Two pairs of degenerate primers were designed based on nucleotide-binding site (NBS) and serine/threonine kinase domain. PCR was performed with the primers and cDNA from the Triticum aestivum-Haynaldia villosa translo...Two pairs of degenerate primers were designed based on nucleotide-binding site (NBS) and serine/threonine kinase domain. PCR was performed with the primers and cDNA from the Triticum aestivum-Haynaldia villosa translocation line 6VS/6AL. Amplified products were cloned and sequenced. Nine clones with NBS and one with serine/threonine kinase domain were obtained. The NBS clones were classified to six groups according to their nucleotide sequence identities (90% or higher). These resistance gene analogs (RGAs) all have open reading frames (ORF), and their amino acid sequences show high similarity to Yr10 in wheat, Mla1 and Mla6 in barley, RPS2 in Arabidopsis and other resistance (R) genes with conserved motifs. They were preliminarily mapped on the chromosomes of homoeologous groups 1, 2 and 5 of common wheat by nulli-tetrasomic analysis. The 5'-end sequence of an RGA N5 was obtained by 5'-RACE PCR. It encodes six leucine zipper (LZ) and has high sequence similarity to RPS2.展开更多
To Investigate the mechanism of resistance to wheat （Triticum aestivum L.） powdery mildew, suppression subtractlve hybridization was conducted between an isogenic resistant line carrying Pm21 and its recurrent paren...To Investigate the mechanism of resistance to wheat （Triticum aestivum L.） powdery mildew, suppression subtractlve hybridization was conducted between an isogenic resistant line carrying Pm21 and its recurrent parent Yangmal 5 to Isolate the resistance relative genes. A cDNA fragment specifically expressed in the resistant line was obtained and its full length was cloned by in silico cloning and RT-PCR. This gene encoded a deduced protein of 219 amino acids with a leucine-rich repeat （LRR） motif, often found In plant resistance genes, and was designated as Ta-LRR2. Ta-LRR2 had an increased expression level in the resistant line after Inoculation with Erysiphe graminis DC. f. sp. tritici Marchal. PCR analysis with different cytogenetlc stocks suggested that Ta-LRR2 was specifically associated with chromosome arms 6VS and 6AS. Linkage analysis further showed that Ta-LRR2 could be used as a resistance gene analog polymorphism marker of Pm21 for marker-assisted selection in germplasm enhancement and breeding practice. Moreover, how to Isolate Pm21 based on the Information obtained for Ta-LRR2 is discussed.展开更多
文摘Two pairs of degenerate primers were designed based on nucleotide-binding site (NBS) and serine/threonine kinase domain. PCR was performed with the primers and cDNA from the Triticum aestivum-Haynaldia villosa translocation line 6VS/6AL. Amplified products were cloned and sequenced. Nine clones with NBS and one with serine/threonine kinase domain were obtained. The NBS clones were classified to six groups according to their nucleotide sequence identities (90% or higher). These resistance gene analogs (RGAs) all have open reading frames (ORF), and their amino acid sequences show high similarity to Yr10 in wheat, Mla1 and Mla6 in barley, RPS2 in Arabidopsis and other resistance (R) genes with conserved motifs. They were preliminarily mapped on the chromosomes of homoeologous groups 1, 2 and 5 of common wheat by nulli-tetrasomic analysis. The 5'-end sequence of an RGA N5 was obtained by 5'-RACE PCR. It encodes six leucine zipper (LZ) and has high sequence similarity to RPS2.
基金Supported by the Hi-Tech Research and Development(863) Program of China(2001 AA222152,2003AA207100,and 2004AA222140)the National Natural Science Foundation of China and the Program for Changjiang Scholars and Innovative Research Team in University
文摘To Investigate the mechanism of resistance to wheat （Triticum aestivum L.） powdery mildew, suppression subtractlve hybridization was conducted between an isogenic resistant line carrying Pm21 and its recurrent parent Yangmal 5 to Isolate the resistance relative genes. A cDNA fragment specifically expressed in the resistant line was obtained and its full length was cloned by in silico cloning and RT-PCR. This gene encoded a deduced protein of 219 amino acids with a leucine-rich repeat （LRR） motif, often found In plant resistance genes, and was designated as Ta-LRR2. Ta-LRR2 had an increased expression level in the resistant line after Inoculation with Erysiphe graminis DC. f. sp. tritici Marchal. PCR analysis with different cytogenetlc stocks suggested that Ta-LRR2 was specifically associated with chromosome arms 6VS and 6AS. Linkage analysis further showed that Ta-LRR2 could be used as a resistance gene analog polymorphism marker of Pm21 for marker-assisted selection in germplasm enhancement and breeding practice. Moreover, how to Isolate Pm21 based on the Information obtained for Ta-LRR2 is discussed.
