Deciphering the environmental adaptation and functional trait of core and noncore bacterial communities in impacted coral reef seawater.

Microorganisms play pivotal roles in different biogeochemical cycles within coral reef waters. Nevertheless, our comprehension of the microbially mediated processes following environmental perturbation is still limited. To gain a deeper insight into the environmental adaptation and nutrient cycling, particularly within core and noncore bacterial communities, it is crucial to understand reef ecosystem functioning.

Symbiotic Relationship of Comasterschlegelii (Crinoidea: Comatulidae) and Gymnolophus obscura (Ophiuroidea: Ophiotrichidae) Derived from Stable Isotope and Fatty Acid Analyses.

Coral reef community exhibits high species diversity and a broad range of biological relationships, including widespread symbiosis and complex food utilization patterns. In our study, we investigated the symbiotic relationship between the commonly crinoid host Comaster schlegelii and its ophiuroid obligatory symbiont Gymnolophus obscura. Using a combination of fatty acid biomarkers and stable isotopic compositions, we explored differences in their organic matter utilization strategies and nutritional relationships.

Response of coral bacterial composition and function to water quality variations under anthropogenic influence.

Microbial communities play key roles in the adaptation of corals living in adverse environments, as the microbiome flexibility can enhance environmental plasticity of coral holobiont. However, the ecological association of coral microbiome and related function to locally deteriorating water quality remains underexplored. In this work, we used 16S rRNA gene sequencing and quantitative microbial element cycling (QMEC) to investigate the seasonal changes of bacterial communities, particularly their functional genes related to carbon (C), nitrogen (N), phosphorus (P) and sulfur (S) cycle, of the scleractinian coral Galaxea fascicularis from nearshore reefs exposed anthropogenic influence.

Consistent responses of coral microbiome to acute and chronic heat stress exposures.

Frequent and intense heat waves lead to bleaching and even death of reef-building corals, and the thermal tolerance ultimately depends on the genetic composition of the holobiont. Here, we compared the effects of acute and chronic heat stress exposures on coral Porites cylindrica holobiont. Regardless of the temperature treatment, corals at 33 °C showed signs of bleaching and a significant decrease in photochemical efficiency (Fv/Fm).

Adaptive changes of coral holobiont in response to nearshore stress.

Global change and local stressors are simultaneously affecting the nearshore corals, and microbiome flexibility may assist corals in thriving under such multiple stressors. Here, we investigated the effects of various environmental variables on holobiont from nearshore and offshore reefs. These nearshore reefs were more turbid, eutrophic, and warm than offshore reefs.

Oxidative stress, apoptosis, and transcriptional responses in Acropora microphthalma under simulated diving activities.

This study simulated the effects of diving activities on the physiology, enzymatic, and transcriptional responses of Acropora microphthalma. Touching had less impact on Fv/Fm, but a few zooxanthellae were decreased and minor MDA was elevated. Caspase 3 was activated to remove damaged cells, and SOD was increased to alleviate oxidative damage.

Different Responses of Bacteria and Microeukaryote to Assembly Processes and Co-occurrence Pattern in the Coastal Upwelling.

Upwelling may generate unique hydrological and environmental heterogeneity, leading to enhanced diffusion to reshape microbial communities. However, it remains largely unknown how different microbial taxa respond to highly complex and dynamic upwelling systems. In the present study, geographic patterns and co-occurrence network of different microbial communities in response to upwelling were examined.

Responses of Symbiodiniaceae Shuffling and Microbial Community Assembly in Thermally Stressed .

Although the importance of coral holobionts is widely accepted, the relationship between the flexibility of the microbial structure and the coral host is very complicated. Particularly, the community dynamics of holobionts and the stability of host-microbe interactions under different thermal stresses remain largely unknown. In the present study, we holistically explored the physiology and growth of in response to increased temperatures (from 26 to 33°C).

Genome-wide identification of PEBP gene family members in potato, their phylogenetic relationships, and expression patterns under heat stress.

Background: The phosphatidylethanolamine-binding protein (PEBP) gene family is involved in regulating many plant traits. Genome-wide identification of PEPB members and knowledge of their responses to heat stress may assist genetic improvement of potato (Solanum tuberosum).

Methods And Results: We identified PEBP gene family members from both the recently-updated, long-reads-based reference genome (DM v6.

Coastal corals during heat stress and eutrophication: A case study in Northwest Hainan coastal areas.

