1a. Objectives (from AD-416)
New citrus scion and rootstock cultivars will be developed with stimulated systemic acquired resistance pathways, to improve resistance to HLB and other pathogens.
1b. Approach (from AD-416)
Molecular studies will be used to identify important components of the SAR pathway in citrus. Arabdopsis will be used as a model system to evaluate pathway components and clone genes. Pathway components appearing useful for stimulating pathogen resistance responses will be engineered into citrus and the resulting transformants used for greenhouse testing with Huanglongbing (HLB).
3. Progress Report
This project is specifically related to Objectives 1 and 2 of the parent project: Create new genetic combinations of citrus, and screen germplasm for important traits and select superior individuals. This cooperative research is focused on manipulating citrus tree defense pathways to increase resistance of trees to Huanglongbing and other diseases. The approach of the project is to use genetic homology with the model plant Arabidopsis to identify defense signaling molecules in citrus. Using this approach we have obtained full-length cDNA sequences for eight citrus genes in the defense signaling pathway and have produced transgenic citrus plants from a construct of the four of these genes. Transformed plants are being prepared for testing with Huanglongbing disease.