Effect of ethylene on the growth and pathogenicity of Botrytis cinerea
L. Xu, L.J. Zhang, Y. Liu, W. Zhang, S.Y. Zhang and H. Toyoda.
Journal of Plant Pathology Volume 90 (2, Supplement) August 2008, Book of Abstract, 9th International Congress of Plant Pathology, August 24-29, 2008 Torino,Italy,. 507 pages.
2008
บทคัดย่อ
Effect of ethylene on the growth and pathogenicity of Botrytis cinerea
During the storage and transportation of fruit and vegetable crops, ethylene promotes not only their senescence, but also the outbreak of disease in the crops. Many pathogenic fungi can produce ethylene, but its role in expression of pathogenicity has remainedobscure. To give some clues to these problems, the present research was conducted usingBotrytis cinereaisolated from harvested grapes. All isolates produced ethylene on methioninecontaining media (M-media). The highest production was on Mmedium supplemented with grape juice, suggesting that ethylene production by the pathogen is largely promoted by host-derived nutrients. Ethylene production varied among the isolates, and solid medium was best for ethylene production, with an average 9.5 times higher than in liquid M-medium.B. cinereacan synthesize ethylene between pH 2 and 5, and the optimum is pH 3.0, corresponding to the physiological pH of grape juice. Exogenous ethylene did not affect spore germination, but significantly promotedB. cinereahyphal growth. Germ tube elongation was promoted to various extents, depending on concentrations of ethylene given. In addition, ethylene treatment enhanced the pathogenicity ofB. cinereato post-harvest berries in a bell-shaped curve to concentrations. The disease index reached a maximum when the inoculated berries were exposed to ethyleneat 50μg/ml. No significant effect of ethylene was detected on the activityof cell wall degrading enzymes secreted byB. cinerea. Thus, the present study suggested that host nutrients induce ethylene production byB. cinereato promote the hyphal growth and pathogenicity of the pathogen.