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UVB-induced DNA and photosystem II damage in two intertidal green macroalgae: Distinct survival strategies in UV-screening and non-screening Chlorophyta

Paper ID Volume ID Publish Year Pages File Format Full-Text
29423 44395 2014 9 PDF Available
Title
UVB-induced DNA and photosystem II damage in two intertidal green macroalgae: Distinct survival strategies in UV-screening and non-screening Chlorophyta
Abstract

•In an alga of the Cladophorales efficient UVB screening protected against damage.•Fluorometrically measured screening quantitatively accounted for PSII-photoprotection.•High PSII repair rate was a UVB resistance strategy in a non-screening Ulva species.•DNA damage was successfully quantified with a new calibrated CPD standard.

Ultraviolet-B-induced (UVB, 280–315 nm) accumulation of cyclobutane pyrimidine dimers (CPDs) and deactivation of photosystem II (PS II) was quantified in two intertidal green macroalgae, Ulva clathrata and Rhizoclonium riparium. The species were chosen due to their shared habitats but contrasting UVB screening potentials. In the non-screening U. clathrata CPDs accumulated and PS II activity declined as a linear function of applied UVB irradiance. In R. riparium UVB-induced damage was significantly lower than in U. clathrata, demonstrating an efficient UVB protection of DNA and PS II by screening. Based on the UVB irradiance reaching the chloroplasts, both species showed an identical intrinsic sensitivity of PS II towards UVB, but DNA lesions accumulated slower in U. clathrata. While repair of CPDs was similar in both species, U. clathrata was capable of restoring its PS II function decidedly faster than R. riparium. In R. riparium efficient screening may represent an adaptation to its high light habitat, whereas in U. clathrata high repair rates of PS II appear to be important to survive natural UVB exposure. The role of shading of the nucleus by the large chloroplasts in U. clathrata is discussed.

Keywords
Rhizoclonium riparium; Ulva clathrata; Cyclobutane pyrimidine dimers; Green alga; Photosynthesis; Repair; Ultraviolet radiation; Screening
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UVB-induced DNA and photosystem II damage in two intertidal green macroalgae: Distinct survival strategies in UV-screening and non-screening Chlorophyta
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Publisher
Database: Elsevier - ScienceDirect
Journal: Journal of Photochemistry and Photobiology B: Biology - Volume 132, 5 March 2014, Pages 85–93
Authors
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Subjects
Physical Sciences and Engineering Chemical Engineering Bioengineering
Get Full-Text Now
Don't Miss Today's Special Offer
Price was $35.95
You save - $31
Price after discount Only $4.95
100% Money Back Guarantee
Full-text PDF Download
Online Support
Any Questions? feel free to contact us