Phytoextraction of cadmium by rice (Oryza sativa L.), soybean (Glycine max (L.) Merr.), and maize (Zea mays L.).

Selecting a phytoextraction plant with high Cd-accumulating ability based on the plant's compatibility with mechanized cultivation techniques may yield more immediately practical results than selection based on high tolerance to Cd. Rice (Oryza sativa L., cv.

Polychlorinated dibenzo-p-dioxins, dibenzofurans, and dioxin-like polychlorinated biphenyls in rice plants: possible contaminated pathways.

Uptake of dioxins was confirmed in rice plants. We determined (i) dioxin concentrations and isomer profiles in leaf+stem samples of rice plants grown in three soils with different dioxin concentrations and isomer profiles and (ii) temporal changes in dioxin concentrations and isomer profiles in rice grown in a paddy field on which agricultural chemicals containing dioxin impurities had been used in previous years. Principal-component and chemical mass-balance analyses of the data showed that dioxin concentrations and isomer profiles in the rice grown in the different soils were similar, even though the dioxin concentrations and isomer profiles of the soils were different.

Production of quorum-sensing-related signal molecules by epiphytic bacteria inhabiting wheat heads.

The production of quorum-sensing-related signal molecules (QSRMs) among culturable bacteria comprising the community on wheat heads was investigated. The taxonomic position of 186 bacterial isolates obtained from ten heads was inferred based on 16S rRNA gene sequences, and their QSRM production was determined using two bioreporter strains of N-acylhomoserine lactones. Approximately 33% of isolates produced QSRMs, though the proportion of QSRM-producing isolates on a wheat head was significantly negatively correlated with population size.

Enhancement of rice canopy carbon gain by elevated CO(2) is sensitive to growth stage and leaf nitrogen concentration.

Increasing our understanding of the factors regulating seasonal changes in rice canopy carbon gain (C(gain): daily net photosynthesis -- night respiration) under elevated CO(2) concentrations ([CO(2)]) will reduce our uncertainty in predicting future rice yields and assist in the development of adaptation strategies. In this study we measured CO(2) exchange from rice (Oryza sativa) canopies grown at c. 360 and 690 micromol mol(-1)[CO(2)] in growth chambers continuously over three growing seasons.

Remediation of cadmium contamination in paddy soils by washing with chemicals: selection of washing chemicals.

The efficiencies of neutral salts, strong acids, and chelates were tested for extracting cadmium (Cd) from three paddy soils. The higher the selectivity of the cations of the added neutral salts toward soil adsorption sites, the lower the pH in the extracts and the more soil Cd could be extracted. In addition, soil carbon and nitrogen contents and mineral composition were closely associated with the amount of Cd extracted.

Fungicide Sensitivity and Phylogenetic Relationship of Anthracnose Fungi Isolated from Various Fruit Crops in Japan.

Anthracnose diseases of fruit crops are mainly caused by Colletotrichum gloeosporioides and C. acutatum. In these Colletotrichum species, intra- and interspecific variation in fungicide sensitivity has been reported; however, the relationship between fungicide sensitivity and molecular phylogeny has not been analyzed.

Challenges of reducing excess nitrogen in Japanese agroecosystems.

Fertilizer N use in Japan has decreased by about 30% from 1960 to 2000, while keeping a little increase in cereal yields. This has resulted in a significant increase in apparent nitrogen use efficiency, in particular for rice. On the other hand, national N load on the environment associated with the production and consumption of domestic and imported agricultural products has almost tripled during this period, mainly due to the dramatic increase of imports of food and feedstuffs.

Synthesis and characterization of 3,13- and 2,13-octadecadienyl compounds for identification of the sex pheromone secreted by a clearwing moth, Nokona pernix.

