The cationic lipid Di-C14-amidine stimulates defenses against microbial pathogens in Arabdopsis

CAMBIAGNO D; RUYSSCHAERT JM; LONEZ C; ALVAREZ ME

Mendoza

Congreso; XLVIII Reunión SAIB; 2012

SAIB

The cationic lipid di-C14-amidine stimulates defenses against microbial pathogen in Arabidopsis. Cambiagno DA*, Ruysschaert JM+, Lonez C+, Álvarez ME*. * CIQUIBIC-CONICET, Facultad Ciencias Químicas, UNC. + Université Libre de Bruxelles, Belgium. Cationic liposomes are able to stimulate cell-mediated immune responses in animal models. Among them, di-C14-amidine (C14) activates the secretion of cytokines and chemokines on dendritic cells through the Toll Like Receptor (TLR)- 4 pathway. Although plants use TLR-like Pathogen Recognition Receptors (PRR) to recognize microbes at extracellular level, the effect of cationic lipids on plant immunity has not been evaluated so far. We here assessed this capacity for C14 by evaluating the salicylic acid- (SA) and jasmonic acid- (JA) dependent defense pathways in Arabidopsis. A single application of the lipid produced sustained activation of SA-sensitive genes in wild type plants. In contrast, reduced or transient induction of these genes is observed in the triple mutant lacking the PRR receptors FLS2, EFR and CERK1, suggesting that C14 stimulates PRR protein/s. At the intracellular level, the effect of C14 seems to be transmitted through the Toll-interleukin Receptor-like- (TIR), but not the Coiled-Coil- (CC) dependent cascade. Moreover, preliminary results showed that C14 immunizes plants against a virulent isolate of Pseudomonas syringae. Taken together these results indicate that C14 induces endogenous plant defense pathway/s providing resistance to biotrophic bacterial pathogens, pointing out this lipid as a new elicitor for identification of novel plant immunity components.