TRANSGENIC PLUMS (PRUNUS-DOMESTICA L) EXPRESS THE PLUM POX VIRUS COATPROTEIN GENE

Plum hypocotyl slices were transformed with the coat protein (CP) gene of plum pox virus (PPV-CP) following cocultivation with Agrobacterium tumefaciens containing the plasmid pGA482GG/PPV-CP-33. This binary ve ctor carries the PPV-CP gene construct, as well as the chimeric neomyc in phosphotransferase and beta-glucuronidase genes. Integration and ex pression of the transferred genes into regenerated plum plants was ver ified through kan resistance, GUS assays, and PCR amplification of the PPV-CP gene. Twenty-two transgenic clones were identified from approx imately 1800 hypocotyl slices. DNA, mRNA, and protein analyses of five transgenic plants confirmed the integration of the engineered CP gene , the accumulation of CP mRNA and of PPV-CP-immunoreactive protein. CP mRNA levels ranged from high to undetectable levels, apparently corre lated with gene structure, as indicated by DNA blot analysis. Western analysis showed that transgenic plants produced amounts of CP which ge nerally correlated with amounts of detected mRNA.