Competition between inoculum and native rhizobia for nodulation of cowpea (Vigna unguiculata (L) Walp): Use of a dark-nodule strain

Summary Cowpea rhizobia strains were examined with indigenous populations in nodulating cowpea (Vigna unguiculata (L) Walp) cv. Laura B. strain IRC256 formed dark nodules on cowpea, and were used as the standard against orthodox pink-nodule strains in evaluating nodulating competitiveness. The dark nodule phenotype and intrinsic antibiotic resistance pattern were used to identify the strains in the nodules. Our results showed the usefulness of the dark-nodule strain in evaluating nodulating competitiveness of cowpea rhizobia in soils where dark-nodule strains were not indigenous.     

The Thiol-Modifier Effects of Organoselenium Compounds and Their Cytoprotective Actions in Neuronal Cells

Neurochemical Research - Most pharmacological studies concerning the beneficial effects of organoselenium compounds have focused on their ability to mimic glutathione peroxidase (GPx). However,...     

Changes in rubisco content in relation to saccharides accumulation in wheat leaves during day

Two wheat varieties, T. durum (HD 4502) and T. aestivum (Kalyansona) were examined for photosynthesis rate and contents of sugars and rubisco protein in the flag leaf, at forenoon and afternoon at anthesis stage. A decrease in photosynthesis rate was observed in the afternoon compared to forenoon in both the varieties and was associated with an increase in non-reducing sugars and a decrease in rubisco content in the leaves.     

Select Small Core Structure Carbamates Exhibit High Contact Toxicity to ��Carbamate-Resistant�� Strain Malaria Mosquitoes, Anopheles gambiae (Akron)

Acetylcholinesterase (AChE) is a proven target for control of the malaria mosquito (Anopheles gambiae). Unfortunately, a single amino acid mutation (G119S) in An. gambiae AChE-1 (AgAChE) confers resistance to the AChE inhibitors currently approved by the World Health Organization for indoor residual spraying. In this report, we describe several carbamate inhibitors that potently inhibit G119S AgAChE and that are contact-toxic to carbamate-resistant An. gambiae. PCR-RFLP analysis was used to confirm that carbamate-susceptible G3 and carbamate-resistant Akron strains of An. gambiae carry wild-type (WT) and G119S AChE, respectively. G119S AgAChE was expressed and purified for the first time, and was shown to have only 3% of the turnover number (k _cat) of the WT enzyme. Twelve carbamates were then assayed for inhibition of these enzymes. High resistance ratios (>2,500-fold) were observed for carbamates bearing a benzene ring core, consistent with the carbamate-resistant phenotype of the G119S enzyme. Interestingly, resistance ratios for two oxime methylcarbamates, and for five pyrazol-4-yl methylcarbamates were found to be much lower (4- to 65-fold). The toxicities of these carbamates to live G3 and Akron strain An. gambiae were determined. As expected from the enzyme resistance ratios, carbamates bearing a benzene ring core showed low toxicity to Akron strain An. gambiae (LC₅₀>5,000 μg/mL). However, one oxime methylcarbamate (aldicarb) and five pyrazol-4-yl methylcarbamates (4a–e) showed good to excellent toxicity to the Akron strain (LC₅₀ = 32–650 μg/mL). These results suggest that appropriately functionalized “small-core” carbamates could function as a resistance-breaking anticholinesterase insecticides against the malaria mosquito.     

Angiopoietins have distinct modular domains essential for receptor binding,dimerization and superclustering

Angiopoietins are a recently discovered family of angiogenic factors that interact with the endothelial receptor tyrosine kinase Tie2, either as agonists (angiopoietin-1) or as context-dependent agonists/antagonists (angiopoietin-2). Here we show that angiopoietin-1 has a modular structure unlike any previously characterized growth factor. This modular structure consists of a receptor-binding domain, a dimerization motif and a superclustering motif that forms variable-sized multimers. Genetic engineering of precise multimers of the receptor-binding domain of angiopoietin-1, using surrogate multimerization motifs, reveals that tetramers are the minimal size required for activating endothelial Tie2 receptors. In contrast, engineered dimers can antagonize endothelial Tie2 receptors. Surprisingly, angiopoietin-2 has a modular structure and multimerization state similar to that of angiopoietin-1, and its antagonist activity seems to be a subtle property encoded in its receptor-binding domain.     

Mitochondrial respiratory chain dysfunction in ageing; influence of vitamin E deficiency

The causes and consequences of ageing are likely to be complex and involve the interaction of many processes. It has been proposed that the decline in mitochondrial function caused by the accumulation of oxidatively damaged molecules plays a significant role in the ageing process. In agreement with previous reports we have shown that the activities of NADH CoQ₁ reductase and cytochrome oxidase declined with increasing age in both rat liver and gastrocnemius muscle mitochondria. However, only in the liver were the changes in lipid peroxidation and membrane fluidity suggestive of an age-related increase in oxidative stress.

