Cloning and sequence analysis of HC-Pro gene of soyabean mosaic virus (SMV).

This study aims to clone and sequence full-length cDNA of HC-Pro gene of six SMV isolates using RT-PCR,to observe the reaction of six SMV isolates to ten hosts,and to discuss the relationships between similarity of the gene sequence and virus virulence,effect of cross-protection.The results showed that full-length cDNA of HC-Pro gene had 1371 nucleotides encoding 457 amino acids.The protein HC-Pro had functional domains such as the CCC motif related to virus movement and the PTK motif related to spread by aphids.Homologies of six SMV isolates nucleotides were 89.2%～99.9% and amino acids were 95.4%～99.8%.There was one different nucleotide in sequence of HC-Pro gene between TS216 and 4434.No certain relationship was found between homology of HC-Pro gene of six SMV isolates and their virulence.While,homology of SMV isolates determined effects of cross-protection to a certain extent.