Efficient “vaccination” of Nicotiana benthamiana and tomato plants using a lab-attenuated strain of Pepino mosaic virus
G. M. CHEWACHONG (1), J. J. Blakeslee (2), M. A. Ellis (1), S. A. Miller (1), F. Qu (1). (1) Department of Plant Pathology, Ohio Agricultural Research and Development Center, The Ohio State University, Wooster, OH, U.S.A.; (2) Department of Horticulture and Crop Science, Ohio Agricultural Research and Development Center, The Ohio State Univer
Cross protection, the act of stimulating plant defense to a virus by pre-inoculating plants with a mild strain (a plant virus “vaccine”) is a viable but underused disease management approach. So far, all known cross protection-inducing vaccines are field isolates associated with milder symptoms which could evolve to become more virulent. Hence, the absence of a rapid and reliable procedure for developing plant virus vaccines is a major obstacle for widespread use of cross protection. The aim of our study is to develop a knowledge-based approach to produce stable vaccines. We used <i>Pepino mosaic virus</i> (PepMV), an emerging pathogen of tomato, as the model virus for our study, and chose its capsid protein (CP) gene for modifications to produce an attenuated strain. Less conserved amino acid (AA) residues within the CP of PepMV were identified by multiple alignments with other potexviruses. Next, we replaced some of these AAs with their counterparts in <i>Potato virus X</i>. Testing the resulting mutants for their ability to cause diseases in <i>Nicotiana benthamiana</i> plants revealed that mutants KD and KD/VC retained the ability to infect plants systemically yet caused mild symptoms. KD was further shown to protect both <i>N. benthamiana</i> and tomato plants against secondary infection of wild-type PepMV. KD remained stable following five passages. Our results establish a reliable method for producing stable plant virus vaccines and provide a novel virus management option for tomato.
View Presentation |
