Two tobacco transgenic lines over-expressing grapevine polygalacturonase-inhibiting protein (Vvpgip1) vs. WT tobacco under normal growth conditions

Polygalacturonase-inhibiting proteins (PGIPs) in plant cell walls inhibit fungal endopolygalacturonases (ePGs). Their action directly limits the effective ingress of the pathogen and is thought to lead to an up-regulated defense response. We previously showed that, PGIP activity, ePG inhibition and decreased Botrytis cinerea susceptibility were correlated in tobacco plants over-expressing grapevine (Vitis vinifera) Vvpgip1. In order to evaluate the base-line impact of PGIP over-expression, the transcriptome and hormone profiles of two transgenic lines with characterized resistance phenotypes were investigated in the absence of pathogen infection. Three microarray slides in total were hybridized: two slides using Vvpgip1 line 37 and WT, with a dye swap included to account for dye bias; and one slide using Vvpgip1 line 45 as test and WT as reference.