This study initially investigated the coral status during the unexpected bleaching event in three coastal areas in Northwest Hainan coastal areas and analyzed changes in coral holobionts of the healthy and bleached Galaxea fascicularis. Coral coverage had declined severely, and the bleaching rate was extremely high during heat stress. The bleached corals had lower maximum photosynthetic yield, actual photosynthetic yield, zooxanthellae density, and chlorophyll a content than the healthy G.

Iron speciation and annual records in black coral as new proxy for mining and environmental impacts.

Iron (Fe) is a micronutrient and plays an important role in regulating ocean primary production and consequently changing oceanic CO uptake. However, approaches for high-resolution of Fe records in marine environment has been a great challenge. In this study, we report for the first time an annual Fe record on black coral organic skeleton from the northern South China Sea (SCS) as an archive to study the environmental change during the past century.

Stable isotopes (δC and δN) in black coral as new proxies for environmental record.

Stable isotopes (δC and δN) in marine ecosystem are useful proxies for environmental record. In this study, a time-series analysis of δC and δN in two black coral samples collected from off-shore and near-shore environment was performed to investigate variations in climate and environment changes over the last 110 years. The results showed a decreasing trend of δC in both samples, implying an increase of fossil fuel consumption in modern age - the Suess effect.

Physiological Characteristics and Environment Adaptability of Reef-Building Corals at the Wuzhizhou Island of South China Sea.

The health of coral reef has declined significantly around the world due to the impact of human activities and natural environment changes, and corals have to develop effective resistance mechanisms to survive. In this study, we examined the physiological characteristics and types of four dominant scleractinian corals in the reefs at the Wuzhizhou Island (WZZ) in South China Sea. The water environmental conditions are complex on the north side of WZZ due to regional geography and tourism development, and all corals had their unique physiological conditions and types.

A Steroid-Type Antioxidant Targeting the Keap1/Nrf2/ARE Signaling Pathway from the Soft Coral Dendronephthya gigantea.

Four new steroids, named 7-dehydroerectasteroid F (1), 11α-acetoxyarmatinol A (2), 22,23-didehydroarmatinol A (3), and 3-O-acetylhyrtiosterol (4), together with 11 previously described analogues, were isolated from a South China Sea collection of the soft coral Dendronephthya gigantea. The structures of the new steroids were elucidated by comprehensive spectroscopic analysis and by comparison with previously reported data. Compound 1 showed potent protection against HO-induced oxidative damage in neuron-like PC12 cells by promoting nuclear translocation of Nrf2 and enhancing the expression of HO-1.

Organelle DNA contents and starch accumulation in potato tubers.

Starch contents were found to be positively correlated with organelle/nuclear DNA ratios, suggesting that these ratios are involved in starch accumulation and may serve as a target trait in genetic engineering and a biomarker in breeding for improving the dry matter and starch production in potato. Starch is the main dry matter component of various staple food crops, including potato. Starch synthesis and accumulation is in plastids, uses sugar, consumes cellular energy, and requires active expression of starch synthesis genes.

Can private management compensate the ineffective marine reserves in China?

Marine reserves (MRs) have emerged as a preferred method to protect coral reefs from overfishing and human disturbance. However, due to ineffective enforcement by governments, many MRs have been reduced to mere "paper parks" which fail to achieve conservation goals. This is especially true in countries such as China where compliance is low and resources dedicated to enforcement may be scarce.

Cembranoids from a Chinese Collection of the Soft Coral Lobophytum crassum.

Ten new cembrane-based diterpenes, locrassumins A-G (1-7), (-)-laevigatol B (8), (-)-isosarcophine (9), and (-)-7R,8S-dihydroxydeepoxysarcophytoxide (10), were isolated from a South China Sea collection of the soft coral Lobophytum crassum, together with eight known analogues (11-18). The structures of the new compounds were determined by extensive spectroscopic analysis and by comparison with previously reported data. Locrassumin C (3) possesses an unprecedented tetradecahydrobenzo[3,4]cyclobuta[1,2][8]annulene ring system.

Structurally Diverse Metabolites from the Soft Coral Sinularia verruca Collected in the South China Sea.

Nineteen metabolites with diverse structures, including the rare pyrroloindoline alkaloid verrupyrroloindoline (1), the unprecedented highly fused benzosesquiterpenoid verrubenzospirolactone (2), the new asteriscane-type sesquiterpenoid 10-deoxocapillosanane D (3), and the two new cyclopentenone derivatives (4S*,5S*)-4-hydroxy-5-(hydroxymethyl)-2,3-dimethyl-4-pentylcyclopent-2-en-1-one (4) and (S)-4-hydroxy-5-methylene-2,3-dimethyl-4-pentylcyclopent-2-en-1-one (5), were isolated from a South China Sea collection of the soft coral Sinularia verruca. Eleven previously described marine metabolites (7-15, 18, and 19) were also obtained as well as three new EtOH-adduct artifacts (6, 16, and 17). The structures of the new compounds were elucidated by extensive spectroscopic analysis and by comparison with previously reported data.

