Differences in physiological responses to NaCl between salt-tolerant Sesbania rostrata Brem. & Oberm. and non-tolerant Phaseolus vulgaris L.

Sesbania rostrata ( S. rostrata) Brem. & Oberm., a member of the Fabaceae family, has been used as a promising halophytic plant to ameliorate soil salinity in north-east Thailand. To obtain information regarding the mechanism of salt tolerance, the physiological responses of S. rostrata to NaCl was compared with those of the salt-susceptible species, kidney bean ( Phaseolus vulgaris L. cv. Meal). Seedlings were grown hydroponically with 0, 50, 100 and 150 m m NaCl for 10 days and their effects on growth, chlorophyll content, fluorescence yield ( F _v/ F _m), inorganic elements and amino acid content were determined. The results showed that tolerance to NaCl was clearly different between the two plants. At the highest concentration (150 m m ), the dry weight of S. rostrata was more than 50% greater than the control, whereas the kidney bean could not survive. Chlorophyll a content drastically reduced only in the kidney bean. The F _v/ F _m of S. rostrata did not change with increasing concentrations of NaCl, but that of kidney bean decreased. Greater percentages (≥80%) of absorbed Na⁺ and Cl^– were translocated and accumulated in the shoots of S. rostrata , but remained largely in the roots of kidney bean. The enhancement of contents of amino acids, including proline, with increasing NaCl was observed in both species. These results strongly suggest that the salt tolerance of S. rostrata is associated with the ability of the plant to translocate and sequester Na⁺ and Cl^– in the shoot cells.     

Differential safening activity of dymron and fenclorim on pretilachlor injury in rice seedlings in soil

The safening activity of dymron [1-(α,α-dimethylbenzyl)-3-( p -tolyl)urea] and fenclorim [4,6-dichloro-2-phenylpyrimidine] on the phytotoxic activity of pretilachlor [2-chloro-2',6'-diethyl- N- (2-propoxyethyl)acetanilide] on rice seedlings was examined in both water and soil culture. The safening activity of fenclorim in water culture was greater than that of dymron, whereas the activity of fenclorim in soil was lower than that of dymron. The fenclorim concentration in soil water was lower than that of dymron at all times when determined after the application at the same concentrations. The phytotoxic activity of pretilachlor and the safening activities of dymron and fenclorim were well correlated with the concentration of each in soil water but not with the amount in total soil. The adsorption of fenclorim on soil solids was greater than those of dymron and pretilachlor. It was suggested that both the phytotoxic activity of pretilachlor and the safening activities of dymron and fenclorim were dependent on their concentrations in soil water, which were primarily dominated by the adsorption on soil.     

Lipoprotein cholesterol and triglyceride concentrations associated with dog body condition score; effect of recommended fasting duration on sample concentrations in Japanese private clinics

The objectives of this study were to survey clinics’ guidance about recommended fasting duration (FD) prior to lipoprotein analysis, and to characterize lipoprotein cholesterol and triglyceride concentrations in obese and overweight dogs categorized on the basis of the 5-point body condition score (BCS) scale. A dataset was created from lipoprotein analysis medical records of 1,538 dogs from 75 breeds in 354 clinics from 2012 to 2013. A phone survey was conducted to obtain the clinics’ FD. Two-level linear mixed-effects models were applied to the data. Over 50% of the clinics said they recommended fasting for 12 hr or more. Dogs in clinics with FD 12 hr or more had lower chylomicron triglyceride concentrations than those in clinics with FD less than 8 hr (P=0.05). Mean (± SEM) BCS at sampling was 3.7 ± 0.02. Obese and overweight dogs had higher very low density lipoprotein (VLDL) and high density lipoprotein (HDL) cholesterol and triglyceride concentrations than ideal dogs (P<0.05), but no such difference was found for low density lipoprotein cholesterol and triglyceride concentrations (P≥0.07). Across all BCS, as dog age rose from 0 to 8 years old, HDL cholesterol concentrations decreased by 13.5 mg/dl, whereas VLDL triglyceride concentrations increased by 81.7 mg/dl (P<0.05). In conclusion, FD of 8 hr or less may affect lipoprotein lipid concentrations. Obese and overweight dogs were characterized as having high VLDL and HDL cholesterol and triglyceride concentrations.     

A globotetraosylceramide (Gb4) receptor-based ELISA for quantitative detection of Shiga toxin 2e

Currently, no simple assays are available for routine quantitative detection of Escherichia coli-produced Shiga toxin 2e (Stx2e) that causes porcine edema disease. Here, we present a novel quantitative detection method for Stx2e based on the measurement of Stx2e binding to the specific globotetraosylceramide (Gb₄) receptor by ELISA (Gb₄-ELISA). No cross-reactivity was found with the other Shiga toxins Stx1 and Stx2, indicating high specificity. When the recombinant Stx2e B subunit (Stx2eB) was used, the absorbance measured by Gb₄-ELISA increased linearly with Stx2eB concentration in the range of 20–2,500 ng/ml. The Gb₄-ELISA method can be easily performed, suggesting that it would be a useful diagnostic tool for porcine edema disease.     

