ERRγ Preserves Brown Fat Innate Thermogenic Activity

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Transcriptome and physiological analyses reveal that AM1 as an ABA-mimicking ligand improves drought resistance in <Emphasis Type="Italic">Brassica napus</Emphasis>

Abscisic acid (ABA) is the most important stress hormone in the regulation of plant adaptation to drought. Owing to the chemical instability and rapid catabolism of ABA, ABA mimic 1 (AM1) is frequently applied to enhance drought resistance in plants, but the molecular mechanisms governed by AM1 on improving drought resistance in Brassica napus are not entirely understood. To investigate the effect of AM1 on drought resistance at the physiological and molecular levels, exogenous ABA and AM1 were applied to the leaves of two B. napus genotypes (Q2 and Qinyou 8) given progressive drought stress. The results showed that the leaves of 50 µM ABA- and AM1-treated plants shared over 60% differential expressed genes and 90% of the enriched functional pathways in Qinyou 8 under drought. AM1 affected the expression of the genes involved in ABA signaling; they down-regulated pyrabactin resistance/PYR1-like (PYR/PYLs), up-regulated type 2C protein phosphatases (PP2Cs), partially up-regulated sucrose non-fermenting 1-related protein kinase 2s (SnRK2s), and down-regulated ABA-responsive element (ABRE)-binding protein/ABRE-binding factors (AREB/ABFs). Additionally, AM1 treatment repressed the expression of photosynthesis-related genes, those mainly associated with the light reaction process. Moreover, AM1 decreased the stomatal conductance, the net photosynthetic rate, and the transpiration rate, but increased the relative water content in leaves and increased survival rates of two genotypes under drought stress. Our findings suggest that AM1 has a potential to improve drought resistance in B. napus by triggering molecular and physiological responses to reduce water loss and impair growth, leading to increased survival rates.     

Influence of supplemental ultraviolet-B on indoleacetic acid and calmodulin in the leaves of rice (Oryza sativa L.)

IR68 and Dular rice cultivars were grown under ambient, 13.0 (simulating 20% ozone depletion) and 19.1 (simulating 40% ozone depletion) kJ m^-2 day^-1 of biologically effective ultraviolet-B (UV-B_BE) for 4 weeks. Plant height and leaf area were significantly reduced by supplemental UV-B_BE radiation. Greater reduction in leaf area than of plant height was observed. A decrease in indole-3-acetic acid (IAA) content and increase in peroxidase and IAA oxidase activities of UV-B treated plants in both cultivars were observed compared with ambient control. Calmodulin content also decreased after plants were treated with high supplemental UV-B for two weeks and medium UV-B treatment for four weeks. The results indicated that peroxidase and IAA oxidase activities in rice leaves were stimulated by supplemental UV-B, resulting in the destruction of IAA which in turn may cause inhibition of rice leaf growth. Although the mechanism is unclear, calmodulin is most likely involved in leaf growth.     

芽前胡的化学成分

从成都产芽前胡Peucedanum turgeniifolium Wolff.中分离鉴定了12个化合物,分别为香豆素化合物佛手柑内酯(bergapten)(1),异欧芹属乙素(isoimperatorin)(2),(±)diisovaleryl-cis-khellactone(3),(±)dihydrosamidin(4),(±)peuformosin(5),(±)cis-khellactone(6),8-(2’,3’-二羟基,3’-甲基-丁基)-伞形花内酯[8-(2’3’-dihydroxy,3’-methyl-butyl)-umbelliferone](7),(±)selinidin(8),turgeniifolin A(9)以及非香豆素化合物硬脂酸(stearic acid),β-谷甾醇(β-sitosterol),甘露醇(d-mannitol)。     

Soil disturbance regime in relation to micro-scale landforms and its effects on vegetation structure in a hilly area in Japan

