« Previous AbstractEquilibria of semi-volatile isothiazolinones between air and glass surfaces measured by gas chromatography and Raman spectroscopy    Next AbstractFormation and exudation of non-volatile products of the arabidiol triterpenoid degradation pathway in Arabidopsis roots »

Plant Cell

Title:		In planta variation of volatile biosynthesis: an alternative biosynthetic route to the formation of the pathogen-induced volatile homoterpene DMNT via triterpene degradation in Arabidopsis roots
Author(s):		Sohrabi R; Huh JH; Badieyan S; Rakotondraibe LH; Kliebenstein DJ; Sobrado P; Tholl D;
Address:		"Department of Biological Sciences, Virginia Tech, Blacksburg, Virginia 24061. Department of Biochemistry, Virginia Tech, Blacksburg, Virginia 24061. Department of Chemistry, Virginia Tech, Blacksburg, Virginia 24061. Department of Plant Science, University of California, Davis, California 95616. Department of Biological Sciences, Virginia Tech, Blacksburg, Virginia 24061 tholl@vt.edu"
Journal Title:		Plant Cell
Year:		2015
Volume:		20150227
Issue:		3
Page Number:		874 - 890
DOI:		10.1105/tpc.114.132209
ISSN/ISBN:		1532-298X (Electronic) 1040-4651 (Print) 1040-4651 (Linking)
Abstract:		"Plant-derived volatile compounds such as terpenes exhibit substantial structural variation and serve multiple ecological functions. Despite their structural diversity, volatile terpenes are generally produced from a small number of core 5- to 20-carbon intermediates. Here, we present unexpected plasticity in volatile terpene biosynthesis by showing that irregular homo/norterpenes can arise from different biosynthetic routes in a tissue specific manner. While Arabidopsis thaliana and other angiosperms are known to produce the homoterpene (E)-4,8-dimethyl-1,3,7-nonatriene (DMNT) or its C16-analog (E,E)-4,8,12-trimethyl-1,3,7,11-tridecatetraene by the breakdown of sesquiterpene and diterpene tertiary alcohols in aboveground tissues, we demonstrate that Arabidopsis roots biosynthesize DMNT by the degradation of the C30 triterpene diol, arabidiol. The reaction is catalyzed by the Brassicaceae-specific cytochrome P450 monooxygenase CYP705A1 and is transiently induced in a jasmonate-dependent manner by infection with the root-rot pathogen Pythium irregulare. CYP705A1 clusters with the arabidiol synthase gene ABDS, and both genes are coexpressed constitutively in the root stele and meristematic tissue. We further provide in vitro and in vivo evidence for the role of the DMNT biosynthetic pathway in resistance against P. irregulare. Our results show biosynthetic plasticity in DMNT biosynthesis in land plants via the assembly of triterpene gene clusters and present biochemical and genetic evidence for volatile compound formation via triterpene degradation in plants"
Keywords:		"Arabidopsis/genetics/*metabolism/*microbiology *Biosynthetic Pathways Chromatography, Gas Gene Expression Regulation, Plant Genes, Plant Mass Spectrometry Molecular Docking Simulation Organ Specificity Plant Roots/genetics/*metabolism/microbiology Pythium;"
Notes:		"MedlineSohrabi, Reza Huh, Jung-Hyun Badieyan, Somayesadat Rakotondraibe, Liva Harinantenaina Kliebenstein, Daniel J Sobrado, Pablo Tholl, Dorothea eng Research Support, U.S. Gov't, Non-P.H.S. England 2015/03/01 Plant Cell. 2015 Mar; 27(3):874-90. doi: 10.1105/tpc.114.132209. Epub 2015 Feb 27"