title: The effect of UV-B on Arabidopsis leaves depends on light conditions after treatment.
abstract: BACKGROUND
  Ultraviolet B (UV-B) irradiation can influence many cellular processes. Irradiation with high UV-B doses causes chlorophyll degradation, a decrease in the expression of genes associated with photosynthesis and its subsequent inhibition. On the other hand, sublethal doses of UV-B are used in post-harvest technology to prevent yellowing in storage. To address this inconsistency the effect of short, high-dose UV-B irradiation on detached Arabidopsis thaliana leaves was examined.
  
  
  RESULTS
  Two different experimental models were used. After short treatment with a high dose of UV-B the Arabidopsis leaves were either put into darkness or exposed to constant light for up to 4 days. UV-B inhibited dark-induced chlorophyll degradation in Arabidopsis leaves in a dose-dependent manner. The expression of photosynthesis-related genes, chlorophyll content and photosynthetic efficiency were higher in UV-B -treated leaves left in darkness. UV-B treatment followed by constant light caused leaf yellowing and induced the expression of senescence-related genes. Irrespective of light treatment a high UV-B dose led to clearly visible cell death 3 days after irradiation.
  
  
  CONCLUSIONS
  High doses of UV-B have opposing effects on leaves depending on their light status after UV treatment. In darkened leaves short UV-B treatment delays the appearance of senescence symptoms. When followed by light treatment, the same doses of UV-B result in chlorophyll degradation. This restricts the potential usability of UV treatment in postharvest technology to crops which are stored in darkness.
authors.affiliation: Department of Plant Biotechnology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Gronostajowa 7, Krakow, 30-387, Poland. olga.sztatelman@ibb.waw.pl.|Current address: Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warszawa, 02-106, Poland. olga.sztatelman@ibb.waw.pl.
authors.forename: Olga
authors.initials: O
authors.lastname: Sztatelman
authors.affiliation: Laboratory of Biological Physics, Institute of Physics, Polish Academy of Sciences, Al. Lotników 32/46, Warszawa, 02-668, Poland. jgrzyb@ifpan.edu.pl.
authors.forename: Joanna
authors.initials: J
authors.lastname: Grzyb
authors.affiliation: Department of Plant Biotechnology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Gronostajowa 7, Krakow, 30-387, Poland. halina.gabrys@uj.edu.pl.
authors.forename: Halina
authors.initials: H
authors.lastname: Gabryś
authors.affiliation: Department of Plant Biotechnology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Gronostajowa 7, Krakow, 30-387, Poland. a_katarzyna.banas@uj.edu.pl.|The Malopolska Centre of Biotechnology, Jagiellonian University, Gronostajowa 7, Krakow, 30-387, Poland. a_katarzyna.banas@uj.edu.pl.
authors.forename: Agnieszka Katarzyna
authors.initials: AK
authors.lastname: Banaś
mesh_terms: D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism / Q000528:radiation effects*; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D003624:Darkness; D018506:Gene Expression Regulation, Plant / Q000528:radiation effects*; D008027:Light; D010788:Photosynthesis; D018515:Plant Leaves / Q000378:metabolism / Q000528:radiation effects*; D013997:Time Factors; D014466:Ultraviolet Rays
chemical_list: D029681:Arabidopsis Proteins