The transcription factor NAC102 confers cadmium tolerance by regulating WAKL11 expression and cell wall pectin metabolism in Arabidopsis.

Cadmium (Cd) toxicity severely limits plant growth and development. Moreover, Cd accumulation in vegetables, fruits, and food crops poses health risks to animals and humans. Although the root cell wall has been implicated in Cd stress in plants, whether Cd binding by cell wall polysaccharides contributes to tolerance remains controversial, and the mechanism underlying transcriptional regulation of cell wall polysaccharide biosynthesis in response to Cd stress is unknown.

Potential Role of in Starch and Chlorophyll Metabolism to Regulate Leaf Senescence in Tomato.

Deoxyribonucleic acid (DNA) methylation is an important epigenetic mark involved in diverse biological processes. Here, we report the critical function of tomato () () in plant growth and development, especially in leaf interveinal chlorosis and senescence. Using a hairpin RNA-mediated RNA interference (RNAi), we generated -RNAi lines and observed pleiotropic developmental defects including small and interveinal chlorosis leaves.

Evolution of the sink and source of dissolved inorganic nitrogen with salinity as a tracer during summer in the Pearl River Estuary.

In this study, we evaluated the sink and source of the surface water along the PRE using a mixing model method with salinity as tracer. The observational data showed that the decreasing of dissolved inorganic nitrogen (DIN) did not closely follow the physical mixing lines of freshwater and modified seawater. In the western part, DIN consumption by phytoplankton and bacteria uptake (ΔDIN)varied from 15.

Ecotoxicity of two organophosphate pesticides chlorpyrifos and dichlorvos on non-targeting cyanobacteria Microcystis wesenbergii.

Organophosphate pesticides (OPs), as a replacement for the organochlorine pesticides, are generally considered non-toxic to plants and algae. Chlorpyrifos and dichlorvos are two OPs used for pest control all over the world. In this study, the dose-response of cyanobacteria Microcystis wesenbergii on OPs exposure and the stimulating effect of OPs with and without phosphorus source were investigated.

Heavy metals in wild marine fish from South China Sea: levels, tissue- and species-specific accumulation and potential risk to humans.

Heavy metal pollution in marine fish has become an important worldwide concern, not only because of the threat to fish in general, but also due to human health risks associated with fish consumption. To investigate the occurrence of heavy metals in marine fish species from the South China Sea, 14 fish species were collected along the coastline of Hainan China during the spring of 2012 and examined for species- and tissue-specific accumulation. The median concentrations of Cd, Cr, Cu, Zn, Pb and As in muscle tissue of the examined fish species were not detectable (ND), 2.

Metaproteomics reveals the major microbial players and their biogeochemical functions in a productive coastal system in the northern South China Sea.

We study the metaproteome of the GF/F-prefiltered fraction of a microbial community from Shantou coast summer surface waters using a shotgun proteomic approach. Spectra attributed to the marine Roseobacter clade (MRC), the oligotrophic marine Gammaproteobacteria (OMG) group and Flavobacteria dominated in the microbial community, accounting for 21.0%, 23.

Mercury contamination in fish and human hair from Hainan Island, South China Sea: Implication for human exposure.

Hair has long been recognized as a good biomarker for human exposure to Hg. The mercury concentrations in 14 species of marine fish and hair samples from 177 coastal residents in Hainan, South China Sea were investigated to assess the status of mercury exposure associated with marine fish consumption. Concentrations of total Hg (THg) and methylmercury (MeHg) in the fish muscles were 0.

Mangrove trees affect the community structure and distribution of anammox bacteria at an anthropogenic-polluted mangrove in the Pearl River Delta reflected by 16S rRNA and hydrazine oxidoreductase (HZO) encoding gene analyses.

Anaerobic ammonium oxidizing (anammox) bacterial community structures were investigated in surface (1-2 cm) and lower (20-21 cm) layers of mangrove sediments at sites located immediately to the mangrove trees (S0), 10 m (S1) and 1000 m (S2) away from mangrove trees in a polluted area of the Pearl River Delta. At S0, both 16S rRNA and hydrazine oxidoreductase (HZO) encoding genes of anammox bacteria showed high diversity in lower layer sediments, but they were not detectable in lower layer sediments in mangrove forest. S1 and S2 shared similar anammox bacteria communities in both surface and lower layers, which were quite different from that of S0.

Residence of habitat-specific anammox bacteria in the deep-sea subsurface sediments of the South China Sea: analyses of marker gene abundance with physical chemical parameters.

Anaerobic ammonium oxidation (anammox) has been recognized as an important process for the global nitrogen cycle. In this study, the occurrence and diversity of anammox bacteria in the deep-sea subsurface sediments of the South China Sea (SCS) were investigated. Results indicated that the anammox bacterial sequences recovered from this habitat by amplifying both 16S rRNA gene and hydrazine oxidoreductase encoding hzo gene were all closely related to the Candidatus Scalindua genus.

Seasonal dynamics of anammox bacteria in estuarial sediment of the Mai Po Nature Reserve revealed by analyzing the 16S rRNA and hydrazine oxidoreductase (hzo) genes.

