Plant immunity induced by COS-OGA elicitor is a cumulative process that involves salicylic acid.
Plant innate immunity offers considerable opportunities for plant protection but beside flagellin and chitin, not many molecules and their receptors have been extensively characterized and very few have successfully reached the field. COS-OGA, an elicitor that combines cationic chitosan oligomers (COS) with anionic pectin oligomers (OGA), efficiently protected tomato (Solanum lycopersicum) grown in greenhouse against powdery mildew (Leveillula taurica). Leaf proteomic analysis of plants sprayed with COS-OGA showed accumulation of Pathogenesis-Related proteins (PR), especially subtilisin-like proteases. qRT-PCR confirmed upregulation of PR-proteins and salicylic acid (SA)-related genes while expression of jasmonic acid/ethylene-associated genes was not modified. SA concentration and class III peroxidase activity were increased in leaves and appeared to be a cumulative process dependent on the number of sprayings with the elicitor. These results suggest a systemic acquired resistance (SAR) mechanism of action of the COS-OGA elicitor and highlight the importance of repeated applications to ensure efficient protection against disease.
Research Unit in Plant Cellular and Molecular Biology, University of Namur, Belgium.
Géraldine
G
van Aubel
Research Unit in Plant Cellular and Molecular Biology, University of Namur, Belgium.
Pierre
P
Cambier
Laboratory of Cellular Biochemistry and Biology, University of Namur, Belgium.
Marc
M
Dieu
Research Unit in Plant Cellular and Molecular Biology, University of Namur, Rue de Bruxelles, 61, B-5000 Namur, Belgium. Electronic address: pierre.vancutsem@unamur.be.
Pierre
P
Van Cutsem
D001203:Ascomycota / Q000502:physiology; D048271:Chitosan / Q000494:pharmacology*; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D018551:Solanum lycopersicum / Q000187:drug effects / Q000235:genetics / Q000276:immunology* / Q000502:physiology; D010368:Pectins / Q000494:pharmacology*; D009195:Peroxidase / Q000378:metabolism; D010935:Plant Diseases / Q000276:immunology*; D057865:Plant Immunity / Q000187:drug effects*; D018515:Plant Leaves / Q000187:drug effects / Q000235:genetics / Q000276:immunology / Q000502:physiology; D010940:Plant Proteins / Q000378:metabolism; D040901:Proteomics; D020156:Salicylic Acid / Q000378:metabolism*
D010940:Plant Proteins; C053376:pathogenesis-related proteins, plant; D010368:Pectins; D048271:Chitosan; D009195:Peroxidase; D020156:Salicylic Acid
COS-OGA; Leveillula taurica; Plant immunity; SAR; Salicylic acid; Subtilisin-like proteases