目前,人们已从多种植物中分离并克隆了MLO(mildew resistance locus O)基因,构成了MLO基因家族,该基因家族为植物所特有。MLO基因存在于植物的各个组织中,功能各异,研究较多的是MLO基因能够促进白粉菌(Erysiphe)侵入植物细胞中,为植物...目前,人们已从多种植物中分离并克隆了MLO(mildew resistance locus O)基因,构成了MLO基因家族,该基因家族为植物所特有。MLO基因存在于植物的各个组织中,功能各异,研究较多的是MLO基因能够促进白粉菌(Erysiphe)侵入植物细胞中,为植物感染白粉病(powdery mildew)所需,MLO基因可通过缺失或突变获得等位基因mlo,导致MLO蛋白功能丧失,从而获得具有对白粉菌持久而广谱抗性的mlo突变体植株。传统的抗病基因(resistace gene,简称R)专化性较强,维持抗性的时间短,MLO基因弥补了R基因的这种抗性上的缺陷,因此该基因的研究对培育抗病品种具有深远的意义。本文主要对MLO基因的发现、基因的生物信息学研究、基因的抗病机制进行了讨论。展开更多
Based on both cDNA sequence of barley powdery mildew resistance control element Mlo and DNA sequence of the known putative disease resistance gene from Triticum monococcum L., we designed some primers to amplify resis...Based on both cDNA sequence of barley powdery mildew resistance control element Mlo and DNA sequence of the known putative disease resistance gene from Triticum monococcum L., we designed some primers to amplify resistant homologous sequences in the near isogenic lines (NILs) of powdery mildew resistance using RT-PCR method. Two expressed cDNA fragments were isolated from wheat genome. One showed 83% homology to the Mlo gene of barley. The other contained two possible open reading frames (ORFs). NBS conservative domains 2, 3 of disease resistance gene and 13 LRR structures similar to rice Pib protein terminal were found respectively in the two ORFs. It indicated that the latter fragment belongs to NBS-LRR-like genes. The obvious difference of RT-PCR products was observed between the before challenged and the challenged for 72 h by Blumeria graminis f. sp. tritici, which, implied that this sequence could be associated with disease resistance of wheat. Using nulli-tetrasomic lines of 'Chinese Spring', the NBS-LRR-like gene had been located on chromosome 1D.展开更多
文摘Based on both cDNA sequence of barley powdery mildew resistance control element Mlo and DNA sequence of the known putative disease resistance gene from Triticum monococcum L., we designed some primers to amplify resistant homologous sequences in the near isogenic lines (NILs) of powdery mildew resistance using RT-PCR method. Two expressed cDNA fragments were isolated from wheat genome. One showed 83% homology to the Mlo gene of barley. The other contained two possible open reading frames (ORFs). NBS conservative domains 2, 3 of disease resistance gene and 13 LRR structures similar to rice Pib protein terminal were found respectively in the two ORFs. It indicated that the latter fragment belongs to NBS-LRR-like genes. The obvious difference of RT-PCR products was observed between the before challenged and the challenged for 72 h by Blumeria graminis f. sp. tritici, which, implied that this sequence could be associated with disease resistance of wheat. Using nulli-tetrasomic lines of 'Chinese Spring', the NBS-LRR-like gene had been located on chromosome 1D.
