普通烟草短叶柄突变基因精细定位与候选基因分析

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中图分类号：S572；Q943.2文献标识码：A

文章编号：1007-5119（2026）01-0014-09

Abstract：To elucidate themolecular mechanism underlying petiole formationin Nicotina tabacumL.，near-isogenic lines were constructedtoprecisely evaluatethe geneticefectofadominant mutant genecontrolingtheshortpetiole phenotype intobacco.Finemapping was performed by enlargingthe segregation population and developing new molecular markers based on whole genome sequencig.Bioinformaticspredictionandanalysisweresubsequentlyconductedtoidentifycandidategene.Theresultsdemonstrated thatthedomiantmutantgeneprimarilyregulatedtheformationofshort petiole in the mutant，withoutcausing notableefectonother leaf traits. The gene was located to a 210kb interval on Chromosome 7 of NtaSR1， where a KNOXI gene， NtaO7g20040.l ，was identfiedasthecandidategene.Nosequencechanges weredetected inthecodingregionofNtaO7g20o40.1inthemutant;however， four SNP mutations consistent with the ethyl methanesulfonate （EMS）mutagenesis patem were found tens ofkilobases upstreamand downstream ofthecodingsequene.Thesemutations wereabsent in thewild-typetobaccolackingpetiolesandinitsancestralspecies N. sylvestris. It is hypothesized that these SNPs likely have induced a gain-of-function dominant mutation in NtaO7g20040.I ，leading to the degradation of leaf tissue at the base of the midrib and subsequent petiole formation. NtaO7g20040.1 has a highly homologous gene，Nta08g66.1，intbcumndseesilaityalsiicatedatthtgoigiatedfroN.sylstisd N. tomentosiformis，the diploid ancestors of N. tabacum，respectively.

Keywords： Nicotiana tabacum L.; petiole; dominant mutation; ethylmethane sulfonate; KNOXI gene

叶柄是叶中脉着生在主茎上的部位，起机械支撑和物质转运的作用[1]。（剩余13740字）