NON-HORMONAL STIMULATORS AND INHIBITORS OF PLANT GROWTH AND DEVELOPMENT

1. Plants contain growth regulators that are non-hormonal in nature. These regulators change in concentration during ontogeny and when applied exogenously, can either stimulate or depress growth. While the bulk of either the phenolic or terpenoid regulators are localized within the vacuole, they can also be found within other cellular compartments where they may act upon metabolic pathways, modifying either cell multiplication or elongation. 2. Non-hormonal growth regulators may affect the synthesis and/or destruction of phytohormones, mainly indole-3-acetic acid (IAA). These regulators behave non-specifically, modifying the actions of auxins, gibberellins and cytokinins upon growth. 3. A variety of both uncertainties and unresolved contradictions exist that have prevented a thorough elucidation of the mechanisms of actions of both phenolic and terpenoid regulators. These uncertainties and unresolved contradictions include lack of data regarding compartmentalization of many of the inhibitors. This raises the question of whether their intracellular concentrations become elevated sufficiently to affect metabolic pathways in vivo. Exogenously applied regulators of non-hormonal nature usually interfere with growth only at high concentrations. Therefore, the possibility cannot be excluded that under these conditions, reactions occur within the cell that are absent in vivo. 4. The specific properties of natural non-hormonal regulators are similar in certain respects to phytohormones. For example, both of them may be biogenetically bound within metabolic centres: shikimate (phenolics, indoles, alkaloids), bi-benzi (coumarins) or acetate-mevalonate (terpenoids, fluorens, sesquiterpenes, cytokinins). In addition, both non-hormonal regulators and phytohormones exhibit biological activity in growth bioassays. 5. Non-hormonal regulators may possess a number of useful purposes, e.g. test substances such as fusicoccin permit the investigation of the mode of action of phytohormones, specific inhibitors blocking special forms of growth and protectors of phytohormone activity in culture.     

PRODUCTION OF PHYTOCHELATINS AND GLUTATHIONE BY MARINE PHYTOPLANKTON IN RESPONSE TO METAL STRESS1

Phytoplankton deal with metal toxicity using a variety of biochemical strategies. One of the strategies involves glutathione (GSH) and phytochelatins (PCs), which are metal‐binding thiol peptides produced by eukaryotes and these compounds have been related to several intracellular functions, including metal detoxification, homeostasis, metal resistance and protection against oxidative stress. This paper assesses our state of knowledge on the production of PCs and GSH by marine phytoplankton in laboratory and field conditions and the possible applications of PCs for environmental purposes. Good relationships have been observed between metal exposure and PC production in phytoplankton in the laboratory with Cd, Pb, and Zn showing the greatest efficacy, thereby indicating that PCs have a potential for application as a biomarker. Fewer studies on PC distributions in particulate material have been undertaken in the field. These studies show that free Cu has a strong relationship with the levels of PC in the particulate material. The reason for this could be because Cu is a common contaminant in coastal waters. However it could also be due to the lack of measurements of other metals and their speciation. GSH shows a more complex relationship to metal levels both in the laboratory and in the field. This is most likely due to its multifunctionality. However, there is evidence that phytoplankton act as an important source of dissolved GSH in marine waters, which may form part of the strong organic ligands that control metal speciation, and hence metal toxicity.     

ALLOCATION OF CYSTEINE FOR GLUTATHIONE PRODUCTION IN CATERPILLARS WITH DIFFERENT ANTIOXIDANT DEFENSE STRATEGIES: A COMPARISON OF Lymantria dispar AND Malacosoma disstria

