A full set of disease resistance(R) candidate genes encoding nucleotide-binding sites(NBS) in a complete genome of Populus trichocarpa was identified and characterized by structural diversities,physical positions,phyl...A full set of disease resistance(R) candidate genes encoding nucleotide-binding sites(NBS) in a complete genome of Populus trichocarpa was identified and characterized by structural diversities,physical positions,phylogenetic relationships.Based on structures of N-terminal motif and leucine-rich repeat domains motif,we found 381 NBS-coding sequences with 122 non-regular NBS genes and 259 regular NBS genes that were further classified into 13 types such as TNL,CNL,NL,XNL,TN and other minor types.Meanwhile 81.9% of the NBS genes were distributed in cluster,and 81.8% of the cluster genes had duplicates.The results showed that there were many duplicate phenomenon occurred in the evolution of disease resistance genes of P.trichocarpa.After analysis of NBS standard phylogenetic tree in the genome of P.trichocarpa,the structure of tree exhibited a star topology,and the regular NBS genes were classified into 68 groups by less than 30% amino acid sequence diversity in each domain.展开更多
Verticillium wilt of potato is caused by the fungus pathogen Verticillium dahliae. Present sRNA sequencing data revealed that miR482 was in response to V. dahliae infection, but the function in potato is elusive. Here...Verticillium wilt of potato is caused by the fungus pathogen Verticillium dahliae. Present sRNA sequencing data revealed that miR482 was in response to V. dahliae infection, but the function in potato is elusive. Here, we characterized potato miR482 family and its putative role resistance to Verticillium wilt. Members of the potato miR482 superfamily are variable in sequence, but all variants target a class of disease-resistance proteins with nucleotide binding site （NBS） and leucine-rich repeat （LRR） motifs. When potato plantlets were infected with V. dahliae, the expression level of miR482e was downregulated, and that of several NBS-LRR targets of miR482e were upregulated. Transgenic potato plantlets overexpressing miR482e showed hypersensitivity to V. dahliae infection. Using sRNA and degradome datasets, we validated that miR482e targets mRNAs of NBS-LRR disease-resistance proteins and triggers the production of trans-acting （ta）- siRNAs, most of which target mRNAs of defense-relatedproteins. Thus, the hypersensitivity of transgenic potato could be explained by enhanced miR482e and miR482e-derived ta- siRNA-mediated silencing on NBS-LRR-disease-resistance pro- teins. It is speculated that a miR482-mediated silencing cascade mechanism is involved in regulating potato resistance against V. dahliae infection and could be a counter defense action of plant in response to pathogen infection.展开更多
文摘A full set of disease resistance(R) candidate genes encoding nucleotide-binding sites(NBS) in a complete genome of Populus trichocarpa was identified and characterized by structural diversities,physical positions,phylogenetic relationships.Based on structures of N-terminal motif and leucine-rich repeat domains motif,we found 381 NBS-coding sequences with 122 non-regular NBS genes and 259 regular NBS genes that were further classified into 13 types such as TNL,CNL,NL,XNL,TN and other minor types.Meanwhile 81.9% of the NBS genes were distributed in cluster,and 81.8% of the cluster genes had duplicates.The results showed that there were many duplicate phenomenon occurred in the evolution of disease resistance genes of P.trichocarpa.After analysis of NBS standard phylogenetic tree in the genome of P.trichocarpa,the structure of tree exhibited a star topology,and the regular NBS genes were classified into 68 groups by less than 30% amino acid sequence diversity in each domain.
基金supported financially by grants from the National Natural Science Foundation of China (11171155)the National Pear Industry Technology System (CARS-29)a Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions: Modern horticultural science (PAPD)
文摘Verticillium wilt of potato is caused by the fungus pathogen Verticillium dahliae. Present sRNA sequencing data revealed that miR482 was in response to V. dahliae infection, but the function in potato is elusive. Here, we characterized potato miR482 family and its putative role resistance to Verticillium wilt. Members of the potato miR482 superfamily are variable in sequence, but all variants target a class of disease-resistance proteins with nucleotide binding site （NBS） and leucine-rich repeat （LRR） motifs. When potato plantlets were infected with V. dahliae, the expression level of miR482e was downregulated, and that of several NBS-LRR targets of miR482e were upregulated. Transgenic potato plantlets overexpressing miR482e showed hypersensitivity to V. dahliae infection. Using sRNA and degradome datasets, we validated that miR482e targets mRNAs of NBS-LRR disease-resistance proteins and triggers the production of trans-acting （ta）- siRNAs, most of which target mRNAs of defense-relatedproteins. Thus, the hypersensitivity of transgenic potato could be explained by enhanced miR482e and miR482e-derived ta- siRNA-mediated silencing on NBS-LRR-disease-resistance pro- teins. It is speculated that a miR482-mediated silencing cascade mechanism is involved in regulating potato resistance against V. dahliae infection and could be a counter defense action of plant in response to pathogen infection.
