Influence of PAR and UV‐A in Determining Plant Sensitivity and Photomorphogenic Responses to UV‐B Radiation ^¶†

Abstract

The role of photosynthetically active radiation (400-700 nm) (PAR) in modifying plant sensitivity and photomorphogenic responses to ultravioletl (280-320 nm) (UV-B) radiation has been examined by a number of investigators, but few studies have been conducted on ultraviolet-A (320-400 nm) (UV-A), UV-B and PAR interactions. High ratios of PAR-UV-B and UV-A-UV-B have been found to be important in ameliorating

Solar ultraviolet radiation and CO2-induced ocean acidification interacts to influence the photosynthetic performance of the red tide alga Phaeocystis globosa (Prymnesiophyceae)

“…The absorptivity of UV-absorbing compounds (UVACs) were normalized to the contents of chl a. b UVACs of the cells grown at pH 8.07 (open symbols) and the ratios (solid symbols) of the UVACs at pH 7.70 to that at pH 8.07 under different solar radiation treatments. The data represent the means ± SD in triplicate cultures (n = 3) (Dany et al, 2001, Krizek, 2004. Moderate levels of UVA were shown to stimulate the activity of the extracellular CA and synthesis of other periplasmic proteins in the diatom Skeletonema costatum (Wu & Gao, 2009).…”

Content of total phenolics and phenolic acids in tomato (Lycopersicon esculentum Mill.) fruits as influenced by cultivar and solar UV radiation

“…Since the early 1970s there has been keen interest in assessing the impact of stratospheric ozone reduction and the attendant increase in ultraviolet radiation on the growth and development of crop plants and natural ecosystems (Turunen et al, 1999;Hao et al, 2000;Buffoni-Hall et al, 2002;Krizek, 2004;Krizek and Gao, 2004;Krizek and Chalker-Scott 2005;Rozema et al, 2005;Sullivan, 2005). Numerous UV-enhancement studies have been conducted under controlled environments in greenhouses and plant growth chambers; however, the number of UV-B enhancement studies conducted under field conditions is relatively meager.…”

“…Plant productivity in a greenhouse or high tunnel is related to the amount of electromagnetic radiation received, which in turn is dependent on the amount of UV radiation, PAR and infrared (IR) radiation transmitted through the covering material of these structures (Krizek, 2004). The nutrient composition of tomato fruits obtained from plants grown under high tunnels is determined by both genetic and environmental factors.…”

A homozygous recA mutant of Synechocystis PCC6803: construction strategy and characteristics eliciting a novel RecA independent UVC resistance in dark

“…Laboratory cultures of cyanobacteria are continuously exposed to higher light intensities than ambient room light. Additional sensitivity may be expected since the internal milieu of cells are rich in pigments and oxygen that could be responsible for enhanced photosensitized oxidative damage to DNA (Biakowski and Olinski 1999;Isabelle et al 2004, for reviews see Jansen et al 1998;Britt 1999;Huang et al 2002;Krizek 2004). Fluorescent white light was clearly shown to cause DNA damage in nonphotosynthetic systems such as mouse cell cultures in which single strand breaks were dose dependent (Parshad et al 1978).…”