Fatty acid compositions associated with high-light tolerance in the intertidal rhodophytes Mastocarpus stellatus and Chondrus crispus

Abstract

The rhodophytes Mastocarpus stellatus and Chondrus crispus occupy the lower intertidal zone of rocky shores along North Atlantic coastlines, with C. crispus generally occurring slightly deeper. Consequently, M. stellatus is exposed to more variable environmental conditions, related to a generally higher stress tolerance of this species. In order to extend our understanding of seasonal modulation of stress tolerance, we subjected local populations of M. stellatus and C. crispus from Helgoland, North Sea, to short-term high-light stress experiments over the course of a year (October 2011, March, May and August 2012). Biochemical analyses (pigments, antioxidants, total lipids, fatty acid compositions) allowed to reveal mechanisms behind modulated high-light tolerances. Overall, C. crispus was particularly more susceptible to high-light at higher water temperatures (October 2011 and August 2012). Furthermore, speciesspecific differences in antioxidants, total lipid levels and the shorter-chain/longer-chain fatty acid ratio (C14 + C16/ C18 + C20) were detected, which may enhance the tolerance to high-light and other abiotic stress factors in M. stellatus, so that this species is more competitive in the highly variable upper intertidal zone compared to C. crispus. Since the high-light tolerance in C. crispus seemed to be affected by water temperature, interactions between both species may be impacted in the future by rising mean annual sea surface temperature around the island of Helgoland.

Diversity of lipid profiles of Symbiodiniaceae under temperature and nutrient stress

“…Membranes rich in unsaturated fatty acids (UFAs) are more susceptible to oxidation by reactive oxygen species (ROS) (Su et al, 2019). Under abiotic stress induced by temperature or light, accumulation of ROS causes oxidative stress and damage to Symbiodiniaceae cells, evidenced by disruptions to the saturated:unsaturated ratio of membranes, increased oxidation of lipids (Koch et al, 2017;Rezayian et al, 2019) and reduced concentrations of unsaturated fatty acids (UFAs) (Ayala et al, 2014). Increase in the biosynthesis of saturated fatty acids (SFAs) and lipogenesis intermediates was observed in endosymbiotic Breviolum minutum after 6 days of heat stress (Hillyer et al, 2017), which may reflect alterations to structural lipids in order to maintain chloroplast structure and function.…”

Antioxidant effect of Chondrus crispus and Lentinula edodes on different margarines

“…This study investigates the antioxidant activity of Chondrus crispus seaweed (figure 1), a seaweed of commercial interest due to its high PUFA content with 20 carbon atoms [11]. It is an essential component in feeding several mariculture species and is suggested to reduce the risk of thrombosis, atherosclerosis and heart diseases in humans [12]. Red algae contain sulfated polysaccharides, such as galactans, carrageenans and agar.…”