Ultraviolet radiation reduces lichen growth rates
Tóm tắt
We quantified relative growth rates (RGR) in shade-adapted and melanin-deficient thalli of Cetraria islandica and Lobaria pulmonaria cultivated in short-term growth chamber experiments with and without UV-B radiation. In the first experiment done under optimal PAR (125 μmol m−2 s−1), but high UV-B radiation (1 W m−2), UV-B radiation significantly reduced RGR (P < 0.001). The second experiment with higher PAR, but more natural ratios between wavelength ranges (PAR: 500 μmol m−2 s−1; UV-A: 7 W m−2; UV-B: 0.4 W m−2), caused a reduction in mean RGR in L. pulmonaria to just 45% of rates in experiment 1. Lobaria pulmonaria screened from UV-B radiation had 1.9 and 1.6 times higher RGR than non-screened thalli in experiment 1 and 2, respectively. UV-B radiation significantly induced melanin synthesis in the second experiment only, causing significantly less photoinhibition than in thalli receiving just PAR. This is consistent with PAR-protective roles of melanins. Chlorophylls were not affected by UV-B radiation in any experiment. Because UV-B radiation affected RGR more than pure photobiont responses, the mycobiont is likely the more UV-B-susceptible partner. Apart from reduced RGR, we found little evidence for adverse UV-B effects.
Tài liệu tham khảo
Alam MA, Gauslaa Y, Solhaug KA (2015) Soluble carbohydrates and relative growth rates in chloro-, cyano- and cephalolichens: effects of temperature and nocturnal hydration. New Phytol 208(3):750–762. doi:10.1111/nph.13484
Aphalo PJ, Albert A, Björn LO, McLeod A, Robson TM, Rosenqvist E (eds) (2012) Beyond the visible:a handbook of best practice in plant UV photobiology. COST Action FA0906 UV4growth. University of Helsinki, Division of Plant Biology, Helsinki
Armstrong RA, Bradwell T (2011) Growth of foliose lichens: a review. Symbiosis 53(1):1–16
Bidussi M, Gauslaa Y, Solhaug KA (2013a) Prolonging the hydration and active metabolism from light periods into nights substantially enhances lichen growth. Planta 237:1359–1366
Bidussi M, Goward T, Gauslaa Y (2013b) Growth and secondary compounds investments in the epiphytic lichens Lobaria pulmonaria and Hypogymnia occidentalis transplanted along an altitudinal gradient in British Columbia. Botany 91:621–630
Bjerke JW, Lerfall K, Elvebakk A (2002) Effects of ultraviolet radiation and PAR on the content of usnic and divaricatic acids in two arctic-alpine lichens. Photochem Photobiol Sci 1(9):678–685
Bjerke JW, Gwynn-Jones D, Callaghan TV (2005) Effects of enhanced UV-B radiation in the field on the concentration of phenolics and chlorophyll fluorescence in two boreal and arctic–alpine lichens. Environ Exp Bot 53(2):139–149
Brenner M, Hearing VJ (2008) The protective role of melanin against UV damage in human skin. Photochem Photobiol 84(3):539–549. doi:10.1111/j.1751-1097.2007.00226.x
Buffoni-Hall RS, Bornman JF, Björn LO (2002) UV-induced changes in pigment content and light penetration in the fruticose lichen Cladonia arbuscula ssp. mitis. JPhotochemPhotobiol, B 66(1):13–20
Buffoni Hall RS, Paulsson M, Duncan K, Tobin AK, Widell S, Bornman JF (2003) Water-and temperature-dependence of DNA damage and repair in the fruticose lichen Cladonia arbuscula ssp. mitis exposed to UV-B radiation. Physiol Plant 118(3):371–379