Sulfur amino acids [cysteine (Cys) and methionine (Met)] play two major roles during animal development: protein synthesis for growth and glutathione synthesis for defense. For caterpillars, the levels of sulfur amino acids found in foliar protein can be especially low relative to their nutritional needs. Previous work has measured concentrations of glutathione (GSH; containing Cys) in specific animal tissues, but has not examined whole‐body levels to ascertain the costliness of this defense in terms of Cys allocation. This study examined whether the production of GSH varies between species and within individuals in accordance with an insect's need for antioxidant defense. Secondly, we quantified the allocation of total Cys (peptide‐bound plus free Cys) to GSH in caterpillars as an estimate of its cost. Two contrasting species were compared: Lymantria dispar (Lymantriidae), a species that is highly defended, and Malacosoma disstria (Lasiocampidae), a species that is less defended. As expected, GSH levels were significantly higher in L. dispar than in M. disstria. Consistent with the function of the midgut as a first line of defense against ingested toxins, GSH levels were significantly higher in these tissues than in the whole bodies of both species. A major finding in this study was that a large fraction of total Cys is used to produce GSH: GSH in the midguts of L. dispar and M. disstria contained 23 and 21%, respectively, of the total Cys in these tissues, and the GSH in their remaining body tissues contained 19 and 17% of the total Cys in these tissues. Levels of total Cys in caterpillar tissues followed the same pattern of distribution as did GSH, producing a strong association between GSH and total Cys (R² = 0.794). We conclude that GSH is a costly defense, especially in generalist tree‐feeding species such as L. dispar. These results further suggest that the large allocation of Cys to GSH in highly defended species might produce a tradeoff by limiting the amount of Cys available for rapid growth.     

SUBCELLULAR LOCALIZATION OF N-ACETYL-ASPARTYL-GLUTAMATE, N-ACETYL-GLUTAMATE AND GLUTATHIONE IN BRAIN

Abstract— The subcellular distribution of N-acetyl-aspartate, N-acetyl-aspartyl-glutamate, N-acetyl-glutamate and glutathione (reduced) was investigated. Lactate dehydrogenase, potassium, glutamate and aspartate were employed as markers of the cytoplasmatic compartments. Fumarate hydratase and choline acetyltransferase were used as mitochondrial and synaptosomal markers respectively.
Our data show that the highest concentrations of NAA, NAGA, NAAGA and glutathione were localized in the supernatant with a smaller peak in the crude mitochondrial (P₂) fraction. On subfractionating P₂, NAA was distributed similarly to aspartate and K⁺ with a peak in the synaptosome (B) fraction, while glutathione and NAAGA were localized in the mitochondrial fraction. NAA, aspartate and K⁺ were more readily released than glutathione and NAAGA from their particulate form on exposure to hypo-osmotic conditions.     

合成己酸乙酯脂肪酶产生菌的筛选及产酶条件

从２７株脂肪酶产生菌中筛选到能由乙醇和己酸合成己酸乙酯的菌株８株。其中Ｒｈｉｚｏｐｕｓｓｐ．Ｈ－３菌株脂肪酶活力为５０－６０ｕ／ｍｌ,全细胞在有机溶剂中的酯化率可达己酸的９１％。Ｈ３产酶的最适碳源为淀粉或葡萄糖。６％黄豆饼粉加４％蛋白陈复合氮源有利于酶活力的增加。     

A THIOL PROTEINASE HIGHLY ELEVATED IN AND AROUND THE PLAQUES OF MULTIPLE SCLEROSIS

A thiol dependent proteolytic enzyme (tentatively identified as carboxypeptidase B) which liberates phenylalanine from CBZ-glutamyl-phenylalanine at pH 5.3 was shown, by a sensitive micromethod, to be greatly increased in activity in and around MS plaques. These increases exceeded those of other hydrolases previously measured. Plaque tissue, on the basis of lipid-free dry weight, is up to 3-fold richer in this enzyme than control white matter, and most samples of apparently uninvolved MS white matter already show elevated activities. The enzyme is highly dependent on the presence of dithiothreitol. It is unaffected by diisopropyl fluorophosphate and pepstatin, but inhibited by iodoacetate and leupeptin. Macrophages or lymphocytic infiltrations in the tissue do not appear to be the main source of the enzyme. In conjunction with measurements of DNA, reflecting gliosis, invasion by hematogenom cells and proliferation of phagocytes as well as oligodendrocyte loss, and acid lipase-esterase, indicative of the survival or degeneration of oligodendrocytes, these results are interpreted as probably reflecting predominantly the activity of astrocytes. The incidental finding that most samples of unaffected white matter from MS patients contain more DNA per unit lipid free dry weight than average control white matter is considered significant in pointing to more widespread tissue changes independent of or preceding plaque formation.     

