Residual characteristics and safety assessment of the insecticides spiromesifen and chromafenozide in lettuce and perilla.

This study was performed to investigate the residual characteristics, safety assessment, and pre-harvest interval (PHI) of spiromesifen and chromafenozide in lettuce (Latuca sativa L.) and perilla (Perilla frutescens (L.) Britton) leaves. Samples were harvested periodically, extracted using QuEChERS method, and analyzed by LC-MS/MS. Average recoveries of spiromesifen and its metabolite BSN2060-enol and chromafenozide were ranged from 80.6 to 107.9%, with relative standard deviation < 10%. Spiromesifen and cromafenozide initial residues in lettuce were dissipated to 81.45 and 95.52% after 7 days, with half-lives of 2.89 and 1.69 days respectively. Values in perilla leaves were 76.68 and 61.27% after the same period, with half-lives of 4.25 and 6.30 days, respectively. Risk assessment results showed that %ADI (acceptable daily intake) of spiromesifen and chromafenozide was 6.83 and 0.56, in lettuce and 4.60 and 0.25% in perilla leaves, respectively. Theoretical maximum daily intakes of spiromesifen and chromafenozide were 67.49 and 3.43%, respectively, indicating that residues of both compounds pose no considerable health risks to consumers. This study provides data for setting maximum residue limits and PHIs for the safe use of spiromesifen and chromafenozide in lettuce and perilla.

Insecticide Residues in Cotton, Sorghum and Fallow Soil from the Nuba Mountains Cotton Corporation of South Kordofan State, Sudan.

BACKGROUND: Soil is the final depot of most environmental contaminants, including pesticides. Soil may be contaminated by pesticides as a result of direct application or drift during spray activities. Soil contamination with pesticide residues may affect the quality of food crops, animal products, and soil micro-organisms which may in turn negatively affect human health and the environment. OBJECTIVES: The main objective of the current study was to determine the soil residues of commonly used pesticides in rain-fed crops grown by the Nuba Mountains Cotton Corporation (NMCC) in South Kordofan state of Western Sudan. METHODS: Four locations (representing the four directions around the state capital Kadugli) were chosen for sample collection: Alefain (East Kadugli), Elmashaish (West Kadugli), Ed Dalling uncultivated area (North Kadugli) and Lagawa (Southwest Kadugli). Nine soil samples were randomly taken from each location representing areas under cotton, sorghum, and uncultivated land covered with natural vegetation. Soil samples were analyzed by gas chromatography (GC) equipped with electron capture detector (ECD) and GC-mass spectrometry (MS). RESULTS: The results generally indicated that organophosphate levels were greater than organochlorine and pyrethroids with heptachlor, malathion, and dimethoate present in all samples analyzed, while the level of p,p-dichlorodiphenyltrichloroethane (DDT) was below the detection limit. Endosulfan α and ß isomers were detected in some samples. Dimethoate had the highest level (22.02 mg/kg), while ß endosulfan was found at the lowest level (0.015 mg/kg). Generally, samples collected from cotton soils showed higher residue levels compared to sorghum soil with average concentrations of 307.25 mg/kg versus 58.63 mg/kg, respectively. Almashaish showed the highest residues levels followed by Alefain, Lagawa, and Ed Dalling with total residues of 57.56 mg/kg, 26.34 mg/kg, 22.63 mg/kg, and 17.07 mg/kg, respectively. CONCLUSIONS: The current study sheds light on the residue levels of some of the commonly used pesticides in the cotton rain-fed scheme in South Kordofan State, western Sudan. The study calls for regular residue monitoring in various environmental components in the area and suggests possible management measures. COMPETING INTERESTS: The authors declare no competing financial interests.

Phenolic Profile, Antioxidant, and Antidiabetic Potential Exerted by Millet Grain Varieties.

