Complete Nucleotide Sequence and Genome Organization of Soybean Crinkle Leaf Virus

The genomic DNA of soybean crinkle leaf virus (SCLV) from Thailand has been sequenced. The single circular DNA molecule comprises 2737 nucleotides, and contains eight open reading frames each capable of encoding a protein with a molecular weight greater than 10 kDa. A 39‐base potential stem‐loop forming region occurs in the intergenic region (IR) that also includes the conserved nonanucleotide sequence TAATATTAC. The iterative sequence (TCAATCGGTGT), which is specific to SCLV, is also found in the IR. SCLV is most closely related (90% identity) to the monopartite geminivirus ageratum yellow vein virus. As the two viruses differ in host range, and the iterative sequence is specific to SLCV, the virus is a distinct monopartite geminivirus of soybean.     

Tomato leaf curl geminivirus associated with cantaloupe yellow leaf disease in Thailand

Geminivirus associated with yellow leaf disease of cantaloupe plants was detected using polymerase chain reaction (PCR) with geminivirus-specific degenerate primers which anneal within the AC1 ORF (replication initiator protein gene) and the AV1 ORF (coat protein gene). A DNA fragment of 1.2 kbp was amplified, cloned and sequenced. The 32-base stem loop region was found in the amplified fragment. This included the conserved nonanucleotide sequence TAATATTAC present in all geminiviruses. The nucleotide sequence of the intergenic region (IR) was compared with 28 whitefly-transmitted geminiviruses. The geminivirus associated with yellow leaf disease of cantaloupe plants showed 96.2% sequence identity with DNA A of tomato leaf curl geminivirus from India (ToLCV-In2). These data suggest that cantaloupe yellow leaf disease was caused by ToLCV.