title: A Temporarily Red Light-Insensitive Mutant of Tomato Lacks a Light-Stable, B-Like Phytochrome.
abstract: We have selected four recessive mutants in tomato (Lycopersicon esculentum Mill.) that, under continuous red light (R), have long hypocotyls and small cotyledons compared to wild type (WT), a phenotype typical of phytochrome B (phyB) mutants of other species. These mutants, which are allelic, are only insensitive to R during the first 2 days upon transition from darkness to R, and therefore we propose the gene symbol tri (temporarily red light insensitive). White light-grown mutant plants have a more elongated growth habit than that of the WT. An immunochemically and spectrophotometrically detectable phyB-like polypeptide detectable in the WT is absent or below detection limits in the tri1 mutant. In contrast to the absence of an elongation growth response to far-red light (FR) given at the end of the daily photoperiod (EODFR) in all phyB-deficient mutants so far characterized, the tri1 mutant responds to EODFR treatment. The tri1 mutant also shows a strong response to supplementary daytime far-red light. We propose that the phyB-like phytochrome deficient in the tri mutants plays a major role during de-etiolation and that other light-stable phytochromes can regulate the EODFR and shade-avoidance responses in tomato.
authors.affiliation: Department of Genetics, Wageningen Agricultural University, Dreijenlaan 2, NL-6703 HA Wageningen, The Netherlands (A.v.T., M.K.).
authors.forename: A.
authors.initials: A
authors.lastname: Van Tuinen
authors.forename: LHJ.
authors.initials: L
authors.lastname: Kerckhoffs
authors.forename: A.
authors.initials: A
authors.lastname: Nagatani
authors.forename: R. E.
authors.initials: RE
authors.lastname: Kendrick
authors.forename: M.
authors.initials: M
authors.lastname: Koornneef