This study evaluated the potential antioxidant and antidiabetic properties in vitro of four millet grain varieties cultivated in South Korea. The free fractions were tested for their total antioxidant capacity using 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS+) and 2,2'-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assays, followed by α-glucosidase, α-amylase, and advanced glycation endproducts (AGEs) formation inhibition assays. The total phenolics, flavonoids, and condensed tannins in the free fractions ranged from 107.8 to 136.4 mg ferulic acid equivalent (FAE)/100 g, 101.3 to 115.8 mg catechin equivalent (CE)/100 g, and 17.65 to 59.54 mg catechin equivalent (CE)/100 g, respectively. Finger Italian millet had the highest total phenolic content (136.4 mg FAE/100 g) and flavonoid content (115.8 mg CE/100 g). Barnyard and finger Italian millet showed the highest DPPH (IC50 = 359.6 µg/mL and 436.25 µg/mL, respectively) and ABTS radical scavenging activity (IC50 = 362.40 µg/mL and 381.65 µg/mL, respectively). Similarly, finger Italian millet also exhibited significantly lower IC50 values for the percentage inhibition of α-glucosidase (18.07 µg/mL) and α-amylase (10.56 µg/mL) as compared with acarbose (IC50 = 59.34 µg/mL and 27.73 µg/mL, respectively) and AGEs formation (33.68 µg/mL) as compared with aminoguanidine (AG) (52.30 µg/mL). All eight phenolic compounds identified in finger Italian millet were flavonoids, with flavanols being the predominant subclass. Taken together, millet flavonoids play important roles in the prevention and management of type 2 diabetes, and hence finger Italian millet has the potential to be developed as a functional food.

Rapid detection of heavy metal-induced toxicity in water using a fed-batch sulfur-oxidizing bacteria (SOB) bioreactor.

A fed-batch bioreactor based on sulfur-oxidizing bacteria (SOB) was tested for rapid detection of heavy metal-induced toxicity in water. For this evaluation, SOB were exposed to water contaminated by selenium, mercury, hexavalent chromium, arsenic, cyanide, cadmium, and lead for 2 h and their inhibition rates were analyzed based on changes in electrical conductivity (EC). The results demonstrate that SOB were highly inhibited by selenium, mercury, hexavalent chromium, and arsenic but not by cyanide, cadmium, and lead. The 2 h half maximum effective concentrations (EC50) of SOB for selenium, mercury, hexavalent chromium, and arsenic were estimated to be 0.33, 0.89, 1.18, and 0.24 mg/L, respectively, which are comparable or lower than earlier reports in the literature. However, the EC50 or EC20 values of SOB for cyanide, cadmium, and lead were notably higher compared to findings from previous toxicity tests that employed other microorganisms. The findings from the current study suggest that the fed-batch SOB bioreactor is suitable for rapid detection of toxicity induced by selenium, mercury, hexavalent chromium, and arsenic in water.

Toxicological effects of clofibric acid and diclofenac on plasma thyroid hormones of an Indian major carp, Cirrhinus mrigala during short and long-term exposures.

In the present investigation, the toxicity of most commonly detected pharmaceuticals in the aquatic environment namely clofibric acid (CA) and diclofenac (DCF) was investigated in an Indian major carp Cirrhinus mrigala. Fingerlings of C. mrigala were exposed to different concentrations (1, 10 and 100µgL(-1)) of CA and DCF for a period of 96h (short term) and 35 days (long term). The toxic effects of CA and DCF on thyroid hormones (THs) such as thyroid stimulating hormone (TSH), thyroxine (T4) and triiodothyronine (T3) levels were evaluated. During the short and long-term exposure period TSH level was found to be decreased at all concentrations of CA (except at the end of 14(th) day in 1 and 10µgL(-l) and 21(st) day in 1µgL(-l)) whereas in DCF exposed fish TSH level was found to be increased when compared to control groups. T4 level was found to be decreased at 1 and 100µgL(-l) of CA exposure at the end of 96h. However, T4 level was decreased at all concentrations of CA and DCF during long-term (35 days) exposure period. Fish exposed to all concentrations of CA and DCF had lower level of T3 in both the treatments. These results suggest that both CA and DCF drugs induced significant changes (P<0.01 and P<0.05) on thyroid hormonal levels of C. mrigala. The alterations of these hormonal levels can be used as potential biomarkers in monitoring of pharmaceutical drugs in aquatic organisms.

