Search

Liu, Qi, Li, Jiajia, Wang, Quanxi, Kociolek, John Patrick, Xie, Shulian (2021): Encyonema oblonga (Bacillariophyta, Cymbellaceae), a new species from Shanxi Province, China. Phytotaxa 480 (3): 284-290, DOI: 10.11646/phytotaxa.480.3.8, URL: http://dx.doi.org/10.11646/phytotaxa.480.3.8

Urbanization is conducive to promoting social development and improving living standards. However, the changing land use attributed to urbanization has placed both the environment and humans at risk. Based on the long-term monitoring and the land use change during 2010–2017, we investigated the exposure of fluoride (F) and arsenic (As) in groundwater. We analyzed the temporal and spatial variation of F and As from different land use changes. The study assessed health risk for children by calculating carcinogenic risk and non-carcinogenic risk. Furthermore, we mapped the distribution pattern of F and As using GIS. For the 768 water samples collected from 2010 to 2017, F concentrations ranged between 0.10 and 5.70 mg L−1 (M = 0.68 ± 0.02 mg L−1), As concentrations ranged between 0.50 and 71.50 μg L−1 (M = 4.28 ± 0.28 μg L−1). A concerning result showed that 6.77% of F concentrations larger than 1.5 mg L−1 and 11.46% of As concentrations larger than 10 μg L−1 based on the recommendation by WHO, respectively. Results proved that land use change caused by human activity increased groundwater pollution and placed human health at risk. High F and As risk were found in southern Taiyuan City. In particular, the groundwater of industrial land suffered from more severe pollution, especially at the frontier of urban and suburban areas in the southern part of Taiyuan City. Land use change attributed to industrial land resulted in major increases in the F and As concentrations in groundwater across 2010–2017. Both carcinogenic risk and non-carcinogenic risk in 2016–2017 were higher than that in 2010–2015. Rational land use planning, strict groundwater protection policies and the regular monitoring of pollution levels are necessary in order to prevent the adverse health of residents.

Background: As a thermoacidophilic microalga, Galdieria sulphuraria has a unique biological function. MicroRNA (miRNA) plays an important regulating role in plant various stress responses. Objective: In this study, we identified lots of conserved and novel miRNAs in G. sulphuraria (gsu-miRNAs), and predicted their putative targets for the first time. Materials and Methods: Conserved and novel gsu-miRNAs were predicted via deep sequencing on the Illumina HiSeq 4000 platform combined with bioinformatics analysis with a series of filtration criteria. Characterization of gsu-miRNAs and their targets were searched by different bioinformatics software. Some gsu-miRNAs were validated by Northern blot and RT-PCR analysis. MiRNA target gene function was predicted via GO and KEGG analysis. The interrelationship between gsu-miRNAs and target genes was constructed via Cytoscape networks analysis. Results: A total of 134 gsu-miRNAs belonging to 124 MIRNA families were identified. Characterization analysis and experimental validation revealed that most of them were credible. A few miRNAs showed conservatism between G. sulphuraria and 20 representative plants. 1,589 putative miRNA targets were predicted. GO analysis revealed that the genes targeted by gsu-miRNAs involved in some important physiological processes of this alga, such as the ETC, and KEGG pathway analysis revealed that RNA transport and the PPP were predicted to be the two most enriched pathways. Cytoscape networks between miRNAs and target genes indicated their various interactions. Conclusions: Research on gsu-miRNAs, which act as key regulators during gene expression in G. sulphuraria will open a new avenue for further developing this thermoacidophilic alga at the post-transcriptional level.

Excessive and inadequate intake of fluoride may cause adverse effects in children, such as dental caries and dental fluorosis. This study reports the results of monitoring fluoride concentrations in drinking water from an endemic fluorosis region during the ten-year period (2008 through 2017). The fluoride concentration had a range of 0.03–9.42 mg L−1 (mean = 0.55 ± 0.01 mg L−1). Approximately 10%, 1.3% and 0.06% children are at risk for dental decay, dental fluorosis and skeletal fluorosis, respectively. Probabilistic risks for children were assessed and the fluoride endemic areas were marked by GIS mapping system. On several water consumption points, the hazard quotient (HQ) values for children were higher than 1, indicating potential non-cancer health risks due to fluoride exposure. The results of this study will help governmental agencies to develop better policies for protecting children from exposure to fluoride.

