Absorption of UV-B by DNA induces the formation of covalent bonds between adjacent pyrimidines. In maize and arabidopsis, plants deficient in chromatin remodeling show increased DNA damage compared to WT plants after a UV-B treatment. However, the role of enzymes that participate in DNA methylation in DNA repair after UV-B damage was not previously investigated. In this work, we analyzed how ch...

Ultraviolet-B (UV-B) radiation and nitrogen are expected to increase simultaneously with future changes in global climate. In this study, growth and photosynthetic responses of Picea asperata seedlings to enhanced UV-B and to nitrogen supply were studied. The experimental design included two levels of UV-B treatments (ambient UV-B, 11.02 kJ m-2 d-1; enhanced UV-B, 14.33 kJ m-2 d-1) and two nitr...

UV-B radiation (280-315 nm) incident on the leafy liverwort Cephaloziella varians growing at Rothera Point on the Western Antarctic Peninsula was manipulated in late austral spring 1998 by screens consisting of a novel combination of plexiglass panes and polyester sheets. The screens transmitted c. 79%, 68%, 48%, 41% and 31% of daily UV-B radiation dose. Plants from under and outside the screen...

The UV-B spectral band (280–315 nm) contributes less than 2% of the short-wave photons received by terrestrial organisms in most natural environments. Concerns about potential impacts of stratospheric ozone depletion contributed to spark interest in studies of plant responses to enhanced UV-B levels during the last two decades (Caldwell et al., 2003). In connection with this research, two relat...

BACKGROUND AND AIMS Anthropogenic depletion of stratospheric ozone in Arctic latitudes has resulted in an increase of ultraviolet-B radiation (UV-B) reaching the biosphere. UV-B exposure is known to reduce above-ground biomass and plant height, to increase DNA damage and cause accumulation of UV-absorbing compounds in polar plants. However, many studies on Arctic mosses tended to be inconclusiv...

PURPOSE To demonstrate the antimicrobial properties of riboflavin/UV-A (365 nm) against fungal pathogens. METHODS The antimicrobial properties of riboflavin/UV-A (365 nm), with or without previous treatment with amphotericin B, were tested on three groups of fungi selected from severe cases of keratomycosis: Candida albicans, Fusarium sp, and Aspergillus fumigatus. They were tested by using K...

The nuclear proteomes of maize (Zea mays) lines that differ in UV-B tolerance were compared by two-dimensional gel electrophoresis after UV light treatment. Differential accumulation of chromatin proteins, particularly histones, constituted the largest class identified by mass spectrometry. UV-B-tolerant landraces and the B73 inbred line show twice as many protein changes as the UV-B-sensitive ...

Arabidopsis has 12 histone acetyltransferases grouped in four families: the GNAT/HAG, the MYST/HAM, the p300/CBP/HAC and the TAFII250/HAF families. We previously showed that ham1 and ham2 mutants accumulated higher damaged DNA after UV-B exposure than WT plants. In contrast, hag3 RNA interference transgenic plants showed less DNA damage and lower inhibition of plant growth by UV-B, and increase...

P1 is a R2R3-MYB transcription factor that regulates the accumulation of a specific group of flavonoids in maize floral tissues, such as flavones and phlobaphenes. P1 is also highly expressed in leaves of maize landraces adapted to high altitudes and higher levels of UV-B radiation. In this work, we analyzed the epigenetic regulation of the P1 gene by UV-B in leaves of different maize landraces...