Changes in Phenolic Compounds and Cellular Ultrastructure of Arctic and Antarctic Strains of Zygnema (Zygnematophyceae, Streptophyta) after Exposure to Experimentally Enhanced UV to PAR Ratio

• DOI: 10.1007/s00248-012-0096-9
• Publication Date: 2012-08-17T06:17:02Z
• Authors: Martina Pichrtová; Daniel Remias; Louise A. Lewis; Andreas Holzinger
• Keywords: Ozone Depletion; Green algae

Ultraviolet (UV) radiation has become an important stress factor in polar regions due to anthropogenically induced ozone depletion. Although extensive research been conducted on adaptations of organisms this factor, few studies have focused semi-terrestrial algae so far, spite their apparent vulnerability. This study investigates the effect UV two arctic strains (B, G) and one Antarctic strain (E) green alga Zygnema, isolated from Arctic habitats. Isolates Zygnema were exposed experimentally enhanced A B (predominant A) photosynthetic active (PAR) ratio. The pigment content, performance ultrastructure studied by means high-performance liquid chromatography (HPLC), chlorophyll a fluorescence transmission electron microscopy (TEM). In addition, phylogenetic relationships investigated characterised using rbcL sequences, which determined that isolate isolates (B) closely related, while G is distinct lineage. production protective phenolic compounds was confirmed all tested HPLC analysis for both controls UV-exposed samples. Moreover, E, content phenolics increased significantly (p = 0.001) after treatment. Simultaneously, maximum quantum yield photosystem II photochemistry decreased E < 0.001), showing clear response. most probably stored at cell periphery vacuoles cytoplasmic bodies appear as electron-dense particles when observed TEM high-pressure freeze fixation. While reacted moderately exposure ultrastructure, G, damage found chloroplasts mitochondria. Plastidal pigments xanthophyll cycle analysis; A- B-exposed samples had higher deepoxidation state controls, particularly evident B. results indicate are involved protection also revealed different responses across three strains, suggesting other mechanisms may be these organisms.