Comparison of PR1 expression in grapevine cultures after inoculation with a host- and a non-host pathogen

different grapevine cultures that were inoculated with Plasmopara viticola as a host pathogen and Pseudoperonospora cubensis as a non-host pathogen. The results of the expression analysis showed that the PR1 mRNA level in Vitis vinifera cv. Riesling and Vitis riparia cv. Gloire de Montpellier is mainly affected by the culture system. PR1 is constitutively expressed in callus cultures. In vitro plants showed a low basal expression of PR1 that is enhanced af-