As part of an overall decline in biodiversity, amphibian populations throughout the world are disappearing. There are a number of potential causes for these declines, including those related to environmental changes such as increasing ultraviolet-B (UV-B) radiation due to stratospheric ozone depletion. UV-B radiation can kill amphibian embryos or can cause sublethal effects that can harm amphib...

Heterotrimeric G proteins have been shown to transmit ultraviolet B (UV-B) signals in mammalian cells, but whether they alsotransmit UV-B signals in plant cells is not clear. In this paper, we report that 0.5 Wm22 UVB induces stomatal closure inArabidopsis(Arabidopsis thaliana) by eliciting a cascade of intracellular signaling events including Gaprotein, hydrogen peroxide (H2O2), and nitric oxi...

The Arabidopsis radical-induced cell death1 (rcd1) mutant is sensitive to ozone fumigation and apoplastic superoxide, but tolerant to methyl viologen. In the present article, we report that the rcd1 mutant is also tolerant to supplementary UV-B radiation. The rcd1-1 mutant exhibits less accumulation of TT dimers, increased hypocotyl growth inhibition and higher accumulation of flavonoids under ...

In Arabidopsis, ultraviolet (UV)-B-induced photomorphogenesis is initiated by a unique photoreceptor UV resistance locus 8 (UVR8) which utilizes its tryptophan residues as internal chromophore to sense UV-B. As a result of UV-B light perception, the UVR8 homodimer shaped by its arginine residues undergoes a conformational switch of monomerization. Then UVR8 associates with the constitutively ph...

Current ambient UV-B levels can significantly depress productivity in aquatic habitats, largely because UV-B inhibits several steps of photosynthesis, including the photooxidation of water catalyzed by photosystem II. We show that upon UV-B exposure the cyanobacterium Synechococcus sp. PCC 7942 rapidly changes the expression of a family of three psbA genes encoding photosystem II D1 proteins. I...

Studies that have attempted to estimate the rate of deleterious mutation have typically been conducted under low levels of ultraviolet-B (UV-B) radiation, a naturally occurring mutagen. We conducted experiments to test whether the inclusion of natural levels of UV-B radiation in mutation-accumulation (MA) experiments influences the rate and effects of mildly deleterious mutation in the plant Ar...

Ultraviolet B radiation (UV-B) is an important environmental driver that can affect locomotor performance negatively by inducing production of reactive oxygen species (ROS). Prolonged regular exercise increases antioxidant activities, which may alleviate the negative effects of UV-B-induced ROS. Animals naturally performing exercise, such as humans performing regular exercise or fish living in ...

Interspecific differences in sensitivity to ultraviolet-B radiation (UV-B; 280–315 nm) are well documented for amphibians. However, few studies have addressed physiological mechanisms underlying differential species survival to such exposure. One potential mechanism that might protect amphibians from damaging UV-B involves melanin production and resultant skin darkening. In this study, we exami...