Black coral as a new environmental recorder: The lead profiles in coral skeletons over the past century.

Lead (Pb) is a typical heavy metal pollutant in the environment, and most Pb contamination comes from human activities. In the present work, the Pb contents of two black coral specimens (Cirrhipathes spp.) collected from the northern South China Sea were measured by synchrotron radiation micro X-ray fluorescence (SR μ-XRF) analysis with 2.

Four New 7,8-epoxycembranoids from a Chinese soft coral Lobophytum sp.

Four new 7,8-epoxycembranoids, namely (2S*,7S*,8S*,12R*,1Z,3E,10E)-7,8:2,16-diepoxycembra-1(15),3,10-trien-12-ol (1), (2S*,7S*,8S*,11R*,1Z,3E)-7,8:2,16-diepoxycembra-1(15),3,12(20)-trien-11-ol (2), (4S*,7S*,8S*,1Z,2E,11E)-16-acetoxy-7,8-epoxycembra-1(15),2,11-trien-4-ol (3), and (7S*,8S*,15S*,1E,3E,11E)-7,8-epoxycembra-1,3,11-trien-15,16-diol (4) were isolated from a Chinese soft coral Lobophytum sp., together with eleven known analogues 5-15. The structures of the new compounds were determined by extensive spectroscopic data analysis.

New 18-oxygenated polyhydroxy steroid from a South China Sea soft coral Sarcophyton sp.

One new 18-oxygenated polyhydroxy steroid, (24S)-ergostan-3β,5α,6β,18,25-pentaol 18,25-diacetate (1), along with five known analogues (2-6), was isolated from a soft coral Sarcophyton sp. collected from the South China Sea. The structure of the new compound (1) was elucidated by 1D NMR, 2D NMR and mass spectrometry.

New cembrane diterpenoids from a Hainan soft coral Sinularia sp.

Five new cembrane diterpenoids, named sinuflexibilins A-E (1-5), along with nine other known diterpenoids (6-14), have been isolated from the organic extract of a Hainan soft coral Sinularia sp. Their structures were determined on the basis of extensive spectroscopic analyses and by comparison of their spectral data with those of related metabolites. Compound 13, flexibilide, exhibited significant inhibitory activity of NF-κB activation using the cell-based HEK293 NF-κB luciferase reporter gene assay.

Polyoxygenated sterols from the South China Sea soft coral Sinularia sp.

Chemical investigation of the ethanol extract of soft coral Sinularia sp. collected from the South China Sea led to the isolation of three new polyoxygenated sterols, (3S,23R,24S)-ergost-5-ene-3β,23α,25-triol (1), (24S)-ergostane-6-acetate-3β,5α,6β,25-tetraol (2), (24S)-ergostane-6-acetate-3β,6β,12β,25-tetraol (3) together with three known ones (4-6). The structures, including relative configurations of the new compounds (1-3), were elucidated by detailed analysis of spectroscopic data (IR, UV, NMR, MS) and by comparison with related reported compounds.

Diterpenes from the Hainan soft coral Lobophytum cristatum Tixier-Durivault.

Two new prenylgermacrane-type diterpenoids, lobophytumins A and B (1 and 2), two new prenyleudesmane-type diterpenoids, lobophytumins C and D (3 and 4), and two new spatane-type diterpenoids, lobophytumins E and F (5 and 6), were isolated from the Hainan soft coral Lobophytum cristatum Tixier-Durivault. Their structures, including relative configuration, were elucidated by detailed analysis of spectroscopic data and by comparison with related known compounds. In addition, the absolute configuration of lobophytumin C (3) was tentatively assigned by comparing its specific rotation with that of the closely related model compound (-)-β-selinene (8).

Tritoniopsins A-D, cladiellane-based diterpenes from the South China Sea nudibranch Tritoniopsis elegans and its prey Cladiella krempfi.

Four diterpenes, tritoniopsins A-D (1-4), have been isolated from the South China Sea nudibranch Tritoniopsis elegans and its prey, the soft coral Cladiella krempfi. They display an unprecedented pyran ring in the cladiellane framework, thus representing a novel cladiellane-based diterpene family. Their structures have been mainly characterized by NMR and mass spectrometric techniques, whereas the relative configuration of compound 1 was secured by X-ray analysis.