Submitted to: Plant Disease
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/11/1997
Publication Date: N/A
Citation: N/A Interpretive Summary: Potato leafroll virus (PLRV) causes a very costly disease of potatoes in the Columbia Basin of the northwestern United States and in most, if not all, countries where potatoes are grown. Russet Burbank potatoes, the favored cultivar of the American industry for more than 100 years, is highly susceptible to the disease. Approximately 15 million pounds of insecticide are currently used to control the insects that spread the viru in the Columbia Basin alone. Using a genetic engineering technique, Russet Burbank potatoes were altered to resist spread of the PLRV by aphids in the field. This resistance markedly reduced infection and damage caused by the disease in the field. In other characteristics, the new Russet Burbank potatoes are the same as the parent cultivar. This resistance could reduce the amount of pesticides required to control PLRV and disease losses that occur despite the use of pesticides.
Technical Abstract: Russet Burbank potato was transformed with plant expression vectors containing the potato leafroll virus (PLRV) coat protein (CP) gene. Transgenic potato lines contain a gene expression cassette with two copies of a PLRV CP gene in which the nucleotide sequence was modified to improve expression of the gene. In addition, the two copies of the PLRV CP gene were each driven by a different promoter. Field test screening for PLRV resistance identified 15 lines which showed moderate resistance to PLRV infection and virus titer build up, and a longer incubation period for systemic infection. By conducting field resistance assays during a period when PLRV is not introduced into plots as a contaminant, it was possible to test whether the observed resistance was sufficient to restrict aphid transmission of PLRV in a field test environment. Two years of field testing demonstrated that PLRV spread from an infected plant of the same line was severely restricted in nearly all the transgenic lines in the field. These lines have useful resistance to PLRV and could aid in managing PLRV disease in Russet Burbank potato.