Submitted to: Plant Disease
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/10/1997
Publication Date: N/A
Interpretive Summary: Cucumber mosaic virus (CMV) has been described as one of the most damaging diseases which affects field-grown vegetable crops worldwide. This report describes the results of field trials to evaluate use of a novel technology for protecting tomatoes against CMV. Three different tomato lines were genetically engineered to produce a small moiety termed a satellite. This satellite protects tomatoes against CMV. Engineered and non-engineered plants were infected with CMV to simulate disease epidemic conditions. Plant yield, disease ratings, and virus and satellite levels were evaluated in field tests of these tomatoes over two consecutive years. Plants expressing satellite were protected against disease caused by CMV as compared to unprotected plants. Protected plants exhibited higher yield, mild or no CMV symptoms and low levels of virus relative to non-transformed plants. A risk assessment component included in the study to monitor the possible movement of satellite into plants outside the test area demonstrated that spread of satellite was minimal. The research will benefit crop producers in production areas where CMV is endemic and provide information to assist other researchers who develop virus resistant plants.
Technical Abstract: Field trials of transgenic tomato plants expressing an ameliorative satellite RNA of cucumber mosaic virus (CMV) were conducted to test the efficacy of satellite-transgenic technology to protect against CMV infection. Three transgenic tomato lines derived from two susceptible genotypes were evaluated over two growing seasons for fruit yield, viral symptoms and titers, and satellite expression. Total marketable yield of CMV infected satellite-transgenic lines was 40% to 84% greater than that of CMV-infected parent lines. Importantly, yield of CMV-infected satellite transgenic lines did not differ significantly from mock inoculated parent lines. Satellite-transgenic lines exhibited mild or no CMV symptoms and low viral titers relative to nontransformed plants. A significant negative correlation between satellite levels and disease severity was evident in transgenic lines. Risk assessment results demonstrated low levels of satellite transmission within the test site and no evidence of satellite-induced damage on surrounding plants.