title: The aurea mutant of tomato is deficient in spectrophotometrically and immunochemically detectable phytochrome.
abstract: The aurea locus mutant (au (w)) of tomato contains less than 5% of the level of phytochrome in wild-type tissue as measured by in vivo difference spectroscopy. Immunoblot analysis using antibodies directed against etiolated-oat phytochrome demonstrates that crude extracts of etiolated mutant tissue are deficient in a major immunodetectable protein (116 kDa) normally present in the parent wild type. Analyses of wild-type tissue extracts strongly indicate that the 116-kDa protein is phytochrome by showing that this protein: a) is degraded more rapidly in vitro after a brief far-red irradiation than after a brief red irradiation (Vierstra RD, Quail PH, Planta 156: 158-165, 1982); b) contains a covalently bound chromophore as detected by Zn-chromophore fluorescence on nitrocellulose blots; and c) has an apparent molecular mass comparable to phytochrome from other species on size exclusion chromatography under non-denaturing conditions. The demonstration that the aurea mutant is deficient in this 116-kDa phytochrome indicates that the lack of spectrally detectable phytochrome in this mutant is the result of a lesion which affects the abundance of the phytochrome molecule as opposed to its spectral integrity.
authors.affiliation: Botany Department, University of Wisconsin, 53706, Madison, WI, USA.
authors.forename: B M
authors.initials: BM
authors.lastname: Parks
authors.forename: A M
authors.initials: AM
authors.lastname: Jones
authors.forename: P
authors.initials: P
authors.lastname: Adamse
authors.forename: M
authors.initials: M
authors.lastname: Koornneef
authors.forename: R E
authors.initials: RE
authors.lastname: Kendrick
authors.forename: P H
authors.initials: PH
authors.lastname: Quail