PRODUCTION OF MEMBRANE WHORLS IN RAT LIVER BY SOME INHIBITORS OF PROTEIN SYNTHESIS

Inhibitors of protein synthesis capable of differential effects on nascent peptide synthesis on membrane-bound and free polyribosomes were employed to investigate the structure and function of cellular membranes of liver. The formation of membranous whorls in the cytoplasm and distension of nuclear membranes were induced by inhibitors of protein synthesis (i.e., cycloheximide and emetine) which predominantly interfere with nascent peptide synthesis on membrane-bound polyribosomes in situ. Other inhibitors of protein synthesis such as puromycin and fusidic acid, which inhibit nascent peptide synthesis on both free and membrane-bound polyribosomes, and chloramphenicol, which inhibits mitochondrial protein synthesis, did not induce these alterations. Cycloheximide, puromycin, and chloramphenicol produce some common cellular lesions as reflected by similar alterations in morphology, such as swelling of mitochondria, degranulation of rough endoplasmic reticulum, and aggregation of free ribosomes. The process of whorl formation in the cytoplasm, the incorporation of [³H]leucine and of [³H]choline into endoplasmic reticulum and the total NADPH-cytochrome c reductase activity of the endoplasmic reticulum were determined. During maximum formation of membranous whorls, [³H]leucine incorporation into cytoplasmic membranes was inhibited, while [³H]choline incorporation into these structures was increased; maximum inhibition of protein synthesis and stimulation of choline incorporation into endoplasmic reticulum, however, preceded whorl formation. Cycloheximide decreased the activity of NADPH-cytochrome c reductase of rough endoplasmic reticulum, but increased NADPH-cytochrome c reductase activity of smooth endoplasmic reticulum. In addition, cycloheximide decreased the content of hemoprotein in both the microsomal and mitochondrial fractions of rat liver, and the activities of mixed function oxidase and of oxidative phosphorylation were impaired to different degrees. Succinate-stimulated microsomal oxidation was also inhibited. The possible mechanisms involved in the formation of membranous whorls, as well as their functions, are discussed.     

PREPARATION OF GLUTATHIONE IMPRINTED POLYMER

Glutathione imprinted polymer was prepared using 1-vinyl imidazole and ethylene glycol dimethacrylate as the functional monomer and crosslinker, respectively, in dimethyl sulfoxide. The adsorption selectivity of glutathione-imprinted polymer was tested by reduced glutathione, oxidized glutathione, and L-Gly-Leu-Tyr in 30% phosphate buffer (0.01 M, pH 5.0)–70% acetonitrile and binding affinity values were compared. Reusability of molecularly imprinted polymer particles was also investigated. Molecularly imprinted polymer particles were found to be stable and to maintain glutathione adsorption capacity at 95% when washed with methanol–acetic acid (10%) after seven usages. Functional monomer 1-vinyl imidazole and cross linker ethylene glycol dimethacrylate-based glutathione imprinted polymer could be used as solid phase extraction material for recognition of glutathione in biological samples.     

木霉GXC产β-葡聚糖酶条件和酶学性质

研究了木霉GXC产β-葡聚糖酶的条件.结果表明,最适产酶碳源为麸皮,氮源为硫酸铵;产酶的最适条件为初始pH为4.0～5.0,30℃培养44h.粗酶液经硫酸铵沉淀、Sephadex G-25、Sephadex G-100和DEAE-Sehadex A-50柱层析得到纯β-葡聚糖酶,SDS-PAGE凝胶电泳显示一条带,测得分子量为35kD.该酶最适反应pH5.0,最适反应温度为60℃,在40℃以下、pH4.0～5.0酶活力相对稳定.5.0mmol/L以下的Ca2+、Zn2+和Fe2+,以及10.0mmol/L以下的Co2+对酶活力有激活作用;而Cu2+和Fe3+具有抑制作用.     

