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We have examined the seed germination in Arabidopsis thaliana of wild type (wt), and phytochrome A (PhyA)- and B (PhyB)-mutants in terms of incubation time and environmental light effects. Seed germination of the wt and PhyA-null mutant (phyA) was photoreversibly regulated by red and far-red lights of 10-1,000 micromol m-2 when incubated in darkness for(More)
Phytochromes are a family of plant photoreceptors that mediate physiological and developmental responses to changes in red and far-red light conditions. In Arabidopsis, there are genes for at least five phytochrome proteins. These photoreceptors control such responses as germination, stem elongation, flowering, gene expression, and chloroplast and leaf(More)
UV irradiation stimulates expression of the gene encoding the key enzyme chalcone synthase (CHS), which leads to the generation of protective flavonoids in parsley cell cultures. CHS transcripts increase after 3 to 4 hr, and early genes are involved in the signal transduction to the CHS promoter. By using the fluorescent differential display technique in a(More)
We have used a tobacco transgenic plant system to assay the structure/function relationship of phytochrome A (phyA), a plant photoreceptor. The amino terminus of phyA from different plant species is very rich in serine residues. To investigate whether these serine residues are required for phytochrome function, the first 10 serine codons encoding amino acid(More)
By screening suppressor mutants of the hy2 mutation of Arabidopsis thaliana, two dominant photomorphogenic mutants, shy1-1D and shy2-1D, for two genetic loci designated as SHY1 and SHY2 (suppressor of hy2 mutation) have been isolated. Both of these non-allelic, extragenic suppressor mutations of hy2 are located on chromosome 1 of the Arabidopsis genome.(More)
Elementary processes of photoperception by phytochrome A (PhyA) for the high-irradiance response (HIR) of hypocotyl elongation in Arabidopsis were examined using a newly designed irradiator with LED. The effect of continuous irradiation with far-red (FR) light could be replaced by intermittent irradiation with FR light pulses if given at intervals of 3 min(More)
We have examined the biological activity of rice type I phytochrome (PI) in transgenic tobacco seedlings. The progeny of four independent transformants that expressed the rice PI gene segregated 3:1 for shorter hypocotyl length under dim white light (0.04 W/m2). By contrast, this phenotype was not observed either in the dark or under white light at higher(More)
To elucidate phytochrome A (phyA) function in rice, we screened a large population of retrotransposon (Tos17) insertional mutants by polymerase chain reaction and isolated three independent phyA mutant lines. Sequencing of the Tos17 insertion sites confirmed that the Tos17s interrupted exons of PHYA genes in these mutant lines. Moreover, the phyA(More)
We previously reported a photomorphogenic mutation of Arabidopsis thaliana, shy2-1D, as a dominant suppressor of a hy2 mutation. Here, we report that shy2-1D confers various photo-responsive phenotypes in darkness and the dark phenotypes of the mutant are affected by phytochrome deficiency. Dark-grown seedlings of the mutant developed several(More)
Phytochrome A (PhyA) mediates most, if not all, various plant responses to far-red (FR) light. Here, we report a novel genetic mutation that impairs a variety of responses in the PhyA-signaling pathway of Arabidopsis thaliana. The mutation was isolated by screening seedlings that show reduced sensitivity to continuous far-red (FRc) light irradiation, but(More)