Alcohol dehydrogenase 1 of barley modulates susceptibility to the parasitic fungus Blumeria graminis f.sp. hordei

Abstract

Plant primary energy metabolism is profoundly reorganized under biotic stress conditions and there is increasing evidence for a role for the fermentative pathway in biotic interactions. However, the mechanisms regulating metabolic reprogramming are not well understood despite its critical function in the biotic stress response. Here the function of alcohol dehydrogenase (ADH) in the interaction of barley with the parasitic fungus Blumeria graminis f.sp. hordei (Bgh) is addressed. Challenge of susceptible barley leaves with Bgh resulted in transcriptional activation of HvADH1 and an induction of ADH enzyme activity starting 24 h after infection and reaching a clear-cut effect 4 d after infection. This increase in ADH enzyme activity was not observed in the resistant near-isogenic mlo5 line. Moreover, an induction of ADH enzyme activity by Bgh was enhanced in the presence of sucrose in hydroponically grown seedlings. Transient knock-down or overexpression of HvADH1 in barley epidermal cells mediated a decrease or increase in the penetration success of Bgh, respectively. Inhibition of ADH activity by pyrazole resulted in a delay in symptoms. The pyrazole effect could be overcome by adding glucose to the incubation medium, pinpointing a nutritional effect of ADH in the barley–Bgh interaction. Taken together, misexpression of pathogen-inducible HvADH1 or variation of ADH activity modulates the pathogen response of barley to the biotrophic fungal parasite Bgh. In this way, ADH knock-down/inhibition results in reduced fungal success. The possibility is discussed that ADH activity supports biotrophy by maintaining glycolytic metabolism in pathogen-stressed barley.

Jasmonate application influences endogenous abscisic acid, jasmonic acid and aroma volatiles in grapes infected by a pathogen (Glomerella cingulata)

“…In our study, ethanol was the most-identified compound in the alcohol class, and it was derived from fermentation, which transforms to ethanol through the action of the enzyme alcohol dehydrogenase (ADH) (Hopkins and Hüner, 2008). ADH enzyme activity and HvADH1 were stimulated by the inoculation of Blumeria graminis in barley (Hordeum vulgare L.) (Pathuri et al, 2011). Therefore, ethanol production may also be a signal that plants are resistant to pathogen infection.…”

Infection Structure-Specific Expression of -1,3-Glucan Synthase Is Essential for Pathogenicity of Colletotrichum graminicola and Evasion of -Glucan-Triggered Immunity in Maize

“…In addition to genes actively involved in defense responses, downregulation of susceptibility genes can contribute to resistance. Transient RNAimediated silencing experiments suggested that the germin genes GER3 or GER5 (Zimmermann et al, 2006) and alcohol dehydrogenase 1 (Pathuri et al, 2011) mediate compatibility between barley (Hordeum vulgare) and the biotrophic barley pathogen Blumeria graminis f. sp hordei and its host. Likewise, several genes strongly downregulated in maize leaves in response to infection by P trpC :GLS1 strains may represent susceptibility factors, and downregulation of these factors may contribute to b-glucan-triggered immunity (see Supplemental Data Set 2 online).…”

A proteomics survey on wheat susceptibility to Fusarium head blight during grain development

“…More than 30 potential host susceptibility genes (S-genes) in different plant species have been reported in the literature (Pavan et al 2010), depicting either that transient knock-down of such genes could increase the plant resistance or that the overexpression of other ones could lead to increasing susceptibility. For instance, among S-genes, PMR6 and MLO genes were discovered as genes coding for susceptibility factors promoting growth of powdery mildews (Eckardt 2002), ADH1 gene modulates the susceptibility of hordei spp plant to Blumeria graminis fungus (Pathuri et al 2011) and recently IAA-Asp gene was identified as a susceptibility gene as it promotes the growth of Botrytis cinerea in Arabidopsis thaliana (González-Lamothe et al 2012). Digging into S-genes or S-factors could provide a wealth of additional knowledge to understand plant susceptibility and could be a means to find new strategies aiming at sustainable plant resistance.…”