大叶苦丁茶成分提取及抗氧化性能研究

对冬青科大叶苦丁茶进行成分提取、分离 ,并采用可见分光光度计法测定其所含几种主要成分的POV值 ,以及测定不同提取条件对提取物POV值的影响 ,同时进行抗氧化性能分析及评价 ;其中所含多酚和黄酮类成分的抗氧化性能较强 ,具有进一步开发及应用的价值     

乙醛磺酸的制备及对中国仓鼠卵巢细胞生长的影响

以２－溴－１,１－二乙氧基乙烷为起始物,制备了牛磺酸的一种类似物乙醛磺酸（ｓｕｌｆｏｎｉｃａｌｄｅｈｙｄｅ;ＳＡＤ）,并对其部分化学性质、光吸收以及细胞半致死量进行了测定。所合成的ＳＡＤ在２０３ｎｍ和２５０ｎｍ分别有吸收,在ＨＰＬＣ分离谱上为单一的峰。ＳＡＤ在碱性溶液中不稳定,在酸性条件下相对稳定。ＳＡＤ对中国仓鼠卵巢细胞（ＣＨＯ）的生长具有抑制和毒性作用,其半致死量为３００μｍｏｌ／Ｌ。由于ＳＡＤ含有较为活泼的醛基,可与肼及氨基反应,因此,ＳＡＤ的合成为我们制备新的牛磺酸类化合物打下了基础,同时对进一步研究牛磺酸的生理学功能提供了信息     

Statine乃其类似物的合成

Statine及其类似物存在于一些具有抗肿瘤、抗病毒、抗炎症等生理活性的天然产物之中.本文简要介绍Statine及其类似物的存在及生理活性,并从不同的起始原料出发,介绍它们的立体选择性合成.     

SYNTHESIS AND NMR-ANALYSIS OF TRICYCLIC NUCLEOSIDES

Two anomeric tricyclic nucleosides have been synthesised from diacetone-D-glucose using oxidation, stereoselective Grignard-addition of a vinyl-group, a stereoselective dihydroxylation followed by a tandem ring closing reaction, and finally a nucleobase coupling. The main β-configured product was examined and its configuration confirmed using NMR-spectroscopy in connection to ab initio calculations. The preferred conformation of this tricyclic nucleoside was described.     

棉铃虫的谷胱甘肽S-转移酶(GSTs):杀虫药剂和植物次生性物质的诱导与GSTs对杀虫药剂的代谢

棉铃虫Helicoverpaarmigera（Hubner）中肠谷胱甘肽S-转移酶（GSTs）对甲基对硫磷和灭多威的代谢能力明显高于对马来酸二乙酯（DEM）和两个混剂。LD5剂量的对硫磷和灭多威对棉铃虫3龄幼虫GSTs的活性均没有诱导增加的影响,用LD50的选择剂量仅对硫磷组GSTs活性增加15％。用含0．01％的芸香苷、2-十三烷酮和槲皮素的人工饲料饲养棉铃虫经1～4代后,GSTs活性提高4～18倍。3种植物次生性物质诱导组对灭多威和溴氰菊酯的敏感度均没有明显的变化,而槲皮素组对甲基对硫磷的敏感度则降低近一半,芸香苷和2-十三烷酮组对甲基对硫磷的敏感度略有降低。这种对甲基对硫磷敏感度的变化可能与上述GSTs活性的变化有关。     

SYNTHESIS AND CHARACTERIZATION OF ADENOSINE ADDUCTS OF ARYLAMINES

ABSTRACT

The synthesis of adducts of arylamines with adenosine are reported.     

杂交鲤的生产和推广

1974年湖北省水生生物研究所送给我场一批散鳞镜鲤、龙州镜鲤和兴国红鲤。1975和1976年并派出技术人员到我场协助进行鲤鱼品种间的杂交试验,两年共繁殖了杂交鲤苗713,000多尾,经过饲养,效果良好,深受群众欢迎,并把它誉为“丰鲤”。       

人胎盘型谷胱甘肽S-转移酶的ELISA及用于肝癌的诊断

从人体胎盘提纯GST-π,制备兔抗GST-π血清,纯化其IgG,并降解成Fab′片断,通过SMCC与HRP交联成Fab′-HRP,用于夹心ELISA以测定GST-π,灵敏度可达11pg,超过国外的放射免疫法。用此法测定正常人血清GST-π为1.06±0.94ng/ml,原发性肝癌血清较正常高20倍以上。阳性率达90％左右。