Agroinfection of Nicotiana spp. with Cloned DNA of Tomato Golden Mosaic Virus

Abstract

Summary Head-to-tail dimers of cloned DNA A and DNA B of tomato golden mosaic virus (TGMV) were integrated between the T-DNA border sequences of a broad host range binary vector and transferred into cells of Nicotiana benthamiana seedlings using an Agrobacterium tumefaciens-mediated delivery system. Most of the inoculated plants developed golden-yellow mosaic and leaf curling symptoms typical of TGMV infection. Extracts of infected leaves were shown to contain both double-stranded and single-stranded TGMV DNA forms of genome length and the virus capsid polypeptide. Infection was also achieved by inoculating plants with mixtures of Agrobacterium strains containing dimers of DNA A or DNA B, with a strain containing a partial dimer of DNA A and a dimer of DNA B and with a strain containing a dimer of DNA B and a partial dimer of DNA A with a 603 bp deletion in the coat protein gene. In the latter case, mosaic symptoms were mild and leaves did not curl. Transgenic N. tabacum cv. Samsun plants containing head-to-tail dimers of DNA A (A2 plants) or DNA B (B2 plants) were produced by transformation with Ti plasmid vectors. A2 plants and B2 plants were agroinfected with dimeric DNA B and dimeric DNA A, respectively. In both cases, symptoms typical of TGMV infection were induced and viral single-stranded DNA of both components was detected in the systemically infected tissue.