Burchard P, Bilger W, Weissenböck G (2000) Contribution of hydroxycinnamates and flavonoids to epidermal shielding of UV-A and UV-B radiation in developing rye primary leaves as assessed by ultraviolet-induced chlorophyll fluorescence measurements. Plant Cell Environ 23:1373–1380
Caldwell MM, Björn LO, Bornman JF, Flint SD, Kulandaivelu G, Teramura AH, Tevini M (1998) Effects of increased solar ultraviolet radiation on terrestrial ecosystems. J Photochem Photobiol B Biol 46(1):40–52
Eaton S, Ellis CJ (2014) High demographic rates of the model epiphyte Lobaria pulmonaria in an oceanic Hazelwood (western Scotland). Fungal Ecol 11:60–70. doi:10.1016/j.funeco.2014.03.007
Gauslaa Y (2006) Trade-off between reproduction and growth in the foliose old forest lichen Lobaria pulmonaria. Basic and Applied Ecology 7:455–460
Gauslaa Y, Goward T (2012) Relative growth rates of two epiphytic lichens, Lobaria pulmonaria and Hypogymnia occidentalis, transplanted within and outside of Populus dripzones. Botany 90:954–965
Gauslaa Y, McEvoy M (2005) Seasonal changes in solar radiation drive acclimation of the sun-screening compound parietin in the lichen Xanthoria parietina. Basic and Applied Ecology 6:75–82
Gauslaa Y, Solhaug KA (1996) Differences in the susceptibility to light stress between epiphytic lichens of ancient and young boreal forest stands. Funct Ecol 10:344–354
Gauslaa Y, Solhaug KA (1999) High-light damage in air-dry thalli of the old forest lichen Lobaria pulmonaria - interactions of irradiance, exposure duration and high temperature. J Exp Bot 50:697–705
Gauslaa Y, Solhaug KA (2001) Fungal melanins as a sun screen for symbiotic green algae in the lichen Lobaria pulmonaria. Oecologia 126:462–471
Gauslaa Y, Lie M, Solhaug KA, Ohlson M (2006) Growth and ecophysiological acclimation of the foliose lichen Lobaria pulmonaria in forests with contrasting light climates. Oecologia 147:406–416
Grishkan I, Nevo E (2010) Spatiotemporal distribution of soil microfungi in the Makhtesh Ramon area, central Negev desert, Israel. Fungal Ecol 3(4):326–337. doi:10.1016/j.funeco.2010.01.003
Hideg É, Jansen MAK, Strid Å (2013) UV-B exposure, ROS, and stress: inseparable companions or loosely linked associates? Trends Plant Sci 18(2):107–115. doi:10.1016/j.tplants.2012.09.003
Jenkins GI (2009) Signal transduction in responses to UV-B radiation. Annu Rev Plant Biol 60:407–431
Larsson P, Večeřová K, Cempírková H, Solhaug KA, Gauslaa Y (2009) Does UV-B influence biomass growth in lichens deficient in sun-screening pigments? Environ Exp Bot 67(1):215–221
Leppik E, Jüriado I, Suija A, Liira J (2015) Functional ecology of rare and common epigeic lichens in alvar grasslands. Fungal Ecol 13:66–76. doi:10.1016/j.funeco.2014.08.003
Li F-R, Peng S-L, Chen B-M, Hou Y-P (2010) A meta-analysis of the responses of woody and herbaceous plants to elevated ultraviolet-B radiation. Acta Oecol-Int J Ecol 36(1):1–9. doi:10.1016/j.actao.2009.09.002
Lichtenthaler H, Wellburn A (1983) Determinations of total carotenoids and chlorophylls a and b of leaf extracts in different solvent. Biochem Soc Trans 603:591–593
Lutsak T, Fernández-Mendoza F, Kirika P, Wondafrash M, Printzen C (2016) Mycobiont-photobiont interactions of the lichen Cetraria aculeata in high alpine regions of East Africa and South America. Symbiosis 68(1–3):25–37. doi:10.1007/s13199-015-0351-1
