Cryptochromes (CRY) are blue light photoreceptors that mediate various light-induced responses in plants and animals. Arabidopsis CRY (CRY1 and CRY2) functions through negatively regulating constitutive photomorphogenic (COP) 1, a repressor of photomorphogenesis. Water evaporation and photosynthesis are regulated by the stomatal pores in plants, which are closed in darkness but open in response...

Stomata in the plant epidermis open in response to blue light and affect photosynthesis and plant growth by regulating CO2 uptake and transpiration. In stomatal guard cells under blue light, plasma membrane H+-ATPase is phosphorylated and activated via blue light-receptor phototropins and a signaling mediator BLUS1, and H+-ATPase activation drives stomatal opening. However, details of the signa...

Plant photoreceptors that regulate photomorphogenic development include red/far-red-light-absorbing phytochromes and blue/UV-A-light-absorbing cryptochromes. We have undertaken a genetic screen to identify additional components downstream of the photoreceptors in Arabidopsis thaliana. We identified a short hypocotyl mutant under red and blue light, hypersensitive to red and blue 1 (hrb1). Mutat...

Blue light has many direct and indirect effects on photosynthesis. The impact of blue light on mesophyll conductance (g(m)), one of the main diffusive limitation to photosynthesis, was investigated in leaves of Nicotiana tabacum and Platanus orientalis, characterized by high and low g(m), respectively. Leaves were exposed to blue light fractions between 0% and 80% of incident light intensity (3...

Casein kinase1 (CK1) plays crucial roles in regulating growth and development via phosphorylating various substrates throughout the eukaryote kingdom. Blue light is crucial for normal growth of both plants and animals, and blue light receptor cryptochrome2 (CRY2) undergoes blue light–dependent phosphorylation and degradation in planta. To study the function of plant CK1s, systematic genetic ana...

OBJECTIVE Erythemagenic (295-305 nm) ultraviolet-B (UVB) radiation is toxic to patients with systemic lupus erythematosus (SLE). Cool white fluorescent lamp emissions produce a similar toxicity even though the UVB radiation emitted is primarily at the relatively non-erythemagenic wavelength of 313 nm. The purpose of this study was to determine if fluorescent light, presumably acting predominant...

In a conventional photocatalytic or photochemical process, either a photocatalyst or a molecule is excited by irradiation light that has energy greater than the forbidden band (i.e., the band gap) of the semiconductor or the transition energy of an excited state of the molecule, respectively, for a reaction to occur. However, in this work, we found that a considerable amount of H2 can be genera...

Plants possess multiple photoreceptors to mediate light regulation of growth and development, but it is not well understood how different photoreceptors coordinate their actions to jointly regulate developmental responses, such as flowering time. In Arabidopsis, the photoexcited cryptochrome 2 interacts with the transcription factor CRYPTOCHROME-INTERACTING basic helix-loop-helix 1 (CIB1) to ac...

In this study we have evaluated the use of blue light (peak at 415 nm) and a mixed blue and red light (peaks at 415 and 660 nm) in the treatment of acne vulgaris. One hundred and seven patients with mild to moderate acne vulgaris were randomized into four treatment groups: blue light, mixed blue and red light, cool white light and 5% benzoyl peroxide cream. Subjects in the phototherapy groups u...

low level lasers, cold or soft lasers: these lasers do not produce thermal effects on tissues and induce photoreactions in cellsthrough light stimulation which is called photobiostimulation. power of these lasers is usually under 250mw. the main point differentiating low level lasers and high power ones is the activation of photochemical reactions without heat formation. the most important fact...