title: Phenol homeostasis is ensured in vanilla fruit by storage under solid form in a new chloroplast-derived organelle, the phenyloplast.
abstract: A multiple cell imaging approach combining immunofluorescence by confocal microscopy, fluorescence spectral analysis by multiphotonic microscopy, and transmission electron microscopy identified the site of accumulation of 4-O-(3-methoxybenzaldehyde) β-d-glucoside, a phenol glucoside massively stockpiled by vanilla fruit. The glucoside is sufficiently abundant to be detected by spectral analysis of its autofluorescence. The convergent results obtained by these different techniques demonstrated that the phenol glucoside accumulates in the inner volume of redifferentiating chloroplasts as solid amorphous deposits, thus ensuring phenylglucoside cell homeostasis. Redifferentiation starts with the generation of loculi between thylakoid membranes which are progressively filled with the glucoside until a fully matured organelle is obtained. This peculiar mode of storage of a phenolic secondary metabolite is suspected to occur in other plants and its generalization in the Plantae could be considered. This new chloroplast-derived organelle is referred to as a 'phenyloplast'.
authors.affiliation: UMR SPO, INRA-SupAgro-UMI, Montpellier, France.
authors.forename: Jean-Marc
authors.initials: JM
authors.lastname: Brillouet
authors.affiliation: Histocytology and Plant Cell Imaging Platform (PHIV), UMR Amélioration Génétique et Adaptation des Plantes, CIRAD-INRA-SupAgro, and UMR Biochimie et Physiologie Moléculaire des Plantes, INRA-CNRS-UMII-SupAgro, Montpellier, France.
authors.forename: Jean-Luc
authors.initials: JL
authors.lastname: Verdeil
authors.affiliation: UMR Résistance des Plantes aux Bio-agresseurs, IRD/CIRAD/UM2, Montpellier, France.
authors.forename: Eric
authors.initials: E
authors.lastname: Odoux
authors.affiliation: Histocytology and Plant Cell Imaging Platform (PHIV), UMR Amélioration Génétique et Adaptation des Plantes, CIRAD-INRA-SupAgro, and UMR Biochimie et Physiologie Moléculaire des Plantes, INRA-CNRS-UMII-SupAgro, Montpellier, France.
authors.forename: Marc
authors.initials: M
authors.lastname: Lartaud
authors.affiliation: UMR Peuplements Végétaux et Bioagresseurs en Milieu Tropical, CIRAD, Saint Pierre, La Réunion, France.
authors.forename: Michel
authors.initials: M
authors.lastname: Grisoni
authors.affiliation: Histocytology and Plant Cell Imaging Platform (PHIV), UMR Amélioration Génétique et Adaptation des Plantes, CIRAD-INRA-SupAgro, and UMR Biochimie et Physiologie Moléculaire des Plantes, INRA-CNRS-UMII-SupAgro, Montpellier, France conejero@supagro.inra.fr.
authors.forename: Geneviève
authors.initials: G
authors.lastname: Conéjéro
mesh_terms: D002736:Chloroplasts / Q000378:metabolism; D005638:Fruit / Q000378:metabolism*; D006706:Homeostasis; D015388:Organelles / Q000378:metabolism*; D019800:Phenol / Q000378:metabolism*; D031669:Vanilla / Q000378:metabolism*
chemical_list: D019800:Phenol
keywords: 4-O-(3-methoxybenzaldehyde) β-d-glucoside; Vanilla planifolia.; chloroplast; homeostasis; phenyloplast