Distribution and persistence of tricyaclazole in agricultural field soils.

Soil is the major sink for majority of pesticides applied on agricultural crops and its fate depends on variety of factors. There is little research on fate of pesticide in field soil under different climatic conditions and there is a need of study on the influence of climate on pesticide degradation and persistence in soil. In the present study, the persistence and distribution of tricyclazole was investigated in rice field soil under the influence of cold winter condition. Field experiment was carried at 35 different field sites from 6 provinces in Republic of Korea. Limit of detection and limit of quantification of tricyclazole were found to be 0.005 and 0.0165 mg/kg, respectively. The concentrations of tricyclazole in soil samples ranged from 0.387 mg/kg in sites in Gyeongsangbuk-do areas and lowest 0.021 mg/kg in sites from Chuncheongnam-do areas. In natural environmental conditions, tricyclazole persisted longer than 11 months post application in agricultural field soils. Our result indicates the influence of cold climatic condition on the persistence of tricyclazole.

Complete genome sequence of Japanese erwinia strain ejp617, a bacterial shoot blight pathogen of pear.

The Japanese Erwinia strain Ejp617 is a plant pathogen that causes bacterial shoot blight of pear in Japan. Here, we report the complete genome sequence of strain Ejp617 isolated from Nashi pears in Japan to provide further valuable insight among related Erwinia species.

Induction of cell cycle arrest and apoptosis by the ethyl acetate fraction of Kalopanax pictus leaves in human colon cancer cells.

Kalopanax pictus is a deciduous tree used in traditional medicine; its leaves are also consumed as a vegetable. In this study, the ethyl acetate fraction of K. pictus leaves (EFK) was tested in vitro for anticancer activity against four cell lines: human colon cancer (HT-29) cells, human stomach cancer (NCI-N87) cells, human breast cancer (MDA-MB231) cells, and mouse melanoma (B16F1) cells. Results indicated that EFK showed the most potent tumor selective growth inhibitory activity against HT-29 cells with less cytotoxic effect on normal cell lines. Cytotoxicity of EFK on HT-29 cells was associated mainly with cell chromatin condensation, DNA fragmentation, and loss of membrane phospholipid asymmetry with appearance of G2/M phase arrest. Cell death induced by EFK displayed features characteristic of apoptosis, and was associated with generation of reactive oxygen species (ROS) and increase of Bax/Bcl-2 ratio. These findings suggest that K. pictus leaves have anticancer properties and may be valuable for application in pharmaceutical industry.

Amelioration of streptozotocin-induced diabetes by Agrocybe chaxingu polysaccharide.

The aim of this study was to investigate the preventive effect of Agrocybe chaxingu polysaccharide on streptozocin (STZ)-induced pancreatic beta-cells destruction. Agrocybe chaxingu polysaccharide markedly reduced nitric oxide (NO) production and iNOS expression levels in RINm5F cells in a dose-dependent manner. In addition, Agrocybe chaxingu polysaccharide significantly inhibited iNOS expression and blood glucose levels in STZ-induced diabetic mice. Moreover, immunohistochemical analysis revealed that it enhanced pancreatic beta-cells resistance to destruction by STZ. These results suggest that Agrocybe chaxingu polysaccharide may have value as a therapeutic agent against diabetes mellitus.

Agrocybe chaxingu polysaccharide prevent inflammation through the inhibition of COX-2 and NO production.

