Mw. O.I. (Ourania) Pavli, MSc: “Molecular Characterization of Beet Necrotic Yellow Vein Virus in Greece and Transgeneic Approaches towards Enhancing Rhizomania Disease Resistance”

Rhizomania disease of sugar beet, caused by Beet necrotic yellow vein virus (BNYVV), is responsible for severe economic losses. Due to its widespread occurrence and the absence of other efficient control measures, economic viability of the crop is to the largest extent dependent on the use of varieties genetically resistant to the disease. Recent reports on the emergence of virus strains capable of compromising the currently used resistance as well as on the spread of highly pathogenic isolates have necessitated a detailed investigation of the situation as it evolves in Greece. The study revealed the widespread occurrence of BNYVV throughout the country as well as the prevalence of pathotype A isolates in all sugar beet growing regions. In addition, a survey for a possible occurrence of related to rhizomania soil-borne viruses revealed the co-existence of both Beet Soilborne Virus (BSBV) and Beet Virus Q (BVQ) in rhizomania infested fields. Towards engineering RNA silencing-based rhizomania resistance, three intron hairpin constructs carrying parts of the BNYVV replicase gene, proved capable of conferring transgenic rhizomania resistance in sugar beet hairy roots. In addition, the possibility to exploit non-viral genes for the purposes of achieving disease resistance was explored by expressing the HrpZPsph protein in transgenic N. benthamiana plants.