Fig. 4.

Effect of mutations in prnA and trpE of Pseudomonas chlororaphis O6 on induced systemic resistance activity in tobacco against Pectobacterium carotovorum SCCI. Roots of three week-old tobacco grown in microtiter wells were inoculated with wild type (Wt), the gacS mutant (GacS-), the complemented gacS mutant (ComGacS-), the trp mutant (TrpE) and the prnA mutant (PrnA) or were treated with water as a negative control prior to pathogen challenge. After one week, leaves were challenged with P. carotovorum subsp. carotovorum SCCI and soft rot symptomic leaves were scored after two days. Different letters indicate significant differences between treatments according to Duncan’s multiple range test (p< 0.05). Two independent experiments were performed with at least 21 plants/treatment.