The effect of straw-returning on antimony and arsenic volatilization from paddy soil and accumulation in rice grains.

Pollution by antimony (Sb) and arsenic (As) in soil can pose a great threat to human health. Straw-returning is widely applied to paddy fields for improving and remediating soil. A pot experiment was conducted to investigate the effect of straw-returning on Sb and As transformation and translocation in a soil-rice system.

Rice nitrogen use efficiency does not link to ammonia volatilization in paddy fields.

Ammonia (NH) volatilization is a major pathway of nitrogen (N) losses from paddy fields, and could be potentially mitigated by cultivation of high nitrogen use efficiency (high-NUE) rice cultivars. However, the relationship between NUE and NH volatilization has not been validated under field conditions. A field experiment was conducted to evaluate the impact of four rice cultivars with different NUE [Wuyunjing 23 (W23), Zhendao 11 (Z11), Wuyujing 3 (W3), and Aoyusi 386 (A386)] on NH volatilization, as well as the related mechanisms.

Acetotrophic methanogens are sensitive to long-term nickel contamination in paddy soil.

Paddy soil accounts for approximately one-fifth of the world's cultivated area and faces a serious threat from nickel (Ni). Ni pollution has an impact on the activity, composition and emission of methanogens in paddy, which is a major natural source of methane (CH4) emissions. We combined a high-throughput sequencing approach and laboratory incubation methods to evaluate the impact of long-term Ni pollution on the methanogenic archaeal community in paddy soil.

The characterization of arsenic biotransformation microbes in paddy soil after straw biochar and straw amendments.

Straw biochar and straw application to paddy soil dramatically altered arsenic (As) biogeochemical cycling in soil-rice system, but it remains unknown how As biotransformation microbes (ABMs) contribute to these processes. In this study, rice pot experiments combining terminal restriction fragment length polymorphism (T-RFLP) analysis and clone library were performed to characterize ABMs. Through linear discriminant analysis (LDA) effect size (LEfSe) and correlation analysis, results revealed that arrA-harbouring iron-reducing bacteria (e.

NHHPO-extractable arsenic provides a reliable predictor for arsenic accumulation and speciation in pepper fruits (Capsicum annum L.).

Dietary arsenic (As) intake from food is of great concern, and developing a reliable model capable of predicting As concentrations in plant edible parts is desirable. In this study, pot experiments were performed with 16 Chinese upland soils spiked with arsenate [As(V)] to develop a predictive model for As concentrations in pepper fruits (Capsicum annum L.).

Microbiota in non-flooded and flooded rice culms.

Rice plants are the habitat for large and diverse populations of microbes, which play important roles on rice health and productivity. However, the response of microbiome on rice culm to water flooding is poorly understood. In this study, the bacterial community on non-flooded (RSA) and flooded (RSB) rice culms was investigated through 16S rRNA gene sequencing.

Turning pig manure into biochar can effectively mitigate antibiotic resistance genes as organic fertilizer.

The composting of fresh manure is an effective way to inactivate pathogens and reduce the levels of antibiotics and some antibiotic resistance genes (ARGs) prior to its application on agricultural land as organic fertilizer. However, some ARGs could still exist and even be enriched after composting. This study investigated whether converting composted pig manure into biochar could reduce the dissemination of ARGs into the soil in comparison with a compost amendment.

[Effects of Straw Incorporation on Cadmium Accumulation and Subcellular Distribution in Rice].

Cadmium (Cd) is classified as a Group-1 human carcinogen and rice consumption constitutes a major source of dietary intake of Cd for populations whose staple food is rice. Straw incorporation is widely performed in Cd-contaminated paddy fields, which may significantly affect the bioavailability of Cd in soil and the distribution of Cd in rice plants, consequently altering Cd accumulation in rice grains. In this study, both pot and field trials were conducted to investigate the effects of different amounts of straw incorporation (0.

Genotypic-dependent effects of N fertilizer, glutathione, silicon, zinc, and selenium on proteomic profiles, amino acid contents, and quality of rice genotypes with contrasting grain Cd accumulation.

Soil heavy metal (HM) contamination has posed a serious problem for safe food production. For restricting the translocation of HM into grain, many proteins were regulated to involve in the process. To identify these proteins, 2D-based proteomic analysis was carried out using different rice genotypes with distinct Cd accumulation in grains and as affected by an alleviating regulator (AR) in field experiments.

Genotypic and environmental variation in cadmium, chromium, lead and copper in rice and approaches for reducing the accumulation.

The field scale trials revealed significant genotypic and environmental differences in grain heavy metal (HM) concentrations of 158 newly developed rice varieties grown in twelve locations of Zhejiang province of China. Grain Pb and Cd contents in 5.3% and 0.

Effects of pH, Fe, and Cd on the uptake of Fe(2+) and Cd (2+) by rice.

