应用cDNA-AFLP技术分离应答BABA诱导的番茄抗病相关基因

Isolation of genes induced by β-aminobutyric acid from Lycopersicon esculentum

应用cDNA-AFLP技术研究番茄根部组织应答BABA(β-Aminobutyric Acid,β-氨基丁酸)诱导后基因转录谱,得到与植物获得性抗性相关的差异表达片段29条,克隆测序后获得10个上调基因片断.经过生物信息学分析和功能预测,其同源基因都是植物体在抗病、抗逆反应中的表达序列标签.根据功能可将其分为5类:第1类是防御反应基因,为病程相关蛋白基因P69家族成员,具有蛋白水解酶功能;第2类是转运蛋白基因,负责细胞内外离子、水和小分子物质的跨膜运输;第3类是信号传导蛋白,是Ca2+信号传导途径上重要的功能蛋白;第4类是分子伴侣蛋白BIF1,协助蛋白质的复性;第5类属功能未知基因.研究表明:BABA诱导植物根部抗病机制涉及植物多方面生理生化反应,由多个功能不同基因共同参与控制.差异表达片段的获得将有助于下一步全长抗病基因的克隆和BABA诱导植物抗性机制的研究.

cDNA amplified fragment length polymorphism analysis（cDNA-AFLP） was used to display transcripts whose expression is rapidly altered during the treatment of soil drench of BABA to tomato（Lycopersicon esculentum） roots. Among 5 000 transcript-derived fragments, 23 showed increased abundance and 6 showed decreased abundance. By cloning and sequencing, 10 gene fragments were obtained. BLAST search results showed that these TDFs could be divided into 5 groups. The first group are such as pathogenesis-related proteins（PR）, BIF1 3, BIF 14 are members of a PR protein family P69. Second group are transporters, BIF 2, BIF 3, 6, 17, BIF 4 have homologies to genes all responsible for transduction across membrane system of little molecular materials such as H2O, Ca^2＋ and anti-fungal agents. The third group is signal transduction proteins, BIF5 was found to have a high homology to Ca^2＋-binding protein which is an important element in Ca^2＋ signaling pass way. The forth group is molecular chaperone protein, BIF1 help keep activity of certain proteins under stress condition. The fifth groups which include BIF10, BIF 11, BIF 12, are those that have no homology to known genes.