ABCC Transporters Mediate the Vacuolar Accumulation of Crocins in Saffron Stigmas

TitleABCC Transporters Mediate the Vacuolar Accumulation of Crocins in Saffron Stigmas
Publication TypeArticolo su Rivista peer-reviewed
Year of Publication2019
AuthorsDemurtas, Olivia Costantina, R. Francisco de Brito, Diretto Gianfranco, Ferrante Paola, Frusciante Sarah, Pietrella M., Aprea Giuseppe, Borghi L., Feeney M., Frigerio L., Coricello A., Costa G., Alcaro S., Martinoia E., and Giuliano Giovanni
JournalTHE PLANT CELL
Volume31
Pagination2789–2804
ISSN1532298X
KeywordsABC transporter, ATP-Binding Cassette Transporters, biosynthesis, Biosynthetic Pathways, Carotenoid, Carotenoids, cell vacuole, Cloning, crocin, Crocus, cytology, flower, Flowers, gene expression regulation, genetics, Kinetics, metabolism, Molecular, molecular cloning, physiology, Plant, Plant extract, Plant extracts, plant leaf, Plant leaves, plant protein, Plant Proteins, Saccharomyces cerevisiae, Tissue Distribution, Tobacco, Vacuoles
Abstract

Compartmentation is a key strategy enacted by plants for the storage of specialized metabolites. The saffron spice owes its red color to crocins, a complex mixture of apocarotenoid glycosides that accumulate in intracellular vacuoles and reach up to 10% of the spice dry weight. We developed a general approach, based on coexpression analysis, heterologous expression in yeast (Saccharomyces cerevisiae), and in vitro transportomic assays using yeast microsomes and total plant metabolite extracts, for the identification of putative vacuolar metabolite transporters, and we used it to identify Crocus sativus transporters mediating vacuolar crocin accumulation in stigmas. Three transporters, belonging to both the multidrug and toxic compound extrusion and ATP binding cassette C (ABCC) families, were coexpressed with crocins and/or with the gene encoding the first dedicated enzyme in the crocin biosynthetic pathway, CsCCD2. Two of these, belonging to the ABCC family, were able to mediate transport of several crocins when expressed in yeast microsomes. CsABCC4a was selectively expressed in C. sativus stigmas, was predominantly tonoplast localized, transported crocins in vitro in a stereospecific and cooperative way, and was able to enhance crocin accumulation when expressed in Nicotiana benthamiana leaves.plantcell;31/11/2789/FX1F1fx1. © 2019 American Society of Plant Biologists. All rights reserved.

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URLhttps://www.scopus.com/inward/record.uri?eid=2-s2.0-85075091050&doi=10.1105%2ftpc.19.00193&partnerID=40&md5=2f0bf4fe8b5984659ca445690cfb9b33
DOI10.1105/tpc.19.00193