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The content of four phthalate acid esters (PAEs) in air, soil, plants, organic films, and water of the arid city of Changji, China, was investigated and the concentration distribution and fate was simulated using a multimedia urban model (MUM). Analysis indicated that PAEs are ubiquitous environmental contaminants, with the dominant being DBP and DEHP. The mean PAE concentrations of air, soil, plants, organic films, and water was 5.54×10-7 g/m3, 1.09×10-2 g/m3, 6.57×10-2 g/m3, 0.28 g/m3, and 9.84×10-2 g/m3, respectively. By using MUM, we found that the total residues of PAEs in each environmental medium was 2.61×107 g. The regularity of concentration distribution was organic films > sediment > plants > water > soil >air, and the regularity of total amount distribution was air > soil > water > sediment > plants > organic films. The regularity showed that air and soil were the main sink of PAEs (up to 99.59% of total mass). The reliability of the model was verified by the agreement between the measured and calculated concentrations
In order to investigate characteristics of wet deposition of heavy metals in an arid city, precipitation samples were collected for 16 precipitation events in the arid city of Changji. A total of 16 samples were collected and concentrations of principal heavy metals in the atmosphere were examined by inductively coupled plasma-mass spectrometry (ICP-MS) to discuss levels, variation, and wet deposition fluxes of heavy metals. Among these heavy metals in wet deposition, Fe, Zn, and Cu were found to be the highest. Levels of As, Ni, and Cr ranked second, while Pb, Cd, and Hg were found to be the lowest. The concentrations of heavy metals in wet deposition showed distinct seasonal variations, having high values in winter and low values in other seasons. Besides, in general, concentrations of heavy metals in snow were higher than those in rain. Because the winter was cold and long in Xinjiang, emissions from coal-fired heating were high, which was associated with enhanced concentrations of heavy metals. The order of wet deposition fluxes of heavy metals in the whole year was Fe > Cu, Zn > As, Ni, Cr, Pb > Cd, Hg. Compared to other areas, wet deposition fluxes of heavy metals were low in Changji, which may be due to minimal rainfall in the arid city, having a weak scavenging effect of atmospheric pollutants. In addition, because the level of urbanization and industrialization was not high in Changji, emissions of atmospheric pollutants were low.
We collected and analyzed atmospheric particulates in Changji, China, in order to investigate size distribution of atmospheric particulates and Pb concentrations in TSP during cold-weather heating periods. The results indicated that during such periods, contamination increased as particle size decreased. As compared with the non-heating period, the concentrations of atmospheric particulates were relatively higher during the heating period. The concentrations of TSP, PM10, PM5, and PM2.5 had two peaks during this time. Coal combustion and meteorological variables – especially temperature – could be the main contributing factors. The size distribution of atmospheric particulates had certain regularity. The ratio of atmospheric particulates with size under 2.5 μm in TSP first increased and then decreased during the heating period. Atmospheric particulates with size between 2.5 to 5, 5 to 10, and 10 to 100 μm in TSP had the same change trend of first decreasing and then increasing. The change in the Pb trend was contrary to the temperature during the heating period, which may be caused by the fact that as temperature decreased, the intensity of coal combustion for heating increased, which emitted a lot of Pb. Conducting this study plays a significant role in prevention and control of atmospheric pollution and ecological environmental protection.
This study investigated the concentrations of 11 metals in soils sampled in 1994 and 2014 from 17 cities throughout Anhui Province in China. Among the tested metals, Mn had the highest concentration and Hg the lowest. In the past 20 years, soil Cd, Co, Mn, and Cu concentrations demonstrated an increasing trend. In 1994, only Tongling City had a total metal concentration over 1,000 mg/kg, but in 2014, the seriously polluted cities also included Bengbu, Chizhou, Fuyang, Huannai, Huangshan, and Maanshan. Four assessment methods (two pollution indexes and two fuzzy mathematical models) were employed to investigate the soil environment quality of 17 cities. Environmental quality was determined to be Class I (excellent) or Class II (good) for each soil with single-factor index method, and most was identified as Class I for soils with the comprehensive index model. Different from the single-factor index method, the comprehensive index model concerned both the predominant index and average contribution of all pollution indices to integrated environmental quality. Using each of the two fuzzy mathematical methods (single-factor deciding and weighted average models), the environmental risks were determined to be Class I. However, divergence of the membership degree to each pollution class still occurred between the two methods. For fuzzy mathematical methods, membership functions were used to describe the limits between different pollution degrees, and different weights were allocated for the factors according to pollution contribution. Introduction of membership degree and weight of each factor to fuzzy mathematical models made the methods more reasonable in the field of environmental risk assessment.
A method has been developed for embryogenic cell suspension cultures, plant regeneration and transformation of the important ornamental lily genotype (Lilium tenuifolium oriental × trumpet ‘Robina’). Bulb scales, filaments, ovaries and stem axis tissues were used as explants for callus induction in Murashige and Skoog (MS) medium with additions of growth regulators: picloram on its own, or in combination with 1-naphthaleneacetic acid (NAA), and thidiazuron (TDZ). The results show that the optimum medium for callus induction in bulb scale and filament tissue is MS + picloram 1.0 mg L⁻¹, and for the ovary, it is MS + picloram 1.5 mg L⁻¹. The stem axis had the highest rate (89.2 %) of callus induction with MS + NAA 2.2 mg L⁻¹ + TDZ 0.1 mg L⁻¹. The suspension cultures were established with the combination of NAA and TDZ with 2–5 mm cell clusters. These took a long time compared with suspension cultures established by picloram with 1–3 mm cell clusters. In three suspension cultures induced by picloram, the best callus from the point of view of proliferation and regeneration was derived from filaments. For plant regeneration, the growth rate of suspension cultures from the stem axis was higher than from the other three suspension culture induced by picloram. Vector pCAMBIA1301 with the β-glucuronidase (GUS) gene as reporter was transformed by Agrobacterium mediation into suspension cultures initiated from filament and stem axis material. After co-cultivation, the numbers of blue spots in material from the two sources were 26.8 ± 4.3 and 24.0 ± 4.7, respectively (difference not significant). Hygromycin-resistant callus was successfully regenerated into plantlets on plant growth regulator-free MS medium. Transgenic plants were also confirmed by the GUS histochemical assay, polymerase chain reaction.
Salt stress inhibited the growth of both tasg1 and wild-type (WT) wheat seedlings, but the inhibition in tasg1 plants was relatively weaker than that of WT. Compared to the WT, the chlorophyll content, thylakoid membrane polypeptides, Hill reaction activity, actual photochemical efficiency of PSII (ΦPSII), and Mg²⁺- and Ca²⁺-ATPase activities were higher in tasg1 under salt stress. At the same time, the photosynthetic activity of the tasg1 was significantly higher than that of WT. In addition, tasg1 plants displayed relatively less accumulation of reactive oxygen species and oxidative damage accompanied by higher activity of some antioxidant enzymes, and the up-regulation of antioxidant genes further demonstrated the improvement of antioxidant activity in tasg1 under salt stress. Furthermore, tasg1 plants also showed relatively weaker Na⁺ fluorescence and lower Na⁺ content, but relatively higher content of K⁺ in their roots and shoots, and then, the roots of tasg1 plants enhanced net outward Na⁺ flux and a correspondingly increased net inward K⁺ flux during salt stress. This might be associated with the relatively higher activity of H⁺-ATPase in tasg1 plants. These results suggest that the improved antioxidant competence and Na⁺/K⁺ ion homeostasis play an important role in the enhanced salinity tolerance of tasg1 plants.
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