Biosynthesis of Territrems by Aspergillus terreus

Different radioactive precursors were added to 8-day potato-dextrose liquid cultures of Aspergillus terreus 23-1. Territrems were isolated from chloroform extracts of the cultures at day 14 and purified by thin-layer chromatography and high-pressure liquid chromatography. The territrem B obtained was treated with alkaline hydrogen peroxide, and 3, 4, 5-trimethoxy benzoic acid was isolated from an ethyl acetate extract of the reaction mixture and purified by thin-layer chromatography and high-pressure liquid chromatography. By comparison of the specific radioactivities of territrem B and its cleaved aromatic product (disintegrations per minute per micromole of compound), it was demonstrated that the radioactivity of territrem B was located mainly on its aromatic moiety when [U-C]shikimate, l-[methyl-C]methionine, and l-[methyl-H]methionine were precursors; however, the radioactivity of territrem B was located mainly on its nonaromatic moiety when [2-C]mevalonate was the precursor. Mevinolin, a specific inhibitor of beta-hydroxyl beta-methyl glutaryl coenzyme A reductase, was shown to inhibit production of territrems by A. terreus 23-1. When [U-C]acetate was used as a precursor, mevinolin inhibited the incorporation of radioactive carbon into territrem but mevinolin did not inhibit incorporation of radioactive carbon from [2-C]mevalonate into territrem.     

Sucrose synthase in rice plants : growth-associated changes in tissue specific distributions

Different parts of the rice (Oryza sativa L.) plant at different growth stages were analyzed for sucrose synthase (SS) by enzyme activity assay and enzyme-linked immunosorbent assay directly on the extracts or on the eluates from a gel filtration column. On a dry matter basis, the amount of soluble protein and SS activity decreased significantly, but the amount of enzyme protein changed little in growing leaves. In the grain, the SS activity was the highest at the early ripening stage and decreased later, but the amount of SS protein increased with the increase in maturity. In the root, a low activity of SS was detectable only in the tillering but not in other stages. Immunoblotting of SS protein extracted from different parts of rice showed two bands. Elution patterns of crude extracts from a gel filtration column showed the presence of several types of SS protein. Among them, two to three types with larger elution volumes had the SS activity but others with smaller elution volumes (considered as the aggregated forms) had no activity. The SS purified from different parts of the plant showed similar but distinctly different electrophoretic mobilities in a native gel. It has been concluded that different isozymes are expressed in different tissues at different growth stages.     

γ射线诱发大鼠胚胎细胞转化与N－ras的激活

以γ射线诱发转化的大鼠胚胎细胞(REC:myc:γ33)的DNA构建粘粒基因库,用总基因库DNA转染NIH/3T3细胞,产生转化灶的DNA作二轮转染,二轮转化的NIH/3T3细胞内有大鼠REC:myc:γ33DNA中具转化活性的N-ras基因,用不对称PCR和DNA序列分析法证明,REC:myc:γ33细胞中鼠N-ras的活化是由于第61位密码子的A→G点突变.NIH/3T3转化灶中鼠N-ras也有同样点突变,但NIH/3T3细胞的内源性N-ras基因则无此突变.     

A REVIEW OF THE CLASSIFICATION,DISTRIBUTION AND APPLICATION OF ARTEMISIA L. AND SERIPHIDIUM ( BESS. ) POLJAK. ( COMPOSITAE ) IN CHINA

<正> The paper is a review, in which author showed 1). A view of the classification, including history and taxonomic evidence of the genera, Artemisia L. and Seriphidium (Bess.) Poljak.; 2). the distribution, including migration in geological period, the speciation and present distributional mass center and so-called "3 oblique mass zones" in China, as well as the secondary speciation and developing centers in Hengduang-Himalayan Mts. and 3). the application, mainly in medicine, but also for herbage in steppe and for the windbreaks and assist to sand fixation at the desert and semi-desert areas.     

Blockage of glucocorticoid receptors during memory acquisition, retrieval and reconsolidation prevents the expression of morphine-induced conditioned place preferences in mice

Association between the reward caused by consuming drugs and the context in which they are consumed is essential in the formation of morphine-induced conditioned place preference (CPP). Glucocorticoid receptor (GRs) activation in different regions of the brain affects reward-based reinforcement and memory processing. A wide array of studies have demonstrated that blockage of GRs in some brain areas can have an effect on reward-related memory; however, to date there have been no systematic studies about the involvement of glucocorticoids (GCs) in morphine-related reward memory. Here, we used the GR antagonist RU38486 to investigate how GRs blockage affects the sensitization and CPP behavior during different phases of reward memory included acquisition, retrieval and reconsolidation. Interestingly, our results showed RU38486 has the ability to impair the acquisition, retrieval and reconsolidation of reward-based memory in CPP and sensitization behavior. But RU38486 by itself cannot induce CPP or conditioned place aversion (CPA) behavior. Our data provide a much more complete picture of the potential effects that glucocorticoids have on the reward memory of different phases and inhibit the sensitization behavior.     

