The Influence of Ultraviolet-B Radiation on Spore Release and Growth of the Kelp Laminaria saccharina

Макаров, М. В.; Воскобойников, Г. М.

doi:10.1515/bot.2001.012

Cited by 34 publications

(20 citation statements)

References 15 publications

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“…UVBR causes a range of deleterious effects in algae including damage to photosystem II, thylakoid membranes, microtubules, DNA and the formation of superoxide radicals (Franklin and Forster, 1997). The early life stages are particularly susceptible, and UVBR has been shown to inhibit germination, photosynthesis and survival of spores and zygotes of various species of brown algae (Dring et al, 1996;Huovinen et al, 2000;Swanson and Druehl, 2000;Wiencke et al, 2000Wiencke et al, , 2004Makarov and Voskoboinikov, 2001;FloresMoya et al, 2002;Altamirano et al, 2003;Schoenwaelder et al, 2003;Henry and Van Alstyne, 2004;Roleda et al, 2005Roleda et al, , 2006. In plants, UVBR induces genes of the phenylpropanoid pathway that lead to the synthesis of phenolics such as flavonoids, lignin and tannins, compounds that, like phlorotannins, absorb UVBR and have broad defence-related functions (Jordan, 1996(Jordan, , 2002.…”

Section: A U T H O R ' S P E R S O N a L C O P Ymentioning

confidence: 99%

Screening capacity of UV-absorbing compounds in spores of Arctic Laminariales

Roleda

Clayton

Wiencke

2006

Journal of Experimental Marine Biology and Ecology

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The functional significance of phlorotannins as ultraviolet radiation screens in brown algae is presented. Spectral analysis of zoospore suspensions of the three Arctic Laminariales Saccorhiza dermatodea, Alaria esculenta and Laminaria digitata showed strong absorption in the UV waveband, characteristic of phlorotannins. An induction in the synthesis of the UV-absorbing compound in zoospore suspensions of S. dermatodea and A. esculenta was observed as an increase in absorbance in the UV region after 8 h exposure to the whole light spectrum. Transmission of UVR was also negatively correlated with zoospore density in both these species but not in L. digitata. 'Biofilters' constructed from UV-transparent acrylic sheet, containing zoospore suspensions or solutions of phloroglucinol showed varying capacity to protect zoospore cultures from the lethal effects of ultraviolet radiation. Phloroglucinol protects the zoospores from damage by screening out the much harmful shorter UV-B spectra (280-290 nm). Cultured spores of A. esculenta and L. digitata after exposure to the whole light spectrum covered by filters containing phloroglucinol showed high rates of germination, unlike controls covered by seawater-only filters that showed 100% mortality. Biofilters containing zoospore suspensions act as buffers and showed variable UV-protection properties on the germination of its conspecies. At highest zoospore density (∼4 ×10 6 spores ml − 1 ), zoospores were observed to screen UV radiation maintaining viability among shielded spores in all species investigated. The protective function of zoospore film is, however, density-dependent in L. digitata. At lower spore density, UV-screening function in S. dermatodea and A. esculenta is attributed to their capacity to accumulate and release UV-absorbing compounds into the medium. Ultraviolet radiation transmission by zoospore suspensions of Saccorhiza and Alaria decreased during exposure to the whole light spectrum which is consistent with the earlier observation of enlarged phenolic vesicles following UVR exposure. The increase in vesicle size and the corresponding increase in UV-absorbing capacity may contribute to greater tolerance of UVR exposure in both species.

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Section: A U T H O R ' S P E R S O N a L C O P Ymentioning

confidence: 99%

Screening capacity of UV-absorbing compounds in spores of Arctic Laminariales

Roleda

Clayton

Wiencke

2006

Journal of Experimental Marine Biology and Ecology

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“…2005). Other negative effects of UVR include a decrease of the motility of zoospores from L. saccharina (Makarov & Voskoboinikov 2001) and of the phototaxis of spores of Scytosiphon lomentaria and Petalonia fascia (FloresMoya et al . 2002).…”

