Abstract |
Triterpenoids produced by plants play important roles in the protection against biotic stress. Roots of Arabidopsis thaliana produce different triterpenoids, which include the tricyclic triterpene diol, arabidiol. In a degradation reaction induced by infection with the oomycete pathogen, Pythium irregulare, arabidiol is cleaved to the 11-carbon volatile homoterpene, (E)-4,8-dimethyl-1,3,7-nonatriene (DMNT), and the 19-carbon ketone, apo- arabidiol. The arabidiol pathway and its volatile breakdown product DMNT have been implicated in the defense against P. irregulare infection. Here we show that the non-volatile breakdown product apo- arabidiol is further converted to the acetylated derivative α-14-acetyl-apo-arabidiol via a presumed epimerization and subsequent acetylation reaction. α-14-acetyl-apo-arabidiol and the detected intermediates in the derivatization pathway are partially exuded from the root indicating possible defensive activities of these molecules in the rhizosphere. The conversion steps of apo- arabidiol vary among different Arabidopsis accessions and are present in only rudimentary form in the close relative Arabidopsis lyrata, which supports an intra- and inter-specific modularity in triterpenoid metabolism.
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Authors | Reza Sohrabi, Tehane Ali, Liva Harinantenaina Rakotondraibe, Dorothea Tholl |
Journal | Plant signaling & behavior
(Plant Signal Behav)
Vol. 12
Issue 1
Pg. e1265722
(01 02 2017)
ISSN: 1559-2324 [Electronic] United States |
PMID | 27918234
(Publication Type: Journal Article)
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Chemical References |
- 4,8-dimethyl-1,3,7-nonatriene
- Alkenes
- Arabidopsis Proteins
- Triterpenes
- Volatile Organic Compounds
- arabidiol
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Topics |
- Alkenes
(metabolism)
- Arabidopsis
(metabolism)
- Arabidopsis Proteins
(metabolism)
- Gene Expression Regulation, Plant
- Plant Roots
(metabolism)
- Triterpenes
(metabolism)
- Volatile Organic Compounds
(metabolism)
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