Cytophysiological impacts of Metosulam herbicide on Vicia faba plants

The hazardous potential of the Metosulam herbicide, particularly the cytogenetic and physiological effects on Vicia faba cv Assuit 25 plants has been studied. The results showed that the mitotic index (MI) decreased and chromosomal aberrations frequency increased by increasing of the concentration of herbicide and prolonging the duration of treatment. In the roots treated with highest concentration used (1 × 10^?5 %) for 24 h, complete inhibition of cell division was observed. The chromosomal anomalies include chromosomal bridges and breaks that are regarded were indicative of a mutagenic potential of the herbicide. Seedling growth (fresh and dry weight) adversely affected as the duration and concentration of Metosulam herbicide increased. Soluble sugars, soluble proteins, total free amino acids and photosynthetic pigment content decreased significantly in root, stem and leaves of Vicia faba with increasing both the herbicide concentration and treatment duration. In contrast, proline content was highly accumulated, especially at the highest concentration (10^?4 %) and the longest duration used (24 h). The results of antioxidant enzymes reveal that while the peroxidase activity decreased by increasing the concentration of herbicide and duration, the activities of catalase and ascorbate peroxidase increased.     

Assessment of soil contamination caused by underground fuel leakage from selected gas stations in Riyadh,Saudi Arabia

ABSTRACT

Spills and leakage from underground fuel storage tanks (UFSTs) can potentially contaminate soil and groundwater and pose harmful effects to public health and the environment. This study evaluated the feasibility of using volatile organic compounds (VOCs), total petroleum hydrocarbons (TPHs), electrical conductivity (EC), and pH to examine the contamination caused by leaking UFSTs. Screening water assessments for VOCs and general water quality parameters were conducted on the premises of 53 gas stations in Riyadh, Saudi Arabia, to identify potentially contaminated sites, and 25 ground bores were drilled for the quantification of TPH concentrations, EC, and pH values in 407 soil samples. The experimental approach followed in this study included geochemical analyses based on borehole drilling at five targeted gas stations, analyses of water samples from underground storage reservoirs, and analyses of soil core samples obtained from different depths to determine the degree of TPH contamination. Thirty-five VOCs were identified in the water samples collected from gas stations. Methylene chloride, tribromomethane, toluene, chlorobenzene, dibromochloromethane, and benzene were frequently encountered in most of the water samples. Some of these samples exceeded the World Health Organization and Saudi Arabian guidelines for acceptable levels of pH, total dissolved solids, chloride, nitrate, sulfate, calcium, and total hardness. The measured TPH levels were clearly indicative of subsoil contamination and subsequent accumulation in soil over time, particularly at depths of 1–6 m; there was not a noticeable dependence or impact on pH.     

Multienvironment genomic variance decomposition analysis of open-pollinated Interior spruce (<Emphasis Type="Italic">Picea glauca</Emphasis> x <Emphasis Type="Italic">engelmannii</Emphasis>)

The advantages of open-pollinated (OP) family testing over controlled crossing (i.e., structured pedigree) are the potential to screen and rank a large number of parents and offspring with minimal cost and efforts; however, the method produces inflated genetic parameters as the actual sibling relatedness within OP families rarely meets the half-sib relatedness assumption. Here, we demonstrate the unsurpassed utility of OP testing after shifting the analytical mode from pedigree- (ABLUP) to genomic-based (GBLUP) relationship using phenotypic tree height (HT) and wood density (WD) and genotypic (30k SNPs) data for 1126 38-year-old Interior spruce (Picea glauca (Moench) Voss x P. engelmannii Parry ex Engelm.) trees, representing 25 OP families, growing on three sites in Interior British Columbia, Canada. The use of the genomic realized relationship permitted genetic variance decomposition to additive, dominance, and epistatic genetic variances, and their interactions with the environment, producing more accurate narrow-sense heritability and breeding value estimates as compared to the pedigree-based counterpart. The impact of retaining (random folding) vs. removing (family folding) genetic similarity between the training and validation populations on the predictive accuracy of genomic selection was illustrated and highlighted the former caveats and latter advantages. Moreover, GBLUP models allowed breeding value prediction for individuals from families that were not included in the developed models, which was not possible with the ABLUP. Response to selection differences between the ABLUP and GBLUP models indicated the presence of systematic genetic gain overestimation of 35 and 63% for HT and WD, respectively, mainly caused by the inflated estimates of additive genetic variance and individuals’ breeding values given by the ABLUP models. Extending the OP genomic-based models from single to multisite made the analysis applicable to existing OP testing programs.     

