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Verticillium wilt of potato is caused by the fungus pathogen Verticillium dahliae. Present s RNA 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 mi R482 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 s RNA and degradome datasets, we validated that miR482e targets m RNAs of NBS-LRR disease-resistance proteins and triggers the production of trans-acting(ta)si RNAs, most of which target m RNAs of defense-related proteins. Thus, the hypersensitivity of transgenic potato could be explained by enhanced miR482e and miR482e-derived tasi RNA-mediated silencing on NBS-LRR-disease-resistance proteins. 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.
Verticillium wilt of potato is caused by the fungus pathogen Verticillium dahliae. Present s RNA 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 mi R482 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 s RNA and degradative datasets, we validated that miR482e targets m RNAs of NBS-LRR disease-resistance proteins and triggers the production of trans-acting (ta) si RNAs, most of which target m RNAs of defense-related proteins. Thus, the hypersensitivity of transgenic potato could be explained by enhanced miR482e and miR482e-derived tasi RNA-mediated silencing on NBS-LRR-disease-resistance proteins. 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.