Stress-induced expression of cucumber chitinase and Nicotiana plumbaginifolia β -1,3-glucanase genes in transgenic potato plants

The genes encoding for a cucumber class III chitinase and Nicotiana plumbaginifolia class I glucanase were co-introduced into Slovak potato ( Solanum tuberosum L.) cultivar ETA using Agrobacterium tumefaciens . Expression of both genes was driven by wound-inducible polyubiquitin promoter isolated from Slovak potato breeding line 116/86. Analyses showed inducible, peel-specific expression of both transgenes under stress conditions. The effect of transgene expression on fungal susceptibility of transformants was evaluated in vitro and in vivo . Experiments with crude protein extracts isolated from transgenic microtubers showed growth inhibition of Rhizoctonia solani hyphae in the range from 7.3 to 14.2%. In contrast, experiments performed in growth chamber conditions revealed that the polyubiquitin promoter driven transgene expression did not ensure any obvious increase of transgenic potato resistance against Rhizoctonia solani .