Gene coexpression analysis reveals complex metabolism of the monoterpene alcohol linalool in Arabidopsis flowers.

Jean-Francois Ginglinger (1) , Benoit Boachon (1) , René Höfer (1) , Christian Paetz (2) , Tobias G. Köllner (2) , Laurence Miesch (3) , Raphaël Lugan (1) , Raymonde Baltenweck (4) , Jérome Mutterer (1) , Pascaline Ullmann (1) , Franziska Beran (2) , Patricia Claudel (4) , Francel Verstappen (5) , Marc Fischer (4) , Francis F. Karst (4) , Harro Bouwmeester (5) , Michel Miesch (3) , Bernd Schneider (2) , Jonathan Gershenzon (2) , Jürgen Ehlting (6) , Danièle Werck-Reichhart (1)

1 IBMP - Institut de Biologie Moléculaire des Plantes
2 Max Planck Institute for Chemical Ecology
3 Institut de Chimie de Strasbourg
4 SVQV - Santé de la vigne et qualité du vin
5 Laboratory of Plant Physiology
6 Department of Biology, Centre for Forest Biology

The cytochrome P450 family encompasses the largest family of enzymes in plant metabolism, and the functions of many of its members in Arabidopsis thaliana are still unknown. Gene coexpression analysis pointed to two P450s that were coexpressed with two monoterpene synthases in flowers and were thus predicted to be involved in monoterpenoid metabolism. We show that all four selected genes, the two terpene synthases (TPS10 and TPS14) and the two cytochrome P450s (CYP71B31 and CYP76C3), are simultaneously expressed at anthesis, mainly in upper anther filaments and in petals. Upon transient expression in Nicotiana benthamiana, the TPS enzymes colocalize in vesicular structures associated with the plastid surface, whereas the P450 proteins were detected in the endoplasmic reticulum. Whether they were expressed in Saccharomyces cerevisiae or in N. benthamiana, the TPS enzymes formed two different enantiomers of linalool: (-)-(R)-linalool for TPS10 and (+)-(S)-linalool for TPS14. Both P450 enzymes metabolize the two linalool enantiomers to form different but overlapping sets of hydroxylated or epoxidized products. These oxygenated products are not emitted into the floral headspace, but accumulate in floral tissues as further converted or conjugated metabolites. This work reveals complex linalool metabolism in Arabidopsis flowers, the ecological role of which remains to be determined.

Domaines: Sciences du Vivant [q-bio]; Biologie végétale; Biologie moléculaire; Biologie cellulaire

Jean-Francois Ginglinger, Benoit Boachon, René Höfer, Christian Paetz, Tobias G. Köllner, et al.. Gene coexpression analysis reveals complex metabolism of the monoterpene alcohol linalool in Arabidopsis flowers.. The Plant cell, 2013, 25 (11), pp.4640-4657. ⟨10.1105/tpc.113.117382⟩. ⟨hal-02648067⟩