COAT PROTEIN GENE REPLACEMENT RESULTS IN WHITEFLY TRANSMISSION OF AN INSECT NONTRANSMISSIBLE GEMINIVIRUS ISOLATE

Geminiviruses are transmitted by whiteflies, leafhoppers, or treehoppe rs. The whitefly species Bemisia tabaci (Gennadius) is the most effici ent vector of Subgroup III geminiviruses. An isolate of Abutilon mosai c virus (AbMV), a bipartite geminivirus, was not detectable in the DNA extract from insects by Southern blot analysis, nor was the isolate t ransmissible by the B-biotype of B, tabaci, although the virus DNA was amplified (by PCR) from some insects. In contrast, Side golden mosaic virus (SiGMV-Co), a closely related geminivirus, was acquired and tra nsmitted by B. tabaci to various host plants. The coat protein of AbMV was replaced with that of SIG MV-Co. The resulting chimeric AbMV was acquired and transmitted to various host plants by B, tabaci, indicati ng that the coat protein plays an essential role in the transmission p rocess by B, tabaci. (C) 1997 Academic Press.