Transgenic tobacco plants carrying a baculovirus enhancin gene slow the development and increase the mortality of Trichoplusia ni larvae

Abstract.

This study was done to assess insect growth and mortality on tobacco plants transformed with baculovirus enhancin genes, as a first step toward the possible use of enhancin transgenes as part of an insect control system. Enhancin genes from Trichoplusia ni or Helicoverpa armigera baculoviruses were introduced into tobacco via Agrobacterium tumefaciens with kanamycin selection. PCR analyses of genomic DNA confirmed the presence of the enhancin genes in the kanamycin-resistant plants; however, the expression of the genes was very low and could be detected only with RT-PCR. Bioassays with Trichoplusia ni larvae showed that larval growth and development was significantly slower on some transgenic lines and that larval mortality was higher. The majority of the enhancin-transgenic plants had little or no inhibitory effect. The low expression of enhancin in plants carrying current expression cassettes and the relevance of these results to pest management are discussed.