,将该突变体的突变基因定位在第5条染色体上的MRB17和MBG8-5的分子标记之间,精确到87.130kb。对MRB17和MBG8-5的分子标记之间的22个基因进行了分析,预测突变体E-210基因可能是At5g54770,编码THI1,即噻唑合成酶。

Abstract:Seeds of the Arabidopsis thaliana ecotype Landsberg erceta were chemically mutagenized with ethyl-methylsulfonate (EMS) and the M₂ progeny screened for seedlings with chloroplast-related mutations affecting leaf coloration.An independent mutant line of reticula controlled by a novel nuclear gene,designated E-210,was generated and identified.Genetics analysis indicates that the mutant was controlled by a single recessive gene E-210.Phenotypic analysis indicates that the reticula mutant grows up more slowly than the wild-type plant and typically has a green vasculature on yellow lamina.Transmission electron microscopic examination shows that the chloroplasts in the mutant are not obviously different from ones in the wild-type plant.We suppose that the gene for E-210 mutant is not directly related to chloroplast development,but probably related to chlorophyll or chloroplast biosynthesis.We have mapped E-210 to a region of 87.130 kb between the molecular markers MRB17 and MBG8-5 on chromosome 5 using map-based cloning technique.We propose At5g54770 encoding TH1,the thizaole biosynthesis enzyme,is responsible for the phyenotype of E-210 mutant by analysis of 87.130 kb.

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