title: The Hevea brasiliensis XIP aquaporin subfamily: genomic, structural and functional characterizations with relevance to intensive latex harvesting.
abstract: X-Intrinsic Proteins (XIP) were recently identified in a narrow range of plants as a full clade within the aquaporins. These channels reportedly facilitate the transport of a wide range of hydrophobic solutes. The functional roles of XIP in planta remain poorly identified. In this study, we found three XIP genes (HbXIP1;1, HbXIP2;1 and HbXIP3;1) in the Hevea brasiliensis genome. Comprehensive bioinformatics, biochemical and structural analyses were used to acquire a better understanding of this AQP subfamily. Phylogenetic analysis revealed that HbXIPs clustered into two major groups, each distributed in a specific lineage of the order Malpighiales. Tissue-specific expression profiles showed that only HbXIP2;1 was expressed in all the vegetative tissues tested (leaves, stem, bark, xylem and latex), suggesting that HbXIP2;1 could take part in a wide range of cellular processes. This is particularly relevant to the rubber-producing laticiferous system, where this isoform was found to be up-regulated during tapping and ethylene treatments. Furthermore, the XIP transcriptional pattern is significantly correlated to latex production level. Structural comparison with SoPIP2;1 from Spinacia oleracea species provides new insights into the possible role of structural checkpoints by which HbXIP2;1 ensures glycerol transfer across the membrane. From these results, we discuss the physiological involvement of glycerol and HbXIP2;1 in water homeostasis and carbon stream of challenged laticifers. The characterization of HbXIP2;1 during rubber tree tapping lends new insights into molecular and physiological response processes of laticifer metabolism in the context of latex exploitation.
authors.affiliation: Clermont Université, Université Blaise Pascal, INRA, UMR 547 PIAF, BP 10448, 63000, Clermont-Ferrand, France.
authors.forename: David
authors.initials: D
authors.lastname: Lopez
authors.affiliation: Clermont Université, Université Blaise Pascal, INRA, UMR 547 PIAF, BP 10448, 63000, Clermont-Ferrand, France.
authors.forename: Maroua Ben
authors.initials: MB
authors.lastname: Amira
authors.affiliation: School of Life Sciences, University of Warwick, Coventry, CV4 7AL, UK.|Biotechnology Unit, Tun Abdul Razak Research Centre, Brickendonbury, Hertford, UK.
authors.forename: Daniel
authors.initials: D
authors.lastname: Brown
authors.affiliation: Institut des Sciences de la Vie, Université catholique de Louvain, 1348, Louvain-la-Neuve, Belgium.
authors.forename: Beatriz
authors.initials: B
authors.lastname: Muries
authors.affiliation: Clermont Université, Université Blaise Pascal, INRA, UMR 547 PIAF, BP 10448, 63000, Clermont-Ferrand, France.
authors.forename: Nicole
authors.initials: N
authors.lastname: Brunel-Michac
authors.affiliation: Laboratoire de Biologie des Ligneux et des Grandes Cultures, Université d'Orléans, UPRES EA 1207, INRA-USC1328, 45067, Orléans, France.
authors.forename: Sylvain
authors.initials: S
authors.lastname: Bourgerie
authors.affiliation: Ecologie, Biologie des Interactions, Equipe SEVE, UMR 7267 CNRS/Université de Poitiers, Bâtiment B31, TSA 51106, 86073, Poitiers Cedex 9, France.
authors.forename: Benoit
authors.initials: B
authors.lastname: Porcheron
authors.affiliation: Ecologie, Biologie des Interactions, Equipe SEVE, UMR 7267 CNRS/Université de Poitiers, Bâtiment B31, TSA 51106, 86073, Poitiers Cedex 9, France.
authors.forename: Remi
authors.initials: R
authors.lastname: Lemoine
authors.affiliation: Institut de Recherche pour le Développement, UR060/CEFE-CNRS, 1029 route de Mende, 34032, Montpellier, France.
authors.forename: Hervé
authors.initials: H
authors.lastname: Chrestin
authors.affiliation: Biotechnology Unit, Tun Abdul Razak Research Centre, Brickendonbury, Hertford, UK.
authors.forename: Ewan
authors.initials: E
authors.lastname: Mollison
authors.affiliation: Biotechnology Unit, Tun Abdul Razak Research Centre, Brickendonbury, Hertford, UK.
authors.forename: Alessandra
authors.initials: A
authors.lastname: Di Cola
authors.affiliation: School of Life Sciences, University of Warwick, Coventry, CV4 7AL, UK.
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Frigerio
authors.affiliation: Clermont Université, Université Blaise Pascal, INRA, UMR 547 PIAF, BP 10448, 63000, Clermont-Ferrand, France.
authors.forename: Jean-Louis
authors.initials: JL
authors.lastname: Julien
authors.affiliation: Clermont Université, Université Blaise Pascal, INRA, UMR 547 PIAF, BP 10448, 63000, Clermont-Ferrand, France.
authors.forename: Aurélie
authors.initials: A
authors.lastname: Gousset-Dupont
authors.affiliation: Clermont Université, Université Blaise Pascal, INRA, UMR 547 PIAF, BP 10448, 63000, Clermont-Ferrand, France.
authors.forename: Boris
authors.initials: B
authors.lastname: Fumanal
authors.affiliation: Clermont Université, Université Blaise Pascal, INRA, UMR 547 PIAF, BP 10448, 63000, Clermont-Ferrand, France.
authors.forename: Philippe
authors.initials: P
authors.lastname: Label
authors.affiliation: Clermont Université, Université Blaise Pascal, INRA, UMR 547 PIAF, BP 10448, 63000, Clermont-Ferrand, France.|CIRAD, UMR AGAP, 63000, Clermont-Ferrand, France.
authors.forename: Valérie
authors.initials: V
authors.lastname: Pujade-Renaud
authors.affiliation: Laboratoire de Biologie des Ligneux et des Grandes Cultures, Université d'Orléans, UPRES EA 1207, INRA-USC1328, 45067, Orléans, France. auguin@univ-orleans.fr.
authors.forename: Daniel
authors.initials: D
authors.lastname: Auguin
authors.affiliation: Clermont Université, Université Blaise Pascal, INRA, UMR 547 PIAF, BP 10448, 63000, Clermont-Ferrand, France. j-stephane.venisse@univ-bpclermont.fr.|Campus Universitaire des Cézeaux, 8 Avenue Blaise Pascal, TSA 60026, CS 60026, 63178, Aubiere Cedex, France. j-stephane.venisse@univ-bpclermont.fr.
authors.forename: Jean-Stéphane
authors.initials: JS
authors.lastname: Venisse
mesh_terms: D020346:Aquaporins / Q000737:chemistry* / Q000235:genetics* / Q000302:isolation & purification; D019295:Computational Biology; D018506:Gene Expression Regulation, Plant; D018745:Genome, Plant; D028482:Hevea / Q000235:genetics*; D007840:Latex / Q000096:biosynthesis*; D008958:Models, Molecular; D005810:Multigene Family; D010802:Phylogeny; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D040681:Structural Homology, Protein; D013347:Subcellular Fractions / Q000378:metabolism
chemical_list: D020346:Aquaporins; D007840:Latex; D010940:Plant Proteins; D012333:RNA, Messenger
keywords: Cell homeostasis; Evolution; Glycerol; Hevea brasiliensis; Latex; XIP aquaporin