z-logo
Premium
Protection Strategies of Cosmarium strains (Zygnematophyceae, Streptophyta) Isolated from Various Geographic Regions Against Excessive Photosynthetically Active Radiation
Author(s) -
Stamenković Marija,
Hanelt Dieter
Publication year - 2013
Publication title -
photochemistry and photobiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.818
H-Index - 131
eISSN - 1751-1097
pISSN - 0031-8655
DOI - 10.1111/php.12083
Subject(s) - photoinhibition , biology , botany , xanthophyll , photosystem ii , photosynthesis
Numerous in vitro investigations have suggested that macroalgae exhibit regular geographic and depth distribution patterns in accordance with the light and temperature predominance at their habitats; however, there have been only a few similar studies concerning microalgae. We examined the potential influence of irradiance on patterns of distribution of four Cosmarium strains isolated from various climatic zones and cultured long term (>15 years) under a constant temperature–light regime. All the Cosmarium strains demonstrated physiological responses that were consistent with the light intensity prevailing at their source location, confirming that these responses are genetically preserved, as concluded from chlorophyll fluorescence and oxygen evolution rates measurements. Addition of inhibitors of chloroplast‐encoded protein synthesis (chloramphenicol and streptomycin) and violaxanthin de‐epoxidase (dithiothreitol) indicated that the Cosmarium strains developed “sun‐ or shade‐plant” protection strategies, in accordance with the climate at their sampling sites. The polar Cosmarium strains exhibited a “shade‐plant strategy”—to suffer some photoinhibition, but acquire increasing protection from photoinhibited PSII centers, whereas the tropical strains displayed a “sun‐plant strategy”—to counteract photoinhibition of PSII by a high rate of repair of photoinhibited PSII reaction centers and a high xanthophyll cycle turnover.

This content is not available in your region!

Continue researching here.

Having issues? You can contact us here