NKJ 122 Enhanced control of Potato mop-top virus in the Nordic and Baltic Sea region

Since 1980's, a disease manifested by necrotic symptoms inside potato tubers (spraing disease) has spread in an uncontrolled manner in all Nordic countries and constitutes the most severe quality problem in a commercial use of potatoes. In this project, n ovel biotechnological methods and tools will be utilised and developed to alleviate problems caused by PMTV, the causal agent of spraing. They include an infectious cDNA of PMTV (site-directed mutagenesis), yeast two hybrid system screens (interactions be tween viral proteins, identification of host proteins interaction with viral proteins), microarray-based analysis of gene expression (resistant and sensitive virus-potato interactions), monoclonal antibodies to PMTV proteins, (new bead method for virus de tection and viral mutant analysis), a vector-transmission system for PMTV, an efficient root transformation system for identification of potato resistance and sensitivity factors (in combination with use of the vector-transmission system for PMTV), high through-put automated, robot-assisted sequencing of viral strains, and advanced computer-assisted analysis of recombinations and phylogenetic relationship. Abilities to detect PMTV in symptomatic and symptomless potato tubers will be increased using novel diagnostic methods combined with improved knowledge about the conditions inductive to symptom development and understanding how such conditions affect different potato cultivars. This research requires 4 years to be carried out. In the first two years, e ffort will be put to screening for PMTV in the Baltic Sea region and for fine-tuning the aforementioned study systems for detailed functional studies on virus-host and virus-interaction. The next two years will be used for improving diagnostic methods in practise and for carrying out the detailed molecular studies described.