title: Gr and hp-1 tomato mutants unveil unprecedented interactions between arbuscular mycorrhizal symbiosis and fruit ripening.
abstract: Systemic responses to an arbuscular mycorrhizal fungus reveal opposite phenological patterns in two tomato ripening mutants depending whether ethylene or light reception is involved. The availability of tomato ripening mutants has revealed many aspects of the genetics behind fleshy fruit ripening, plant hormones and light signal reception. Since previous analyses revealed that arbuscular mycorrhizal symbiosis influences tomato berry ripening, we wanted to test the hypothesis that an interplay might occur between root symbiosis and fruit ripening. With this aim, we screened seven tomato mutants affected in the ripening process for their responsiveness to the arbuscular mycorrhizal fungus Funneliformis mosseae. Following their phenological responses we selected two mutants for a deeper analysis: Green ripe (Gr), deficient in fruit ethylene perception and high-pigment-1 (hp-1), displaying enhanced light signal perception throughout the plant. We investigated the putative interactions between ripening processes, mycorrhizal establishment and systemic effects using biochemical and gene expression tools. Our experiments showed that both mutants, notwithstanding a normal mycorrhizal phenotype at root level, exhibit altered arbuscule functionality. Furthermore, in contrast to wild type, mycorrhization did not lead to a higher phosphate concentration in berries of both mutants. These results suggest that the mutations considered interfere with arbuscular mycorrhiza inducing systemic changes in plant phenology and fruits metabolism. We hypothesize a cross talk mechanism between AM and ripening processes that involves genes related to ethylene and light signaling.
authors.affiliation: Department of Life Sciences and Systems Biology, University of Turin, Viale Mattioli 25, 10125, Turin, Italy.
authors.forename: Matteo
authors.initials: M
authors.lastname: Chialva
authors.affiliation: Department of Life Sciences and Systems Biology, University of Turin, Viale Mattioli 25, 10125, Turin, Italy.
authors.forename: Inès
authors.initials: I
authors.lastname: Zouari
authors.affiliation: Department of Life Sciences and Systems Biology, University of Turin, Viale Mattioli 25, 10125, Turin, Italy.
authors.forename: Alessandra
authors.initials: A
authors.lastname: Salvioli
authors.affiliation: Department of Life Sciences and Systems Biology, University of Turin, Viale Mattioli 25, 10125, Turin, Italy.
authors.forename: Mara
authors.initials: M
authors.lastname: Novero
authors.affiliation: Boyce Thompson Institute for Plant Research, Cornell University, Ithaca, NY, USA.
authors.forename: Julia
authors.initials: J
authors.lastname: Vrebalov
authors.affiliation: Boyce Thompson Institute for Plant Research, Cornell University, Ithaca, NY, USA.|US Department of Agriculture Robert W. Holley Centre for Agriculture and Health, Ithaca, NY, USA.
authors.forename: James J
authors.initials: JJ
authors.lastname: Giovannoni
authors.affiliation: Department of Life Sciences and Systems Biology, University of Turin, Viale Mattioli 25, 10125, Turin, Italy. paola.bonfante@unito.it.
authors.forename: Paola
authors.identifier: http://orcid.org/0000-0003-3576-8530
authors.initials: P
authors.lastname: Bonfante
mesh_terms: D000704:Analysis of Variance; D005030:Ethylenes / Q000378:metabolism; D035264:Flowers / Q000235:genetics / Q000382:microbiology / Q000502:physiology; D005638:Fruit / Q000235:genetics* / Q000382:microbiology / Q000502:physiology; D018506:Gene Expression Regulation, Plant / Q000528:radiation effects; D059647:Gene-Environment Interaction; D008027:Light; D018551:Solanum lycopersicum / Q000235:genetics* / Q000382:microbiology / Q000502:physiology; D009154:Mutation; D038821:Mycorrhizae / Q000254:growth & development* / Q000502:physiology; D010641:Phenotype; D010858:Pigmentation; D018517:Plant Roots / Q000235:genetics / Q000382:microbiology / Q000502:physiology; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013559:Symbiosis
chemical_list: D005030:Ethylenes; C036216:ethylene
keywords: Arbuscular mycorrhiza; Ethylene; Funneliformis mosseae; Light signaling; Ripening mutants; Tomato