Expression of two genes in Castanea dentata, Castanea mollissima, and their hybrid after inoculation with Cryphonectria parasitica

Real-time quantitative PCR was used to assess the expression of two genies in American chestnut (susceptible), Chinese chestnut (resistant), and their F1 hybrid (intermediate resistant). A 13.9 chaperone and Pg (a polygalacuronase beta-subunit) were chosen based upon their PCR efficiencies and lack of primer dimer affects. Relative expression levels were analyzed by both the comparative Ct method and the Pfaffl method. There was no significant change in 13.9 expression among any of the species making it a poor resistance marker. Pg expression increases in immediately (1 day) post inoculation in Chinese chestnut. There was no significant change in Pg expression in American chestnut, while the F1 hybrid showed a delay in significant increases in expression. These preliminary results warrant further analysis of changes in Pg expression alter Cryphonectria parasitica infection.