Virus resistance of plants can be obtained through developing transgenic lines which express the viral coat protein (CP) at high level, a strategy , known as CP-mediated protection.We are studying the interaction of an endemic South American Virus, the Andean potato Mottle Virus (APMV), with different plant species. We wish to apply a similar CP-mediated protection approach in developing resistant crops. For this, we have purified APMV particels and initiated a detailed study of the APMV genome. It comprises of two RNA molecules, a major (5.9Kb) and a minor (3.6Kb). CDNA clones of both genomic RNAS have been synthesised and characterised by DNA sequence analysis. The open reading frames encoding the viral CPs were identified by N-terminal sequencing of the purified CPs ana comparison with the previous reported sequence of the related C0WPea Mosaic Virus. Using PCR strategies, the complete ORF of both Cps were obtained and cloned into appropriate plant transformation vector. Transgenic lines of N. tabacum and S. tuberosum will be obtained and characterised by southern blot analysis (gene copy number), northern analysis (gene expression) ELISA (coat protein concentration)..A dual strategy will be applied. At first, umono-CP' lines will be produced where only one of the Cps is introduced into the host plant. In later stages, "bi-Cp" lines will be generated, co-expressing both Cps. Apmv resistance in both types of transgenic plants will be scored upon mechanical and insect-mediated infection. Resistant lines will be analyzed for harboured cross protection against other viruses including TMV, TNV, PVX and PVY. These analysis will give a detailed view on the effectiveness of CP-mediated protection towards controlling APMV infection. In addition, we wish to explore the possibility of increasing or broad resistance through cooverexpressing the viral Cps and common defense genes. This will be achieved by crossing transaenic tobacco plants overexpressing respectively beta (1,3) glucanase superoxide dismu tase, a glycine-rich protein and extensin, will be crossed with the - CP+transgenic lines. These double transgenic plants Will then be analvzed for altered resistance to APMV.
Funding SchemeCSC - Cost-sharing contracts
21941 Rio De Janeiro