title: Biosynthesis of 2-acetyl-1-pyrroline in rice calli cultures: Demonstration of 1-pyrroline as a limiting substrate.
abstract: The role of 1-pyrroline was studied via feeding experiments using rice calli cultures to gain further insight into the key steps of 2-acetyl-1-pyrroline (2AP) biosynthesis in rice. The origin of the acetyl donor was also studied through stable isotope labelled substrates. Incubation of fresh calli from a fragrant rice variety (Aychade) and a non-fragrant variety (Gladio×Fidji K2) with 1-pyrroline led to a significant increase in 2AP in both varieties. Importantly, the amount of 2AP in the non-fragrant variety could be greatly enhanced by this supplementation. When rice calli were fed with increasing levels of 1-pyrroline, 2AP levels increased accordingly. Our data show that 1-pyrroline is a limiting factor for 2AP synthesis in rice. Heat treatment of calli suggested that 1-pyrroline might be enzymatically acetylated. The presence of labelled 2AP in calli supplemented with [U-(13)C]glucose, sodium acetate (1,2-(13)C2) and sodium octanoate (1,2,3,4-(13)C4) suggested that these compounds are possible candidates for acetyl group-donors of 2AP, predominately in the form of intact labelled (13)C2-units.
authors.affiliation: UMR Qualisud, Université de Montpellier, Place E. Bataillon, 34095 Montpellier Cedex 5, France; UMR Qualisud, CIRAD, 73 Rue J.F. Breton, 34398 Montpellier Cedex 5, France.
authors.forename: Janchai
authors.initials: J
authors.lastname: Poonlaphdecha
authors.affiliation: Université de Montpellier, UMR DAP, Bat 15, CC 002, Place Eugène Bataillon, 34095 Montpellier Cedex 5, France; University of Science and Technology of Hanoi, Department of Biotechnology and Pharmacology, Cau Giay, Hanoi, Viet Nam.
authors.forename: Pascal
authors.initials: P
authors.lastname: Gantet
authors.affiliation: UMR Qualisud, CIRAD, 73 Rue J.F. Breton, 34398 Montpellier Cedex 5, France.
authors.forename: Isabelle
authors.initials: I
authors.lastname: Maraval
authors.affiliation: UMR1083 Sciences pour l'Oenologie, INRA-SupAgro, 2 Place Viala, 34060 Montpellier, France.
authors.forename: François-Xavier
authors.initials: FX
authors.lastname: Sauvage
authors.affiliation: IBMM, UMR 5247, Université de Montpellier, CNRS, Bâtiment E, Faculté de Pharmacie, 15 Avenue Charles Flahault, BP 14491, 34093 Montpellier, France.
authors.forename: Chantal
authors.initials: C
authors.lastname: Menut
authors.affiliation: IBMM, UMR 5247, Université de Montpellier, CNRS, Bâtiment E, Faculté de Pharmacie, 15 Avenue Charles Flahault, BP 14491, 34093 Montpellier, France.
authors.forename: Alain
authors.initials: A
authors.lastname: Morère
authors.affiliation: UMR Qualisud, CIRAD, 73 Rue J.F. Breton, 34398 Montpellier Cedex 5, France.
authors.forename: Renaud
authors.initials: R
authors.lastname: Boulanger
authors.affiliation: University of Bonn, Institute of Nutritional and Food Sciences, Chair of Bioanalytics, Endenicher Allee 11-13, D 53115 Bonn, Germany.
authors.forename: Matthias
authors.initials: M
authors.lastname: Wüst
authors.affiliation: UMR Qualisud, Université de Montpellier, Place E. Bataillon, 34095 Montpellier Cedex 5, France. Electronic address: zgunata@univ-montp2.fr.
authors.forename: Ziya
authors.initials: Z
authors.lastname: Gunata
mesh_terms: D009812:Odorants / Q000032:analysis; D012275:Oryza / Q000378:metabolism*; D010936:Plant Extracts / Q000378:metabolism*; D011758:Pyrroles / Q000378:metabolism*
chemical_list: D010936:Plant Extracts; D011758:Pyrroles; C013231:pyrroline; C426303:2-acetyl-1-pyrroline
keywords: (13)C-labelled precursors; 1-Pyrroline; 2-Acetyl-1-pyrroline; Biosynthesis; Fragrant rice; Proline; Rice callus