The nitrate uptake and growth of wheat were more inhibited under single-layer graphene oxide stress compared to multi-layer graphene oxide.

Although the phytotoxicity of graphene-based materials has been investigated extensively, the effects of different graphene-based materials on nutrient uptake in plants remain unclear. Here, we analyzed the differences in phytotoxicity between single-layer graphene oxide (sGO) and multi-layer graphene oxide (mGO) by analyzing the growth status and nitrate (NO) accumulation in wheat plants at 0, 100, 200, 400, and 800 mg L graphene oxide supply. Both sGO and mGO displayed concentration-dependent inhibitory effects on biomass, root length, number of lateral roots, and nitrogen (N) nutrient status.

[Role and Mechanism of Low Molecular-Weight-Organic Acids in Enhanced Phytoremediation of Heavy Metal Contaminated Soil].

Phytoremediation is an environmentally friendly technology to remove heavy metals from polluted soil by using the physical and chemical roles of plants. This can effectively reduce the production of secondary pollutants and is economically feasible. Low molecular-weight-organic acids (LMWOAs) are biodegradable and environmentally friendly and have strong application potential in the phytoremediation of heavy metal-contaminated soils.

[Effects of dicyandiamide on cadmium accumulation in pakchoi under instant soluble nitrogen fertilizers].

We investigated the effects of dicyandiamide (DCD) on the growth and Cd concentrations in pakchoi cultivated under different instant soluble N fertilizers [ammonium sulfate, ammonium sulfate and sodium nitrate (1:1, ammonium/nitrate), and urea] in Cd-contaminated soils. The results showed that the fresh weight of the edible parts of Cd-stressed pakchoi were increased by 583.3%, 41.

[Research advances in physiological toxicity of graphene on plants].

Graphene is one of the most popular carbon nanomaterials that widely used in many fields due to its unique physical and chemical properties. The expanding production and application of graphene materials has led to their inputs into the environment, with increasing risks of environment and human health. Therefore, elucidating the potential toxic effects of graphene and the related mechanism are of significance to evaluate its ecological risk and bio-safety.

Abscisic acid (ABA)-importing transporter 1 (AIT1) contributes to the inhibition of Cd accumulation via exogenous ABA application in Arabidopsis.

Soil cadmium (Cd) accumulation presents risks to crop safety and productivity. However, through an exogenous application of abscisic acid (ABA), its accumulation in plants can be reduced and its toxicity mitigated, thereby providing an alternative strategy to counteract Cd contamination of arable soil. In the present study, we demonstrated that exogenous ABA application alleviates Cd-induced growth inhibition and photosynthetic damage in wild-type (Col-0) Arabidopsis plants.

Zn stress facilitates nitrate transporter 1.1-mediated nitrate uptake aggravating Zn accumulation in Arabidopsis plants.

Describing the mechanisms of zinc (Zn) accumulation in plants is essential to counteract the effects of excessive Zn uptake in crops grown in contaminated soils. Increasing evidence suggests that there is a positive correlation between nitrate supply and Zn accumulation in plants. However, the role of the primary nitrate transporter NRT1.

Abscisic acid-generating bacteria can reduce Cd concentration in pakchoi grown in Cd-contaminated soil.

Contamination of vegetable plants with cadmium (Cd) has become a serious issue in recent years. In the present study, pakchoi (Brassica chinensis L.) grown in Cd-contaminated soil inoculated with abscisic acid (ABA)-generating bacteria, Azospirillum brasilense and Bacillus subtilis, showed 28%-281% and 26%-255% greater biomass, and 40%-79% and 43%-77% lower Cd concentrations, respectively, than those of the control plants.

Aquatic plant debris changes sediment enzymatic activity and microbial community structure.

The retention of aquatic plant debris in freshwater systems favors a reduction in soluble reactive phosphorus (P) in overlying water through microbe-mediated mechanisms in sediment. For a more complete view of the changes in sediment microbial structure and functioning when receiving plant debris, the enzyme activities and microbial community structure in sediments incubated with or without plant debris were investigated. Significantly higher fluorescein diacetate (FDA) hydrolysis, alkaline phosphatase, polyphenol oxidase, cellulase, β-glucosidase, and dehydrogenase activities were observed with plant debris treatment.

Slow-release nitrogen fertilizers can improve yield and reduce Cd concentration in pakchoi (Brassica chinensis L.) grown in Cd-contaminated soil.

Cadmium (Cd) pollution in vegetable crops has become a serious problem in recent years. Owing to the limited availability of arable land resources, large areas of Cd-contaminated lands are inevitably being used for the production of vegetables, posing great risks to human health via the food chain. However, strategies to improve yield and reduce Cd concentration in crops grown in contaminated soils are being developed.

[Oxidative stress-related signals and their regulation under Cd stress: A review.].

Contamination of heavy metal in soil causes several severe environmental problems. Cadmium is one of the most toxic metals to organisms. In plants, Cd toxicity often results in over-accumulation of reactive oxygen species (ROS), which causes oxidative damage to the plant organs.

Exogenous abscisic acid application decreases cadmium accumulation in Arabidopsis plants, which is associated with the inhibition of IRT1-mediated cadmium uptake.

Cadmium (Cd) contamination of agricultural soils is an increasingly serious problem. Measures need to be developed to minimize Cd entering the human food chain from contaminated soils. We report here that, under Cd exposure condition, application with low doses of (0.

