Effect of hydrogen peroxide exposures on mucous cells and lysozymes of gill tissues of olive flounder Paralichthys olivaeceus

We investigated the effects of hydrogen peroxide on mucous cells and lysozymes in gill tissue of olive flounder. Morphological analysis revealed significant changes in the number of mucous cells after exposure to 300 and 500 mg L ^{? 1} hydrogen peroxide; however, there was no detectable difference in the 100 mg L ^{? 1} group. Lysozyme activities declined gradually in the gill mucus, but in contrast activities in serum increased significantly following the completion of treatment. The hepatic c‐ and g‐type lysozyme levels showed significant responses, indicating that the liver is a major lysozyme producer in response to stress condition; however, in the head kidney, there were no significant changes in the g‐type lysozyme level in all the groups, while the only detectable difference with the c‐type gene in the 300 mg L ^{? 1}. While the treatments showed no significant changes compared with the control for either branchial lysozyme, there were significant differences in c‐type lysozyme between the 3rd treatment and 5 day. Taken together, our data indicate that hydrogen peroxide treatment may lead to modulation of the innate immune response of olive flounder; therefore, the application of hydrogen peroxide in a field system will require more attention to dose and timing effects.     

Metal levels in street sediment from an industrial city: spatial trends, chemical fractionation, and management implications

Background, aim and scope  Street sediment samples were collected at 50 locations in a mixed land use area of Hamilton, Ontario, Canada, and metal levels were analyzed using a sequential extraction procedure for different particle size classes to provide an estimate of potential toxicity as well as the potential for treatment through best management practices (BMPs). Methodology  The street sediment samples were dry sieved into four different particle size categories and a sequential extraction procedure was done on each size category following the methodology proposed by Tessier et al. 1979 using a Hitachi 180-80 Polarized Zeeman Atomic Absorption Spectrophotometer. Results and discussion  Analysis of variance, post hoc least-significant difference tests, and kriging analysis showed that spatially Mn and Fe levels were associated with a well-defined heavy industrial area that includes large iron- and steel-making operations; Cu and Pb were associated with both the industrial and high-volume traffic areas, while Zn tended to be more associated with high-volume traffic areas. The potential bioavailability of the metals, based on the sum of chemical fractions 1 (exchangeable) and 2 (carbonate-bound), decreased in order: Zn > Cd > Mn > Pb > Cu > Fe. Based on aquatic sediment quality guidelines, there is some concern regarding the potential impact of the street sediment when runoff reaches receiving waters. Conclusions  It is possible that a combination of BMPs, including street sweeping and constructed wetlands, could help to reduce street sediment impact on environmental quality in the Hamilton region. The data presented here would be important in developing and optimizing the design of these BMPs.     

Photosynthetic characteristics of highbush blueberry (Vaccinium corymbosum cv. Bluecrop) leaves in response to water stress and subsequent re-irrigation

SUMMARY

Gas exchange and photosystem II (PSII) activities in the leaves of 2-year-old ‘Bluecrop’ highbush blueberry (Vaccinium corymbosum) were monitored during water stress and subsequent re-irrigation to investigate the effects of the intensity of water stress on changes in photosynthetic characteristics. The blueberry shrubs were not irrigated for 3 to 5 weeks, then re-irrigated daily up to 8 weeks. The decrease in soil water potential during water stress caused a progressive decrease in leaf water potential. Soil water potentials decreased to -0.26 MPa and -0.34 MPa at 3 and 5 weeks, respectively, following water stress, but recovered following subsequent re-irrigation, while the soil water potential in daily-irrigated shrubs was maintained at over -0.13 MPa throughout the experiment. Chlorophyll concentrations decreased with an increasing duration of water stress. Chlorophyll concentrations in leaves on shrubs subjected to water stress for 5 weeks did not recover following re-irrigation, unlike those subjected to water stress for 3 weeks. The leaves on shrubs subjected to water stress for 5 weeks maintained lower levels of chlorophyll during reirrigation. The net rate of CO₂ assimilation (A_n) decreased significantly with an increasing duration of water stress. Reirrigation reversed the decrease in A_n in leaves on shrubs subjected to water stress for 3 weeks. Stomatal conductance (g_s) exhibited a similar pattern to A_n. The actual quantum yield of photosystem II (Φ_PSII) and the electron transport rate (ETR) also decreased significantly with an increasing duration of water stress, although the F_v/F_m ratio was not affected. Φ_PPSII and ETR values in the leaves on shrubs subjected to water stress for 5 weeks did not recover after reirrigation, unlike those subjected to water stress for 3 weeks. Non-photochemical quenching increased with an increasing duration of water stress, but subsequent re-irrigation did not reverse the increase. These results indicate that the timing of re-irrigation of water-stressed ‘Bluecrop’ highbush blueberry is critical in order to maintain their photosynthetic capacity. Among the photosynthetic characteristics measured, Φ_PSII and ETR could be used as sensitive indicators to assess the physiological status of leaves of ‘Bluecrop’ highbush blueberry growing under water stress conditions.     

Effect of different planting times on the quantitative variation of total seed isoflavone content and composition in Korean soybean cultivars (Glycine max (L.) Merr.)

Journal of Crop Science and Biotechnology - There is great interest in the enhancement of isoflavones as one of the functional ingredients in soybean. This study aimed to investigate the effects of...     

Review of rice in Korea: current status,future prospects,and comparisons with rice in other countries

Journal of Crop Science and Biotechnology - Rice has been grown as a staple food in South Korea for several millennia. However, its status has not stayed constant as a result of changes in South...     