The community and population dynamics of anammox bacteria in summer (wet) and winter (dry) seasons in estuarial mudflat sediment of the Mai Po Nature Reserve were investigated by 16S rRNA and hydrazine oxidoreductase (hzo) genes. 16S rRNA phylogenetic diversity showed that sequences related to 'Kuenenia' anammox bacteria were presented in summer but not winter while 'Scalindua' anammox bacteria occurred in both seasons and could be divided into six different clusters. Compared to the 16S rRNA genes, the hzo genes revealed a relatively uniform seasonal diversity, with sequences relating to 'Scalindua', 'Anammoxoglobus', and planctomycete KSU-1 found in both seasons.

Diversity and abundance of anammox bacterial community in the deep-ocean surface sediment from equatorial Pacific.

The community structure and diversity of anaerobic ammonium oxidation (anammox) bacteria in the surface sediments of equatorial Pacific were investigated by phylogenic analysis of 16S rRNA and hydrazine oxidoreductase (hzo) genes and PCoA (principal coordinates analysis) statistical analysis. Results indicated that 16S rRNA and hzo sequences in the P2 (off the center of western Pacific warm pool) and P3 (in the eastern equatorial Pacific) sites all belong to the Candidatus "Scalindua", the dominate anammox bacteria in the low-temperature marine environment proved by previous studies. However, in the P1 site (in center of warm pool of western Pacific), large part of 16S rRNA gene sequences formed a separated cluster.

Physiology and biochemistry of reduction of azo compounds by Shewanella strains relevant to electron transport chain.

Azo dyes are toxic, highly persistent, and ubiquitously distributed in the environments. The large-scale production and application of azo dyes result in serious environmental pollution of water and sediments. Bacterial azo reduction is an important process for removing this group of contaminants.

[Isolation and characterization of a humic-reducing bacterium Shewanella strain W3 from mangrove sediment].

A humus-reducing bacterium strain W3 was isolated from the mangrove sediment. Based on the analysis of morphology, physiobiochemical characteristics and 16S rDNA gene sequence, this strain was identified as Shewanella sp. W3.

Energy generation coupled to azoreduction by membranous vesicles from Shewanella decolorationis S12.

Previous studies have demonstrated that Shewanella decolorationis S12 can grow on the azo compound amaranth as the sole electron acceptor. Thus, to explore the mechanism of energy generation in this metabolism, membranous vesicles (MVs) were prepared and the mechanism of energy generation investigated. The membrane, which was fragmentized during preparation, automatically formed vesicles ranging from 37.

Identification of an uptake hydrogenase for hydrogen-dependent dissimilatory azoreduction by Shewanella decolorationis S12.

Shewanella decolorationis S12, a representative dissimilatory azo-reducing bacterium of Shewanella genus, can grow by coupling the oxidation of hydrogen to the reduction of azo compounds as the sole electron acceptor, indicating that an uptake hydrogenase is an important component for electron transfer for azoreduction. For searching to the uptake hydrogenase in the genome of S. decolorationis, two operons, hyd and hya, were cloned and sequenced, which encode periplasmically oriented Fe-only hydrogenase and a Ni-Fe hydrogenase, respectively, according to the homologous comparison with other bacterial hydrogenases.

Humic substances act as electron acceptor and redox mediator for microbial dissimilatory azoreduction by Shewanella decolorationis S12.

The potential for humic substances to serve as terminal electron acceptors in microbial respiration and the effects of humic substances on microbial azoreduction were investigated. The dissimilatory azoreducing microorganism Shewanella decolorationis S12 was able to conserve energy to support growth from electron transport to humics coupled to the oxidation of various organic substances or H2. Batch experiments suggested that when the concentration of anthraquinone-2-sulfonate (AQS), a humics analog, was lower than 3 mmol/l, azoreduction of strain S12 was accelerated under anaerobic condition.

[Isolation, identification and characterization of a broad-spectrum azo-reducing Citrobacter strain AzoR-2].

A broad-spectrum azo-reducing bacterial strain, AzoR-2, was isolated from a active-sludge of textile-printing wastewater treatment plant and the strain was identified and characterized. This strain was identified as Citrobacter sp. according to its morphological, physiobiochemical characteristics and analysis of its 16S rDNA and beta-lactamase gene sequence.

[Recenct progress in electricigens and microbial fuel cell].

The discovery of Electricigens substantially changed the meaning of Microbial Fuel Cell (MFC) and exhibited a broad prospect for application. This kind microorganism can completely oxidize organic compounds with electrode as sole electron acceptor and then transfer the electrons derived from that oxidation onto the anode of a MFC through electron transport chain. When the electrons transfer from anode to cathode, the current was generated continuously.

[Anaerobic humus respiration by Shewanella cinica D14T].

Experimental results suggested Shewanella cinica D14T is capable of humus respiration utilizing various organic acids and some important environmental pollutants (e.g., toluene.

[The effects of the humic substances on Azoreduction by Shewanella spp].

Under anaerobic conditions, Shewanella cinicaD14(T), Shewanella baltica and Shewane-lla putrefaciens are capable of high-rate azoreduction and humus reduction. The results indicated that at low concentration ( <2 mmol/L) AQS was a accelerator for bacterial azoreduction. However, when the concentration of AQS was more than 5 mmol/L a strong inhibition was occurred.

[Bacterial Fe(III) reduction].

Bacterial Fe(III) reduction is an important pathway of bioenergy metabolism in the process of life evolution. Many kinds of archaebacteria and eubacteria are capable of reducing Fe(III) to conserve energy. Anaerobic Fe(III) respiration pathway involves many membranous proteins and regulating factors, especially the muti-haem c-type cytochromes are very important in the course of electron transportation.