Atmospheric application of trace amounts of nitric oxide enhances tolerance to salt stress and improves nutritional quality in spinach (Spinacia oleracea L.).

The increased salinity in greenhouses has become a problem of great concern. In this study, it was observed that the salt-induced oxidative damages (indicated by MDA, H2O2 and antioxidant enzymes, including POD, SOD and CAT) could be alleviated by application of NO gas. Consequently, although both photosynthesis and growth in plants were inhibited by NaCl stress, they were restored by NO gas application, and the fresh and dry biomasses of edible parts increased by 60% and 27% over NaCl stress treatment, respectively.

Inhibition of nitrate transporter 1.1-controlled nitrate uptake reduces cadmium uptake in Arabidopsis.

Identification of mechanisms that decrease cadmium accumulation in plants is a prerequisite for minimizing dietary uptake of cadmium from contaminated crops. Here, we show that cadmium inhibits nitrate transporter 1.1 (NRT1.

[A review on current situations of steroid estrogen in the water system].

Steroid estrogens are a group of biologically active endocrine disruptors. An extremely low level of steroid estrogens is sufficient to result in reproduction and behavior disorders, and larval mutation of both human being and animals. The ecological and environmental effects of steroid estrogens should be more direct on organisms in water system as compared with those in other environment systems.

Aquatic plant debris improve phosphorus sorption into sediment under anoxic condition.

The effects of plant debris on phosphorus sorption by anoxic sediment were investigated. Addition of plant debris significantly enhanced the decrease of soluble relative phosphorus (SRP) in overlying water at both 10 and 30 °C during the 30-day investigation. Both cellulose and glucose, two typical plant components, also clearly enhanced the SRP decrease in anoxic overlying water.

Mild Fe-deficiency improves biomass production and quality of hydroponic-cultivated spinach plants (Spinacia oleracea L.).

It is of great practical importance to improve yield and quality of vegetables in soilless cultures. This study investigated the effects of iron-nutrition management on yield and quality of hydroponic-cultivated spinach (Spinacia oleracea L.).

[Growth kinetics of aquatic worms feeding on activated sludge].

The growth kinetics of aquatic worms was investigated from juvenile to decline phase for 18 weeks by cultivating with activated sludge in batch test. Results showed that the growth of aquatic worms well fit Gauss function for cultivating 18 weeks. The maximum specific growth rate, growth yield of aquatic worms and sludge reduction rate was 0.

Iron uptake system mediates nitrate-facilitated cadmium accumulation in tomato (Solanum lycopersicum) plants.

Nitrogen (N) management is a promising agronomic strategy to minimize cadmium (Cd) contamination in crops. However, it is unclear how N affects Cd uptake by plants. Wild-type and iron uptake-inefficient tomato (Solanum lycopersicum) mutant (T3238fer) plants were grown in pH-buffered hydroponic culture to investigate the direct effect of N-form on Cd uptake.

NO synthase-generated NO acts downstream of auxin in regulating Fe-deficiency-induced root branching that enhances Fe-deficiency tolerance in tomato plants.

In response to Fe-deficiency, various dicots increase their root branching which contributes to the enhancement of ferric-chelate reductase activity. Whether this Fe-deficiency-induced response eventually enhances the ability of the plant to tolerate Fe-deficiency or not is still unclear and evidence is also scarce about the signals triggering it. In this study, it was found that the SPAD-chlorophyll meter values of newly developed leaves of four tomato (Solanum lycocarpum) lines, namely line227/1 and Roza and their two reciprocal F(1) hybrid lines, were positively correlated with their root branching under Fe-deficient conditions.

Differential regulatory role of nitric oxide in mediating nitrate reductase activity in roots of tomato (Solanum lycocarpum).

Background And Aims: Nitric oxide (NO) has been demonstrated to stimulate the activity of nitrate reductase (NR) in plant roots supplied with a low level of nitrate, and to affect proteins differently, depending on the ratio of NO to the level of protein. Nitrate has been suggested to regulate the level of NO in plants. This present study examined interactive effects of NO and nitrate level on NR activity in roots of tomato (Solanum lycocarpum).

Elevated carbon dioxide improves plant iron nutrition through enhancing the iron-deficiency-induced responses under iron-limited conditions in tomato.

The increases in atmospheric carbon dioxide (CO(2)) concentrations can enhance plant growth and change their nutrient demands. We report that when tomato (Lycopersicon esculentum 'Zheza 809') plants were grown in iron (Fe)-limited medium (with hydrous ferric iron oxide) and elevated CO(2) (800 microL L(-1)), their biomass and root-to-shoot ratio were greater than plants grown in ambient CO(2) (350 microL L(-1)). Furthermore, the associated increase in Fe concentrations in the shoots and roots alleviated Fe-deficiency-induced chlorosis.

Factors determining copper concentration in tea leaves produced at Yuyao County, China.

Over consumption of copper (Cu) from food and beverages is detrimental to human health. In this study, we investigated Cu accumulation in tea leaves produced in Yuyao County in China. Copper concentrations in all tea leaves sampled from tea gardens were below 60mgkg(-1), the permissible level given by the Chinese Ministry of Health; however, 15% of the samples were over 15mgkg(-1), the allowable level of 'green food' as defined by the Chinese Ministry of Agriculture.