The adaptive evolution and coevolution of the ribulose-1,5-bisphosphate carboxylase/oxygenase large subunit ( rbcL) gene in the genus Hildenbrandia were studied based on phylogenetic tree construction and the physicochemical properties and the secondary structures of protein encoded by rbcL (Rubisco large subunit) were analyzed. The amino acids compositions and grand average of hydropathicity of freshwater H. rivularis and marine H. rubra were similar. Rubisco large subunit of Hildenbrandia was hydrophilic and the secondary structure was primarily composed of α-helixes and β-sheets, revealing the relatively stable structure of this protein. The predicted phosphorylation sites in H. rivularis and H. rubra were 33 and 36, respectively. No positive selection sites were detected in the genus Hildenbrandia, implying that rbcL gene evolved either neutrally or under purifying selection. A total of 41 coevolutionary groups were detected in the Rubisco large subunit of Hildenbrandia and the coevolving sites are in closer proximity in 3-dimensional structure of the protein. Despite the long evolutionary history, rbcL gene in genus Hildenbrandia under different environments is rather conservative.

In this study, preparation of Phragmites australis activated carbon (PAAC) was optimized and applied for the removal of hydroquinone from aqueous solution. The Box-Behnken surface design (33) was used to statistically visualize the interactions among microwave power (A), microwave radiation time (B) and the ingredient ratio (C) (H3PO4: P. australis powder, in g). The desirability function was utilized to simultaneously optimize the multi-response indicators. A regression analysis showed that the experimental data of BBD optimization experimental results fit well to a quadratic model. PAAC was characterized according to its morphology, structure and composition. Dynamic adsorption data showed that the best fit was obtained by a pseudo-second-order model and the Freundlich isotherm model. The maximum adsorption capacity for hydroquinone adsorption onto PAAC was 156.25 mg/g at 30 ℃ and the adsorption mechanism may be attributed to multi-layer surface and chemisorption via donor-acceptor and coupling interaction of the electron. The present study showed that PAAC has the potential for use as a biosorbent for the adsorption treatment of water pollutants.

The phytoplankton community structures in Ningwu subalpine lakes have been studied and 291 taxa,belonging to 8 divisions,45 families and 108 genera,have been identified.The species numbers of each sampling station are quite different.The most abundant species are occurred in Lake Mayinghai,and the least in Lake Ganhai.Bacillariophyta,Chlorophyta and Cyanophyta dominate the area,in addition,dominant families,dominant genera and dominant species are also relatively clear.There are 8 dominant species and they are Aphanocapsa elachista,Microcystis aeruginosa,Phormidium tenue,Cyclotella kuetzingii,Fragilaria ulna,Synedra acus,Ankistrodesmus angustus and Chlorella vulgaris.The average phytoplankton cell density is 3.49×106cells/L in the lakes.The cell density in 0.5 m depth was higher than that on the surface.The initially assessment by four biodiversity indexes is that the water quality in Ningwu subalpine lakes is light-polluted.

Clavibater michiganense subsp. sepedonicum, the causal agent of a serious disease called bacterial ring rot of potato, is widespread under both greenhouse and field cultivation. In order to find a promising method for the control of this disease, Athyrium sinense extracts were investigated in the study presented here. Results showed that the A. sinense extracts had significantly inhibitory activity against C. michiganense subsp. sepedonicum. Eight organic solvents were used to obtain A. sinense extracts, and ethanol was selected as an ideal extraction solvent. Based on single factor experiment results and L273(13) orthogonal experiment results, optimum extraction conditions were obtained. They were A2B3C3, solid to liquid ratio 1:20 (g:mL), temperature 97°C and extraction time 10h. Stability assays revealed that Zn2+, Fe3+, acidic and neutral conditions enhanced inhibitory activity, and extracts were stable under ultraviolet (UV). Transmission electron microscopy (TEM) showed drastic changes caused by A. sinense extracts, including lack of cytoplasmic materials, formation of vacuoles and bacterial deformation. These results revealed A. sinense extracts have strong inhibitory activity against C. michiganense subsp. sepedonicum, and can be used as a potent phytochemical fungicide., Journal of Applied Botany and Food Quality, Vol 88 (2015), p.314-321