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Magenta Bat 5 Bat Detector 5. When the pho1phot2 double mutant was examined with an increased fluence rate of blue light in a red light background, no blue light response was detected with respect to stomatal opening Kinoshita et al. Because the stomatal opening response was normal in both the phot1 and the phot2 monogenic mutants, phot1 and phot2 apparently act in a functionally redundant manner. It remains to be examined whether there is a separate photoreceptor that contributes to the stomatal opening response and contains zeaxanthin as the chromophore.
Photomorphogenesis in Plants and Bacteria: Function and Signal Transduction Mechanisms
The stomatal aperture size is controlled by the volume and shape of guard cells Christie and Briggs, ; Schroeder et al. In response to light, salt concentration increases in the guard cells, causing an inflow of water, expansion of guard cells, and opening of stomatal aperture. The initial photochemical reaction of a phototropin has been investigated using recombinant LOV domain proteins expressed and purified from heterologous systems Salomon et al.
It was found that the LOV domains undergo a self-contained photocycle of formation and decay of the FMN-cysteinyl adducts, accompanied by a decreased and recovered blue light absorption. This result is supported by a recent crystal structure study of the LOV domain Crosson and Moffat, One possible phototropin substrate may be NPH3. NPH3 protein showed a blue light—induced migration mobility shift, implying that phot1 may catalyze a blue light—dependent phosphorylation of NPH3.
Phot1 and NPH3 are both plasma membrane proteins, but neither of them contains a membrane spanning sequence. Therefore, a post-translational lipid modification of either protein may be required for their colocalization at the plasma membrane. Another protein important for phototropin signal transduction is the recently isolated RPT2 Sakai et al.
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The rpt2 mutant was identified because of its defect in root phototropism, but it also showed a defect in hypocotyl phototropism. However, it turned out that the nph4 mutation affects not only phototropism but also gravitropism, auxin-resistant growth, and auxin-regulated gene expression Stowe-Evans et al. Moreover, unlike nph1 , the aphototropic phenotype of nph4 can be suppressed by ethylene, suggesting a role of the NPH4 gene in hormonal interaction Harper et al.
This finding is particularly interesting with respect to the signaling process of phototropins, because auxin is well known for its involvement in phototropism Briggs et al. Phototropin may also confer its effect through the change of ion homeostasis. A transient blue light—induced increase of cytosolic calcium was shown in transgenic plants expressing the recombinant calcium-binding fluorescent protein aequorin Baum et al.
This transient change in calcium homeostasis is specifically relevant to phototropic responses because it was attenuated in the nph1 mutant but not in the cry1 or cry2 mutants Baum et al. It is conceivable that phot1 may catalyze phosphorylation of calcium transporters at the plasma membrane, triggering other changes in the cell and consequently the differential growth of hypocotyls. It was suggested that blue light activation of phototropins may influence cryptochrome signaling leading to hypocotyl inhibition Folta and Spalding, b.
Alternatively, membrane depolarization and rapid growth inhibition may be independently associated with differential growth response of phototropism and long-term growth inhibition response of de-etiolation.
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Although stomatal opening is the latest movement response for which the identity of the responsible photoreceptors has became known, we seem to know much more about the downstream molecular mechanism associated with stomatal opening than that associated with either phototropic curvature or chloroplast relocation Zeiger, ; Christie and Briggs, ; Schroeder et al. It is likely that our knowledge of blue light—induced stomatal opening may provide additional clues regarding where to look for the signaling components downstream from phototropins associated with phototropic and chloroplast movement responses.
For example, phototropins may regulate ion transporters at the plasma membrane in leaf cells. This could change ion homeostasis in leaf cells, which could alter the network of the cytoskeleton, change the status of the cytoplasmic stream, and eventually change the location of chloroplasts. It is also conceivable that phototropins may interact with and phosphorylate auxin transporters at the plasma membrane to alter the signaling process of this phytohormone, resulting in differential growth.
Our understanding of blue light photoreceptors, like that of many other aspects of signal transduction in plants, has been greatly facilitated by Arabidopsis genetic studies. However, detailed molecular mechanisms of photoreceptor signal perception, signal transduction, and desensitization remain to be elucidated. For example, the biochemical nature of the initial photoreaction of cryptochromes is not clear.
Protein phosphorylation or other types of protein modification have been found for almost every well-characterized photoreceptor; cryptochrome is unlikely to be the exception. It is important to examine blue light—dependent biochemical modification of cryptochromes and the manner in which such modifications are associated with cryptochrome activity and regulation. With respect to the initial photoreaction, we currently know more about phototropins than about cryptochromes. Cryptochrome and phototropin signal transductions are integral parts of plant growth and developmental programs, and our immediate challenge is to identify all the genes associated with photoreceptor function and regulation.