Matee LP, Beckett RP, Solhaug KA, Minibayeva FV (2016) Characterization and role of tyrosinases in the lichen Lobaria pulmonaria (L.) Hoffm. Lichenologist 48(4):311–322. doi:10.1017/s0024282916000293
McEvoy M, Nybakken L, Solhaug KA, Gauslaa Y (2006) UV triggers the synthesis of the widely distributed secondary compound usnic acid. Mycol Prog 5:221–229
McEvoy M, Solhaug KA, Gauslaa Y (2007) Solar radiation screening in usnic acid-containing cortices of the lichen Nephroma arcticum. Symbiosis 43:143–150
Meeßen J, Sánchez F, Sadowsky A, de la Torre R, Ott S, de Vera J-P (2013) Extremotolerance and resistance of lichens: comparative studies on five species used in astrobiological research II. Secondary lichen compounds. Orig Life Evol Biosph 43(6):501–526
Merinero S, Martínez I, Rubio-Salcedo M, Gauslaa Y (2015) Proximity to the ground boosts epiphytic lichen growth in Mediterranean forests. Basic Appl Ecol 55:59–64
Nybakken L, Julkunen-Tiitto R (2006) UV-B induces usnic acid in reindeer lichens. Lichenologist 38:477–485
Nybakken L, Solhaug KA, Bilger W, Gauslaa Y (2004) The lichens Xanthoria elegans and Cetraria islandica maintain a high protection against UV-B radiation in Arctic habitats. Oecologia 140:211–216
Palmqvist K, Sundberg B (2002) Characterising photosynthesis and respiration in freshly isolated or cultured lichen photobionts. In: Protocols in Lichenology. Springer, pp 152–181
Riley P (1997) Melanin. Int J Biochem Cell Biol 29(11):1235–1239
Robson TM, Klem K, Urban O, Jansen MAK (2015) Re-interpreting plant morphological responses to UV-B radiation. Plant Cell Environ 38(5):856–866. doi:10.1111/pce.12374
Routaboul C, Denis A, Vinche A (1999) Immediate pigment darkening: description, kinetic and biological function. Eur J Dermatol 9(2):95–99
Rozema J, Björn LO, Bornman JF, Gaberscik A, Häder DP, Trost T, Germ M, Klisch M, Gröniger A, Sinha RP, Lebert M, He YY, Buffoni-Hall R, de Bakker NVJ, van de Staaij J, Meijkamp BB (2002) The role of UV-B radiation in aquatic and terrestrial ecosystems - an experimental and functional analysis of the evolution of UV-absorbing compounds. J Photochem Photobiol B 66(1):2–12
Searles PS, Flint SD, Caldwell MM (2001) A meta-analysis of plant field studies simulating stratospheric ozone depletion. Oecologia 127:1–10
Solhaug KA, Gauslaa Y (1996) Parietin, a photoprotective secondary product of the lichen Xanthoria parietina. Oecologia 108(3):412–418
Solhaug KA, Gauslaa Y (2004) Photosynthates stimulate the UV-B induced fungal anthraquinone synthesis in the foliose lichen Xanthoria parietina. Plant Cell Environ 27:167–176
Solhaug KA, Gauslaa Y (2012) Secondary lichen compounds as protection against excess solar radiation and herbivores. In: Progress in Botany 73. Springer, pp 283–304
Solhaug KA, Gauslaa Y, Nybakken L, Bilger W (2003) UV-induction of sun-screening pigments in lichens. New Phytol 158:91–100
Solhaug KA, Larsson P, Gauslaa Y (2010) Light screening in lichen cortices can be quantified by chlorophyll fluorescence techniques for both reflecting and absorbing pigments. Planta 231:1003–1011
Sonesson M, Callaghan T, Björn LO (1995) Short-term effects of enhanced UV-B and CO 2 on lichens at different latitudes. Lichenologist 27(06):547–557
Wellburn AR (1994) The spectral determination of chlorophylls a and b, as well as total carotenoids, using various solvents with spectrophotometers of different resolution. J Plant Physiol 144(3):307–313