After 12 weeks on a vitamin E deficient diet, vitamin E levels were undetectable in both gastrocnemius muscle and liver. In skeletal muscle, this was associated with a statistically significant increase in lipid peroxidation, a decrease in cytochrome oxidase activity after 48 weeks, and an exacerbation in the age-related rate of decline of NADH CoQ₁ reductase activity. This was consistent with the suggestion that an imbalance between free radical generation and antioxidant defence may contribute to the mitochondrial dysfunction with age. In contrast to this, vitamin E deficiency in the liver caused a significant increase in mitochondrial respiratory chain activities with increasing age despite evidence of increased lipid peroxidation. Comparison of other features in these samples suggested vitamin E deficiency; did not have a significant impact upon mtDNA translation; induced a compensatory increase in glutathione levels in muscle, which was less marked in the liver, but probably most interestingly caused a significant decrease in the mitochondrial membrane fluidity in muscle but not in liver mitochondria.

These data suggest that while increased lipid peroxidation exacerbated the age-related decline in muscle respiratory chain function this relationship was not observed in liver. Consequently other factors are likely to be contributing to the age-related decline in mitochondrial function and specific stimuli may influence or even reverse these age-related effects as observed with vitamin E deficiency in the liver.     

Ellis–van Creveld syndrome and profound deafness resulted by sequence variants in the <Emphasis Type="Italic">EVC</Emphasis> / <Emphasis Type="Italic">EVC2</Emphasis> and <Emphasis Type="BoldItalic">TMC1</Emphasis> genes

Ellis–van Creveld syndrome is an autosomal recessive skeletal dysplasia primarily characterized by the features such as disproportionate dwarfism, short ribs, short limbs, dysplastic nails, cardiovascular malformations, post-axial polydactyly (PAP) (bilateral) of hands and feet. EVC/EVC2 located in head-to-head arrangement on chromosome 4p16 are the causative genes for EvC syndrome. In the study, we present two families, A and B, with Pakistani and Republic of Kosovo origin, respectively. They showed features of EvC syndrome and were clinically and genetically characterized. In family A, the affected members showed an additional feature of profound deafness. The whole exome sequencing (WES) in this family revealed two homozygous variants in EVC2 (c.30dupC; p.Thr11Hisfs*45) and TMC1 (\(\hbox {c}.1696\hbox {-}1\hbox {G}{>}\hbox {A}\)) genes. In family B, WES revealed novel compound heterozygous variants (p.Ser307Pro, \(\hbox {c}.2894{+}3\hbox {A}{>}\hbox {G}\)) in the EVC gene. This study reports first case of variants in the genes causing EvC syndrome and profound deafness in the same family.     

Morpho-anatomical and physiological attributes for salt tolerance in sewan grass (Lasiurus scindicus Henr.) from Cholistan Desert,Pakistan

Three differently adapted populations of sewan grass (Lasiurus scindicus Henr.) were evaluated for structural and functional adaptations to high salinity. The habitats were Derawar Fort (DF, least saline, ECe 15.21), Bailahwala Dahar (BD, moderately saline, ECe 27.56 dS m^?1) and Ladam Sir (LS, highly saline, ECe 39.18 dS m^?1) from within the Cholistan Desert. The adaptive components of salt tolerance in sewan grass were assessed by determining various morpho–anatomical and physiological attributes. The degree of salt tolerance of all three ecotypes of L. scindicus from the saline habitats was compared in a controlled hydroponic system to evaluate the adaptive components that are expected to be genetically fixed during a long evolutionary process. Salinity tolerance in the most tolerant LS population relied on increased root length and total leaf area, restricted uptake of toxic Cl^?, increased uptake of Ca²⁺, high excretion of Na⁺, accumulation of organic osmolytes, high water use efficiency, increased root, thicker leaf and cortical region, intensive sclerification, large metaxylem vessels, and dense pubescence on abaxial leaf surface. The BD population (from moderately saline soil) relied on high Ca²⁺ uptake, Na⁺ excretion, epidermal thickness, large cortical cells, thick endodermis and large vascular tissue. The DF population (from less saline soil) showed a significant decrease in all morphological characteristics; however, it accumulated organic osmolytes for its survival under high salinities. Structural modifications in all three populations were crucial for checking undue water loss under physiological stress that is caused by high amounts of soluble salts in the soil.     

Two-sex life table and predation rate of Cybocephalus flavocapitis Smith (Coleoptera: Cybocephalidae) reared on Aulacaspis yasumatsui Takagi (Hemiptera: Diaspididae), in Taiwan

Development, survival, and fecundity of the predator, Cybocephalus flavocapitis Smith, reared on its host Aulacaspis yasumatsui Takagi, were studied at 24 °C, 70 ± 10% RH, and photoperiod of 12:12 (L:D) h under laboratory conditions. Developmental periods for egg, larval, and pupal stages were 6.4, 12.1 and 14.3 d, respectively. The mean longevity of adults was 85.1 d. Raw life history data of all individuals were pooled and analyzed according to the age-stage, two-sex life table theory. The intrinsic rate of increase (r) was 0.05 d^? 1, the finite rate of increase (λ) was 1.05 d^? 1, the net reproductive rate (R₀) was 29.1 offspring, and the mean generation time (T) was 63.3 d. When we incorporated the age-stage variability of predation rate with the two-sex life table, our results indicated that the predation rates of larvae and adults were 743 eggs and 1595 scales, respectively. The net predation rate of C. flavocapitis is 1874 scales. Additionally, we compared life table results of C. flavocapitis with those of a previous life table study on Cybocephalus nipponicus because both species are currently used for the biological control of A. yasumatsui in Taiwan.