First report of detection of the putative receptor of Bacillus thuringiensis toxin Vip3Aa from black cutworm (Agrotis ipsilon)

Black cutworm (BCW) Agrotis ipsilon, an economically important lepidopteran insect, has attracted a great attention. Bacillus thuringiensis (Bt) is spore forming soil bacteria and is an excellent environment-friendly approach for the control of phytophagous and disease-transmitting insects. In fact, bio-pesticide formulations and insect resistant transgenic plants based on the bacterium Bt delta-endotoxin have attracted worldwide attention as a safer alternative to harmful chemical pesticides. The major objective of the current study was to understand the mechanism of interaction of Bt toxin with its receptor molecule(s). The investigation involved the isolation, identification, and characterization of a putative receptor – vip3Aa. In addition, the kinetics of vip toxin binding to its receptor molecule was also studied. The present data suggest that Vip3Aa toxin bound specifically with high affinity to a 48-kDa protein present at the brush border membrane vesicles (BBMV) prepared from the midgut epithelial cells of BCW larvae.     

CASP4/caspase-11 promotes autophagosome formation in response to bacterial infection

CASP4/caspase-11-dependent inflammasome activation is important for the clearance of various Gram-negative bacteria entering the host cytosol. Additionally, CASP4 modulates the actin cytoskeleton to promote the maturation of phagosomes harboring intracellular pathogens such as Legionella pneumophila but not those enclosing nonpathogenic bacteria. Nevertheless, this non-inflammatory role of CASP4 regarding the trafficking of vacuolar bacteria remains poorly understood. Macroautophagy/autophagy, a catabolic process within eukaryotic cells, is also implicated in the elimination of intracellular pathogens such as Burkholderia cenocepacia. Here we show that CASP4-deficient macrophages exhibit a defect in autophagosome formation in response to B. cenocepacia infection. The absence of CASP4 causes an accumulation of the small GTPase RAB7, reduced colocalization of B. cenocepacia with LC3 and acidic compartments accompanied by increased bacterial replication in vitro and in vivo. Together, our data reveal a novel role of CASP4 in regulating autophagy in response to B. cenocepacia infection.     

Scenedesmus obliquus: Antioxidant and antiviral activity of proteins hydrolyzed by three enzymes

Purpose

To obtain protein hydrolysates from fresh water green algae Scenedesmus obliquus by three different enzymes and evaluate its antioxidant and antiviral activity.

Effects of UV-C radiation on <Emphasis Type="Italic">Chlorella vulgaris</Emphasis>, a biofilm-forming alga

Photosynthetic biofilms proliferating on heritage monuments represent a major threat for curators leading to biodegradation and esthetic issues. Previous studies demonstrated that UV-C, used as a tool for biofilm eradication, is a promising avenue to combat microbial proliferation. In this study, this environmentally friendly method was tested on biofilm-forming Chlorella vulgaris suspension. Algal physiological response to UV-C was then assessed. Results showed that >?10 kJ m^?2 UV-C exposure was enough to directly kill cells whereas low UV-C exposure reduced quantum yield of photosystem II and inhibited both respiration and photosynthesis. Clear relationships between UV-C exposure times and physiological responses were found. In addition, the use of VIS-light after UV-C treatment enhances chlorophyll bleaching. Our findings contribute to a better understanding of the physiological responses of Chlorella vulgaris to UV-C radiation allowing thus an optimization of the UV-C treatment reported in our previous studies.     

