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Local and systemic effects of oxylipins on powdery mildew infection in barley
Author(s) -
Cowley Tracy,
Walters Dale
Publication year - 2005
Publication title -
pest management science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.296
H-Index - 125
eISSN - 1526-4998
pISSN - 1526-498X
DOI - 10.1002/ps.1026
Subject(s) - blumeria graminis , powdery mildew , oxylipin , mildew , biology , inoculation , fungus , phenylalanine ammonia lyase , peroxidase , botany , peroxynitrite , biochemistry , horticulture , enzyme , plant disease resistance , gene , superoxide
Treatment of the first leaves of barley seedlings with the oxylipin colneleic acid, or the two trihydroxy oxylipins 9,12,13‐trihydroxy‐11( E )‐octadecenoic acid and 9,12,13‐trihydroxy‐10( E )‐octadecenoic acid, reduced infection of that leaf by the powdery mildew fungus Blumeria graminis Speer f sp hordei Marchal. When applied to first leaves, etheroleic acid and colneleic acid, as well as the trihydroxy oxylipin 9,12,13‐trihydroxy‐10( E ),15( Z )‐octadecadienoic acid, also reduced mildew infection in second leaves. In all cases where local and systemic effects against mildew were observed, activity of the defence‐related enzyme phenylalanine ammonia lyase (PAL) was increased, but only following challenge inoculation with powdery mildew. Peroxidase activity was not affected by oxylipin treatment or mildew inoculation. Whether the effects observed were due to the oxylipins or to breakdown products is not known, since no information is available on the stability of these particular oxylipins on leaf surfaces. Nevertheless, these data represent the first report of systemic effects against pathogen infection following pre‐treatment with oxylipins. Copyright © 2005 Society of Chemical Industry