Krinke,O., Flemr,M., Vergnolle, C., Collin,S., Renou,J.P., Taconnat,L., Yu,A., Burketová,L., Valentová,O., Zachowski,A., and Ruelland,E.
PLANT PHYSIOLOGY
150:
424-436,
2009
Klíčová slova:
Abstrakt:
Salicylic acid (SA) plays a central role in defense against pathogen attack, as well as in germination, flowering, senescence, and
the acquisition of thermotolerance. In this report we investigate the involvement of phospholipase D (PLD) in the SA signaling
pathway. In presence of exogenous primary alcohols, the production of phosphatidic acid by PLD is diverted toward
the formation of phosphatidylalcohols through a reaction called transphosphatidylation. By in vivo metabolic phospholipid
labeling with 33Pi, PLD activity was found to be induced 45 min after addition of SA. We show that incubation of Arabidopsis
(Arabidopsis thaliana) cell suspensions with primary alcohols inhibited the induction of two SA-responsive genes, PATHOGENESIS-
RELATED1 and WRKY38, in a dose-dependent manner. This inhibitory effect was more pronounced when the
primary alcohols were more hydrophobic. Secondary or tertiary alcohols had no inhibitory effect. These results provide
compelling arguments for PLD activity being upstream of the induction of these genes by SA. A subsequent study of n-butanol
effects on the SA-responsive transcriptome identified 1,327 genes differentially expressed upon SA treatment. Strikingly, the SA
response of 380 of these genes was inhibited by n-butanol but not by tert-butanol. A detailed analysis of the regulation of these
genes showed that PLD could act both positively and negatively, either on gene induction or gene repression. The overlap with
the previously described phosphatidylinositol-4-kinase pathway is discussed.
Autoři z ÚEB: Lenka Burketová
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English