Tomato yellow leaf curl China virus: monopartite genome organization and agroinfection of plants

The complete DNA sequence (2734 nucleotides) of the monopartite genome of t omato yellow leaf curl China virus (TYLCCNV), a begomovirus transmitted by the whitefly Bemisia tabaci, was determined. The circular genomic DNA conta ins six open reading frames (ORFs) encoding proteins of molecular weights > 10 kDa, of which two (V1 and V2) are located on the virion-sense strand an d four (C1, C2, C3 and C4) on the complementary-sense strand. The ORFs are comparable to those of other whitefly-transmitted begomoviruses with a mono partite genome and to those encoded by DNA-A of bipartite begomoviruses. Se quence comparisons with other geminiviruses showed that TYLCCNV belongs to Begomovirus from the Old World. No putative DNA-B genome was found. Nicotia na species and tomato plants agroinoculated with the TYLCCNV monopartite ge nome developed typical yellowing and leaf-curling symptoms. The cloned mole cule carried all the information needed for virus replication and systemic infection of plants. (C) 2001 Elsevier Science B.V. All rights reserved.