The inhibition of nitric oxide (NO) and cyclooxygenase-2 (COX-2) production is considered to be a promising approach to the treatment of various diseases, including inflammation and cancer. In this study, we examined the effects of the Agrocybe chaxingu beta-glucan (polysaccharide) on lipopolysaccaride (LPS)-induced nitric oxide (NO) and cyclooxygenase-2 (COX-2) expression in murine macrophage Raw 264.7 cells as well as 12-O-tetradecanoylphorbol 13-acetate (TPA)-induced ear edema in mice. The polysaccharide significantly inhibited (P 0.01) LPS-induced iNOS and COX-2 expression levels in the cells. Furthermore, topical application of polysaccharide resulted in markedly inhibited (P 0.01) TPA-induced ear edema in mice. These results suggest that this polysaccharide may be used for NO- and COX-2-related disorders such as inflammation and cancer.

Genetic organization of the hrp genes cluster in Erwinia pyrifoliae and characterization of HR active domains in HrpNEp protein by mutational analysis.

The disease-specific (dsp) region and the hypersensitive response and pathogenicity (hrp) genes, including the hrpW, hrpNEp, and hrpC operons have previously been sequenced in Erwinia pyrifoliae WT3 [Shrestha et al. (2005a)]. In this study, the remaining hrp genes, including the hrpC, hrpA, hrpS, hrpXY, hrpL and hrpJ operons, were determined. The hrp genes cluster (ca. 38 kb) was comprised of eight transcriptional units and contained nine hrc (hrp conserved) genes. The genetic organization of the hrp/hrc genes and their orientation for the transcriptions were also similar to and collinear with those of E. amylovora, showing > or = 80% homologies. However, ORFU1 and ORFU2 of unknown functions, present between the hrpA and hrpS operons of E. amylovora, were absent in E. pyrifoliae. To determine the HR active domains, several proteins were prepared from truncated fragments of the N-terminal and the C-terminal regions of HrpN(Ep) protein of E. pyrifoliae. The proteins prepared from the N-terminal region elicited HR, but not from those of the C-terminal region indicating that HR active domains are located in only N-terminal region of the HrpN(Ep) protein. Two synthetic oligopeptides produced HR on tobacco confirming presence of two HR active domains in the HrpN(Ep). The HR positive N-terminal fragment (HN delta C187) was further narrowed down by deleting C-terminal amino acids and internal amino acids to investigate whether amino acid insertion region have role in faster and stronger HR activity in HrpN(Ep) than HrpN(Ea). The HrpN(Ep) mutant proteins HN delta C187 (D1AIR), HN delta C187 (D2AIR) and HN delta C187 (DM41) retained similar HR activation to that of wild-type HrpN(Ep). However, the HrpN(Ep) mutant protein HN delta C187 (D3AIR) lacking third amino acid insertion region (102 to 113 aa) reduced HR when compared to that of wild-type HrpN(Ep). Reduction in HR elicitation could not be observed when single amino acids at different positions were substituted at third amino acids insertion region. But, substitution of amino acids at L103R, L106K and L110R showed reduction in HR activity on tobacco suggesting their importance in activation of HR faster in the HrpN(Ep) although it requires further detailed analysis.

Antiviral activity of the exopolysaccharide produced by Serratia sp. strain Gsm01 against Cucumber mosaic virus.

The potential of the exopolysaccharide (EPS) from a Serratia sp. strain Gsm01 as an antiviral agent against a yellow strain of Cucumber mosaic virus (CMV-Y) was evaluated in tobacco plants (Nicotiana tabacum cv. Xanthi-nc). The spray treatment of plants using an EPS preparation, 72 before CMV-Y inoculation, protected them against symptom appearance. Fifteen days after challenge inoculation with CMVY, 33.33% of plants showed mosaic symptoms in EPS-treated plants compared with 100% in the control plants. The EPS-treated plants, which showed mosaic symptoms, appeared three days later than the controls. The enzyme-linked immunosorbent assay (ELISA) and reverse transcriptase polymerase chain reaction (RT-PCR) analyses of the leaves of the protected plants revealed that the EPS treatment affected virus accumulation in those plants. Analysis of phenylalanine ammonia lyase, peroxidase, and phenols in protected plants revealed enhanced accumulation of these substances. The pathogenesis-related (PR) genes expression represented by PR-1b was increased in EPS-treated plants. This is the first report of a systemic induction of protection triggered by EPS produced by Serratia sp. against CMV-Y.

