title: A visible marker for antisense mRNA expression in plants: inhibition of chlorophyll synthesis with a glutamate-1-semialdehyde aminotransferase antisense gene.
abstract: Glutamate 1-semialdehyde aminotransferase [(S)-4-amino-5-oxopentanoate 4,5-aminomutase, EC 5.4.3.8] catalyzes the last step in the conversion of glutamate to delta-aminolevulinate of which eight molecules are needed to synthesize a chlorophyll molecule. Two full-length cDNA clones that probably represent the homeologous Gsa genes of the two tobacco (Nicotiana tabacum) genomes have been isolated. The deduced amino acid sequences of the 468-residue-long precursor polypeptides differ by 10 amino acids. The cDNA sequence of isoenzyme 2 was inserted in reverse orientation under the control of a cauliflower mosaic virus 35S promoter derivative in an expression vector and was introduced by Agrobacterium-mediated transformation into tobacco plants. Antisense gene expression decreased the steady-state mRNA level of glutamate 1-semialdehyde aminotransferase, the translation of the enzyme, and chlorophyll synthesis. Remarkably, partial or complete suppression of the aminotransferase mimics in tobacco a wide variety of chlorophyll variegation patterns caused by nuclear or organelle gene mutations in different higher plants. The antisense gene is inherited as a dominant marker.
authors.affiliation: Schering AG, Pflanzenschutzforschung, Berlin, Germany.
authors.forename: R
authors.initials: R
authors.lastname: Höfgen
authors.forename: K B
authors.initials: KB
authors.lastname: Axelsen
authors.forename: C G
authors.initials: CG
authors.lastname: Kannangara
authors.forename: I
authors.initials: I
authors.lastname: Schüttke
authors.forename: H D
authors.initials: HD
authors.lastname: Pohlenz
authors.forename: L
authors.initials: L
authors.lastname: Willmitzer
authors.forename: B
authors.initials: B
authors.lastname: Grimm
authors.forename: D
authors.initials: D
authors.lastname: von Wettstein
mesh_terms: D000595:Amino Acid Sequence; D002734:Chlorophyll / Q000096:biosynthesis; D003001:Cloning, Molecular; D015870:Gene Expression; D017343:Genes, Plant; D005819:Genetic Markers; D005822:Genetic Vectors; D019751:Intramolecular Transferases; D007535:Isomerases / Q000235:genetics; D008969:Molecular Sequence Data; D010641:Phenotype; D030821:Plants, Genetically Modified; D010947:Plants, Toxic; D016372:RNA, Antisense / Q000235:genetics*; D012333:RNA, Messenger / Q000235:genetics*; D014026:Nicotiana / Q000235:genetics* / Q000378:metabolism; D014170:Transformation, Genetic
chemical_list: D005819:Genetic Markers; D016372:RNA, Antisense; D012333:RNA, Messenger; D002734:Chlorophyll; D007535:Isomerases; D019751:Intramolecular Transferases; C061049:glutamate-1-semialdehyde 2,1-aminomutase