Cloning and Characterization of a PGIP-Encoding Gene from Solanum torvum

Verticillium wilt is a severe disease in eggplant caused by Verticillium dahliae. Polygalacturonase-inhibiting proteins (PGIPs) have been shown to be involved in preventing the invasion of fungus including V. dahliae. Cloning genes encoding PGIPs is quite valuable for plant resistance breeding to Verticillium wilt. In this study, a cDNA encoding the polygalacturonase-inhibiting protein was isolated from Solanum torvum by RT-PCR and RACE, designated StPGIP (accession no. FJ943498). The cDNA sequence of StPGIP was 1 097 bp long and contained an open reading frame of 990 bp. The predicted amino acid sequence of the gene consisted of 329 amino acids and had conserved LRRs. The StPGIP protein had a high identity with PGIPs from other species. Analysis of StPGIP expression at the mRNA level by RT-PCR showed that the gene was expressed in all organs and could be induced to increase expression by V. erticillium dahliae infection.