title: The Accumulation of miRNAs Differentially Modulated by Drought Stress Is Affected by Grafting in Grapevine.
abstract: Grapevine (Vitis vinifera) is routinely grafted, and rootstocks inducing drought tolerance represent a source for adapting vineyards to climate change in temperate areas. Our goal was to investigate drought stress effects on microRNA (miRNA) abundance in a drought-resistant grapevine rootstock, M4 (Vitis vinifera×Vitis berlandieri), compared with a commercial cultivar, Cabernet Sauvignon, using their autografts and reciprocal grafts. RNA extracted from roots and leaves of droughted and irrigated plants of different graft combinations was used to prepare cDNA libraries for small RNA sequencing and to analyze miRNAs by quantitative real-time polymerase chain reaction (RT-qPCR). Measurements of leaf water potential, leaf gas exchange, and root hydraulic conductance attested that, under irrigation, M4 reduced water loss in comparison with cultivar Cabernet Sauvignon mostly through nonhydraulic, root-specific mechanisms. Under drought, stomatal conductance decreased at similar levels in the two genotypes. Small RNA sequencing allowed the identification of 70 conserved miRNAs and the prediction of 28 novel miRNAs. Different accumulation trends of miRNAs, observed upon drought and in different genotypes and organs, were confirmed by RT-qPCR Corresponding target transcripts, predicted in silico and validated by RT-qPCR, often showed opposite expression profiles than the related miRNAs. Drought effects on miRNA abundance differed between the two genotypes. Furthermore, the concentration of drought-responsive miRNAs in each genotype was affected by reciprocal grafting, suggesting either the movement of signals inducing miRNA expression in the graft partner or, possibly, miRNA transport between scion and rootstock. These results open new perspectives in the selection of rootstocks for improving grapevine adaptation to drought.
authors.affiliation: Department of Agricultural, Forest, and Food Sciences, University of Turin, I-10095 Grugliasco, Italy (C.P., M.V., M.F., M.I., C.L., A.S.); and chiara.pagliarani@unito.it.|Department of Biology, University of Padua, I-35121 Padua, Italy (N.V., G.V.) chiara.pagliarani@unito.it.
authors.forename: Chiara
authors.identifier: 0000-0003-4656-6192
authors.initials: C
authors.lastname: Pagliarani
authors.affiliation: Department of Agricultural, Forest, and Food Sciences, University of Turin, I-10095 Grugliasco, Italy (C.P., M.V., M.F., M.I., C.L., A.S.); and.|Department of Biology, University of Padua, I-35121 Padua, Italy (N.V., G.V.).
authors.forename: Marco
authors.initials: M
authors.lastname: Vitali
authors.affiliation: Department of Agricultural, Forest, and Food Sciences, University of Turin, I-10095 Grugliasco, Italy (C.P., M.V., M.F., M.I., C.L., A.S.); and.|Department of Biology, University of Padua, I-35121 Padua, Italy (N.V., G.V.).
authors.forename: Manuela
authors.identifier: 0000-0003-1504-5976
authors.initials: M
authors.lastname: Ferrero
authors.affiliation: Department of Agricultural, Forest, and Food Sciences, University of Turin, I-10095 Grugliasco, Italy (C.P., M.V., M.F., M.I., C.L., A.S.); and.|Department of Biology, University of Padua, I-35121 Padua, Italy (N.V., G.V.).
authors.forename: Nicola
authors.initials: N
authors.lastname: Vitulo
authors.affiliation: Department of Agricultural, Forest, and Food Sciences, University of Turin, I-10095 Grugliasco, Italy (C.P., M.V., M.F., M.I., C.L., A.S.); and.|Department of Biology, University of Padua, I-35121 Padua, Italy (N.V., G.V.).
authors.forename: Marco
authors.initials: M
authors.lastname: Incarbone
authors.affiliation: Department of Agricultural, Forest, and Food Sciences, University of Turin, I-10095 Grugliasco, Italy (C.P., M.V., M.F., M.I., C.L., A.S.); and.|Department of Biology, University of Padua, I-35121 Padua, Italy (N.V., G.V.).
authors.forename: Claudio
authors.identifier: 0000-0001-8825-2904
authors.initials: C
authors.lastname: Lovisolo
authors.affiliation: Department of Agricultural, Forest, and Food Sciences, University of Turin, I-10095 Grugliasco, Italy (C.P., M.V., M.F., M.I., C.L., A.S.); and.|Department of Biology, University of Padua, I-35121 Padua, Italy (N.V., G.V.).
authors.forename: Giorgio
authors.identifier: 0000-0003-4377-5685
authors.initials: G
authors.lastname: Valle
authors.affiliation: Department of Agricultural, Forest, and Food Sciences, University of Turin, I-10095 Grugliasco, Italy (C.P., M.V., M.F., M.I., C.L., A.S.); and.|Department of Biology, University of Padua, I-35121 Padua, Italy (N.V., G.V.).
authors.forename: Andrea
authors.identifier: 0000-0001-7355-5865
authors.initials: A
authors.lastname: Schubert
mesh_terms: D000222:Adaptation, Physiological; D000383:Agriculture / Q000379:methods; D002245:Carbon Dioxide / Q000378:metabolism; D055864:Droughts; D020869:Gene Expression Profiling / Q000379:methods; D018506:Gene Expression Regulation, Plant; D005838:Genotype; D035683:MicroRNAs / Q000235:genetics* / Q000378:metabolism; D010100:Oxygen / Q000378:metabolism; D018515:Plant Leaves / Q000235:genetics / Q000378:metabolism; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D018517:Plant Roots / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013045:Species Specificity; D013312:Stress, Physiological; D027843:Vitis / Q000145:classification / Q000235:genetics* / Q000378:metabolism; D014867:Water / Q000378:metabolism
chemical_list: D035683:MicroRNAs; D010940:Plant Proteins; D014867:Water; D002245:Carbon Dioxide; D010100:Oxygen