title: Phytochrome A regulates red-light induction of phototropic enhancement in Arabidopsis.
abstract: Phytochrome A (phyA) and phytochrome B photoreceptors have distinct roles in the regulation of plant growth and development. Studies using specific photomorphogenic mutants and transgenic plants overexpressing phytochrome have supported an evolving picture in which phyA and phytochrome B are responsive to continuous far-red and red light, respectively. Photomorphogenic mutants of Arabidopsis thaliana that had been selected for their inability to respond to continuous irradiance conditions were tested for their ability to carry out red-light-induced enhancement of phototropism, which is an inductive phytochrome response. We conclude that phyA is the primary photoreceptor regulating this response and provide evidence suggesting that a common regulatory domain in the phyA polypeptide functions for both high-irradiance and inductive phytochrome responses.
authors.affiliation: Department of Plant Biology, Ohio State University, Columbus 43210, USA.
authors.forename: B M
authors.initials: BM
authors.lastname: Parks
authors.forename: P H
authors.initials: PH
authors.lastname: Quail
authors.forename: R P
authors.initials: RP
authors.lastname: Hangarter
mesh_terms: D017360:Arabidopsis / Q000502:physiology* / Q000528:radiation effects; D029681:Arabidopsis Proteins; D004307:Dose-Response Relationship, Radiation; D008027:Light; D009154:Mutation; D010786:Photoreceptor Cells; D018524:Phototropism; D010834:Phytochrome / Q000235:genetics / Q000378:metabolism*; D051942:Phytochrome A; D051939:Phytochrome B; D014157:Transcription Factors
chemical_list: D029681:Arabidopsis Proteins; C497973:PHYA protein, Arabidopsis; C497952:PHYB protein, Arabidopsis; D051942:Phytochrome A; D014157:Transcription Factors; D010834:Phytochrome; D051939:Phytochrome B