Existing antioxidant levels are more important in acclimation to supplemental UV-B irradiation than inducible ones: Studies with high light pretreated tobacco leaves
Year: 2012
Type: article
Abstract: Greenhouse grown tobacco plants were exposed to supplemental ultraviolet irradiation (280-400 nm, UV-B \ncentered) for 6 days and changes in their photosynthesis (gas exchange and electron transport) and general and \nspecific antioxidant activities were measured. UV irradiation corresponded to 8.95 kJ m-2 d-1 biologically \neffective dose and was supplemented to below ambient (200 μmol m-2 s-1 photon flux density) photosynthetic \nphoton flux density (PPFD, 400-700 nm). Two groups of plants, which were different in their leaf antioxidant \ncapacities due to one of them having been acclimated to high irradiance (1000 μmol m-2 s-1 PPFD) before the \nUV treatment, responded differently. High light pretreated leaves lost approximately 25% of photosynthetic \nactivity during the UV exposure and showed no change either in the amounts of UV-absorbing pigments or \nantioxidant levels. On the other hand, leaves which were exposed to UV irradiation without the preceding high \nlight acclimation had 60% lower photosynthesis by the end of the treatment, and increased antioxidant \nactivities. Our results emphasize the importance of base antioxidant levels over inducible pools in leaf responses \nto low doses of UV irradiation and may also contribute to hypotheses on acclimation under field conditions.
Authors: Petra Majer, Éva Hideg
Institutions: Hungarian Academy of Sciences, University of Pecs
Language: English
Topic: Light effects on plants
Subfield: Plant Science
Domain: Life Sciences
SDG: Zero hunger
Open Access status: diamond
OpenAlex ID: W2097250040