MiR6024 overexpression increases the susceptibility of Nicotiana tabacum to Sclerotinia sclerotiorum

Sclerotinia sclerotiorum is a devastating fungal pathogen that causes losses in economically important crops. Given that some miRNAs may have an important role in biotic stress responses, particularly those exclusively found in the Solanaceae, this work was focused on lineage-specific miRNAs for which most of the predicted target genes are associated with biotic stress in tomato (Solanum lycopersicum) and tobacco (Nicotiana tabacum). The putative target genes for miR5300, miR5301, and miR6024 were mainly related to disease resistance in both plant species. Enrichment of Gene Ontology terms, interaction networks, and gene expression assays suggest that miR6024 is involved in the interaction of two Solanaceae plants with S. sclerotiorum. The overexpression of miR6024 in tobacco plants resulted in a greater susceptibility to S. sclerotiorum in comparison to wild-type plants, demonstrating that miR6024 is involved in plant susceptibility to fungal pathogens. These results open the possibility of manipulating the expression of miR6024 as a means to improve resistance to fungal pathogens in tobacco and tomato.

Automated summary

A specific miRNA (miR6024) in Solanaceae plants has been found to be associated with the interaction between the plants and Sclerotinia sclerotiorum, and overexpression of this miRNA increases the susceptibility of plants to fungal pathogens. Manipulating the expression of miR6024 may be a potential strategy to improve resistance to fungal pathogens in Solanaceae plants.