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A plastid-derived signal plays an important role in the coordinated expression of both nuclear- and chloroplast-localized genes that encode photosynthesis-related proteins. Arabidopsis GUN (genomes uncoupled) loci have been identified as components of plastid-to-nucleus signal transduction. Unlike wild-type plants, gun mutants have nuclear Lhcb1 expression(More)
Phototropins 1 and 2 (phot1 and phot2) function as blue light (BL) photoreceptors for phototropism, chloroplast relocation, stomatal opening and leaf flattening in Arabidopsis thaliana. Phototropin consists of two functional domains, the N-terminal photosensory domain and the C-terminal Ser/Thr kinase domain. However, little is known about the signal(More)
Plants make full use of light signals to determine the timing of flowering. In Arabidopsis thaliana, a blue/UV-A photoreceptor, CRYPTOCHROME 2 (cry2), and a red/far-red photoreceptor, PHYTOCHROME B (phyB), are two major photoreceptors that control flowering. The light stimuli for the regulation of flowering are perceived by leaves. We have recently shown(More)
Phytochrome is a ubiquitous photoreceptor of plants and is encoded by a small multigene family. We have shown recently that a functional nuclear localization signal may reside within the COOH-terminal region of a major member of the family, phytochrome B (phyB) (Sakamoto, K., and A. Nagatani. 1996. Plant J. 10:859-868). In the present study, a fusion(More)
Lhcb and other nuclear genes for chloroplastic proteins are regulated by several signals. Among them, light and retrograde signals from the plastid itself appear to act through closely related mechanisms. To investigate this interaction, we analysed an Arabidopsis mutant, hy1, deficient in plastidic heme oxygenase. hy1 is defective in phytochrome(More)
Light is one of the most important environmental factors that determine the timing of a plant's transition from the vegetative to reproductive, or flowering, phase. Not only daylength but also the spectrum of light greatly affect flowering. The shade of nearby vegetation reduces the ratio of red to far-red light and can trigger shade avoidance responses,(More)
A pool of Arabidopsis lines transformed with the activation vector was screened for short hypocotyl mutants under dim far-red light, and three mutant lines designated chibi1-3 (chi) were isolated. Among the chi mutants, chi2 was dominant. The chi2 seedlings were short, regardless of the light conditions. The chi2 mature plants exhibited phenotypic features(More)
Tetrapyrroles such as chlorophyll and heme are co-factors for essential proteins involved in a wide variety of crucial cellular functions. Nearly 2% of the proteins encoded by the Arabidopsis thaliana genome are thought to bind tetrapyrroles, demonstrating their central role in plant metabolism. Although the enzymes required for tetrapyrrole biosynthesis(More)
Phototropins mediate various blue-light responses such as phototropism, chloroplast relocation, stomatal opening and leaf flattening in plants. Phototropins are hydrophilic chromoproteins that are mainly bound to the plasma membrane. One of two phototropins in Arabidopsis thaliana, phot2, associates with the Golgi apparatus in a light-dependent manner. In(More)
A plant modulates its developmental processes in response to light by several informational photoreceptors such as phytochrome. Phytochrome is a dimeric chromoprotein which regulates various aspects of plant development from seed germination to flowering. Upon absorption of red light, phytochrome translocates from the cytoplasm to the nucleus, and regulates(More)