Evidence that nematodes may vector the soft rot-causing enterobacterial phytopathogens

Nykyri, J., Fang, X., Dorati, F., Bakr, R., Pasanen, M., Niemi, O., Palva, E. T., Jackson, R. W. and Pirhonen, M. (2013) Evidence that nematodes may vector the soft rot-causing enterobacterial phytopathogens. Plant Pathology, 63 (4). pp. 747-757. ISSN 0032-0862 doi: 10.1111/ppa.12159

Abstract/Summary

Bacterial soft rot is a globally significant plant disease that causes major losses in the production of many popular crops, such as potato. Little is known about the dispersal and ecology of soft-rot enterobacteria, and few animals have been identified as vectors for these pathogens. This study investigates whether soil-living and bacterial-feeding nematodes could act as vectors for the dispersal of soft-rot enterobacteria to plants. Soft-rot enterobacteria associated with nematodes were quantified and visualized through bacterial enumeration, GFP-tagging, and confocal and electron scanning microscopy. Soft-rot enterobacteria were able to withstand nematode grazing, colonize the gut of Caenorhabditis elegans and subsequently disperse to plant material while remaining virulent. Two nematode species were also isolated from a rotten potato sample obtained from a potato storage facility in Finland. Furthermore, one of these isolates (Pristionchus sp. FIN-1) was shown to be able to disperse soft-rot enterobacteria to plant material. The interaction of nematodes and soft-rot enterobacteria seems to be more mutualistic rather than pathogenic, but more research is needed to explain how soft-rot enterobacteria remain viable inside nematodes.