title: Transcriptional Characterization of a Widely-Used Grapevine Rootstock Genotype under Different Iron-Limited Conditions.
abstract: Iron chlorosis is a serious deficiency that affects orchards and vineyards reducing quality and yield production. Chlorotic plants show abnormal photosynthesis and yellowing shoots. In grapevine iron uptake and homeostasis are most likely controlled by a mechanism known as "Strategy I," characteristic of non-graminaceous plants and based on a system of soil acidification, iron reduction and transporter-mediated uptake. Nowadays, grafting of varieties of economic interest on tolerant rootstocks is widely used practice against many biotic and abiotic stresses. Nevertheless, many interspecific rootstocks, and in particular those obtained by crossing exclusivelynon-viniferagenotypes, can show limited nutrient uptake and transport, in particular for what concerns iron. In the present study, 101.14, a commonly used rootstock characterized by susceptibility to iron chlorosis was subjected to both Fe-absence and Fe-limiting conditions. Grapevine plantlets were grown in control, Fe-deprived, and bicarbonate-supplemented hydroponic solutions. Whole transcriptome analyses, via mRNA-Seq, were performed on root apices of stressed and unstressed plants. Analysis of differentially expressed genes (DEGs) confirmed that Strategy I is the mechanism responsible for iron uptake in grapevine, since many orthologs genes to theArabidopsis"ferrome" were differentially regulated in stressed plant. Molecular differences in the plant responses to Fe absence and presence of bicarbonate were also identified indicating the two treatments are able to induce response-mechanisms only partially overlapping. Finally, we measured the expression of a subset of genes differentially expressed in 101.14 (such asIRT1, FERRITIN1, bHLH38/39) or known to be fundamental in the "strategy I" mechanism (AHA2andFRO2) also in a tolerant rootstock (M1) finding important differences which could be responsible for the different degrees of tolerance observed.
authors.affiliation: Dipartimento di Agronomia Animali Alimenti Risorse Naturali e Ambiente, Università di PadovaLegnaro, Italy; Centro Interdipartimentale per la Ricerca in Viticoltura ed EnologiaConegliano, Italy.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Vannozzi
authors.affiliation: Dipartimento di Scienze Agrarie e Ambientali, Università di Milano Milano, Italy.
authors.forename: Silvia
authors.initials: S
authors.lastname: Donnini
authors.affiliation: Dipartimento di Scienze Agrarie e Ambientali, Università di Milano Milano, Italy.
authors.forename: Gianpiero
authors.initials: G
authors.lastname: Vigani
authors.affiliation: Dipartimento di Agronomia Animali Alimenti Risorse Naturali e Ambiente, Università di PadovaLegnaro, Italy; Centro Interdipartimentale per la Ricerca in Viticoltura ed EnologiaConegliano, Italy.
authors.forename: Massimiliano
authors.initials: M
authors.lastname: Corso
authors.affiliation: Centro di Ricerca Interdipartimentale per le Biotecnologie Innovative Padova, Italy.
authors.forename: Giorgio
authors.initials: G
authors.lastname: Valle
authors.affiliation: Centro di Ricerca Interdipartimentale per le Biotecnologie Innovative Padova, Italy.
authors.forename: Nicola
authors.initials: N
authors.lastname: Vitulo
authors.affiliation: Dipartimento di Agronomia Animali Alimenti Risorse Naturali e Ambiente, Università di PadovaLegnaro, Italy; Centro Interdipartimentale per la Ricerca in Viticoltura ed EnologiaConegliano, Italy.
authors.forename: Claudio
authors.initials: C
authors.lastname: Bonghi
authors.affiliation: Dipartimento di Scienze Agrarie e Ambientali, Università di Milano Milano, Italy.
authors.forename: Graziano
authors.initials: G
authors.lastname: Zocchi
authors.affiliation: Dipartimento di Agronomia Animali Alimenti Risorse Naturali e Ambiente, Università di PadovaLegnaro, Italy; Centro Interdipartimentale per la Ricerca in Viticoltura ed EnologiaConegliano, Italy.
authors.forename: Margherita
authors.initials: M
authors.lastname: Lucchin
keywords: Vitis; ferrome; mRNA-Seq; micronutrients; strategy I