Defence reactions during Cuscuta reflexa infection

• Applicant: Professor Dr. Ralf Kaldenhoff
• Subject Area: Plant Physiology
• Term: from 2006 to 2010
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 34978821

The root and leafless plant parasite Cuscuta reflexa penetrates a host plant by hyphae that transfer water and nutrition from the host to the parasite. Cuscuta infects virtually all herbaceous plants and thus is an important pest plant in warm climates all over the world. Only very few plant species, like e.g. young tomatoes, are able to repel C. reflexa by a hypersensitive reaction. We could show that, as a response to Cuscuta-contact, tomato changed local Ca2+-concentrations and expressed genes coding for cell wall modification proteins. The aim of the proposed project is to understand molecular events during this parasite-host interaction and to develop new strategies against Cuscuta infection. In preliminary work a subtracted cDNA library of tomato was built up and differentially screened for genes which are upregulated in tomato due to C. reflexa attack. Defence reactions will be now analyzed by investigations of such sequences via RNAi and Virus Induced Gene Silencing techniques to identify defence genes. For gene expression studies promoter fusions to GUS or Luciferase and analysis via corresponding assays will be carried out. Transformation of the compatible host tobacco with tomato cDNAs should show the responsibility of these genes for the resistance of tomato to C. reflexa attack.

• DFG Programme: Research Grants