APS Homepage

Poster: Biology & Disease Mgmt: Virology


Mixed Infection of Two Economically Important Tospoviruses in Nicotiana benthamiana
K. ZHAO (1), C. Rosa (1) (1) The Pennsylvania State University, U.S.A.

Tomato spotted wilt virus (TSWV) and Impatiens necrotic spot virus (INSV) are two economically important tospoviruses. Mixed infection of TSWV and INSV was first reported on tomato plants from Italy in 2000; and mixed infection has also been found in tobacco in many states in the US for more than two years. Sialer and Gallitelli suggested that mixed infection in tomato could represent progressive adaption of INSV to vegetable crops. To test this hypothesis, healthy Nicotiana benthamiana plants were mechanically inoculated with different ratios of TSWV/INSV and examined for how mixed infections influence disease development. After two weeks, systemically infected leaves were collected to measure the viral titer by ELISA. Results show that TSWV is a poor competitor compared to INSV, since INSV could establish infection and reach high titer even when inoculated with equal amount of TSWV inoculum, but TSWV was not able to infect N. benthamiana efficiently in the presence of INSV. Mixed infections of tospoviruses are commonly found in nature, but the interaction between these two economically important tospoviruses and how mixed infections affect viral host range have not been studied yet. Our results provide insights into the interaction between TSWV and INSV in N. benthamiana and basic knowledge for future tospovirus mixed infection studies.