title: Auxin Response Factor SlARF2 Is an Essential Component of the Regulatory Mechanism Controlling Fruit Ripening in Tomato.
abstract: Ethylene is the main regulator of climacteric fruit ripening, by contrast the putative role of other phytohormones in this process remains poorly understood. The present study brings auxin signaling components into the mechanism regulating tomato fruit ripening through the functional characterization of Auxin Response Factor2 (SlARF2) which encodes a downstream component of auxin signaling. Two paralogs, SlARF2A and SlARF2B, are found in the tomato genome, both displaying a marked ripening-associated expression but distinct responsiveness to ethylene and auxin. Down-regulation of either SlARF2A or SlARF2B resulted in ripening defects while simultaneous silencing of both genes led to severe ripening inhibition suggesting a functional redundancy among the two ARFs. Tomato fruits under-expressing SlARF2 produced less climacteric ethylene and exhibited a dramatic down-regulation of the key ripening regulators RIN, CNR, NOR and TAGL1. Ethylene treatment failed to reverse the non-ripening phenotype and the expression of ethylene signaling and biosynthesis genes was strongly altered in SlARF2 down-regulated fruits. Although both SlARF proteins are transcriptional repressors the data indicate they work as positive regulators of tomato fruit ripening. Altogether, the study defines SlARF2 as a new component of the regulatory network controlling the ripening process in tomato.
authors.affiliation: University of Toulouse, INPT, Laboratory of Genomics and Biotechnology of Fruit, Castanet-Tolosan, France.|INRA, UMR990 Génomique et Biotechnologie des Fruits, Chemin de Borde Rouge, Castanet-Tolosan, France.
authors.forename: Yanwei
authors.initials: Y
authors.lastname: Hao
authors.affiliation: University of Toulouse, INPT, Laboratory of Genomics and Biotechnology of Fruit, Castanet-Tolosan, France.|INRA, UMR990 Génomique et Biotechnologie des Fruits, Chemin de Borde Rouge, Castanet-Tolosan, France.
authors.forename: Guojian
authors.initials: G
authors.lastname: Hu
authors.affiliation: Weizmann Institute of Science, Department of Plant Sciences, Faculty of Biochemistry, Rehovot, Israel.
authors.forename: Dario
authors.initials: D
authors.lastname: Breitel
authors.affiliation: University of Toulouse, INPT, Laboratory of Genomics and Biotechnology of Fruit, Castanet-Tolosan, France.|INRA, UMR990 Génomique et Biotechnologie des Fruits, Chemin de Borde Rouge, Castanet-Tolosan, France.
authors.forename: Mingchun
authors.initials: M
authors.lastname: Liu
authors.affiliation: University of Toulouse, INPT, Laboratory of Genomics and Biotechnology of Fruit, Castanet-Tolosan, France.|INRA, UMR990 Génomique et Biotechnologie des Fruits, Chemin de Borde Rouge, Castanet-Tolosan, France.
authors.forename: Isabelle
authors.initials: I
authors.lastname: Mila
authors.affiliation: University of Toulouse, INPT, Laboratory of Genomics and Biotechnology of Fruit, Castanet-Tolosan, France.|INRA, UMR990 Génomique et Biotechnologie des Fruits, Chemin de Borde Rouge, Castanet-Tolosan, France.
authors.forename: Pierre
authors.initials: P
authors.lastname: Frasse
authors.affiliation: University of Toulouse, INPT, Laboratory of Genomics and Biotechnology of Fruit, Castanet-Tolosan, France.|INRA, UMR990 Génomique et Biotechnologie des Fruits, Chemin de Borde Rouge, Castanet-Tolosan, France.
authors.forename: Yongyao
authors.initials: Y
authors.lastname: Fu
authors.affiliation: Weizmann Institute of Science, Department of Plant Sciences, Faculty of Biochemistry, Rehovot, Israel.
authors.forename: Asaph
authors.initials: A
authors.lastname: Aharoni
authors.affiliation: University of Toulouse, INPT, Laboratory of Genomics and Biotechnology of Fruit, Castanet-Tolosan, France.|INRA, UMR990 Génomique et Biotechnologie des Fruits, Chemin de Borde Rouge, Castanet-Tolosan, France.
authors.forename: Mondher
authors.initials: M
authors.lastname: Bouzayen
authors.affiliation: University of Toulouse, INPT, Laboratory of Genomics and Biotechnology of Fruit, Castanet-Tolosan, France.|INRA, UMR990 Génomique et Biotechnologie des Fruits, Chemin de Borde Rouge, Castanet-Tolosan, France.
authors.forename: Mohamed
authors.initials: M
authors.lastname: Zouine
mesh_terms: D002467:Cell Nucleus / Q000235:genetics / Q000378:metabolism; D005030:Ethylenes / Q000378:metabolism; D005638:Fruit / Q000235:genetics / Q000502:physiology*; D018506:Gene Expression Regulation, Plant; D007210:Indoleacetic Acids / Q000378:metabolism*; D018551:Solanum lycopersicum / Q000235:genetics / Q000502:physiology*; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D030821:Plants, Genetically Modified; D034622:RNA Interference
chemical_list: D005030:Ethylenes; D007210:Indoleacetic Acids; D010940:Plant Proteins; C036216:ethylene