Delay of Disease Development in Transgenic Plants That Express the Tobacco Mosaic Virus Coat Protein Gene

TLDR

A chimeric gene encoding the TMV coat protein was inserted into tobacco cells via a tumor‑gene‑deleted Agrobacterium Ti plasmid, and transgenic seedlings were inoculated with TMV to assess disease progression. Transgenic plants expressing the coat protein showed delayed or absent symptom development, with 10–60 % remaining symptom‑free, and higher inoculum concentrations shortened the delay, demonstrating that genetic transformation can confer resistance to TMV disease.

Abstract

A chimeric gene containing a cloned cDNA of the coat protein (CP) gene of tobacco mosaic virus (TMV) was introduced into tobacco cells on a Ti plasmid of Agrobacterium tumefaciens from which tumor inducing genes had been removed. Plants regenerated from transformed cells expressed TMV mRNA and CP as a nuclear trait. Seedlings from self-fertilized transgenic plants were inoculated with TMV and observed for development of disease symptoms. The seedlings that expressed the CP gene were delayed in symptom development and 10 to 60 percent of the transgenic plants failed to develop symptoms for the duration of the experiments. Increasing the concentration of TMV in the inoculum shortened the delay in appearance of symptoms. The results of these experiments indicate that plants can be genetically transformed for resistance to virus disease development.