Details zur Publikation

Kategorie Textpublikation
Referenztyp Zeitschriften
DOI 10.1016/j.aquabot.2004.01.010
Titel (primär) Light acclimation of photosynthesis in three charophyte species
Autor Küster, A.; Schaible, R.; Schubert, H.
Quelle Aquatic Botany
Erscheinungsjahr 2004
Department BIOTOX
Band/Volume 79
Heft 2
Seite von 111
Seite bis 124
Sprache englisch
Keywords Charophyceae; Lamprothamnium; Irradiance; Photosynthesis; Pigmentation
Abstract

The main aim of this study was to investigate if the charophyte species Chara baltica, Chara canescens (two populations from the Baltic Sea (BS) and the Gulf of Korinth, Greece (GK)), and Lamprothamnium papulosum exhibit different acclimation capacities to irradiance. Growth, photosynthesis and pigment content were examined in the laboratory under six irradiance conditions (35–500 μmol photons m−2 s−1). Growth experiments showed increasing growth rates from 35 μmol photons m−2 s−1 (∼10 mg fresh weight (FW)) up to 70 μmol photons m−2 s−1 (∼20 mg FW) in C. baltica, from 35 μmol photons m−2 s−1 (∼15 mg FW) up to 380 μmol photons m−2 s−1 (∼145 mg FW) in C. canescens (BS), and up to the highest growth irradiance in algae of L. papulosum (35 μmol: ∼5 mg FW; 500 μmol: ∼20 mg FW). The species were tested for their ability to acclimate to different growth irradiances (Eg) by calculating Pmax (maximum photosynthesis rate at saturating irradiances), α (the efficiency of light utilization at limiting irradiance), and Ek (the light saturation point of photosynthesis, Pmax/α). All species exhibited increasing Pmax with increasing Eg. Whereas both populations of C. canescens increased α with increasing Eg, L. papulosum and C. baltica did not acclimate α at all. Ek, the irradiance at which photosynthesis ceased to be light-limited, was constant for all Chara species within the range of irradiances tested. Chl a/Chl b ratios of all species were constant over the whole range of Eg. Chl a/carotenoid ratios were constant in C. baltica, whereas Chl a/carotenoid ratios in L. papulosum and C. canescens (BS) decreased from 250 and 70 μmol photons m−2 s−1 upwards, respectively. Pigmentation analysis showed that Chl a/carotenoid acclimation was mainly caused by species-specific capacity to raise the content of lutein and carotene (C. canescens (BS), C. canescens (GK)) and xanthophyll cycle pigments (XCP; L. papulosum). The non-photochemical quenching (NPQ) capacities of L. papulosum, C. canescens (BS), and C. canescens (GK) were dependent from preacclimation status of algae, whereas NPQ of C. baltica was independent from growth irradiance.

Our results indicate that C. baltica and C. canescens (BS) were light saturated within the chosen irradiances, whereas C. canescens (GK) and L. papulosum did not reach their limits of high-light acclimation. The photosynthetic pigments lutein, α- and β-carotene are suggested to act as photo-protective pigments in L. papulosum and C. canescens.

dauerhafte UFZ-Verlinkung https://www.ufz.de/index.php?en=20939&ufzPublicationIdentifier=4292
Küster, A., Schaible, R., Schubert, H. (2004):
Light acclimation of photosynthesis in three charophyte species
Aquat. Bot. 79 (2), 111 - 124 10.1016/j.aquabot.2004.01.010