title: Cryptochrome 1 contributes to blue-light sensing in pea.
abstract: Cryptochromes are widespread in higher plants but their physiological roles as blue-light photoreceptors have been examined in relatively few species. Screening in a phyA null mutant background has identified several blue-light response mutants in pea (Pisum sativum), including one that carries a substitution of a highly conserved glycine residue in the N-terminal photolyase-homologous domain of the pea CRY1 gene. Analyses of cry1, phyA, and phyB mutants show that all three photoreceptors contribute to seedling photomorphogenesis under high-irradiance blue light, whereas phyA is the main photoreceptor active under low irradiances. Triple phyA phyB cry1 mutants grown under high-irradiance blue light are indistinguishable from dark-grown wild-type plants in length and leaf expansion but show a small residual response to higher-irradiance white light. Monogenic cry1 mutants have little discernable phenotype at the seedling stage, but later in development are more elongated than wild-type plants. In addition, the loss of cry1 moderates the short-internode phenotype of older phyA mutants, suggesting an antagonism between phyA and cry1 under some conditions. Pea cry1 has a small inhibitory effect on flowering under long and short days. However, the phyA cry1 double mutant retains a clear promotion of flowering in response to blue-light photoperiod extensions, indicating a role for one or more additional blue-light photoreceptors in the control of flowering in pea.
authors.affiliation: School of Plant Science, University of Tasmania, Hobart, Tasmania 7001, Australia.
authors.forename: J Damien
authors.initials: JD
authors.lastname: Platten
authors.forename: Eloise
authors.initials: E
authors.lastname: Foo
authors.forename: Robert C
authors.initials: RC
authors.lastname: Elliott
authors.forename: Valérie
authors.initials: V
authors.lastname: Hecht
authors.forename: James B
authors.initials: JB
authors.lastname: Reid
authors.forename: James L
authors.initials: JL
authors.lastname: Weller
mesh_terms: D000595:Amino Acid Sequence; D003116:Color; D056931:Cryptochromes; D004307:Dose-Response Relationship, Radiation; D005420:Flavoproteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D035264:Flowers / Q000502:physiology; D018506:Gene Expression Regulation, Plant; D005838:Genotype; D008027:Light; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics; D018532:Pisum sativum / Q000235:genetics / Q000254:growth & development / Q000502:physiology* / Q000528:radiation effects*; D010641:Phenotype; D010834:Phytochrome; D051942:Phytochrome A / Q000235:genetics / Q000378:metabolism; D051939:Phytochrome B / Q000235:genetics / Q000378:metabolism; D018520:Plant Shoots; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D036226:Seedlings / Q000254:growth & development / Q000528:radiation effects; D016415:Sequence Alignment
chemical_list: D056931:Cryptochromes; D005420:Flavoproteins; D051942:Phytochrome A; D012333:RNA, Messenger; C406684:phytochrome E; D010834:Phytochrome; D051939:Phytochrome B