Several geometrical isomers of 3,13- and 2,13-octadecadien-1-ols and their acetates were synthesized starting from 1,8-octanediol or 1,9-nonanediol utilizing acetylene coupling reactions. In addition to commercially available compounds, all geometrical isomers of each dienyl compound were analyzed by NMR and GC-MS to accumulate chemical data for studies of sex pheromones secreted from clearwing moths classified into the family Sesiidae of Lepidoptera. Although acetoxy derivatives of the 3,13- and 2,13-dienes showed almost the same mass spectra, the alcohols were distinguished by comparing the relative intensities of [M-18](+) at m/z 248, indicating direct differentiation of the two positional isomers without derivatization.

Levels of dioxins in Japanese fruit in 1999 to 2002 and estimation of their intake.

A total of 148 samples of nine species of fruit were collected between 1999 and 2002 and analyzed for PCDDs, PCDFs (PCDD/Fs) and Coplanar PCBs. Sampling points within about 1 km of operational municipal waste incinerators that were considered sources of dioxins were defined as "near-source" areas, and all other sampling points were defined as "general" areas. The TEQ of apples collected from near-source areas was significantly higher than that from general areas (p < 0.

Evaluation of performance of a commercial monoclonal antibody-based fenitrothion immunoassay and application to residual analysis in fruit samples.

The performance of a commercially available enzyme-linked immunosorbent assay (ELISA) kit containing highly sensitive monoclonal antibodies against fenitrothion was assessed. The experimentally estimated dynamic range (0.087 to 2 ng/g) agreed with that established by the kit manufacturer (0.

O-atom-transfer oxidation of [molybdenum(IV) oxo{3,6-(acylamino)2- 1,2-benzenedithiolato}2]2- promoted by intramolecular NH...S hydrogen bonds.

Novel molybdenum dithiolene compounds having neighboring amide groups as models for molybdoenzymes, (NEt(4))(2)[Mo(IV)O{1,2-S(2)-3,6-(RCONH)(2)C(6)H(2)}(2)] (R = CH(3), CF(3), t-Bu, Ph(3)C), were designed and synthesized. The contributions of the NH..

Comparison between Rosellinia necatrix isolates from soil and diseased roots in terms of hypovirulence.

The white root rot fungus, Rosellinia necatrix, is a devastating soil-borne pathogen of many plant species. Biocontrol with the hypovirulence factor is promising, but disease symptoms, signs or culture morphology of the pathogen cannot be reliably used as markers for hypovirulence in this fungus. We attempted to obtain hypovirulent isolates from soil rather than from diseased roots, based on the hypothesis that hypovirulent isolates were more likely to persist in soil as saprobes.

Dynamics of double-stranded RNA segments in a Helicobasidium mompa clone from a tulip tree plantation.

Eighty-three isolates of the violet root rot fungus, Helicobasidium mompa, were collected in a tulip tree plantation and analyzed for the dynamics of double-stranded (ds) RNA for five years. They were divided into eight mycelial compatibility groups (MCGs). Prevalent MCGs 60 and 68 included 61 and 11 isolates, respectively.

Direct quantitative determination of cyanamide by stable isotope dilution gas chromatography-mass spectrometry.

Cyanamide is a multifunctional agrochemical used, for example, as a pesticide, herbicide, and fertilizer. Recent research has revealed that cyanamide is a natural product biosynthesized in a leguminous plant, hairy vetch (Vicia villosa). In the present study, gas chromatography-mass spectrometry (GC-MS) equipped with a capillary column for amines was used for direct quantitative determination of cyanamide.

Redox reaction of iodine in paddy soil investigated by field observation and the I K-Edge XANES fingerprinting method.

In order to elucidate the cause for the leaching of iodine in a flooded paddy field, we investigated the transformation of an iodine species affected by the water management of the paddy field. The increased concentration of iodide (I(-)) in soil solution of a flooded paddy field suggested that I(-) was leached from the soil under anaerobic conditions. The post-edge feature of X-ray absorption near-edge structure (XANES) for iodate (IO(3)(-)) spiked to soil totally disappeared after anaerobic incubation of the soils, and I(-) was dissolved in the solution.

Chromosomal regions with quantitative trait loci controlling cadmium concentration in brown rice (Oryza sativa).

