Alexins as new antifungal compounds - IOBC-WPRS

32 Pages·2013·3.29 MB·English

Département fédéral de l'économie DFE
Station de recherche Agroscope Changins-Wädenswil ACW
Alexins as new antifungal
compounds
in plant and human pathology
Katia Gindro
Olivier Viret
16 october 2013
Alexins ?
• Low molecular-weight secondary metabolites synthetized after
biotic or abiotic stresses - INDUCED metabolites
• Acting as general antimicrobials of interest for Agriculture and
medicine
• Observed and named by Harry Marschall Ward in 1891
Infection with a
pathogen depends on
the presence of
enzymes, toxins and
antitoxins in the
parasite and host.
IOBC-WPRS Meeting | Integrated protection and production in viticulture 2
Katia Gindro and Olivier Viret, Ascona, 14-17 October 2013
Alexins: main sources
• Plants: officially named by Müller & Börger en 1940
PHYTOALEXINS
On internet: > 1’000’000 references
• Fungi: officially named by Katia Gindro et al. en 2010
MYCOALEXINS
8 1
2-Me
8a 2
7 O
On internet: 31 references
6 5 4
4a 3
O O
5-OMe
IOBC-WPRS Meeting | Integrated protection and production in viticulture 3
Katia Gindro and Olivier Viret, Ascona, 14-17 October 2013
Phytoalexins
• Several chemical classes, several different
pathways
• Related to defence reactions of the plants
against aggression: happens only in living
cells.
• Molecules related to the death of the cells of
the host (collateral damage)
IOBC-WPRS Meeting | Integrated protection and production in viticulture 4
Katia Gindro and Olivier Viret, Ascona, 14-17 October 2013
Phytoalexins
6-methoxymelleine (carrot)
Phenolic compounds
Coniferol (Gymno-Angiospermes)
Alcohol
Capsidiol (tobacco, pepper)
Terpenoid
Brassinine (cabbage)
Camalexine (Arabidopsis)
Indole
Indole
Pisatine (pea)
Pterocarpane
Avenanthramide A (oat) STILBENES
Polyphenol
IOBC-WPRS Meeting | Integrated protection and production in viticulture 5
Katia Gindro and Olivier Viret, Ascona, 14-17 October 2013
Stilbenes
• Natural phenolic compounds
• Identical basic chemical stucture (biphenyl)
• Family of molecules
benzene biphenyl Phenol
HO
IOBC-WPRS Meeting | Integrated protection and production in viticulture 6
Katia Gindro and Olivier Viret, Ascona, 14-17 October 2013
Stilbenes ?
• The first stilbene was identified in 1939 by Prof. Takaoka
(Japan) from Veratrum grandiflorum
IOBC-WPRS Meeting | Integrated protection and production in viticulture 7
Katia Gindro and Olivier Viret, Ascona, 14-17 October 2013
Stilbenes ?
• named R E S V E R A T R O L
Class of the molecule Alcohol function
Resorcinol -OH
Plant
Veratrum
IOBC-WPRS Meeting | Integrated protection and production in viticulture 8
Katia Gindro and Olivier Viret, Ascona, 14-17 October 2013
R E S V E R A T R O L
OH
H H
IOBC-WPRS Meeting | Integrated protection and production in viticulture 9
Katia Gindro and Olivier Viret, Ascona, 14-17 October 2013
Roles of stilbenes in plants?
• Molecules with antifungal activities
• Linked to defence reactions against fungal pathogens, and in
some cases against insects
White Pine Spruce Grapevine
Pinosylvin Piceatannol Resveratrol + others
IOBC-WPRS Meeting | Integrated protection and production in viticulture 10
Katia Gindro and Olivier Viret, Ascona, 14-17 October 2013