Light is an important regulator of plant morphogenesis and plant-pathogen interactions via specific photoreceptors signaling pathways. Besides visible light, other electromagnetic radiations may play roles, notably ultraviolet (UV) light. The UV part the spectrum includes UV-A (315 nm - 400 nm), UV-B (280 315 nm) UV-C (200 280 nm). have been reported to increase resistance pathogens after perce...

in the present work, the znfe2o4 nanoparticle has been successfully synthesized. the obtained sample was characterized by x-ray diffraction (xrd), emission scanning electron microscopy (fe-sem) and its optical property was examined by uv-vis spectrophotometer. fe-sem revealed that the particle size of the znfe2o4 of about 47 nm was synthesized. the photocatalytic performance under uv-vis and vi...

UV and blue light stimulate transcription of key flavonoid biosynthesis genes in a range of higher plants. Here, we provide evidence that several distinct "inductive" and "synergistic" UV/blue phototransduction pathways regulate chalcone synthase (CHS) gene transcription and transcript accumulation in Arabidopsis leaf tissue. Experiments with the long-hypocotyl hy4-2.23N mutant showed that sepa...

UV and blue light stimulate transcription of key flavonoid biosynthesis genes in a range of higher plants. Here, we provide evidence that several distinct "inductive" and ''synergistic" UV/blue phototransduction pathways regulate chalcone synthase (CHS) gene transcription and transcript accumulation in Arabidopsis leaf tissue. Experiments with the long-hypocotyl hy4-2.23N mutant showed that sep...

Ultraviolet-B radiation (UV-B) is generally considered to negatively impact the photosynthetic apparatus and plant growth. UV-B damages PSII but does not directly influence PSI. However, PSI and PSII successively drive photosynthetic electron transfer, therefore, the interaction between these systems is unavoidable. So we speculated that UV-B could indirectly affect PSI under chilling-light con...

This chapter presents and discusses information on the application of ultraviolet light (UV) technology in continuous and pulse modes for processing whole and fresh cut fruits, and fruit juices. It starts with a brief overview of the fundamentals of UV light generation and propagation in solid and fluid products and followed by the review of available UV sources. Recent reports are reviewed to ...

Induction of apoptosis in keratinocytes by UV light is a critical event in photocarcinogenesis. Although p53 is of importance in this process, evidence exists that other pathways play a role as well. Therefore, we studied whether the apoptosis-related surface molecule CD95 (Fas/APO-1) is involved. The human keratinocyte cell line HaCaT expresses CD95 and undergoes apoptosis after treatment with...

BACKGROUND UVC light generated by conventional germicidal lamps is a well-established anti-microbial modality, effective against both bacteria and viruses. However, it is a human health hazard, being both carcinogenic and cataractogenic. Earlier studies showed that single-wavelength far-UVC light (207 nm) generated by excimer lamps kills bacteria without apparent harm to human skin tissue in vi...

Photoreactivation was observed in airborne Mycobacterium parafortuitum exposed concurrently to UV radiation (254 nm) and visible light. Photoreactivation rates of airborne cells increased with increasing relative humidity (RH) and decreased with increasing UV dose. Under a constant UV dose with visible light absent, the UV inactivation rate of airborne M. parafortuitum cells decreased by a fact...

background : the aim of this study was to investigate the effect of pulsed ultra-violet (uv) irradiation on inactivation of beer spoilage microorganisms. uv irradiation is nowadays cost effective enough to compete with traditional biological, physical, and chemical treatment technologies and has become an alternative to such methods. material and methods : photoinactivation effects of pulsed uv...