TRANSFORMATION OF 2 POTATO CULTIVARS SPUNTA AND CLAUSTAR (SOLANUM-TUBEROSUM) WITH LETTUCE MOSAIC-VIRUS COAT PROTEIN GENE AND HETEROLOGOUS IMMUNITY TO POTATO-VIRUS-Y

The coat protein (CP) gene of the lettuce mosaic potyvirus (LMV) was i ntroduced into two potato cultivars-Spunta and Claustar-via Agrobacter ium tumefaciens-mediated transformation. Gene expression was verified by Southern, Northern and Western blot. The regenerated plants have be en tested for resistance against potato virus Y (PVY-0) in greenhouse. We observed an immune phenotype in four transgenic lines expressing t he CP-LMV protein at different delectable levels. However, in two othe r transgenic plant lines, symptoms were developed at a frequency of 25 and 60% with a delay in their appearance. Transgene transcripts of th e CP-LMV gene were detected by Northern blot in these two lines, but t he protein could not be detected by Western blot. The correlation betw een the presence of the CP protein at a detectable level and the expre ssion of an immune phenotype is discussed. (C) 1998 Elsevier Science I reland Ltd. All rights reserved.