This Article Full Text (PDF) Other Versions of this Article: AEM.01334-07v1 73/20/6629    most recent Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Reprints and Permissions Copyright Information Books from ASM Press MicrobeWorld Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Makovitzki, A. Articles by Shai, Y. Search for Related Content PubMed PubMed Citation Articles by Makovitzki, A. Articles by Shai, Y. Agricola Articles by Makovitzki, A. Articles by Shai, Y.

 Previous Article  |  Next Article 

Appl. Environ. Microbiol. doi:10.1128/AEM.01334-07
Copyright (c) 2007, American Society for Microbiology and/or the Listed Authors/Institutions. All Rights Reserved.

Inhibition of Fungal and Bacterial Plant Pathogens in Vitro and in Planta with Ultrashort Cationic Lipopeptides

Departments of Biological Chemistry and Plant Science, The Weizmann Institute of Science, Rehovot, 76100 Israel

^* To whom correspondence should be addressed. Email: Yechiel.Shai{at}weizmann.ac.il.

	Abstract

Plant diseases constitute an emerging threat for global food security. Many of the currently available antimicrobial agents for agriculture are highly toxic, non-biodegradable, and cause extended environmental pollution. Moreover, an increasing number of phytopathogens develop resistance to them. Recently, we have reported on a new family of ultrashort antimicrobial lipopeptides which are composed of only four amino acids linked to fatty acids (Makovitzki, A., D. Avrahami, and Y. Shai. 2006. Proc. Natl. Acad. Sci. USA). Here we investigated the activity in vitro and in planta and the mode of action of these short lipopeptides against plant pathogenic bacteria and fungi. They act rapidly, at low micromolar concentrations on the membranes of the microorganisms via a lytic mechanism. In vitro microscopic analysis revealed wide-scale damage to the microorganism's membrane, in addition to inhibition of pathogen growth. In planta potent antifungal activity was demonstrated on cucumber fruits and leaves infected with the pathogen Botrytis cinerea, as well as on corn leaves infected with Cochliobolus heterostrophus. Similarly, treatment with the lipopeptides of Arabidopsis leaves infected with the bacterial leaf pathogen Pseudomonas syringae efficiently and rapidly reduced the number of bacteria. Importantly, in contrast with many native lipopeptides, no toxicity was observed on the plant tissues. These data suggest that the ultrashort lipopeptides could serve as native-like antimicrobial agents economically feasible for use in plant protection.