But, chl-a contents might vary from species to species (Boyer et al. 2009) and be changed with environmental conditions, such as irradiance (Falkowski and Laroche 1991), nutrient limitations (Latasa and Berdalet 1994, Todd et al. 2008) and the physiological status (Brunet et al. 1996). In this study, we have checked the ratios of chl-a to dry weight of the studied species under water stress. The results showed that the contents of chl-a in stressed cells are correlated highly with biomass over the time studied. This suggests that the chl-a

estimated growth rate for deducing the tendency of tolerance should be compatible to those on the basis of biomass. The four studied organisms displayed various degrees https://www.selleckchem.com/products/LBH-589.html of tolerance to desiccation. Drought stress induced the enhancement of the activities of some free radical scavenging enzymes and the intracellular levels of proline and a lipid degradation compound. It is confirmed that the levels of proline, carotenoids, and the activities of SOD are the best representatives for reflecting the tolerance to drought stress in soil algae and cyanobacteria. Our results suggest that both the cyanobacterium Selumetinib L. boryana and green alga C. vulgaris are suitable pioneer organisms for soil restoration. “
“Coralline algae are among the most sensitive calcifying organisms to ocean

acidification as a result of increased atmospheric carbon dioxide (pCO2). Little is known, however, about the combined impacts of increased pCO2, ocean acidification, and sea surface temperature on tissue mortality and skeletal dissolution of coralline algae. To address this issue, we conducted factorial manipulative

experiments of elevated CO2 and temperature and examined the consequences on tissue survival and skeletal dissolution of the crustose coralline alga (CCA) Porolithon (=Hydrolithon) onkodes (Heydr.) Foslie (Corallinaceae, Rhodophyta) on the southern Great Barrier Reef (GBR), Australia. We observed that warming amplified the negative effects of high pCO2 on the health of the Doxorubicin algae: rates of advanced partial mortality of CCA increased from <1% to 9% under high CO2 (from 400 to 1,100 ppm) and exacerbated to 15% under warming conditions (from 26°C to 29°C). Furthermore, the effect of pCO2 on skeletal dissolution strongly depended on temperature. Dissolution of P. onkodes only occurred in the high-pCO2 treatment and was greater in the warm treatment. Enhanced skeletal dissolution was also associated with a significant increase in the abundance of endolithic algae. Our results demonstrate that P. onkodes is particularly sensitive to ocean acidification under warm conditions, suggesting that previous experiments focused on ocean acidification alone have underestimated the impact of future conditions on coralline algae. Given the central role that coralline algae play within coral reefs, these conclusions have serious ramifications for the integrity of coral-reef ecosystems.