In this respect, protein interaction analyses and genetics studies, which have provided most of our current advances in the field of photoreceptor signal transduction, will continue to serve as two powerful approaches. It is also expected that the recently available bioinformatics and genomics tools in Arabidopsis will further enhance our ability not only to identify all the genes involved in the signal transduction of blue light receptors but also to understand the more-complex problems of how blue light receptor signal transduction interacts with other signaling pathways and cellular activities to eventually bring about growth and developmental changes in plants.
The author thanks Todd Mockler and Dr.
CRYPTOCHROMES AND PHOTOMORPHOGENESIS
May Santiago-Ong for critical readings of the manuscript, and Hongyun Yang for preparation of figures. Article, publication date, and citation information can be found at www. We only request your email address so that the person you are recommending the page to knows that you wanted them to see it, and that it is not junk mail. We do not capture any email address. Skip to main content. You have access Restricted Access. Cryptochrome Genes and Proteins Cryptochromes, which were historically defined by their action spectra, are photolyase-like blue light receptors Gressel, ; Briggs and Huala, ; Cashmore et al.
Domain Organization of Blue Light Receptors. Cryptochromes Are Mostly Nuclear Proteins Unlike Arabidopsis phytochromes that are imported to the nucleus upon exposure to light Kircher et al. Functions of Cryptochromes in Plant Photomorphogenesis It seems clear now that, at least in Arabidopsis, the function of cryptochromes in plant photomorphogenesis overlaps almost entirely with the function of phytochromes.
Function of Cryptochromes in De-Etiolation A dicot plant germinated in dark develops an etiolated seedling with a rapidly elongating hypocotyl that allows the unopened cotyledons containing no photosynthetically competent chloroplasts to emerge rapidly from soil.
Function of Cryptochromes in the Control of Flowering Time Plant flowering time is controlled by a network of signal transduction cascades that connects various environmental signals to developmental programs. Function of Cryptochromes in the Circadian Clock and Light Regulation of Gene Expression Regulation of gene expression is intuitively a major mechanism through which photoreceptors exert roles in plant development such as control of photoperiodic flowering.
Functions of Cryptochromes in the Circadian Clock of Animals Cryptochrome as a photoreceptor functioning in the entrainment of the circadian clock has been well established in Drosophila. Signal Transduction of Cryptochromes The detailed molecular mechanism of cryptochrome signal transduction is unclear. The Initial Photoreaction of Cryptochrome The primary photoresponse of cryptochrome has been hypothesized to be a redox reaction involving electron transfers Cashmore et al.
Cryptochromes Physically Interact with Other Proteins Blue light signal transduction has been shown to involve direct protein—protein interactions of cryptochromes with other proteins. Phototropins Mediate Similar Blue Light Responses with Different Photosensitivities The question of what photoreceptor mediates hypocotyl phototropism in high light or chloroplast accumulation in low light was answered by a study of the phot1phot2 double mutant Sakai et al. Phototropins and Stomatal Opening Stomatal opening is another movement response mediated by phototropins.
Phototropin Signal Transduction The initial photochemical reaction of a phototropin has been investigated using recombinant LOV domain proteins expressed and purified from heterologous systems Salomon et al. Acknowledgments The author thanks Todd Mockler and Dr. Footnotes Article, publication date, and citation information can be found at www.
HY4 gene of A.
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Nature , — The blue-light receptor cryptochrome 1 shows functional dependence on phytochrome A or phytochrome B in Arabidopsis thaliana. Chimeric proteins between cry1 and cry2 Arabidopsis blue light photoreceptors indicate overlapping functions and varying protein stability. Plant Cell 10 , — Cell 1 , — Cryptochrome blue-light photoreceptors of Arabidopsis implicated in phototropism. Mutations throughout an Arabidopsis blue-light photoreceptor impair blue-light-responsive anthocyanin accumulation and inhibition of hypocotyl elongation.
Blue light activates electrogenic ion pumping in guard cell protoplasts of Vicia faba.
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Blue-light promotion of flowering is absent in hy4 mutants of Arabidopsis. Planta , — A plant gene for photolyase: USA 96 , — The phototropic responses of higher plants.
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Blue-light photoreceptors in higher plants. Photoreceptors in plant photomorphogenesis to date. Phototropic auxin redistribution in corn coleoptiles. Science , — The phototropin family of photoreceptors. Plant Cell 13 , — Photoreceptor interactions in plants. Co-action between phytochrome B and HY4 in Arabidopsis thaliana. Conditional synergism between cryptochrome 1 and phytochrome B is shown by the analysis of phyA, phyB, and hy4 simple, double, and triple mutants in Arabidopsis. Blue light receptors for plants and animals. An anion channel on Arabidopsis hypocotyls activated by blue light.
