Cinnamaldehyde Altered Cellular Immune Responses of Tongue Sole (Cynoglossus semilaevis) In Vitro

Cinnamaldehyde, a liposoluble extract from cinnamon, is a natural compound with immunity enhancement efficacy on terrestrial animals. However, its immunoregulation effects on aquatic animals has rarely been investigated due to its poor water solubility and easy oxidability. Thus, cinnamaldehyde micro emulsion (CME) was prepared to overcome these limitations. Phagocytic, respiratory burst, bactericidal, and proliferative activity of Cynoglossus semilaevis leukocytes stimulated by CME were evaluated in vitro. Leukocytes were incubated with 0, 1, 10, 100 and 1000 μg/ml cinnamaldehyde or 100 μg/ml lipopolysaccharide. Results showed that cinnamaldehyde affected leukocytes phagocytic, respiratory burst, bactericidal and proliferative activity significantly. In conclusion, low doses of cinnamaldehyde (1, 10 μg/ml) exhibited significantly high bactericidal activity, while high doses (100, 1000 μg/ml) inhibited cellular immunity of C. semilaevis

Past climate conditions predict the influence of nitrogen enrichment on the temperature sensitivity of soil respiration

The response of soil carbon release to global warming is largely determined by the temperature sensitivity of soil respiration, yet how this relationship will be affected by increasing atmospheric nitrogen deposition is unclear. Here, we present a global synthesis of 686 observations from 168 field studies to investigate the relationship between nitrogen enrichment and the temperature sensitivity of soil respiration. We find that the temperature sensitivity of total and heterotrophic soil respiration increased with latitude. In addition, for total and autotrophic respiration, the temperature sensitivity responded more strongly to nitrogen enrichment with increasing latitude. Temperature and precipitation during the Last Glacial Maximum were better predictors of how the temperature sensitivity of soil respiration responds to nitrogen enrichment than contemporary climate variables. The tentative legacy effects of paleoclimate variables regulate the response through shaping soil organic carbon and nitrogen content. We suggest that careful consideration of past climate conditions is necessary when projecting soil carbon dynamics under future global change.ISSN:2662-443

The biogeography of relative abundance of soil fungi versus bacteria in surface topsoil

Fungi and bacteria are the two dominant groups of soil microbial communities worldwide. By controlling the turnover of soil organic matter, these organisms directly regulate the cycling of carbon between the soil and the atmosphere. Fundamental differences in the physiology and life history of bacteria and fungi suggest that variation in the biogeography of relative abundance of soil fungi versus bacteria could drive striking differences in carbon decomposition and soil organic matter formation between different biomes. However, a lack of global and predictive information on the distribution of these organisms in terrestrial ecosystems has prevented the inclusion of relative abundance of soil fungi versus bacteria and the associated processes in global biogeochemical models. Here, we used a global-scale dataset of >3000 distinct observations of abundance of soil fungi versus bacteria in the surface topsoil (up to 15 cm) to generate the first quantitative and high-spatial-resolution (1 km2) explicit map of soil fungal proportion, defined as fungi/fungi + bacteria, across terrestrial ecosystems. We reveal striking latitudinal trends where fungal dominance increases in cold and high-latitude environments with large soil carbon stocks. There was a strong nonlinear response of fungal dominance to the environmental gradient, i.e., mean annual temperature (MAT) and net primary productivity (NPP). Fungi dominated in regions with low MAT and NPP and bacteria dominated in regions with high MAT and NPP, thus representing slow vs. fast soil energy channels, respectively, a concept with a long history in soil ecology. These high-resolution models provide the first steps towards representing the major soil microbial groups and their functional differences in global biogeochemical models to improve predictions of soil organic matter turnover under current and future climate scenarios. Raw datasets and global maps generated in this study are available at 10.6084/m9.figshare.19556419 (Yu, 2022)