Comparative analysis of osmotin-like PR5 and PA13 proteins in potato infected by late blight (Phytophthora infestans)

Induction and accumulation of osmotin-like proteins are crucial components of innate immune responses in plants challenged with pathogens. One of these proteins, PR5 and PA13 , are abundantly secreted and are able to elicit plant defenses, however, their native function in potato plants infected with Phytophthora infestans remains unknown. Here, the pathway signaling of the two genes were monitored in potato plants at early points of infection with P. infestans using quantitative real-time PCR (qPCR). Our data demonstrated significant gene expression variance of the two genes in infected plants as compared to the non-infected controls. It is also notable that PA13 gene had higher expression than PR5 in the resistant cultivar 'Sponta' as compared to the susceptible one 'Draga' with a maximum expression for PR5 (3.5 and 1.2-fold) and PA13 (8.2 and 2.7-fold) respectively, at 48 hours post infection. The obtained results suggested that PR5 and PA13 genes, positively regulate P. infestans -resistance in potato plants during disease progress, which can offer testable hypotheses that will need straight upcoming experiments to define how the PR5 and PA13 pathway signaling may be specified in potato defense system.