title: Chlorophyll reduction in the seed of Brassica napus with a glutamate 1-semialdehyde aminotransferase antisense gene.
abstract: Chlorophyll reduction in the seed of Brassica can be achieved by downregulating its synthesis. To reduce chlorophyll synthesis, we have used a cDNA clone of Brassica napus encoding glutamate 1-semialdehyde aminotransferase (GSA-AT) to make an antisense construct for gene manipulation. Antisense glutamate 1-semialdehyde aminotransferase gene (Gsa) expression, directed by a Brassica napin promoter, was targeted specifically to the embryo of the developing seed. Transformants expressing antisense Gsa showed varying degrees of inhibition resulting in a range of chlorophyll reduction in the seeds. Seed growth and development were not affected by reduction of chlorophyll. Seeds from selfed transgenic plants germinated with high efficiency and growth of seedlings was vigorous. Seedlings from T2 transgenic lines segregated into three distinctive phenotypes: dark green, light green and yellow, indicating the dominant inheritance of Gsa antisense gene. These transgenic lines have provided useful materials for the development of a low chlorophyll seed variety of B. napus.
authors.affiliation: Plant Biotechnology Institute, National Research Council of Canada, 110 Gymnasium Place, Saskatoon, Saskatchewan, S7N 0W9 Canada. Ed.Tsang@nrc.ca
authors.forename: Edward W T
authors.initials: EW
authors.lastname: Tsang
authors.forename: Jingyi
authors.initials: J
authors.lastname: Yang
authors.forename: Qing
authors.initials: Q
authors.lastname: Chang
authors.forename: Goska
authors.initials: G
authors.lastname: Nowak
authors.forename: Allan
authors.initials: A
authors.lastname: Kolenovsky
authors.forename: D Ian
authors.initials: DI
authors.lastname: McGregor
authors.forename: Wilfred A
authors.initials: WA
authors.lastname: Keller
mesh_terms: D000595:Amino Acid Sequence; D029688:Brassica napus / Q000201:enzymology / Q000235:genetics / Q000378:metabolism*; D002734:Chlorophyll / Q000378:metabolism*; D003001:Cloning, Molecular; D016373:DNA, Antisense / Q000235:genetics*; D018076:DNA, Complementary / Q000737:chemistry / Q000235:genetics; D019751:Intramolecular Transferases / Q000037:antagonists & inhibitors / Q000235:genetics* / Q000378:metabolism; D007527:Isoenzymes / Q000235:genetics / Q000378:metabolism; D008969:Molecular Sequence Data; D010641:Phenotype; D030821:Plants, Genetically Modified; D016372:RNA, Antisense / Q000235:genetics; D012639:Seeds / Q000235:genetics / Q000378:metabolism*; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D014170:Transformation, Genetic
chemical_list: D016373:DNA, Antisense; D018076:DNA, Complementary; D007527:Isoenzymes; D016372:RNA, Antisense; D002734:Chlorophyll; D019751:Intramolecular Transferases; C061049:glutamate-1-semialdehyde 2,1-aminomutase