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Adaptations in Pigment Composition and Photosynthesis by Far Red Radiation in Chlorella pyrenoidosa
Author(s) -
ÖQuist Gunnar
Publication year - 1969
Publication title -
physiologia plantarum
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.351
H-Index - 146
eISSN - 1399-3054
pISSN - 0031-9317
DOI - 10.1111/j.1399-3054.1969.tb07406.x
Subject(s) - chlorella pyrenoidosa , photosynthesis , pigment , far red , chlorella , action spectrum , photosynthetic pigment , botany , chlorophyll , photosynthetically active radiation , chlorophyll a , carotenoid , absorption (acoustics) , biology , chemistry , algae , red light , materials science , organic chemistry , composite material
Abstract Chlorella pyrenoidosa has been cultivated in radiation of wavelengths between 690–975 nm for several months. Absorption spectra and action spectra of photo‐synthesis have been determined for far red and “white” light brown cultures, In vivo spectrophotometric analyses and action spectra showed that fur red growth Chlorella adapted to the extreme light conditions by an increase both in absorption and photosynthesis above 700 nm. It is proposed that som of the in vivo normal chlorophyll a forms were converted to a far red absorbing chlorophyll a form, giving the far red exposed suspension an increased photosynthetic activity between 700–740 nm. The analyses of far red grown Chlorella have also shown an increased photosynthesis in the blue part of the spectrum, presumably due to a decrease in photosynthetically inactive carotenoid content. By culturing Chlorella in a “white” light gradient between 0.5 × 10 4 and 3.7 × 10 4 erg cm −2 s −1 , it has been demonstrated that light intensity did not influence pigment ratios between 500–750 nm. In the blue part, however, high light levels caused increased absorption because of increased carotenoid content. Some ecological aspects of this far red effect have also been discussed.