title: Oilseed rape seeds with ablated defence cells of the glucosinolate-myrosinase system. Production and characteristics of double haploid MINELESS plants of Brassica napus L.
abstract: Oilseed rape and other crop plants of the family Brassicaceae contain a unique defence system known as the glucosinolate-myrosinase system or the 'mustard oil bomb'. The 'mustard oil bomb' which includes myrosinase and glucosinolates is triggered by abiotic and biotic stress, resulting in the formation of toxic products such as nitriles and isothiocyanates. Myrosinase is present in specialist cells known as 'myrosin cells' and can also be known as toxic mines. The myrosin cell idioblasts of Brassica napus were genetically reprogrammed to undergo controlled cell death (ablation) during seed development. These myrosin cell-free plants have been named MINELESS as they lack toxic mines. This has led to the production of oilseed rape with a significant reduction both in myrosinase levels and in the hydrolysis of glucosinolates. Even though the myrosinase activity in MINELESS was very low compared with the wild type, variation was observed. This variability was overcome by producing homozygous seeds. A microspore culture technique involving non-fertile haploid MINELESS plants was developed and these plants were treated with colchicine to produce double haploid MINELESS plants with full fertility. Double haploid MINELESS plants had significantly reduced myrosinase levels and glucosinolate hydrolysis products. Wild-type and MINELESS plants exhibited significant differences in growth parameters such as plant height, leaf traits, matter accumulation, and yield parameters. The growth and developmental pattern of MINELESS plants was relatively slow compared with the wild type. The characteristics of the pure double haploid MINELESS plant are described and its importance for future biochemical, agricultural, dietary, functional genomics, and plant defence studies is discussed.
authors.affiliation: Department of Biology, Norwegian University of Science and Technology, Realfagbygget, N-7491 Trondheim, Norway.
authors.forename: Ishita
authors.initials: I
authors.lastname: Ahuja
authors.forename: Birgit Hafeld
authors.initials: BH
authors.lastname: Borgen
authors.forename: Magnor
authors.initials: M
authors.lastname: Hansen
authors.forename: Bjørn Ivar
authors.initials: BI
authors.lastname: Honne
authors.forename: Caroline
authors.initials: C
authors.lastname: Müller
authors.forename: Jens
authors.initials: J
authors.lastname: Rohloff
authors.forename: John Trevor
authors.initials: JT
authors.lastname: Rossiter
authors.forename: Atle Magnar
authors.initials: AM
authors.lastname: Bones
mesh_terms: D029688:Brassica napus / Q000166:cytology / Q000201:enzymology* / Q000235:genetics / Q000378:metabolism; D005961:Glucosinolates / Q000378:metabolism*; D006026:Glycoside Hydrolases / Q000235:genetics / Q000378:metabolism*; D006238:Haploidy; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D030821:Plants, Genetically Modified / Q000166:cytology / Q000201:enzymology* / Q000235:genetics / Q000378:metabolism; D012639:Seeds / Q000166:cytology / Q000201:enzymology / Q000235:genetics* / Q000378:metabolism
chemical_list: D005961:Glucosinolates; D010940:Plant Proteins; D006026:Glycoside Hydrolases; C022739:thioglucosidase