2008 Annual Report
Some plant pathogens produce infection structures (appressoria) that are very resistant to chemical fungicides. An artificial membrane system composed of fruit waxes is being developed that will be used to study the interaction between the appressoria of the brown rot pathogen (Monilinia fructicola) and biocontrol agents. The system has been shown to be effective for studying pear and apple pathogens. This research falls within NP 303 – Plant Diseases, Component 4B: Pathogen, Plant, and Antagonist Interactions.
In order to develop effective biocontrol strategies, more information is needed about how pathogens interact with their hosts and avoid innate resistance mechanisms. Tissue samples have been collected from peach fruit wounded, wounded-inoculated with a pathogen, and wounded-inoculated with a non-pathogen. Identification of the expressed genes (ESTs) in each of the samples is in progress. This research falls within NP 303 – Plant Diseases, Component 4B: Pathogen, Plant, and Antagonist Interactions.
A fungal enzyme (polygalacturanase) involved in the breakdown and infection of fruit tissues has been isolated. Polyclonal antibodies directed against the enzyme have been developed and shown to inhibit the fungal enzyme in a test tube (in vitro). This research falls within NP 303 – Plant Diseases, Component 4B: Pathogen, Plant, and Antagonist Interactions.
5.Significant Activities that Support Special Target Populations
Janisiewicz, W.J., Saftner, R.A., Conway, W.S., Forsline, P.L. 2008. Preliminary evaluation of apple germplasm from Kazakhstan for resistance to blue mold decay caused by Penicillium expansum after harvest. HortScience.43(2):420-426.
Chen, Y.P., Siede, R. 2007. Honey Bee Viruses. Advances in Virus Research. 70:33-80.
Macarisin, D., Cohen, L., Eick, A., Rafael, G., Belausov, E., Wisniewski, M.E., Droby, S. 2007. Penicillium digitatum suppresses production of hydrogen peroxide in host tissue during infection of citrus fruit. Phytopathology. 97(11):1491-1500.
Droby, S., Eick, A., Macarisin, D., Cohen, L., Rafael, G., Stange Jr, R.R., Mccollum, T.G., Dudai, N., Nasser, A., Wisniewski, M.E., Shapira, R. 2008. The role of citrus volatiles in germination and growth of Penicillium digitatum and Penicillium italicum. Postharvest Biology and Technology. 49:386-396.