A pathogen-derived resistance strategy for the broad-spectrum control of grapevine leafroll disease
Freeborough, M J
University of Stellenbosch. Department of Genetics
Vivier, M A
Burger, J T
The Institute for Wine Biotechnology (IWBT) chose the subject of manipulated disease resistance as main theme for the grapevine improvement programme. In this broad subject we are currently focusing on resistance to fungal infections as well as resistance to viral infections (in collaboration with Dr J T Burger, University of Stellenbosch. Department of Genetics). We aim to introduce broad-spectrum resistance to grapevine leafroll disease by genetically modifying grapevines. We wish to transfer a dysfunctional movement protein gene, derived from grapevine leafroll-associated virus-3 (GLRaV-3) into grapevines. This dysfunctional movement protein will interfere with the function of the wild-type movement protein, in a dominant negative manner, and therefore disrupt the infection cycle of GLRaV-3 and other closteroviruses associated with grapevine leafroll disease. This should be possible as leafroll associated closteroviruses are expected to use similar strategies for movement from cell to cell. We plan to clone the GLRaV-3 HSP70-h movement protein gene, disrupt the gene in order to make dysfunctional forms of the protein and transform the disrupted gene constructs into grapevine plants.
This project aims to introduce broad-spectrum resistance to control the numerous viruses associated with grapevine leafroll disease. The strategy is based on movement protein mediated resistance (MP-MR), which has been used successfully to control a variety of viruses infecting single plants. This resistance is achieved by a dominant-negative interaction between the functional virus encoded movement protein and the transformed (virus-derived) plant-encoded dysfunctional movement protein. Delayed symptom development and reduced virus load are achieved by this strategy.
Freeborough, M-J, Burger, J T and Pretorius, I S. 1999. A new approach for the control of grapevine leafroll disease. Paper presented at the 24th National Congress of the South African Society for Enology and Viticulture. 18-19 November, Somerset West, South Africa.
Freeborough, M-J, Burger, J T and Pretorius, I S. 2004. A mutated GLRaV-3 protein provides resistance against the unrelated PVX. Paper presented at the 18th Congress of the South African Genetics Society. 4-7 April, Stellenbosch, South Africa.
Laubscher, A E, Freeborough, M-J and Burger, J T. 2004. Molecular evaluation of virus resistance in transgenic plants. Paper presented at the 18th Congress of the South African Genetics Society. 4-7 April, Stellenbosch, South Africa.