Section: Introductionmentioning

confidence: 99%

Susceptibility of zoospores to UV radiation determines upper depth distribution limit of Arctic kelps: evidence through field experiments

et al. 2006

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Summary 1The UV susceptibility of zoospores of the brown seaweeds Saccorhiza dermatodea , Alaria esculenta and Laminaria digitata (Laminariales) was determined in field experiments in June 2004 on Spitsbergen (78 ° 55 ′ N, 11 ° 56 ′ E). 2 Freshly released zoospores were exposed for 1 or 2 days at various water depths to ambient solar radiation, ambient solar radiation depleted of UVB radiation (UVBR) and ambient solar radiation depleted of both UVBR and UVAR. Subsequently, germination rates were determined after exposure to favourable light and temperature conditions in the laboratory. 3 The radiation regime was monitored at the water surface and in the water column using data loggers attached adjacent to each experimental platform for the duration of the field exposure. 4 Under ambient solar radiation, the tolerance of zoospores to UVR was highest in the shallow water species S. dermatodea , intermediate in the upper to mid sublittoral A. esculenta and lowest in the upper to mid sublittoral L. digitata . There was, however, no difference in the susceptibility of the zoospores to ambient solar radiation or to solar radiation depleted of UVBR. 5 The water column was relatively UV transparent, especially in the upper water layers. The 1% UVB depth ranged between 5.35 and 6.87 m, although on one stormy day the 1% UVB depth was only 3.57 m, indicating resuspension of sediments. 6 Early developmental stages are most susceptible to environmental stress. Tolerance of zoospores to UVR is a major if not one of the most important factors determining the upper distribution limit of different Laminariales on the shore. 7 Kelps are very important primary producers in inshore coastal ecosystems, serving as food for herbivores and as habitat for many organisms. Enhanced UVBR due to stratospheric ozone depletion may lead to changes in the depth distribution of kelps and may cause significant ecological domino effects.

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“…Effects of UVR on photosynthesis have been studied on gametophytes and zoospores of laminariales (Dring et al 1996b and unicells of ulvales (Cordi et al 2001). Other studies on the impact of UVR on the early life stages of green, red and brown macroalgae have focused either on (1) the sporulation of fertile thalli, (2) germination and photomovement of spores, (3) growth of germlings or (4) DNA synthesis in gametophytes (Huovinen et al 2000, Swanson & Druehl 2000, Cordi et al 2001, Makarov & Voskoboinikov 2001, Bañares et al 2002, Altamirano et al 2003a,b, Han et al 2003. All these studies indicated high sensitivity of the early life stages of macroalgae to UV-B.…”

Section: Introductionmentioning

confidence: 99%

PAR and UVBR effects on photosynthesis, viability, growth and DNA in different life stages of coexisting Gigartinales: implications for recruitment and zonation pattern

Roleda¹,

Poll²,

Hanelt³

et al. 2004

Mar. Ecol. Prog. Ser.

113

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The effects that ultraviolet radiation (UVR, 280 to 400 nm) and photosynthetically active radiation (PAR, 400 to 700 nm) had on early life stages of Mastocarpus stellatus and Chondrus crispus were studied to determine if differences in UVR tolerance could influence their recruitment success on the upper eulittoral shores of Helgoland (North Sea). Photosynthesis, germination capacity, DNA damage and carpospore repair were measured after exposures to different time lengths and intensities of PAR + UV-A + UV-B, PAR + UV-A or PAR alone, and also after recovery in low white light. Germination and photosynthesis of the low light adapted carpospores of both species were inhibited as PAR was increased. Supplemental UV-A and UV-B had a small additional effect on the F v /F m of M. stellatus but this effect was more pronounced in C. crispus. However, photosynthesis of both species significantly recovered after 48 h. Carpospore viability in C. crispus was more sensitive than in M. stellatus to UVR, while a higher dose was needed to achieve 50% germination inhibition in M. stellatus. Furthermore, UV-B-induced DNA damage, measured as cyclobutane-pyrimidine dimers (CPDs), was less in M. stellatus spores, which also exhibited an efficient DNA repair mechanism compared with C. crispus. In contrast, growth and chlorophyll a contents in young gametophytes of both species were not affected by repeated UV exposures. Higher total carotenoid was measured in plants exposed to UVR, indicating a photoprotection role, because photosynthesis completely acclimated to UVR after 3 d. Furthermore, DNA damage was not detected on mature fronds of both species when exposed to the full solar spectrum. Therefore, the susceptibility of carpospores to UVR could influence species recruitment to the upper eulittoral zone.

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The Influence of Ultraviolet-B Radiation on Spore Release and Growth of the Kelp Laminaria saccharina

Cited by 34 publications

References 15 publications

Screening capacity of UV-absorbing compounds in spores of Arctic Laminariales

Screening capacity of UV-absorbing compounds in spores of Arctic Laminariales

Susceptibility of zoospores to UV radiation determines upper depth distribution limit of Arctic kelps: evidence through field experiments

PAR and UVBR effects on photosynthesis, viability, growth and DNA in different life stages of coexisting Gigartinales: implications for recruitment and zonation pattern

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