Reverse transcription Polymerase Chain Reaction (RT-PCR) was performed using cDNAs as templates from wheat Haynaldia villosa 6VS/6AL translocationline and “Yangmai 5" induced with fungus Erysiphe graminis, and degenerate primers designed based on the conserved amino acid sequences of known plant disease resistance genes. The cDNA sequences encoding cyclophilin like and H+ ATPase like genes were first isolated and characterized in wheat. The putative amino acid sequences of the two clones showed that they were highly homologous to those of cyclophilin proteins and H+ ATPases isolated from other plants. Thus they were designated as Ta-Cyp and Ta-MAH. The obvious expression differences could be observed between wheat H. villosa 6VS/6AL translocation line and susceptible wheat cultivar “Yangmai 5", implying that the two genes may be related with the resistance of wheat H. villosa 6VS/6AL translocation line to disease. Southern blot indicated that the wheat genome contained 2-3 copies of Ta-Cyp gene and one copy of the Ta MAH gene. Chinese Spring nulli tetrasomic line analysis located the Ta-Cyp homologous genes on wheat chromosome 6A, 6B and 6D. Southern blot using Ta-Cyp clone as a probe showed that the polymorphic bands existed among the H. villosa, amphiploid of Triticum durum H. villosa, wheat H. villosa 6VS/6AL translocation line and “Yangmai 5", suggesting that Ta-Cyp homologies exist in wheat genome as well as on the short arm of chromosome 6V in H. villosa.
小麦中与白粉病抗性相关的两个新基因序列的克隆、特征分析及染色体定位
于 玲* 牛吉山** 马正强 陈佩度*** 齐莉莉 刘大钧
(南京农业大学农业部细胞遗传重点开放实验室,南京210095)
摘要: 根据抗病基因保守结构域设计简并性引物,以被白粉菌(Erysiphe graminis)诱导后的小麦-簇毛麦6VS/6AL易位系和"扬麦5号"cDNA为模板进行反转录PCR(Reverse-transcription Polymerase Chain Reaction, RT-PCR)筛选,从小麦(Triticum aestivum Linn.)中分离到2个cDNA片段.蛋白质一级结构分析表明,它们分别与植物中已分离的cyclophilin蛋白和H+-ATP酶高度同源,将小麦中这2个基因分别定名为:Ta-Cyp 和Ta-MAH.经Northern杂交分析表明,这2个基因在抗病的小麦-簇毛麦6VS/6AL易位系及感病"扬麦5号"中的表达水平有一定差异,因此推断这2个基因有可能与小麦-簇毛麦6VS/6AL易位系的抗病性相关.Southern杂交发现Ta-Cyp基因在小麦基因组中的拷贝数为2-3个,Ta-MAH为单拷贝.利用中国春缺体-四体系,已将Ta-Cyp基因定位在小麦6A、6B及6D染色体上.用Ta-Cyp作探针,Southern杂交显示在簇毛麦、硬粒小麦-簇毛麦双二倍体、小麦-簇毛麦6VS/6AL易位系与"扬麦5号"之间表现多态,表明小麦基因组和簇毛麦染色体6VS上有其同源基因.
关键词: 克隆;小麦Z簇毛麦6VS/6AL易位系;cyclophilin 基因;H+-ATP酶基因
通讯作者。E-mail: <pdchen @ njau.edu.cn>
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