USA 93 , — Arabidopsis thaliana mutant that develops as a light-grown plant in the absence of light. Cell 58 , — Blue light sensing in higher plants. Plant Cell 8 , — LOV light, oxygen, or voltage domains of the blue-light photoreceptor phototropin nph1: Binding sites for the chromophore flavin mononucleotide. Phytochrome A mediates blue light and UV-A-dependent chloroplast gene transcription in green leaves. Structure of a flavin-binding plant photoreceptor domain: Insights into light-mediated signal transduction.
USA 98 , — USA 97 , — The Power of Movement in Plants. A regulatory locus involved in light-controlled development and gene expression in Arabidopsis. Cryptochromes are required for phytochrome signaling to the circadian clock but not for rhythmicity. Plant Cell 12 , — Molecular bases for circadian clocks. Cell 96 , — An extraretinally expressed insect cryptochrome with similarity to the blue light photoreceptors of mammals and plants.
Genet 29 , — CRY, a Drosophila clock and light-regulated cryptochrome, is a major contributor to circadian rhythm resetting and photosensitivity. Cell 95 , — A unique circadian-rhythm photoreceptor. Drosophila CRY is a deep brain circadian photoreceptor. Cell 26 , — Opposing roles of phytochrome A and phytochrome B in early cryptochrome-mediated growth inhibition. Unexpected roles for cryptochrome 2 and phototropin revealed by high- resolution analysis of blue light-mediated hypocotyl growth inhibition.
UV-B, UV-A, and blue light signal transduction pathways interact synergistically to regulate chalcone synthase gene expression in Arabidopsis. Light-mediated changes in two proteins found associated with plasma membrane fractions from pea stem sections. USA 85 , — How does auxin turn on genes? The Arabidopsis blue light receptor cryptochrome 2 is a nuclear protein regulated by a blue light-dependent post-transcriptional mechanism.
Regulation of flowering time by Arabidopsis photoreceptors. Orchestrated transcription of key pathways in Arabidopsis by the circadian clock. Functional interaction of cryptochrome 1 and phytochrome D. Control of hypocotyl elongation in Arabidopsis thaliana by photoreceptor interaction. Light-induced nuclear translocation of endogenous pea phytochrome A visualized by immunocytochemical procedures. PHH1, a novel gene from Arabidopsis thaliana that encodes a protein similar to plant blue-light photoreceptors and microbial photolyases.
Biochemistry 35 , — A protein kinase with a putative redox-sensing domain. Cryptochrome light signals control development to suppress auxin sensitivity in the moss Physcomitrella patens. Plant Cell 14 , — Cryptochrome nucleocytoplasmic distribution and gene expression are regulated by light quality in the fern Adiantum capillus-veneris. Plant Cell 12 , 81 — Phototropin-related NPL1 controls chloroplast relocation induced by blue light. UV-A and blue light signal transduction in Arabidopsis.
A phototropin homolog controlling the chloroplast high-light avoidance response. Chloroplast-avoidance response induced by high-fluence blue light in prothallial cells of the fern Adiantum capillus-veneris as analyzed by microbeam irradiation. Blue light-induced chloroplast relocation in Arabidopsis thaliana as analyzed by microbeam irradiation.
Isolation and characterization of homologues of plant blue-light photoreceptor cryptochrome genes from the fern Adiantum capillus-veneris. The origin and early evolution of plants on land.
Nature , 33 — Light quality-dependent nuclear import of the plant photoreceptors phytochrome A and B. Plant Cell 11 , — A factor involved in the regulation of flowering time in arabidopsis. Nuclear localization of the Arabidopsis blue light receptor cryptochrome 2. A genetic and physiological analysis of late flowering mutants in Arabidopsis thaliana. Genetic control of light-inhibited hypocotyl elongation in Arabidopsis thaliana L.
Comparing sequenced segments of the tomato and Arabidopsis genomes: Large-scale duplication followed by selective gene loss creates a network of synteny.
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Regulation of flavonoid biosynthetic genes in germinating Arabidopsis seedlings. Plant Cell 4 , — Cell 98 , — Arabidopsis contains at least four independent blue-light-activated signal transduction pathways. Posttranslational mechanisms regulate the mammalian circadian clock. Cell , — Photoreceptors and regulation of flowering time. Arabidopsis cryptochrome 1 is a soluble protein mediating blue light-dependent regulation of plant growth and development. CRY2, a second member of the Arabidopsis cryptochrome gene family. Christie And Trevor E. Signal Transduction In Photomorphogenesis: General Introduction-- Peter H.
Turk And Jason M. Franklin And Garry C. Larkin And Joanne Chory. Photomorphogenesis Of Mosses-- Tilman Lamparter. Photomorphogenesis - Where Now? Nielsen Book Data Publisher's Summary This unique resource reviews progress made by scientists researching into how ambient changes in the wavelength, intensity, direction and duration of light environment affect plant growth and development.