Compensation of lack of UV screening by cellular tolerance in green macroalgae (Ulvophyceae) from the upper eulittoral
Living side by side in the upper eulittoral of the Baltic different species of green macroalgae can be assumed to require similar resistance against solar ultraviolet-B radiation (UVB, 280–315 nm). Avoidance of UVB absorption by UV-screening pigments acts as a fundamental UVB resistance mechanism in the majority of phototrophs, including green macroalgae from the order Cladophorales. Contrastingly, other orders of green macroalgae, like the Ulvales, Ulotrichales, or Bryopsidales, lack UV screening. Field grown thalli of coexisting species representative for all four orders were exposed to experimental UVB radiation and photosystem II (PSII) and DNA damage and its repair were assessed. UV-screening Cladophora sp. showed only half as much UVB-induced damage in comparison with the non-screening species Acrosiphonia sp., Bryopsis hypnoides, and Ulva intestinalis. However, intrinsic UVB sensitivity of PSII and DNA was very similar in all species. We hypothesized that the non-screening species would compensate the lack of protection by increased repair rates. UVA-driven CPD removal was more than twice as fast in non-UV screening as in screening species. Recovery of PSII was very efficient in Acrosiphonia sp. and U. intestinalis but not in B. hypnoides or Cladophora sp.. We conclude that DNA and PSII repair are important cellular tolerance mechanisms which compensate for the lack of UV-screening compounds in the green macroalgae Acrosiphonia sp. and U. intestinalis. Bryopsis hypnoides turned out to be more sensitive than the other species and may avoid UVB damage by growing in greater depth.
Many thanks go to Susanne Wolf for skilled help with DNA extraction. Karin Krupinska is thankfully acknowledged for the opportunity to use a dark room. We thank the reviewers for their valuable comments.
Compliance with ethical standards
We hereby declare that all applicable international, national and/or institutional guidelines for sampling, care and experimental use of organisms for the study have been followed.
Conflict of interest
The authors declare that they have no conflict of interest.
- Bischof K, Kräbs G, Wiencke C, Hanelt D (2002b) Solar ultraviolet radiation affects the activity of ribulose-1,5-bisphosphate carboxylase-oxygenase and the composition of photosynthetic and xanthophyll cycle pigments in the intertidal green alga Ulva lactuca L. Planta 215:502–509CrossRefPubMedGoogle Scholar
- Dany A-L, Douki T, Triantaphylides C, Cadet J (2001) Repair of the main UV-induced thymine dimeric lesions within Arabidopsis thaliana DNA: evidence for the major involvement of photoreactivation pathways. J Photochem Photobiol B Biol 65:127–135. https://doi.org/10.1016/S1011-1344(01)00254-8 CrossRefGoogle Scholar
- Franklin LA, Forster RM (1997) The changing irradiance environment: consequences for marine macrophyte physiology, productivity and ecology. Eur J Phycol 32:207–232Google Scholar
- Gocke K, Lenz J, Koppe R, Rheinheimer G, Hoppe H-G (2010) Bacterial activity and turnover rates of organic substances in the Kiel Canal. Hydrol Wasserbewirtsch 54:18–27Google Scholar
- Kang HS, Hidema J, Kumagai T (1998) Effects of light environment during culture on UV-induced cyclobutyl pyrimidine dimers and their photorepair in rice (Oryza sativa L.). Photochem Photobiol 68:71–77. https://doi.org/10.1111/j.1751-1097.1998.tb03254.x CrossRefGoogle Scholar
- Li N, Teranishi M, Yamaguchi H, Matsushita T, Watahiki MK, Tsuge T, Li S-S, Hidema J (2015) UV-B-induced CPD photolyase gene expression is regulated by UVR8-dependent and -independent pathways in Arabidopsis. Plant Cell Physiol. https://doi.org/10.1093/pcp/pcv121 PubMedCentralCrossRefPubMedGoogle Scholar
- Pescheck F, Lohbeck KT, Roleda MY, Bilger W (2014) UVB-induced DNA and photosystem II damage in two intertidal green macroalgae: distinct survival strategies in UV-screening and non-screening Chlorophyta. J Photochem Photobiol B Biol 132:85–93. https://doi.org/10.1016/j.jphotobiol.2014.02.006 CrossRefGoogle Scholar
- Provasoli L (1968) Media and prospects for cultivation of marine algae. In: Watanabe A, Hattori A (eds) Cultures and collections of algae. Japanese Society of Plant Physiology, Tokyo, pp 47–74Google Scholar
- Wobbrock JO, Findlater L, Gergle D, Higgins JJ (2011) The aligned rank transform for nonparametric factorial analyses using only Anova procedures. In: Proceedings of the SIGCHI conference on human factors in computing systems. ACM, New York, NY, USA, pp 143–146Google Scholar