Real-time quantitative polymerase chain reaction was used to study the expression of some marker genes involved in the interaction between grape (Vitis vinifera L.) and the erineum mite Colomerus vitis Pagenstecher (Acari: Eriophyidae). Potted vines of cultivars Atabaki (resistant to C. vitis), Ghalati (susceptible to C. vitis) and Muscat Gordo (moderately resistant to C. vitis) were infested at the six-leaf stage. The expression of protease inhibitor (PIN), beta-1,3-glucanase (GLU), polygalacturonase inhibitor (PGIP), Vitis vinifera proline-rich protein 1 (PRP1), stilbene synthase (STS), and lipoxygenase (LOX) genes was assessed on young leaves collected 96, 120 and 144 h after mite infestation (hami). As a control, non-infested leaves collected 24 h before mite infestations were used. Differences were detected in expression of the selected genes during the C. vitis-grapevine interaction. The resistant cultivar Atabaki increased the expression of LOX, STS, GLU, PGIP and PRP1 genes during the first 120 hami. On the contrary, in the susceptible Ghalati, all selected genes showed an expression level similar or lower than non-infested leaves. Muscat Gordo increased the expression of all selected genes in comparison with non-infested leaves, but it was lower than in Atabaki. Significant transcript accumulation of PIN gene was detected for Muscat Gordo whereas it was slightly up-regulated in Ghalati and Atabaki. LOX, STS, PIN, GLU, PGIP and PRP1 genes were clearly expressed in response to C. vitis infestation. We therefore infer that expression of PGIP, PIN and PRP1 genes could represent a defense strategy against C. vitis infestations in grapevine leaves.
Keywords: Grape erineum mite; PR proteins; Plant resistance; Real-time quantitative PCR; Vitis vinifera.