Induction of calcium-dependent protein kinase activity and HmCDPK1 expression in the early response of Hami melons to Penicillium infection

Abstract

Calcium-dependent protein kinase (CDPK) plays an important role in plant resistance to disease. In this study, we assessed CDPK activity in Hami melons during Penicillium infection, in order to investigate the possible role of CDPK in this context. The results showed the induction of CDPK by Penicillium infection may contribute to the early stages of disease resistance in Hami melons. In order to further study the molecular mechanisms underlying this response, relatively high expression of HmCDPK1 was screened form the transcriptome database of Hami melons. Bioinformatics analysis showed HmCDPK1 had a length of 2365 bp, with a maximum open reading frame of 1560 nucleotides, encoding 519 amino acids with a molecular weight of 58,646.83. Moreover, its theoretical isoelectric point was 6.34, as a hydrophilic and non-transmembrane protein. Real-time quantitative PCR showed the transcript of HmCDPK1 was persistently increased after Penicillium infection and reached its maximum at 12 h, being significantly higher than in non-infected plants. These results suggest the induction of CDPK activity and HmCDPK1 expression in the early response of Hami melons to Penicillium may contribute to the resistance against this infection.