Isolation and functional analysis of a 24-residue linear alpha-helical antimicrobial peptide from Korean blackish cicada, Cryptotympana dubia (Homoptera).

A new antimicrobial peptide, cryptonin, was isolated and characterized from the adult Korean blackish cicada, Cryptotympana dubia. It consists of 24 amino acid residues and has a molecular weight of 2,704 Da on mass spectroscopy. The predicted alpha-helical structure analysis and increased helix percent in 40% trifloroethanol of cryptonin suggests that it belongs to the typical linear alpha-helix forming peptide. Binding of the biotin-labeled cryptonin at the surface of E. coli cells and increased influx of propidium iodide in E. coli after cryptonin treatment indicates that it kills microbial cells by binding bacterial cell surfaces and disrupting the cell permeability. Cryptonin showed strong antibacterial (MIC 1.56-25 microg/ml) and antifungal (MIC 3.12-50 microg/ml) activities against tested bacteria and fungi including two antibiotic-resistant bacterial strains; methicilin-resistant S. aureus and vancomycin-resistant Enterococci (MIC 25 microg/ml, each).

Transgenic tobacco expressing the hrpN(EP) gene from Erwinia pyrifoliae triggers defense responses against botrytis cinerea.

HrpN(EP), from the gram-negative pathogen, Erwinia pyrifoliae, is a member of the harpin group of proteins, inducing pathogen resistance and hypersensitive cell death in plants. When the hrpN(EP) gene driven by the OsCc1 promoter was introduced into tobacco plants via Agrobacterium-mediated transformation, their resistance to the necrotrophic fungal pathogen, Botrytis cinerea, increased. Resistance to B. cinerea was correlated with enhanced induction of SA-dependent genes such as PR-1a, PR2, PR3 and Chia5, of JA-dependent genes such as PR-1b, and of genes related to ethylene production, such as NT-EFE26, NT-1A1C, DS321, NT-ACS1 and NT-ACS2. However the expression of NPR1, which is thought to be essential for multiple-resistance, did not increase. Since the pattern of expression of defense-related genes in hrpN(EP)-expressing tobacco differed from that in plants expressing hpaG(Xoo) from Xanthomonas oryzae pv. Oryzae, these results suggest that different harpins can affect the expression of different defense-related genes, as well as resistance to different plant pathogens.

Tomato plants overexpressing CaKR1 enhanced tolerance to salt and oxidative stress.

CaKR1 from pepper leaves encodes an ankyrin repeat domain zinc finger that is thought to be involved in transcriptional regulation in response to pathogens and abiotic stresses. Transgenic tomato plants expressing CaKR1 show enhanced resistance to Phytophthora infestans. In this study, we further characterized this CaKR1-overexpressing transgenic tomato line. Morphologically, the leaves of the transgenic plants were thicker than those of control plants. Overexpressed transgenic plants also produced lower levels of free oxygen radicals, such as superoxide (O2-) and hydrogen peroxide (H2O2), and showed enhanced resistance to salinity and oxidative stress. In particular, transgenic plants produced higher levels of transcripts encoding the pathogenesis-related (PR) proteins LePR1, LePR2, and LePR3, as well as oxidative stress response proteins, such as superoxide dismutase (LeSOD2) and ascorbate peroxidase (LeAPX2 and LeAPX3). These results suggest that CaKR1 is a key signaling molecule regulating plant antioxidant metabolism and defense responses.

WITHDRAWN: Erratum to "Tomato plants overexpressing CaKR1 enhanced tolerance to salt and oxidative stress" [Biochem. Biophys. Res. Commun. 363 (2007) 983-988].

This article has been withdrawn at the request of the author. The Publisher apologizes for any inconvenience this may cause. The full Elsevier Policy on Article Withdrawal can be found at http://www.elsevier.com/locate/withdrawalpolicy.

