ARS | Publication request: Transgenic plums expressing the plum pox virus (PPV) coat protein gene do not assist the development of PPV recombinants under field conditions

Submitted to: Journal of Plant Pathology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: April 16, 2010
Publication Date: N/A

Interpretive Summary: Genetic engineering offers the promise of disease control through a non-chemical means. This technology could have important uses for tree fruits which are subject to a number of disease problems that are difficult to control including virus diseases. One of the most devastating virus diseases affecting stone fruit trees (plums, apricots, peaches, cherries) is Plum pox virus (PPV) which is an exotic disease organism that has recently invaded the U.S. We have developed PPV resistant plum trees through genetic engineering. In order to understand the role of PPV resistant plums in the environment, we evaluated plum trees for changes in PPV populations that might occur in a planting of genetically engineered PPV resistant plum trees. Our findings showed that there was no change in virus populations in the genetically engineered plums when compared with non-genetically plums. This information added additional support for the benign nature of PPV resistant genetically engineered plums in the environment, and it shows the great potential of genetic engineering for virus disease control in fruit trees.

Technical Abstract: The serological and molecular variability of Plum pox virus (PPV) detected in transgenic plum trees harboring PPV capsid gene versus those found in conventional plums were analyzed. Strain characterization was serologically determined by TAS-ELISA using PPV-D and PPV-M specific monoclonal antibodies and by molecular typing. Three genomic regions corresponding to (Cter)CP, (Cter)Nib-(Nter)CP-CI, and RFLP analysis at the C-ter of CP cistron verified the occurrence of different PPV strains. PCR products spanning (Cter)CP and (Cter)Nib-(Nter)CP regions were sequenced and revealed that there was no significant difference between PPV isolates collected from susceptible transgenic plums released in the field and do not represent an environmental risk through the emergence of new PPV variants.