Systemic movement and symptom production following agroinoculation with a single DNA of tomato yellow leaf curl geminivirus (Thailand).

Two different DNA species were cloned from purified tomato yellow leaf curl geminivirus particles after annealing a specific primer to virus DNA and generating a second strand; both were approximately 2.8 kbp in length. One clone contains sequences which hybridize to the coat protein gene of tomato golden mosaic virus and most likely represents the A DNA of tomato yellow leaf curl virus (Thailand). The other clone may represent the B DNA of this geminivirus. Both clones contain short sequences which share extensive homology. These sequences have some of the same features of common regions of other geminiviruses. Systemic viral infection of tomato and Nicotiana benthamiana was accomplished by agroinoculation with the proposed A DNA. The symptoms of systemically A-infected plants include stunting, lack of flower production, and mottled, yellowish leaves. At low frequency during agroinoculation of N. benthamiana with a mixture of both DNAs, replication of the second DNA is also detected. In these instances, symptoms are more pronounced than infections where only the A DNA is agroinoculated. This is the first report of a whitefly-transmitted dicot-infecting geminivirus capable of infection (via agroinoculation), symptom induction, and systemic movement using a single DNA.