WITHDRAWN: Erratum to "Tomato plants overexpressing CaKR1 enhanced tolerance to salt and oxidative stress" [Biochem. Biophys. Res. Commun. 363 (2007) 983-988].

This article has been withdrawn at the request of the author. The Publisher apologizes for any inconvenience this may cause. The full Elsevier Policy on Article Withdrawal can be found at http://www.elsevier.com/locate/withdrawalpolicy.

Streptomyces luridiscabiei sp. nov., Streptomyces puniciscabiei sp. nov. and Streptomyces niveiscabiei sp. nov., which cause potato common scab disease in Korea.

Three plant-pathogenic isolates of Streptomyces spp., isolated from potatoes with common scab disease lesions in Korea, are described as novel species. Morphological and physiological properties of these isolates were distinct from those of previously described Streptomyces species. Strain S63(T) has yellow-white, smooth, cylindrical spores that are borne in monoverticillus flexuous spore-chains. Strain S77(T) has purple-red, spiny spores that are borne in simple rectus flexuous spore-chains. Strain S78(T) has white, smooth, cylindrical spores that are borne in simple rectus flexuous spore-chains. These three isolates differed from known pathogenic strains by analysis of 16S rRNA gene sequences in a previous study. Furthermore, genetic uniqueness of our isolates was confirmed by sequencing of the 16S-23S internal transcribed spacer (ITS) region, which indicated that isolates S63(T) and S78(T) belong to the genus Streptomyces and have low homology to other Streptomyces species (less than 71.2 and 75.7 %, respectively). The 16S-23S ITS region of strain S77(T) was not amplified by these primer sets. DNA-DNA hybridization results for all three isolates show distant relationships to previously described Streptomyces species; therefore, on the basis of polyphasic evidence, the names Streptomyces luridiscabiei sp. nov. for strain S63(T) (=LMG 21390(T)=KACC 20252(T)), Streptomyces puniciscabiei sp. nov. for strain S77(T) (=LMG 21391(T)=KACC 20253(T)) and Streptomyces niveiscabiei sp. nov. for strain S78(T) (=LMG 21392(T)=KACC 20254(T)) are proposed.

Characterization of Streptomycetes Causing Potato Common Scab in Korea.

Six representative Korean strains of streptomycetes (S33, S27, S71, S63, S77, and S78) that were pathogenic to potato were characterized based on phenotypic properties, analysis of 16S rRNA genes, production of thaxtomin A, and presence of nec1 and ORFtnp gene homologs. Strains S33 and S27 had typical characteristics of Streptomyces scabies and S. turgidiscabies, respectively, producing thaxtomin A and hybridizing to genes of nec1 and ORFtnp. Strain S71 produced thaxtomin A and had phenotypic and phylogenetic properties similar to those of S. acidiscabies, except having a greater minimum growth pH (4.5), production of a melanoid pigment on tyrosine agar, and failure to hybridize with nec1 and ORFtnp gene probes. In contrast, strains S63, S77, and S78 were phenotypically different from described scab pathogens. Spore colors of strains S63 and S77 were yellow-white or pale orange, respectively, with rectiflexuous chains. Strain S78 had thin and compact spores unlike typical S. acidiscabies (ATCC 49003). Phylogenetic analysis of strains S63, S77, and S78 based on 16S rRNA gene sequences showed low homology to that of described scab pathogens (less than 97.3, 96.0, and 96.3%, respectively). Strain S78 produced thaxtomin A, but did not have homologous sequences to nec1 and ORFtnp genes. Production of thaxtomin A and gene homologs of nec1 and ORFtnp were not detected in strains S63 and S77. All three strains grow at low pH, with minimal growth at pH 3.5 (S77 and S78) or 4.5 (S63). Streptomyces strains S63, S77, and S78 are novel pathogenic streptomycetes adapted to acidic soil conditions in Korea.