Sediment cores and overlying water samples were collected at four sites in Tianjin Coastal Zone, Bohai Bay, to investigate nutrient (N, P and Si) exchanges across the sediment-water interface. The exchange fluxes of each nutrient species were estimated based on the porewater profiles and laboratory incubation experiments. The results showed significant differences between the two methods, which implied that molecular diffusion alone was not the dominant process controlling nutrient exchanges at these sites. The impacts of redox conditions and bioturbation on the nutrient fluxes were confirmed by the laboratory incubation experiments. The results from this study showed that the nutrient fluxes measured directly from the incubation experiment were more reliable than that predicted from the porewater profiles. The possible impacts causing variations in the nutrient fluxes include sewage discharge and land reclamation.
Black pepper (Piper nigrum), dubbed the 'King of Spices' and 'Black Gold', is one of the most widely used spices. Here, we present its reference genome assembly by integrating PacBio, 10x Chromium, BioNano DLS optical mapping, and Hi-C mapping technologies. The 761.2 Mb sequences (45 scaffolds with an N50 of 29.8 Mb) are assembled into 26 pseudochromosomes. A phylogenomic analysis of representative plant genomes places magnoliids as sister to the monocots-eudicots clade and indicates that black pepper has diverged from the shared Laurales-Magnoliales lineage approximately 180 million years ago. Comparative genomic analyses reveal specific gene expansions in the glycosyltransferase, cytochrome P450, shikimate hydroxycinnamoyl transferase, lysine decarboxylase, and acyltransferase gene families. Comparative transcriptomic analyses disclose berry-specific upregulated expression in representative genes in each of these gene families. These data provide an evolutionary perspective and shed light on the metabolic processes relevant to the molecular basis of species-specific piperine biosynthesis.
Global warming has threatened all-rounded hierarchical biosphere by reconstructing eco-structure and bringing biodiversity variations. Pacific white shrimp, a successful model of worldwide utilizing marine ectothermic resources, is facing huge losses due to multiple diseases relevant to intestinal microbiota (IM) dysbiosis during temperature fluctuation. However, how warming mediates shrimp health remains poorly understood. Herein, a global shrimp IM catalogue was conducted via 1,369 shrimp IM data from nine countries, including 918 samples from previously published data and 451 generated in the study. Shrimp IMs were stratified into three enterotypes with distinctive compositions and functions, dominated by Vibrio, Shewanella and Candidatus Bacilloplasma, which showed an obvious distribution bias between enterotypes and diseases. The ratio of Vibrio and Candidatus Bacilloplasma was a crucial indicator for shrimp health. Moreover, temperature was the most driving factor for microbial composition, which potentially led to the migration of enterotypes, and high probability of white feces syndrome and low risk of hepatopancreas necrosis syndrome. Collectively, the warming-driven enterotypes mediated shrimp health, which exemplified the causal relationship between temperature rising and ectothermic animals' health. These findings enlarged the cognition of shrimp health culture management from a microecological perspective, and alerted the inevitable challenge of global warming to ectothermic animals.