title: A peroxisomally localized acyl-activating enzyme is required for volatile benzenoid formation in a Petuniaxhybrida cv. 'Mitchell Diploid' flower.
abstract: Floral volatile benzenoid/phenylpropanoid (FVBP) biosynthesis is a complex and coordinate cellular process executed by petal limb cells of a Petunia×hybrida cv. 'Mitchell Diploid' (MD) plant. In MD flowers, the majority of benzenoid volatile compounds are derived from a core phenylpropanoid pathway intermediate by a coenzyme A (CoA) dependent, β-oxidative scheme. Metabolic flux analysis, reverse genetics, and biochemical characterizations of key enzymes in this pathway have supported this putative concept. However, the theoretical first enzymatic reaction, which leads to the production of cinnamoyl-CoA, has only been physically demonstrated in a select number of bacteria like Streptomyces maritimus through mutagenesis and recombinant protein production. A transcript has been cloned and characterized from MD flowers that shares high homology with an Arabidopsis thaliana transcript ACYL-ACTIVATING ENZYME11 (AtAAE11) and the S. maritimus ACYL-COA:LIGASE (SmEncH). In MD, the PhAAE transcript accumulates in a very similar manner as bona fide FVBP network genes, i.e. high levels in an open flower petal and ethylene regulated. In planta, PhAAE is localized to the peroxisome. Upon reduction of PhAAE transcript through a stable RNAi approach, transgenic flowers emitted a reduced level of all benzenoid volatile compounds. Together, the data suggest that PhAAE may be responsible for the activation of t-cinnamic acid, which would be required for floral volatile benzenoid production in MD.
authors: Plant Innovation Program, Department of Environmental Horticulture, University of Florida, Gainesville, Florida 32611, USA.
authors: Thomas A
authors: TA
authors: Colquhoun
authors: Danielle M
authors: DM
authors: Marciniak
authors: Ashlyn E
authors: AE
authors: Wedde
authors: Joo Young
authors: JY
authors: Kim
authors: Michael L
authors: ML
authors: Schwieterman
authors: Laura A
authors: LA
authors: Levin
authors: Alex
authors: A
authors: Van Moerkercke
authors: Robert C
authors: RC
authors: Schuurink
authors: David G
authors: DG
authors: Clark
mesh_terms: D000595:Amino Acid Sequence; D001555:Benzene Derivatives / Q000378:metabolism*; D018744:DNA, Plant / Q000737:chemistry / Q000235:genetics; D035264:Flowers / Q000737:chemistry / Q000201:enzymology* / Q000235:genetics / Q000648:ultrastructure; D018506:Gene Expression Regulation, Plant; D053858:Metabolic Networks and Pathways; D018613:Microscopy, Confocal; D008969:Molecular Sequence Data; D020675:Peroxisomes / Q000201:enzymology*; D032306:Petunia / Q000737:chemistry / Q000201:enzymology* / Q000235:genetics / Q000648:ultrastructure; D010802:Phylogeny; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D018517:Plant Roots / Q000737:chemistry / Q000201:enzymology / Q000235:genetics / Q000648:ultrastructure; D018547:Plant Stems / Q000737:chemistry / Q000201:enzymology / Q000235:genetics / Q000648:ultrastructure; D020005:Propanols / Q000378:metabolism*; D034622:RNA Interference; D012333:RNA, Messenger / Q000235:genetics; D018749:RNA, Plant / Q000235:genetics; D011994:Recombinant Proteins; D016415:Sequence Alignment
chemical_list: D001555:Benzene Derivatives; D018744:DNA, Plant; D010940:Plant Proteins; D020005:Propanols; D012333:RNA, Messenger; D018749:RNA, Plant; D011994:Recombinant Proteins; C439395:1-phenylpropanol