Role of petal-specific orcinol O-methyltransferases in the evolution of rose scent.
Orcinol O-methyltransferase (OOMT) 1 and 2 catalyze the last two steps of the biosynthetic pathway leading to the phenolic methyl ether 3,5-dimethoxytoluene (DMT), the major scent compound of many rose (Rosa x hybrida) varieties. Modern roses are descended from both European and Chinese species, the latter being producers of phenolic methyl ethers but not the former. Here we investigated why phenolic methyl ether production occurs in some but not all rose varieties. In DMT-producing varieties, OOMTs were shown to be localized specifically in the petal, predominantly in the adaxial epidermal cells. In these cells, OOMTs become increasingly associated with membranes during petal development, suggesting that the scent biosynthesis pathway catalyzed by these enzymes may be directly linked to the cells' secretory machinery. OOMT gene sequences were detected in two non-DMT-producing rose species of European origin, but no mRNA transcripts were detected, and these varieties lacked both OOMT protein and enzyme activity. These data indicate that up-regulation of OOMT gene expression may have been a critical step in the evolution of scent production in roses.
Scalliet
Gabriel
G
Laboratoire Reproduction et Développement des Plantes, Unité Mixte de Recherche 5667 Centre National de la Recherche Scientifique, IFR128 Biosciences Lyon-Gerland, France.
Lionnet
Claire
C
Le Bechec
Mickaël
M
Dutron
Laurence
L
Magnard
Jean-Louis
JL
Baudino
Sylvie
S
Bergougnoux
Véronique
V
Jullien
Frédéric
F
Chambrier
Pierre
P
Vergne
Philippe
P
Dumas
Christian
C
Cock
J Mark
JM
Hugueney
Philippe
P
D000595:Amino Acid Sequence; D000840:Anisoles / Q000378:metabolism; D019470:Biolistics; D015153:Blotting, Western; D019143:Evolution, Molecular; D035264:Flowers / Q000033:anatomy & histology / Q000201:enzymology / Q000502:physiology; D015870:Gene Expression; D007150:Immunohistochemistry; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D008780:Methyltransferases / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D008861:Microsomes / Q000378:metabolism; D008969:Molecular Sequence Data; D009812:Odorants; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D012118:Resorcinols / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D027826:Rosa / Q000033:anatomy & histology / Q000201:enzymology* / Q000502:physiology; D016415:Sequence Alignment
D000840:Anisoles; D008565:Membrane Proteins; D010940:Plant Proteins; D011993:Recombinant Fusion Proteins; D012118:Resorcinols; C465201:3,5-dimethoxytoluene; C005282:orcinol; D008780:Methyltransferases