Disease resistance conferred by expression of a gene encoding H2O2-generating glucose oxidase in transgenic potato plants.

Abstract

Plant defense responses to pathogen infection involve the production of active oxygen species, including hydrogen peroxide (H2O2). We obtained transgenic potato plants expressing a fungal gene encoding glucose oxidase, which generates H2O2 when glucose is oxidized. H2O2 levels were elevated in both leaf and tuber tissues of these plants. Transgenic potato tubers exhibited strong resistance to a bacterial soft rot disease caused by Erwinia carotovora subsp carotovora, and disease resistance was sustained under both aerobic and anaerobic conditions of bacterial infection. This resistance to soft rot was apparently mediated by elevated levels of H2O2, because the resistance could be counteracted by exogenously added H2O2-degrading catalase. The transgenic plants with increased levels of H2O2 also exhibited enhanced resistance to potato late blight caused by Phytophthora infestans. The development of lesions resulting from infection by P. infestans was significantly delayed in leaves of these plants. Thus, the expression of an active oxygen species-generating enzyme in transgenic plants represents a novel approach for engineering broad-spectrum disease resistance in plants.

Oxidative cross‐linking of plasma membrane arabinogalactan proteins

“…The presence of horseradish peroxidase (and H202) was required for cross-linking to occur (data not shown). The relatively high catalase concentration is consistent with that used in previous studies (Behl et aL, 1994;Levine et al, 1994;Wu et al, 1995) and reflects the high K m of the enzyme. The water fractions were solubilized for 15 min at 22°C in sample buffer (Laemmli, 1970) and resolved by SDS-AGE.…”

Effects of glucose oxidase on the growth performance, serum parameters and faecal microflora of piglets

“…Biagi et al (2006) demonstrated that feeding gluconic acid positively influenced the composition and activity of the intestinal microflora of piglets after weaning. It has been reported that sustained oxidative stress through the maintenance of low concentration of H 2 O 2 by GOD's continued catalytic activity to be effective against pathogenic bacteria (Dobbenie et al, 1995;Wu et al, 1995). Etemadzadeh et al (1985) reported that the ability of GOD to kill Streptococcus mutans appears to be enhanced, because the H 2 O 2 produced by GOD acts as a useful bacteriocide.…”

Resistance gene-dependent plant defense responses.

“…The constitutive expression of an H202-generating glucose oxidase from Aspergillus niger in the apoplast of transgenic potato resulted in good resistance to the bacterial soft rot pathogen Erwinia carotovora sp carotovora and enhanced resistance to I? infestans (Wu et al, 1995). However, the mechanism underlying this general disease protection is not known.…”