Ultraviolet Action Spectra in Algology.

Halldal, Per

doi:10.1111/j.1751-1097.1967.tb08744.x

Cited by 60 publications

(23 citation statements)

References 40 publications

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“…UVA can energize algal photosynthesis (McLeod and Kanwisher 1962;Halldall 1964Halldall , 1967Mengelt and Prézelin 2005;Gao et al 2007;Xu and Gao 2010), but can also inhibit growth (Callieri et al 2001;Gao et a. 2007).…”

Section: Uvamentioning

confidence: 99%

Algal and aquatic plant carbon concentrating mechanisms in relation to environmental change

et al. 2011

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Abstract.Carbon dioxide concentrating mechanisms (also known as inorganic carbon concentrating mechanisms; both abbreviated as CCMs) presumably evolved under conditions of low CO 2 availability. However, the timing of their origin is unclear since there are no sound estimates from molecular clocks, and even if there were, there are no proxies for the functioning of CCMs. Accordingly, we cannot use previous episodes of high CO 2 (e.g. the Palaeocene-Eocene Thermal Maximum) to indicate how organisms with CCMs responded. Present and predicted environmental change in terms of increased CO 2 and temperature are leading to increased CO 2 and HCO 3 -and decreased CO 3 2-and pH in surface seawater, as well as decreasing the depth of the upper mixed layer and increasing the degree of isolation of this layer with respect to nutrient flux from deeper waters. The outcome of these forcing factors is to increase the availability of inorganic carbon, photosynthetic active radiation (PAR) and ultraviolet B radiation (UVB) to aquatic photolithotrophs and to decrease the supply of the nutrients (combined) nitrogen and phosphorus and of any non-aeolian iron. The influence of these variations on CCM expression has been examined to varying degrees as acclimation by extant organisms. Increased PAR increases CCM expression in terms of CO 2 affinity, while increased UVB has a range of effects in the organisms examined; little relevant information is available on increased temperature. Decreased combined nitrogen supply generally increases CO 2 affinity, decreased iron availability increases CO 2 affinity, and decreased phosphorus supply has varying effects on the organisms examined. There are few data sets showing interactions among the observed changes, and even less information on genetic (adaptation) 2 changes in response to the forcing factors. In freshwaters, changes in phytoplankton species composition may alter with environmental change with consequences for frequency of species with or without CCMs. The information available permits less predictive power as to the effect of the forcing factors on CCM expression than for their overall effects on growth. CCMs are currently not part of models as to how global environmental change has altered, and is likely to further alter, algal and aquatic plant primary productivity.Keywords CO 2 concentrating mechanism -combined nitrogen -inorganic carboniron -mixing depth -photosynthetically active radiation -phosphorus -temperature -UVA-UVB Abbreviations CCM CO 2 concentrating mechanism DOC Dissolved organic carbon PAR Photosynthetically active radiation (400-700 nm)Rubisco Ribulose bisphosphate carboxylase-oxygenase UVA Ultraviolet A radiation (320-400 nm) UVB Ultraviolet B radiation (280-320 nm)

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Section: Uvamentioning

confidence: 99%

Algal and aquatic plant carbon concentrating mechanisms in relation to environmental change

et al. 2011

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“…However, it seems more probable that the peaks in the ultraviolet were used in a primitive photosynthesis at the surface of the seas and that later these organisms spread to hydrothermal vents where the absorption of the faint infrared light emanating from these vents powered photosynthesis before chemotrophy could be properly developed. Indeed, photosynthetic activation spectrum of bacteria employing bacteriochlorophyll extends into the ultraviolet with photosynthetic inhibition increasing with shorter wavelength but reaching only about 10% at 280 nm (Halldal, 1967).…”

Section: Evolutionmentioning

confidence: 99%

Thermodynamic dissipation theory for the origin of life

Michaelian

2011

Earth Syst. Dynam.

168

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Abstract. Understanding the thermodynamic function of life may shed light on its origin. Life, as are all irreversible processes, is contingent on entropy production. Entropy production is a measure of the rate of the tendency of Nature to explore available microstates. The most important irreversible process generating entropy in the biosphere and, thus, facilitating this exploration, is the absorption and transformation of sunlight into heat. Here we hypothesize that life began, and persists today, as a catalyst for the absorption and dissipation of sunlight on the surface of Archean seas. The resulting heat could then be efficiently harvested by other irreversible processes such as the water cycle, hurricanes, and ocean and wind currents. RNA and DNA are the most efficient of all known molecules for absorbing the intense ultraviolet light that penetrated the dense early atmosphere and are remarkably rapid in transforming this light into heat in the presence of liquid water. From this perspective, the origin and evolution of life, inseparable from water and the water cycle, can be understood as resulting from the natural thermodynamic imperative of increasing the entropy production of the Earth in its interaction with its solar environment. A mechanism is proposed for the reproduction of RNA and DNA without the need for enzymes, promoted instead through UV light dissipation and diurnal temperature cycling of the Archean sea-surface.

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“…Regulation related to absorption of UVA involves the long wavelength tail of UVB pigments such as UVR8 [117] and the short wavelength tail of the blue light-UVA pigments cryptochrome and phototropin [118], as well as via a specific but poorly characterized photoreceptor [119]. Furthermore, UVA can be a significant source of energy for some anaerobic photosynthetic bacteria (on the basis of bacteriochlorophyll absorption spectra) [120] and algae [121][122][123][124][125]. UVB (280-320 nm) screening and damage repair are required by both anoxygenic [21] and oxygenic phototrophs, with the need for additional genes (see above).…”

Section: Photosynthesis-related Damage To Nucleic Acids and Proteinsmentioning

confidence: 99%

Interactions of photosynthesis with genome size and function

Raven

Beardall

Larkum

et al. 2013

Phil. Trans. R. Soc. B

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Photolithotrophs are divided between those that use water as their electron donor (Cyanobacteria and the photosynthetic eukaryotes) and those that use a different electron donor (the anoxygenic photolithotrophs, all of them Bacteria). Photolithotrophs with the most reduced genomes have more genes than do the corresponding chemoorganotrophs, and the fastest-growing photolithotrophs have significantly lower specific growth rates than the fastest-growing chemoorganotrophs. Slower growth results from diversion of resources into the photosynthetic apparatus, which accounts for about half of the cell protein. There are inherent dangers in (especially oxygenic) photosynthesis, including the formation of reactive oxygen species (ROS) and blue light sensitivity of the water spitting apparatus. The extent to which photolithotrophs incur greater DNA damage and repair, and faster protein turnover with increased rRNA requirement, needs further investigation. A related source of environmental damage is ultraviolet B (UVB) radiation (280–320 nm), whose flux at the Earth's surface decreased as oxygen (and ozone) increased in the atmosphere. This oxygenation led to the requirements of defence against ROS, and decreasing availability to organisms of combined (non-dinitrogen) nitrogen and ferrous iron, and (indirectly) phosphorus, in the oxygenated biosphere. Differential codon usage in the genome and, especially, the proteome can lead to economies in the use of potentially growth-limiting elements

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Ultraviolet Action Spectra in Algology.

Cited by 60 publications

References 40 publications

Algal and aquatic plant carbon concentrating mechanisms in relation to environmental change

Algal and aquatic plant carbon concentrating mechanisms in relation to environmental change

Thermodynamic dissipation theory for the origin of life

Interactions of photosynthesis with genome size and function

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