The rhizosphere plays an important role in altering cadmium (Cd) solubility in paddy soils and Cd accumulation in rice. However, more studies are needed to elucidate the mechanism controlling rice Cd solubility and bioavailability under different rhizosphere conditions to explain the discrepancy of previous studies. A rice culture with nutrient solution and vermiculite was conducted to assess the effects of pH, Eh, and iron (Fe) concentration on Cd, Fe fractions on the vermiculite/root surface and their uptake by rice.

[Diversity of plant in Jiaxing Shijiuyang ecological wetland for drinking water during operation].

The Shijiuyang ecological wetland for drinking water of Jiaxing City, Zhejiang Province is one of the biggest constructed wetlands for water resource protection in China. To ensure a deep understanding of the present status of the wetland vegetation of Shijiuyang ecological wetland which has been run for 2.5 years and provide support for the vegetation management of ecological wetland, systematic investigation was carried out by using plot method and quadrat method in October to November, 2010.

Modulation of exogenous glutathione in phytochelatins and photosynthetic performance against cd stress in the two rice genotypes differing in Cd tolerance.

Greenhouse hydroponic experiments were conducted using Cd-sensitive (Xiushui63) and tolerant (Bing97252) rice genotypes to evaluate genotypic differences in response of photosynthesis and phytochelatins to Cd toxicity in the presence of exogenous glutathione (GSH). Plant height, chlorophyll content, net photosynthetic rate (Pn), and biomass decreased in 5 and 50 μM Cd treatments, and Cd-sensitive genotype showed more severe reduction than the tolerant one. Cadmium stress caused decrease in maximal photochemical efficiency of PSII (Fv/Fm) and effective PSII quantum yield [Y(II)] and increase in quantum yield of regulated energy dissipation [Y(NPQ)], with changes in Cd-sensitive genotype being more evident.

Abundance and diversity of tetracycline resistance genes in soils adjacent to representative swine feedlots in China.

Tetracyclines are commonly used antibiotics in the swine industry for disease treatment and growth promotion. Tetracycline resistance was determined in soils sampled from farmlands in the vicinity of nine swine farms located in three cities in China. Totally, 15 tetracycline resistance (tet) genes were commonly detected in soil samples, including seven efflux pump genes (tetA, tetC, tetE, tetG, tetK, tetL, tetA/P), seven ribosomal protection proteins (RPPs) genes (tetM, tetO, tetQ, tetS, tetT, tetW, tetB/P), and one enzymatic modification gene (tetX).

[Effect of iron plaque formation of root surface on as uptake by rice seedlings grown on different types of soils].

The objective of study was to investigate the effect of the amount of iron plaque of root surface on As uptake by rice seedlings grown on 14 types of soils. These results indicated that there were significant differences in the amounts of iron plaque (1.15-61.

Resistance and resilience of Cu-polluted soil after Cu perturbation, tested by a wide range of soil microbial parameters.

Copper (Cu)-polluted and unpolluted soils were used to study the effect of initial pollution on soil biological resistance and resilience by measuring the responses to perturbation using different parameters. Microbial biomass carbon, substrate-induced respiration and copy numbers of 16S rRNA gene were grouped as general parameters, while potential ammonia oxidation rate and copy numbers of amoA gene were grouped as specific functions. In addition, to illustrate how initial pollution affects soil biological resistance and resilience following secondary perturbation, the microbial community structure, together with free Cu(2+) activities ([Cu(2+)]) in soil pore water and soil pH were also measured after secondary perturbation.

Mapping quantitative trait loci associated with arsenic accumulation in rice (Oryza sativa).

The quantitative trait loci (QTLs) associated with arsenic (As) accumulation in rice were mapped using a doubled haploid population established by anther culture of F1 plants from a cross between a Japonica cultivar CJ06 and an Indica cultivar TN1 (Oryza sativa). Four QTLs for arsenic (As) concentrations were detected in the map. At the seedling stage, one QTL was mapped on chromosome 2 for As concentrations in shoots with 24.

Genotypic and environmental variation in chromium, cadmium and lead concentrations in rice.

Genotypic and environmental variation in Cr, Cd and Pb concentrations of rice grains and the interaction between these metals were investigated by using 138 rice genotypes grown in three contaminated soils. There were significant genotypic differences in the three heavy metal concentrations of rice grains, with the absolute difference among 138 genotypes in grain Cr, Cd and Pb concentrations being 24.5-, 9.

Genotypic and environmental variation in cadmium, chromium, arsenic, nickel, and lead concentrations in rice grains.

Genotypic and environmental variation in Cd, Cr, As, Ni and Pb concentrations of grains, and the relationships between these heavy metals and Fe, Zn were investigated using 9 rice genotypes grown in 6 locations for two successive years. Significant genotypic variation was detected in the five heavy metal concentrations in grains, indicating the possibility to reduce the concentration of these heavy metals in grains through breeding approach. The environmental effect varied with metal, with Pb and Ni having greater variation than the other three metals.