title: The down-regulation of the genes encoding Isoamylase 1 alters the starch composition of the durum wheat grain.
abstract: In rice, maize and barley, the lack of Isoamylase 1 activity materially affects the composition of endosperm starch. Here, the effect of this deficiency in durum wheat has been characterized, using transgenic lines in which Isa1 was knocked down via RNAi. Transcriptional profiling confirmed the partial down-regulation of Isa1 and revealed a pleiotropic effect on the level of transcription of genes encoding other isoamylases, pullulanase and sucrose synthase. The polysaccharide content of the transgenic endosperms was different from that of the wild type in a number of ways, including a reduction in the content of starch and a moderate enhancement of both phytoglycogen and β-glucan. Some alterations were also induced in the distribution of amylopectin chain length and amylopectin fine structure. The amylopectin present in the transgenic endosperms was more readily hydrolyzable after a treatment with hydrochloric acid, which disrupted its semi-crystalline structure. The conclusion was that in durum wheat, Isoamylase 1 is important for both the synthesis of amylopectin and for determining its internal structure.
authors.affiliation: Department of Agricultural and Forestry Sciences DAFNE, University of Tuscia, Via S. Camillo de Lellis, SNC, 01100 Viterbo, Italy. Electronic address: francescosestili@unitus.it.
authors.forename: Francesco
authors.initials: F
authors.lastname: Sestili
authors.affiliation: Department of Pharmacy and Biotechnology FABIT, University of Bologna, Via Irnerio 42, 40126 Bologna, Italy. Electronic address: francesca.sparla@unibo.it.
authors.forename: Francesca
authors.initials: F
authors.lastname: Sparla
authors.affiliation: Department of Agricultural and Forestry Sciences DAFNE, University of Tuscia, Via S. Camillo de Lellis, SNC, 01100 Viterbo, Italy. Electronic address: e.botticella@unitus.it.
authors.forename: Ermelinda
authors.initials: E
authors.lastname: Botticella
authors.affiliation: Department of Agricultural and Forestry Sciences DAFNE, University of Tuscia, Via S. Camillo de Lellis, SNC, 01100 Viterbo, Italy; National Research Council CNR-Istituto di Bioscienze e Biorisorse, Via G. Amendola, 165, 70126 Bari, Italy. Electronic address: michela.janni@ibbr.cnr.it.
authors.forename: Michela
authors.initials: M
authors.lastname: Janni
authors.affiliation: Department of Agricultural and Forestry Sciences DAFNE, University of Tuscia, Via S. Camillo de Lellis, SNC, 01100 Viterbo, Italy. Electronic address: dovidio@unitus.it.
authors.forename: Renato
authors.initials: R
authors.lastname: D'Ovidio
authors.affiliation: Department of Chemistry "G. Ciamician", University of Bologna, Via Selmi 2, 40126 Bologna, Italy. Electronic address: giuseppe.falini@unibo.it.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Falini
authors.affiliation: Carlsberg Research Laboratory, Gamle Carlsberg Vej 10, Copenhagen, V DK-1799, Denmark. Electronic address: lucia.marri@carlsberglab.dk.
authors.forename: Lucia
authors.initials: L
authors.lastname: Marri
authors.affiliation: Carlsberg Research Laboratory, Gamle Carlsberg Vej 10, Copenhagen, V DK-1799, Denmark. Electronic address: JoseA.Cuesta.Seijo@carlsberglab.dk.
authors.forename: Jose A
authors.initials: JA
authors.lastname: Cuesta-Seijo
authors.affiliation: National Research Council CNR-Istituto di Biologia Agroambientale e Forestale, Viale Marconi 2, 05010 Porano, TR, Italy. Electronic address: stefano.moscatello@ibaf.cnr.it.
authors.forename: Stefano
authors.initials: S
authors.lastname: Moscatello
authors.affiliation: National Research Council CNR-Istituto di Biologia Agroambientale e Forestale, Viale Marconi 2, 05010 Porano, TR, Italy. Electronic address: alberto.battistelli@ibaf.cnr.it.
authors.forename: Alberto
authors.initials: A
authors.lastname: Battistelli
authors.affiliation: Department of Pharmacy and Biotechnology FABIT, University of Bologna, Via Irnerio 42, 40126 Bologna, Italy. Electronic address: paolo.trost@unibo.it.
authors.forename: Paolo
authors.initials: P
authors.lastname: Trost
authors.affiliation: Department of Agricultural and Forestry Sciences DAFNE, University of Tuscia, Via S. Camillo de Lellis, SNC, 01100 Viterbo, Italy. Electronic address: lafiandr@unitus.it.
authors.forename: Domenico
authors.initials: D
authors.lastname: Lafiandra
mesh_terms: D000687:Amylopectin / Q000096:biosynthesis / Q000378:metabolism; D015536:Down-Regulation; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant; D006851:Hydrochloric Acid / Q000737:chemistry; D006868:Hydrolysis; D007517:Isoamylase / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D030821:Plants, Genetically Modified / Q000378:metabolism; D034622:RNA Interference; D013213:Starch / Q000378:metabolism*; D014908:Triticum / Q000235:genetics / Q000378:metabolism*
chemical_list: D010940:Plant Proteins; D013213:Starch; D000687:Amylopectin; D007517:Isoamylase; D006851:Hydrochloric Acid
keywords: Durum wheat; Isoamylases; RNAi; Starch