title: Carotenoid accumulation during tomato fruit ripening is modulated by the auxin-ethylene balance.
abstract: BACKGROUND
  Tomato fruit ripening is controlled by ethylene and is characterized by a shift in color from green to red, a strong accumulation of lycopene, and a decrease in β-xanthophylls and chlorophylls. The role of other hormones, such as auxin, has been less studied. Auxin is retarding the fruit ripening. In tomato, there is no study of the carotenoid content and related transcript after treatment with auxin.
  
  
  RESULTS
  We followed the effects of application of various hormone-like substances to "Mature-Green" fruits. Application of an ethylene precursor (ACC) or of an auxin antagonist (PCIB) to tomato fruits accelerated the color shift, the accumulation of lycopene, α-, β-, and δ-carotenes and the disappearance of β-xanthophylls and chlorophyll b. By contrast, application of auxin (IAA) delayed the color shift, the lycopene accumulation and the decrease of chlorophyll a. Combined application of IAA + ACC led to an intermediate phenotype. The levels of transcripts coding for carotenoid biosynthesis enzymes, for the ripening regulator Rin, for chlorophyllase, and the levels of ethylene and abscisic acid (ABA) were monitored in the treated fruits. Correlation network analyses suggest that ABA, may also be a key regulator of several responses to auxin and ethylene treatments.
  
  
  CONCLUSIONS
  The results suggest that IAA retards tomato ripening by affecting a set of (i) key regulators, such as Rin, ethylene and ABA, and (ii) key effectors, such as genes for lycopene and β-xanthophyll biosynthesis and for chlorophyll degradation.
authors.affiliation: Université de Toulouse, INP-ENSA Toulouse, UMR990 Génomique et Biotechnologie des Fruits, Avenue de l'Agrobiopole, CS 32607, F-31326, Castanet-Tolosan, France. suliyan029@126.com.|Actual address: Department of Life Sciences, Xi'an University of Arts and Science, Xi'an, 710065, PR China. suliyan029@126.com.
authors.forename: Liyan
authors.initials: L
authors.lastname: Su
authors.affiliation: Italian National Agency for New Technologies, Energy, and Sustainable Development, Casaccia Research Centre, 00123, Rome, Italy. gianfranco.diretto@enea.it.
authors.forename: Gianfranco
authors.initials: G
authors.lastname: Diretto
authors.affiliation: Department Food and Experimental Nutrition; NAPAN/FoRC - Food Research Center, Universidade de São Paulo, School of Pharmaceutical Sciences, Av. Prof. Lineu Prestes 580, Butantã, CEP 05508-000, São Paulo, SP, Brazil. epurgatt@usp.br.
authors.forename: Eduardo
authors.initials: E
authors.lastname: Purgatto
authors.affiliation: Université de Toulouse; UPS; UMR 5546; Laboratoire de Recherche en Sciences Végétales (LRSV), 24 Chemin de Borde Rouge, F-31326, Castanet-Tolosan, France. danoun@lrsv.ups-tlse.fr.
authors.forename: Saïda
authors.initials: S
authors.lastname: Danoun
authors.affiliation: Université de Toulouse, INP-ENSA Toulouse, UMR990 Génomique et Biotechnologie des Fruits, Avenue de l'Agrobiopole, CS 32607, F-31326, Castanet-Tolosan, France. mohamed.zouine@ensat.fr.|INRA, UMR990 Génomique et Biotechnologie des Fruits, 24 Chemin de Borde Rouge, CS 52627, F-31326, Castanet-Tolosan, France. mohamed.zouine@ensat.fr.
authors.forename: Mohamed
authors.initials: M
authors.lastname: Zouine
authors.affiliation: Genetic Engineering Research Centre, Bioengineering College, Chongqing University, Chongqing, 400044, PR China. zhengguoli@cqu.edu.cn.
authors.forename: Zhengguo
authors.initials: Z
authors.lastname: Li
authors.affiliation: Université de Toulouse, INP-ENSA Toulouse, UMR990 Génomique et Biotechnologie des Fruits, Avenue de l'Agrobiopole, CS 32607, F-31326, Castanet-Tolosan, France. roustan@ensat.fr.|INRA, UMR990 Génomique et Biotechnologie des Fruits, 24 Chemin de Borde Rouge, CS 52627, F-31326, Castanet-Tolosan, France. roustan@ensat.fr.
authors.forename: Jean-Paul
authors.initials: JP
authors.lastname: Roustan
authors.affiliation: Université de Toulouse, INP-ENSA Toulouse, UMR990 Génomique et Biotechnologie des Fruits, Avenue de l'Agrobiopole, CS 32607, F-31326, Castanet-Tolosan, France. bouzayen@ensat.fr.|INRA, UMR990 Génomique et Biotechnologie des Fruits, 24 Chemin de Borde Rouge, CS 52627, F-31326, Castanet-Tolosan, France. bouzayen@ensat.fr.
authors.forename: Mondher
authors.initials: M
authors.lastname: Bouzayen
authors.affiliation: Italian National Agency for New Technologies, Energy, and Sustainable Development, Casaccia Research Centre, 00123, Rome, Italy. Giovanni.Giuliano@enea.it.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Giuliano
authors.affiliation: Université de Toulouse, INP-ENSA Toulouse, UMR990 Génomique et Biotechnologie des Fruits, Avenue de l'Agrobiopole, CS 32607, F-31326, Castanet-Tolosan, France. chervin@ensat.fr.|INRA, UMR990 Génomique et Biotechnologie des Fruits, 24 Chemin de Borde Rouge, CS 52627, F-31326, Castanet-Tolosan, France. chervin@ensat.fr.
authors.forename: Christian
authors.initials: C
authors.lastname: Chervin
mesh_terms: D000040:Abscisic Acid / Q000378:metabolism; D053898:Biosynthetic Pathways / Q000187:drug effects / Q000235:genetics; D002265:Carboxylic Ester Hydrolases / Q000235:genetics / Q000378:metabolism; D002338:Carotenoids / Q000378:metabolism*; D002734:Chlorophyll / Q000378:metabolism; D005030:Ethylenes / Q000378:metabolism* / Q000494:pharmacology; D005638:Fruit / Q000187:drug effects / Q000235:genetics / Q000254:growth & development*; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D053263:Gene Regulatory Networks / Q000187:drug effects; D007210:Indoleacetic Acids / Q000378:metabolism* / Q000494:pharmacology; D018551:Solanum lycopersicum / Q000187:drug effects / Q000235:genetics / Q000254:growth & development*; D010858:Pigmentation / Q000187:drug effects; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism
chemical_list: D005030:Ethylenes; D007210:Indoleacetic Acids; D010940:Plant Proteins; D012333:RNA, Messenger; D002734:Chlorophyll; D002338:Carotenoids; D000040:Abscisic Acid; C036216:ethylene; D002265:Carboxylic Ester Hydrolases; C019875:chlorophyllase