The whitefly pest and vector, and the geminiviruses that it transmits, have become the principal deterrents to vegetable production in the U.S. Sunbelt states, in Mexico, and throughout the Caribbean Basin since the introduction and spread of the B biotype whitefly vector in the late 1980's. The most effective means of controlling geminivirus-incited diseases is through resistant tomato varieties. The proposed research is designed to develop pathogen derived resistance using genetic engineering. Dominant defective versions of the geminivirus transcription activator protein (TrAP) will be expressed in transgenic plants which will mimic wild type protein in most respects, but will be unable to activate transcription or interact with SNF-1 kinase. These defective proteins are expected to interfere with the wild type TrAP protein of an incoming virus. State of the art information concerning geminivirus transcription strategies, mechanisms used by geminiviruses to condition their hosts, and proven transgenic tomato technology will be employed to develop genetically engineered tomato cultivars with geminivirus resistance.
Anticipated Results/Potential Commercial Applications of Research: This research will produce transgenic tomatoes with specific and/or broad-spectrum resistance to whitefly transmitted geminiviruses. The availability of the virus resistance tomatoes will avoid the heavy use of pesticides that is presently used for the control of whiteflies in the field. The demonstration of the proposed pathogen derived resistance genetic engineering approach in tomato will provide a sound experimental basis for using this technology in other horticultural industries.
