Reduction of Tissue Maceration in Potatoes by Rose Essential Oil

Erwinia carotovora is a phytopathogen which causes soft-rot disease in a wide variety of economically important plants. E. carotovora is known to produce a range of exoenzymes that enhance its ability to damage the host tissue and cause disease. A cell to cell communication mechanism called quorum sensing which is mediated by small signalling molecules regulates exoenzymes (cellulase, pectinase and protease) and carbapenem production in E. carotovora. Thus the exploration of new strategies to manipulate this communication pathway for the prevention of E. carotovora infections is valuable. In this study, the inhibitory effects of the rose, orange, lavender, clove, cinnamon, black pepper and cumin oils on the production of the exoenzymes (cellulase, pectinase and protease) and carbapenem in the Erwinia carotovora subsp. carotovora ATCC 39048 were investigated. And potato tissue maceration was also tested in the presence of oils. Rose and lavender essential oils markedly inhibited the production of pectinases by 38.7 and 9.7%, cellulases by 36.6 and 31.7% and proteases by 29 and 16.1%, carbapenem by 61.9 and 54%, and maceration of potatoes by 61.4 and 30.7% in the E. carotovora respectively without affecting the growth of cells. Although several studies have reported antibacterial effects of rose and lavender essential oils, there is no report describing their antivirulence potential. To the best of our knowledge, this is the first report on the rose and lavender essential oils with potential antivirulence components against soft rot caused by E. carotovora