Original Research ARTICLE
The antifungal plant defensin HsAFP1 from Heuchera sanguinea induces apoptosis in Candida albicans
- 1 Centre of Microbial and Plant Genetics, Katholieke Universiteit Leuven, Heverlee, Belgium
- 2 Institute of Molecular Biosciences, Karl-Franzens University, Graz, Austria
Plant defensins are active against plant and human pathogenic fungi (such as Candida albicans) and baker’s yeast. However, they are non-toxic to human cells, providing a possible source for treatment of fungal infections. In this study, we characterized the mode of action of the antifungal plant defensin HsAFP1 from coral bells by screening the Saccharomyces cerevisiae deletion mutant library for mutants with altered HsAFP1 sensitivity and verified the obtained genetic data by biochemical assays in S. cerevisiae and C. albicans. We identified 84 genes, which when deleted conferred at least fourfold hypersensitivity or resistance to HsAFP1. A considerable part of these genes were found to be implicated in mitochondrial functionality. In line, sodium azide, which blocks the respiratory electron transport chain, antagonized HsAFP1 antifungal activity, suggesting that a functional respiratory chain is indispensable for HsAFP1 antifungal action. Since mitochondria are the main source of cellular reactive oxygen species (ROS), we investigated the ROS-inducing nature of HsAFP1. We showed that HsAFP1 treatment of C. albicans resulted in ROS accumulation. As ROS accumulation is one of the phenotypic markers of apoptosis in yeast, we could further demonstrate that HsAFP1 induced apoptosis in C. albicans. These data provide novel mechanistic insights in the mode of action of a plant defensin.
Keywords: plant defensin, Candida albicans, Saccharomyces cerevisiae, mitochondria, apoptosis, mode of action
Citation: Aerts AM, Bammens L, Govaert G, Carmona-Gutierrez D, Madeo F, Cammue BPA and Thevissen K (2011) The antifungal plant defensin HsAFP1 from Heuchera sanguinea induces apoptosis in Candida albicans. Front. Microbio. 2:47. doi: 10.3389/fmicb.2011.00047
Received: 10 February 2011;
Accepted: 02 March 2011;
Published online: 16 March 2011.
Edited by:Maurizio Del Poeta, Medical University of South Carolina, USA
Reviewed by:Maurizio Del Poeta, Medical University of South Carolina, USA
Ana Traven, Monash Univerisity, Australia
Copyright: © 2011 Aerts, Bammens, Govaert, Carmona-Gutierrez, Madeo, Cammue and Thevissen. This is an open-access article subject to an exclusive license agreement between the authors and Frontiers Media SA, which permits unrestricted use, distribution, and reproduction in any medium, provided the original authors and source are credited.
*Correspondence: Karin Thevissen, Centre of Microbial and Plant Genetics, Kasteelpark Arenberg 20, B-3001 Heverlee, Belgium. e-mail: email@example.com