Rhizoviticin is an alphaproteobacterial tailocin that mediates biocontrol of grapevine crown gall disease.

Tailocins are headless phage tail structures that mediate interbacterial antagonism. Although the prototypical tailocins, R- and F-pyocins, in Pseudomonas aeruginosa, and other predominantly R-type tailocins have been studied, their presence in Alphaproteobacteria remains unexplored. Here, we report the first alphaproteobacterial F-type tailocin, named rhizoviticin, as a determinant of the biocontrol activity of Allorhizobium vitis VAR03-1 against crown gall.

A fungal microRNA-like RNA subverts host immunity and facilitates pathogen infection by silencing two host receptor-like kinase genes.

Small RNAs (sRNAs) play important roles in various biological processes by silencing their corresponding target genes in most eukaryotes. However, cross-kingdom regulation mediated by fungal microRNA-like RNAs (milRNAs) in plant-pathogen interactions is still largely unknown. Using molecular, genetic, histological, and biochemical approaches, we found that the apple tree Valsa canker pathogen Valsa mali milRNA Vm-milR1 could suppress the host immunity by silencing two host receptor-like kinase genes, MdRLKT1 and MdRLKT2.

Adaptive regulation of virulence genes by microRNA-like RNAs in Valsa mali.

MicroRNAs play important roles in the regulation of gene expression in plants and animals. However, little information is known about the action mechanism and function of fungal microRNA-like RNAs (milRNAs). In this study, combining deep sequencing, molecular and histological assays, milRNAs and their targets in the phytopathogenic fungus Valsa mali were isolated and identified.