To clarify vegetation-landform relationships, we examined the soil disturbance regime in relation to micro-scale landforms and its effects on vegetation structure in a mixed temperate forest in a hilly area in northeastern Japan. Soil profiles in each micro-landform unit were surveyed to elucidate the effects of soil disturbances on the vegetation structure. The hilly area studied consisted of an upper and a lower hillslope area divided by an erosion front, which differed considerably with respect to vegetation structure. In the upper hillslope area, canopy was closed and dominated by Pinus densiflora and Quercus serrata. In the lower hillslope area, on the other hand, canopy was less closed and shrubs, ferns, and herbaceous species were abundant. The species composition changed gradually from the crest slope to the upper sideslope to the head hollow in the upper hillslope area. However, micro-landforms in the lower hillslope area seemed to have less effect on the vegetation structure. This may be because the lower hillslope area, in contrast to the upper hillslope area, has suffered from soil disturbances, and hence shrubs, ferns, and herbs have developed irrespective of micro-landforms. Thus, vegetation can be quite different depending on whether or not sites have suffered from soil disturbance. In disturbed stands, it is suggested that the frequency and intensity of disturbance are more important for species composition than the type of soil disturbance.     

Association of cortactin with developing neuromuscular specializations

During the development of the neuromuscular junction (NMJ), motoneurons grow to the muscle cell and the nerve–muscle contact triggers the development of both presynaptic specialization, consisting of clusters of synaptic vesicles (SVs), and postsynaptic specialization, consisting of clusters of synaptic vesicles (SVs), and postsynaptic specialization, consisting of clusters of acetylcholine receptors (AChRs). Previous studies have shown that the activation of tyrosine kinases and the local assembly of an actin-based cytoskeletal specialization are involved in the development of both types of specializations. To understand the link between tyrosine phosphorylation and the assembly of the cytoskeleton, we examined the localization of cortactin in relationship to synaptic development. Cortactin is a 80/85 kD F-actin binding protein and is a substrate for tyrosine kinases. It contains a proline-rich motif and an SH3 domain and is localized at sites of active F-actin assembly. Using a monoclonal antibody against cortactin, its localization at developing NMJs in culture was observed. To understand the spatial and temporal relationship between cortactin and developing synaptic structures, cultured muscle cells and spinal neurons from Xenopus embryos were treated with beads coated with heparin-binding growth-associated molecule to induce the formation of AChR clusters and SV clusters and the localization of cortactin was followed by immunofluorescence. In untreated muscle cells, cortactin is often co-localized with spontaneously formed AChR clusters. After cells were treated with beads, cortactin became localized at bead-induced AChR clusters at their earliest appearance (1 h after the addition of beads). This association was most reliably detected at the early stage of the clustering process. On the presynaptic side, cortactin localization could be detected as early as 10 min after the bead-neurite contact was established. Cortactin-enriched contacts later showed concentration of F-actin (at 1 h) and clusters of SVs (at 24 h). These data suggest that cortactin mediates the local assembly of the cytoskeletal specialization triggered by the synaptogenic signal on both nerve and muscle.     

Studies on the pharmacological properties of novel arylene bis(methylketone) compounds using solid-phase extraction and high-performance liquid chromatography

A method utilising solid-phase extraction followed by high-performance liquid chromatography has been developed to quantify novel arylene bis(methylketone) chemotherapeutics present in biological samples. The samples are extracted over cyanopropylsilane solid-phase extraction cartridges using 10 mM heptanesulfonate-10 mM tetramethylammonium chloride-4.2 mM H₃PO₄-95% CH₃CN as the eluent. Analytical chromatography utilises a diisopropyl-C₈ reversed-phase column and a 7.5–45% CH₃CN gradient in 10 mM heptanesulfonate-10 mM tetramethylammonium chloride-4.2 mM H₃PO₄-H₂O. Detection was by ultraviolet spectrophotometry at 300 or 240 nm. The linear response of the assay was found to extend from at least 100 μg/ml down to 97.66 ng/ml for a 100 μl injection. The assay system was utilised to determine the plasma kinetics of the compounds in mice, where all the drugs were found to display rapid absorption and elimination following intraperitoneal dosing. In vitro and in vivo studies of metabolism demonstrated that each of the compounds produced several metabolites, and that this conversion could be extensive in vivo.     

椴树阔叶红松林群落主要树种径级结构研究

椴树阔叶红松林群落主要树种径级结构研究孙伟中代力民章一平（中国科学院沈阳应用生态研究所,１１００１５）ＳｔｕｄｙｏｆＤｉａｍｅｔｅｒＢｒｅａｓｔＨｉｇｈＳｔｒｕｃｔｕｒｅｏｆｔｈｅＭａｉｎＴｒｅｅｓｉｎＴｉｌｉａＢｒｏａｄｌｅａｖｅｄＫｏｒｅａｎＰ...