Ultraviolet-B-induced DNA damage and ultraviolet-B tolerance mechanisms in species with different functional groups coexisting in subalpine moorlands
- 330 Downloads
High doses of ultraviolet-B (UV-B; 280–315 nm) radiation can have detrimental effects on plants, and especially damage their DNA. Plants have DNA repair and protection mechanisms to prevent UV-B damage. However, it remains unclear how DNA damage and tolerance mechanisms vary among field species. We studied DNA damage and tolerance mechanisms in 26 species with different functional groups coexisting in two moorlands at two elevations. We collected current-year leaves in July and August, and determined accumulation of cyclobutane pyrimidine dimer (CPD) as UV-B damage and photorepair activity (PRA) and concentrations of UV-absorbing compounds (UACs) and carotenoids (CARs) as UV-B tolerance mechanisms. DNA damage was greater in dicot than in monocot species, and higher in herbaceous than in woody species. Evergreen species accumulated more CPDs than deciduous species. PRA was higher in Poaceae than in species of other families. UACs were significantly higher in woody than in herbaceous species. The CPD level was not explained by the mechanisms across species, but was significantly related to PRA and UACs when we ignored species with low CPD, PRA and UACs, implying the presence of another effective tolerance mechanism. UACs were correlated negatively with PRA and positively with CARs. Our results revealed that UV-induced DNA damage significantly varies among native species, and this variation is related to functional groups. DNA repair, rather than UV-B protection, dominates in UV-B tolerance in the field. Our findings also suggest that UV-B tolerance mechanisms vary among species under evolutionary trade-off and synergism.
KeywordsPhotorepair Ultraviolet-B protection Trade-off Interspecific variation Cyclobutane pyrimidine dimer
We thank Drs Riichi Oguchi, Hiroshi Ozaki, Soichiro Nagano, and Michio Oguro for valuable comments. We are also grateful to Dr Mika Teranishi, Hiroko Yamaguchi, Nan Li, and Mami Kanbayashi for field and laboratory support. This study was supported by grants from MEXT, Japan (KAKENHI, nos. 21114009, 25291095, 25660113); the Global Environment Research Fund (F-092/D-0904) of the Ministry of the Environment, Japan; the Global COE Program the Center for Ecosystem Management Adapting to Global Change (J03) of MEXT, Japan; CREST, JST, Japan; and a research grant from the Mitsui Environment Fund.
Author contribution statement
KH and QWW conceived and designed the experiment. QWW, CK, and KH collected samples in the field. QWW and JH performed the biochemical analyses. QWW analyzed the data and wrote the manuscript. KH, CK, and JH provided comments.
- Ballaré CL, Caldwell MM, Flint SD, Robinson S, Bornman JF (2011) Effects of solar ultraviolet radiation on terrestrial ecosystems. Patterns, mechanisms, and interactions with climate change. Photochem Photobiol SciGoogle Scholar
- Barnes PW, Flint SD, Caldwell MM (1990) Morphological responses of crop and weed species of different growth forms to ultraviolet-B radiation. Am J Bot:1354-1360Google Scholar
- Freeman SE, Blackett AD, Monteleone DC, Setlow RB, Sutherland BM, Sutherland JC (1986) Quantitation of radiation-, chemical-, or enzyme-induced single strand breaks in nonradioactive DNA by alkaline gel electrophoresis: application to pyrimidine dimers. Analytical biochemistry 158:119–129CrossRefPubMedGoogle Scholar
- He J, Huang LK, Chow WS, Whitecross MI, Anderson JM (1993) Effects of supplementary ultraviolet-B radiation on rice and pea plants. Functional Plant Biology 20:129–142Google Scholar
- Johanson U, Gehrke C, Bjorn LO, Callaghan TV (1995) The effects of enhanced UV-B radiation on the growth of dwarf shrubs in a subarctic heathland. Functional Ecology :713-719Google Scholar
- Miazek K, Ledakowicz S (2013) Chlorophyll extraction from leaves, needles and microalgae: A kinetic approach. International Journal of Agricultural & Biological Engineering 6:107–115Google Scholar
- Muraoka H, Takakura S (1988) Explanatory text of the geological map of the Hakkoda Geother-mal area (in Japanese). Geol Surv Japan, TsukubaGoogle Scholar
- Musil CF (1995) Differential effects of elevated ultraviolet-B radiation on the photochemical and reproductive performances of dicotyledonous and monocotyledonous arid-environment ephemerals. Plant, Cell & Environment 18:844-854 %Google Scholar
- Sullivan JH et al (2010) Assessment of DNA damage as a tool to measure UV-B tolerance in soybean lines differing in foliar flavonoid composition. UV Radiation in Global Climate Change. Springer, Berlin Heidelberg New York, pp 437–457Google Scholar
- Sullivan JH, Teramura AH, Ziska LH (1992) Variation in UV-B sensitivity in plants from a 3,000-m elevational gradient in Hawaii. American Journal of Botany:737-743Google Scholar
- Teranishi M, Fujino T, Hidema J, Hirouchi T, Yamamoto K, Kumagai T (2002) Relationship between the UV-sensitivity of rice and structural alteration of CPD photolyase. Plant and Cell Physiology 43:S160–S160Google Scholar
- Tsuyuzaki S, Haraguchi A, Kanda F (2004) Effects of scale-dependent factors on herbaceous vegetation patterns in a wetland, northern Japan. Ecological Research 19:349-355 %@ 1440-1703Google Scholar