Mitochondria-targeted antioxidant peptide SS-31 mediates neuroprotection in a rat experimental glaucoma model

To investigate the neuroprotective effects of the mitochondria-targeted antioxidant Szeto-Schiller peptide 31 (SS-31) in a rat experimental glaucoma model, SS-31 was intraperitoneally (IP) injected into Sprague-Dawley rats, followed by intracameral injection of polystyrene microspheres to induce elevated intraocular pressure (IOP). After 6 weeks, electroretinography (ERG) and flash visual-evoked potentials (F-VEPs) were recorded to assess retinal function. Hematoxylin-eosin staining was performed on retinal cross-sections to measure ganglion cell complex (GCC) thickness. Apoptotic retinal cells were assessed by TUNEL staining. Brn3a-positive retinal ganglion cells (RGCs) were counted in retinal flat mounts via immunofluorescence. The retinal total SOD, SOD2, and MDA expression levels were assessed in retinal tissue homogenates. The cyt c, Baxz and Bcl-2 protein levels in rat retinas were detected by western blot analysis. Bax and Bcl-2 expressions were also evaluated using immunohistochemistry in paraffinized sections. Our results showed that the rats that received microsphere injection developed elevated IOP. SS-31 ameliorated the reductions in the a- and b-wave amplitudes on ERG and the F-VEP amplitude in glaucomatous eyes. GCC thickness was preserved, TUNEL-positive cells were decreased in the retina, and Brn3a-positive RGCs were in creased in the SS-31-treated glaucoma group compared with those in the non-treated glaucoma group. SS-31 significantly reduced MDA levels and increased SOD2 levels after glaucoma induction. Significant suppression of cyt c release, upregulation of Bcl-2, and downregulation of Bax were observed following SS-31 administration. In summary, SS-31 exerts neuroprotective effects in this experimental glaucoma model by inhibiting mitochondrial dysfunction and therefore represents a promising therapeutic agent for glaucoma.     

Potential resistance of tricin in rice against brown planthopper Nilaparvata lugens (Stål)

The aerial parts of resistant rice plant (IR36) was immersed in 85% ethanol at room temperature, and ethanol-soluble extracts were prepared. Different solvents including petroleum ether, ethyl acetate, absolute ethanol, and water were then used to separate the ethanol-soluble extracts and different solvent fractions were obtained. These fractions were tested for their effects on the mortality rate of the brown planthopper nymphae (BPH). The results indicated that EtOAc fractions had significant effects on the mortality of brown planthopper nymphae after the third day of treatment. EtOAc fractions of resistant rice plants (IR36) were separated using column chromatography over silica gel and 5,7,4′ -trihydroxy-3′,5′-dimethoxyflavone (tricin) was isolated. After the BPH were allowed to feed on diets containing tricin for 15 days, it was found that the weight of honeydew of the nymphae showed a decrease as tricin concentrations in the diets increased. The mortality rate of the nymphae increased with increasing tricin concentration. The corrected mortality rate was 58.21% for the 3rd instar nymphae and 31.75% for the 4th instar nymphae, respectively, at 500 μg/ml concentration. In addition, tricin (500 μg/ml) significantly inhibited oviposition behavior and feeding of the brown planthopper females in choice tests when spread on susceptible rice plant (TN1).     

Disease resistance conferred by components of essential chrysanthemum oil and the epigenetic regulation of OsTPS1

The sesquiterpene alpha-bisabolol is the predominant active ingredient in essential oils that are highly valued in the cosmetics industry due to its wound healing, anti-inflammatory, and skin-soothing properties. Alpha-bisabolol was thought to be restricted to Compositae plants. Here we reveal that alpha-bisabolol is also synthesized in rice, a non-Compositae plant, where it acts as a novel sesquiterpene phytoalexin. Overexpressing the gene responsible for the biosynthesis of alpha-bisabolol, Os...     

Selenium deficiency-induced multiple tissue damage with dysregulation of immune and redox homeostasis in broiler chicks under heat stress

Broiler chicks are fast-growing and susceptible to dietary selenium(Se) deficiency. This study sought to reveal the underlying mechanisms of how Se deficiency induces key organ dysfunctions in broilers. Day-old male chicks(n=6 cages/diet, 6 chicks/cage) were fed with a Se-deficient diet(Se-Def, 0.047 mg Se/kg) or the Se-Def+0.3 mg Se/kg(Control, 0.345 mg Se/kg) for 6weeks. The serum, liver, pancreas, spleen, heart, and pectoral muscle of the broilers were collected at week 6 to assay for Se conc...