title: AUXIN RESPONSE FACTOR 2 Intersects Hormonal Signals in the Regulation of Tomato Fruit Ripening.
abstract: The involvement of ethylene in fruit ripening is well documented, though knowledge regarding the crosstalk between ethylene and other hormones in ripening is lacking. We discovered that AUXIN RESPONSE FACTOR 2A (ARF2A), a recognized auxin signaling component, functions in the control of ripening. ARF2A expression is ripening regulated and reduced in the rin, nor and nr ripening mutants. It is also responsive to exogenous application of ethylene, auxin and abscisic acid (ABA). Over-expressing ARF2A in tomato resulted in blotchy ripening in which certain fruit regions turn red and possess accelerated ripening. ARF2A over-expressing fruit displayed early ethylene emission and ethylene signaling inhibition delayed their ripening phenotype, suggesting ethylene dependency. Both green and red fruit regions showed the induction of ethylene signaling components and master regulators of ripening. Comprehensive hormone profiling revealed that altered ARF2A expression in fruit significantly modified abscisates, cytokinins and salicylic acid while gibberellic acid and auxin metabolites were unaffected. Silencing of ARF2A further validated these observations as reducing ARF2A expression let to retarded fruit ripening, parthenocarpy and a disturbed hormonal profile. Finally, we show that ARF2A both homodimerizes and interacts with the ABA STRESS RIPENING (ASR1) protein, suggesting that ASR1 might be linking ABA and ethylene-dependent ripening. These results revealed that ARF2A interconnects signals of ethylene and additional hormones to co-ordinate the capacity of fruit tissue to initiate the complex ripening process.
authors.affiliation: Department of Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot, Israel.
authors.forename: Dario A
authors.initials: DA
authors.lastname: Breitel
authors.affiliation: Department of Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot, Israel.
authors.forename: Louise
authors.initials: L
authors.lastname: Chappell-Maor
authors.affiliation: Department of Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot, Israel.
authors.forename: Sagit
authors.initials: S
authors.lastname: Meir
authors.affiliation: Department of Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot, Israel.
authors.forename: Irina
authors.initials: I
authors.lastname: Panizel
authors.affiliation: Instituto de Biología Molecular y Cellular de Plantas, Consejo Superior de Investigaciones Cientificas- Universidad Politécnica de Valencia, Valencia, Spain.
authors.forename: Clara Pons
authors.initials: CP
authors.lastname: Puig
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: Department of Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot, Israel.
authors.forename: Tamar
authors.initials: T
authors.lastname: Yifhar
authors.affiliation: Plant Stress Physiology Lab, Gilat Research Center, Agricultural Research Organization (ARO), Rural Delivery Negev, Israel.
authors.forename: Hagai
authors.initials: H
authors.lastname: Yasuor
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
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: Instituto de Biología Molecular y Cellular de Plantas, Consejo Superior de Investigaciones Cientificas- Universidad Politécnica de Valencia, Valencia, Spain.
authors.forename: Antonio
authors.initials: A
authors.lastname: Granell Richart
authors.affiliation: Department of Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot, Israel.
authors.forename: Ilana
authors.initials: I
authors.lastname: Rogachev
authors.affiliation: Department of Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot, Israel.
authors.forename: Asaph
authors.initials: A
authors.lastname: Aharoni
mesh_terms: D000040:Abscisic Acid / Q000494:pharmacology; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000235:genetics*; D005030:Ethylenes / Q000494:pharmacology; D005638:Fruit / Q000235:genetics* / Q000254:growth & development; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D007210:Indoleacetic Acids / Q000494:pharmacology; D018551:Solanum lycopersicum / Q000235:genetics* / Q000254:growth & development; D010641:Phenotype; D010937:Plant Growth Regulators / Q000378:metabolism*; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D012097:Repressor Proteins / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects
chemical_list: C503421:ARF2 protein, Arabidopsis; D029681:Arabidopsis Proteins; C091853:Asr1 protein, Lycopersicon esculentum; D004268:DNA-Binding Proteins; D005030:Ethylenes; D007210:Indoleacetic Acids; D010937:Plant Growth Regulators; D010940:Plant Proteins; D012097:Repressor Proteins; D000040:Abscisic Acid; C036216:ethylene