追肥与收获时期对水稻产量和品质影响的研究

通过不同追肥与收获处理对水稻"黄金米"品种的产量、蛋白质含量、直链淀粉含量、食味品质以及外观商品品质的影响进行了研究.结果表明,追肥时期以幼穗形成期最好;追肥量越多,产量越高.蛋白质含量越高,食口品质越差,20 Kg/hm2追肥量(纯N)最适;抽穗后41 d收获食味品质最优;追肥时期、追肥量与直链淀粉含量高低无关.     

Inheritance of resistance to brown leaf spot disease in gentians

Brown leaf spot caused by Mycochaetophora gentianae is a serious disease on gentian in Japan. Previous studies revealed that Gentiana triflora cultivars were susceptible to M. gentianae and that G. scabra cultivars and their interspecific hybrid cultivars were resistant. We subsequently analyzed the mode of inheritance of resistance to M. gentianae in gentians using several populations derived from crosses between G. scabra and G. triflora. Parental G. scabra and G. triflora lines, F₁ and BC₁ plants were inoculated with a conidial suspension and assessed for susceptibility to M. gentianae. All tested F₁ plants were resistant to M. gentianae, indicating that the resistance of G. scabra was inherited dominantly. Segregation ratios in backcross progenies using G. scabra line OK fit the Mendelian ratio of 1:1, showing the involvement of a single dominant locus. These results indicate that the resistance to M. gentianae in G. scabra line OK is controlled by a single dominant allele designated as gentian brown leaf spot resistance (GBLS-1). Finding this allele should facilitate future breeding efforts to develop resistant gentian cultivars.     

Differentiation of skeletal muscle Mesenchymal progenitor cells to myofibroblasts is reversible

Accumulation of intramuscular adipose tissue (IMAT) and development of fibrous tissues due to accumulation of collagen both affect meat quality such as tenderness, texture, and flavor. Thus, it is important for the production of high‐quality meat to regulate the amount of adipose and fibrous tissues in skeletal muscle. IMAT is comprised of adipocytes, while collagens included in fibrous tissues are mainly produced by activated fibroblasts. Both adipocytes and fibroblasts are differentiated from their common ancestors, called mesenchymal progenitor cells (MPC). We previously established rat MPC clone, 2G11 cells. As several reports implicated the plasticity of fibroblast differentiation, in the present study, using 2G11 cells, we asked whether myofibroblasts differentiated from MPC are capable of re‐gaining adipogenic potential in vitro. By treating with bFGF, their αSMA expression was reduced and adipogenic potential was restored partially. Furthermore, by lowering cell density together with bFGF treatment, 2G11 cell‐derived myofibroblasts lost αSMA expression and showed the highest adipogenic potential, and this was along with their morphological change from flattened‐ to spindle‐like shape, which is typically observed with MPC. These results indicated that MPC‐derived myofibroblasts could re‐acquire adipogenic potential, possibly mediated through returning to an undifferentiated MPC‐like state.     

Hydroxytyrosol induces proliferation and cytoprotection against oxidative injury in vascular endothelial cells: role of Nrf2 activation and HO-1 induction

Hydroxytyrosol (HT), a phenolic compound in olive oil and leaves, has been reported to prevent various human pathologies including cardiovascular diseases. This study investigated the effects of HT on proliferation and protection against oxidative stress-induced damage in vascular endothelial cells (VECs) and the molecular mechanism(s) involved. Treatment of VECs with HT increased cell proliferation, promoted wound repair, and protected cells against H(2)O(2) cytotoxicity through the activation of Akt and ERK1/2, but not p38 MAPK. HT increased the expression and nuclear translocation of nuclear factor-E2-related factor-2 (Nrf2). Nrf2 expression was attenuated by LY294002 and U0126, inhibitors of phosphatidylinositol-3-kinase and MEK1/2, respectively. Nrf2 siRNA decreased both proliferative and cytoprotective effects of HT and abrogated HO-1 induction. Moreover, HO-1 inhibition with HO-1 siRNA or zinc protoporphyrin IX significantly prevented HT-induced cell proliferation, cytoprotection, and reduction in intracellular reactive oxygen species (ROS), suggesting that HO-1 is involved in these HT functions. The findings demonstrate that HT positively regulates the antioxidant defense system in VECs through the activation of Nrf2 followed by cell proliferation and resistance to vascular injury. The present study provides a molecular basis for the contribution of HT in the Mediterranean diet to the prevention of cardiovascular diseases.     

Protein structures forming the shell of primitive bacterial organelles

Bacterial microcompartments are primitive organelles composed entirely of protein subunits. Genomic sequence databases reveal the widespread occurrence of microcompartments across diverse microbes. The prototypical bacterial microcompartment is the carboxysome, a protein shell for sequestering carbon fixation reactions. We report three-dimensional crystal structures of multiple carboxysome shell proteins, revealing a hexameric unit as the basic microcompartment building block and showing how these hexamers assemble to form flat facets of the polyhedral shell. The structures suggest how molecular transport across the shell may be controlled and how structural variations might govern the assembly and architecture of these subcellular compartments.