Phospholipases and galactolipases trigger oxylipin-mediated wound-activated defence in the red alga Gracilaria chilensis against epiphytes.
We investigated the wound response of the commercially important red alga, Gracilaria chilensis, in order to obtain insight into its interaction with epiphytic pests. After wounding, the host releases free fatty acids as well as the hydroxylated eicosanoids, 8R-hydroxy eicosatetraenoic acid (8-HETE) and 7S,8R-dihydroxy eicosatetraenoic acid (7,8-di-HETE). While the release of free arachidonic acid and subsequent formation of 8-HETE is controlled by phospholipase A, 7,8-di-HETE production is independent of this lipase. This dihydroxylated fatty acid might be directly released from galactolipids. Physiologically relevant concentrations of oxylipins reduced spore settlement of Acrochaetium sp. (Rhodophyta, Acrochaetiaceae) and suppressed the development of hapteria in Ceramium rubrum (Rhodophyta, Ceramiaceae) when these model epiphytes were exposed to artificial surfaces that contained 8-HETE or 7,8-di-HETE. Thus, the immediate release of oxylipins can be seen as G. chilensis defence against epiphytes.
Max-Planck-Institute for Chemical Ecology, Hans-Knöll-Strasse 8, 07745 Jena, Germany.
Ulrich
U
Lion
Theresa
T
Wiesemeier
Florian
F
Weinberger
Jessica
J
Beltrán
Verónica
V
Flores
Sylvain
S
Faugeron
Juan
J
Correa
Georg
G
Pohnert
D002265:Carboxylic Ester Hydrolases / Q000378:metabolism*; D002855:Chromatography, Thin Layer; D015777:Eicosanoids / Q000378:metabolism; D008401:Gas Chromatography-Mass Spectrometry; D009682:Magnetic Resonance Spectroscopy; D009930:Organic Chemicals / Q000378:metabolism; D010740:Phospholipases / Q000378:metabolism*; D000461:Rhodophyta / Q000201:enzymology / Q000502:physiology*
D015777:Eicosanoids; D009930:Organic Chemicals; C088310:lipine; D010740:Phospholipases; D002265:Carboxylic Ester Hydrolases; C019262:galactolipase