Characterization of the mouseTcra-V22 gene subfamily

 T-cell receptors (Tcrs) of higher organisms play a key role in the specific recognition of self and non-self molecules in the immune system. The large number of Tcr variable (V) genes have been organized into V gene subfamilies according to their sequence similarity at the nucleotide and amino acid level. We cloned and characterized four new members of the Tcra-V22 gene subfamily at the genomic level using a simple and sensitive technique that can rapidly clone members of any multi-member gene family. Sequence analysis reveals that the four Tcra-V22 gene subfamily members have more than 98% sequence similarity in their coding regions, at the nucleotide and amino acid levels. However, the intron between the leader and the coding region varies up to 7% between members of the Tcra-V22 gene subfamily. Comparison of the multi-member Tcra-V22 gene subfamily with other multi-member Tcra-V gene subfamilies (V2, V8, and V11), shows that Tcra-V22 is unique in that it has multiple members with nearly identical amino acid sequence and which are not inherently pseudogenes. Sequence similarity analysis of the Tcra-V22 subfamily with the prototypes of all other Tcra-V subfamilies revealed that the Tcra-V22 subfamily has the closest sequence similarity to that of Tcra-V18 (77% at the nucleotide level and 71% at the amino acid level). Received: 22 March 1996 / Revised: 5 June 1996     

Activated Kupffer cells attenuate the liver response to the peroxisome proliferator perfluorooctanoic acid

It has been suggested that peroxisome proliferators stimulate Kupffer cells, an effect which may be involved in their mechanism of action. To evaluate this hypothesis, this study was designed to investigate the effect of stimulating Kupffer cells on basal as well as induced peroxisomal enzyme activity. Twenty four hours following treatment of male Sprague-Dawley rats with the peroxisome proliferating agent perfluorooctanoic acid (PFOA), in corn oil or with corn oil alone, hepatic peroxisomal -oxidation was 4.6 ± 0.2 and 1.8 ± 0.1 U/g liver, respectively. As expected, PFOA did not influence the catalase activity. Stimulating Kupffer cells in vivo by zymosan A (25 mg/kg, iv) prior to treatment with corn oil or PFOA diminished basal as well as PFOA-induced peroxisomal b-oxidation by 20-35%. Activation of Kupffer cells by zymosan A also diminished catalase activity by over 60%. Furthermore, PFOA reduced blood colloidal carbon clearance by 35% within 2 h of its administration. The data suggest that activation of Kupffer cells exerts a negative effect on basal as well as PFOA-induced peroxisomal enzyme activities. Data also suggest that PFOA inhibits Kupffer cells. Activated Kupffer cells may indeed produce factors which interfere with normal hepatic peroxisomal functions and responses.     

Association of IL‐37 gene polymorphisms with susceptibility to tuberculosis in Saudi subjects

Tuberculosis (TB) is one of the most common infectious diseases worldwide. IL‐37, a novel member of the IL‐1 family, has anti‐inflammatory activity. Various cytokine genes polymorphisms are reportedly associated with susceptibility to TB infection. However, an association between genetic variations in the IL‐37 gene and susceptibility to TB infection has not been investigated. The aim of this case‐control study was therefore to identify such an association in Saudi subjects, in which five single‐nucleotide polymorphisms (SNPs) in the IL‐37 gene were assessed. Serum concentrations of IL‐37 were evaluated using ELISA, and genetic variants genotyped by multiplex PCR and ligase detection reaction. It was found that the C/C genotype of rs2723176 (–6962 A/C) occurs significantly more frequently in patients with active TB and that the C allele of this SNP is associated with TB. In addition, the C allele of rs2723176 SNP was associated with high circulating concentrations of IL‐37. However, the genotype and allele frequency of the other four SNPs (rs3811046, rs3811047, rs2723186 and rs2723187) were not significantly associated with TB infection. In conclusion, the present data suggest that rs2723176 SNP of IL‐37 is involved in the development of TB infection. Furthermore, high circulating concentrations of IL‐37 may have a negative effect on protective immunity against TB infection.