Panax ginseng extract rich in ginsenoside protopanaxatriol attenuates blood pressure elevation in spontaneously hypertensive rats by affecting the Akt-dependent phosphorylation of endothelial nitric oxide synthase

Nitric oxide (NO) produced by endothelial nitric oxide synthase (eNOS) is a fundamental regulator of systemic blood pressure. Ginsenosides from Panax ginseng have been investigated in vitro for the molecular and biochemical mechanisms by which they stimulate NO release in vascular endothelial cells; however, little research has been done to confirm the physiological relevance of these in vitro studies. To address this research gap, the effects of a P. ginseng extract rich in ginsenosides from protopanaxatriol on spontaneously hypertensive rats (SHRs) was examined. Ginseng extract administration stimulated nongenomic Akt-mediated eNOS activation, enhanced NO production, improved vessel wall thickening, and alleviated hypertension in SHRs, confirming the physiological relevance of previous in vitro studies with ginsenosides.     

Proteomic identification of a novel toxin protein (Txp40) from Xenorhabdus nematophila and its insecticidal activity against larvae of Plutella xylostella

For the identification of a novel insecticidal protein, a two-dimensional liquid chromatography (PF-2D) system was used in a quantitative proteomic analysis of Xenorhabdus nematophila CBNU strain isolated from entomophagous nematode Steinernema carpocapsae . Protein patterns obtained from minimum and maximum insecticidal activities during cultivation were contrasted, and a novel toxin protein (Txp40) was identified by MALDI-TOF/MS. The DNA sequence of the cloned toxin gene (1089 bp) has an open reading frame encoding 363 amino acids with a predicted molecular mass of 41162 Da. The txp40 identified in this study is most closely related to the known txp40 cloned from X. nematophila EB (ADQ92844) with 94.4% identical sequence residues. Following the expression of the newly identified toxin gene in Escherichia coli , the insecticidal activity of the recombinant toxin protein was determined against Plutella xylostella larvae; a 56.7% mortality rate was observed within 24 h.     

Mass production of rubusoside using a novel stevioside-specific β-glucosidase from Aspergillus aculeatus

Rubusoside (R) is a natural sweetener and a solubilizing agent with antiangiogenic and antiallergic properties. However, currently, its production is quite expensive, and therefore, we have investigated nine commercially available glycosidases to optimize an economically viable R-production method. A stevioside (ST)-specific β-glucosidase (SSGase) was selected and purified 7-fold from Aspergillus aculeatus Viscozyme L by a two-step column chromatography procedure. The 79 kDa protein was stable from pH 3.0 to pH 7.0 at 50-60 °C. Hydrolysis of ST by SSGase produced R and steviol monoglucosyl ester as determined by (1)H and (13)C nuclear magnetic resonance (NMR). Importantly, SSGase showed higher activity toward ST than other β-linked glucobioses. The optimal conditions for R production were 280 mM ST and 16.6 μL of SSGase at pH 5.1 and 63 °C. This is the first discussion detailing the production of R by enzymatic hydrolysis of ST and is useful for the food additive and pharmaceutical industries.     

Metabolic Profiling of Glucosinolates, Anthocyanins, Carotenoids, and Other Secondary Metabolites in Kohlrabi (Brassica oleracea var. gongylodes)

We profiled and quantified glucosinolates, anthocyanins, carotenoids, and other secondary metabolites in the skin and flesh of pale green and purple kohlrabis. Analysis of these distinct kohlrabis revealed the presence of 8 glucosinolates, 12 anthocyanins, 2 carotenoids, and 7 phenylpropanoids. Glucosinolate contents varied among the different parts and types of kohlrabi. Glucoerucin contents were 4-fold higher in the flesh of purple kohlrabi than those in the skin. Among the 12 anthocyanins, cyanidin 3-(feruloyl)(sinapoyl) diglucoside-5-glucoside levels were the highest. Carotenoid levels were much higher in the skins than the flesh of both types of kohlrabi. The levels of most phenylpropanoids were higher in purple kohlrabi than in pale green ones. trans-Cinnamic acid content was 12.7-fold higher in the flesh of purple kohlrabi than that in the pale green ones. Thus, the amounts of glucosinolates, anthocyanins, carotenoids, and phenylpropanoids varied widely, and the variations in these compounds between the two types of kohlrabi were significant.     

Growth-Inhibitory Effects of Pigmented Rice Bran Extracts and Three Red Bran Fractions against Human Cancer Cells: Relationships with Composition and Antioxidative Activities

We determined the phenolic, anthocyanin, and proanthocyanidin content of three brown, purple, and red rice brans isolated from different rice varieties using HPLC-PDA with the aid of 27 standards of known structure and matching unknown peaks to a spectral library of known compounds. Antioxidative capacities were determined by DPPH and ORAC and cell-inhibiting effects using an MTT assay. Based on the calculated IC(50) values, the light-brown bran had no effect, the purple bran exhibited a minor effect on leukemia and cervical cancer cells, and the red bran exhibited strong inhibitory effects on leukemia, cervical, and stomach cancer cells. High concentrations of protocatechuic acid and anthocyanins in purple bran and proanthocyanidins in red bran were identified. The red bran was further fractionated on a Sephadex column. Fraction 3 rich in proanthocyanidin oligomers and polymers had the greatest activity. Red bran has the potential to serve as a functional food supplement for human consumption.