A novel mapping population consisting of 39 chromosome segment substitution lines (CSSLs) was used to locate the putative quantitative trait loci (QTLs) for cadmium (Cd) concentration in brown rice (Oryza sativa). The mapping population carried a single chromosome segment of 'Kasalath' (indica) in each line overlapping with neighbouring segments in a 'Koshihikari' (japonica) genetic background. The parents and CSSLs were grown in pots filled with Cd-polluted soil until grain filling.

Direct labeling of polyphosphate at the ultrastructural level in Saccharomyces cerevisiae by using the affinity of the polyphosphate binding domain of Escherichia coli exopolyphosphatase.

Inorganic polyphosphate (polyP) is a linear polymer of orthophosphate and has many biological functions in prokaryotic and eukaryotic organisms. To investigate polyP localization, we developed a novel technique using the affinity of the recombinant polyphosphate binding domain (PPBD) of Escherichia coli exopolyphosphatase to polyP. An epitope-tagged PPBD was expressed and purified from E.

Synthesis of haptens for development of antibodies to alkylphenols and evaluation and optimization of a selected antibody for ELISA development.

The development of an enzyme-linked immunosorbent assay (ELISA) based on polyclonal antibodies for a class of endocrine disrupting compounds, 4-nonylphenol, is described. The parent molecule was derivatized at the ortho position of the free phenolic hydroxyl group to obtain the hapten, NP1, and it was conjugated with keyhole limpet hemocyanin, which was used as an immunogen. Four antisera were generated and screened against three coating antigens.

Challenges of reducing excess nitrogen in Japanese agroecosystems.

Fertilizer N use in Japan has decreased by about 30% from 1960 to 2000, while keeping a little increase in cereal yields. This has resulted in a significant increase in apparent nitrogen use efficiency, in particular for rice. On the other hand, national N load on the environment associated with the production and consumption of domestic and imported agricultural products has almost tripled during this period, mainly due to the dramatic increase of imports of food and feedstuffs.

Allelopathic potential of Robinia pseudo-acacia L.

Robinia pseudo-acacia L. (black locust) is a nonindigenous species currently invading the central part of Japanese grasslands. Several allelochemicals were identified and characterized from the leaf tissue.

A water quality analysis system to evaluate the impact of agricultural activities on N outflow in river basins in Japan.

We have developed a personal-computer-based water quality analysis system for river basins. The system estimates potential N outflow by model and calculates actual N outflow from monitoring data. For the former it uses the potential load factor method to estimate annual nitrogen load from various sources and runoff potential from each area of land in a basin.

An algorithm for estimating potential deposition of corn pollen for environmental assessment.

The safety and impact on the environment of transgenic crops are important issues, and studies have shown that pollen from transgenic Bt (Bacillus thuringiensis) corn (Zea mays L.) may kill nontarget insects. To develop an algorithm for assessing the environmental effect of transgenic crops, we arranged a field experiment in Tsukuba, Japan.

Evaluation of a commercial immunoassay for the detection of chlorfenapyr in agricultural samples by comparison with gas chromatography and mass spectrometric detection.

A commercially available enzyme-linked immunosorbent assay (ELISA) kit with a high affinity monoclonal antibody was applied to residual analysis of insecticide chlorfenapyr in agricultural samples, and drawn a parallel between the ELISA and gas chromatography (GC) with mass spectrometry (MS). For standards prepared in water containing 5% (v/v) methanol, the sensitivity (I50 value), the dynamic range, and the limit of detection of the ELISA kit were 2.3, 1 - 10, and 0.

Two kinds of chlorocatechol 1,2-dioxygenase from 2,4-dichlorophenoxyacetate-degrading Sphingomonas sp. strain TFD44.

Two kinds of chlorocatechol 1,2-dioxygenase (CCD), TfdC and TfdC2 were detected in Sphingomonas sp. strain TFD44. These two CCDs could be simultaneously synthesized in TFD44 during its growth with 2,4-D as the sole carbon and energy sources.