The Structures of Water-soluble Polysaccharides Isolated from Bamboo Shoot

The structures of two polysaccharides reported in the previous paper were studied by means of methylation analysis and the Smith degradation. As a result, it was concluded that the water-soluble xylan consisted essentially of a (l→4)-linked β-d-xylopyranosyl chain and contained l-arabinofuranosyl residues linked through the C–l as terminal side units. Unambiguous information concerning the residues of d-glactose and d-glucuronic acid as the constituents of the xylan has not been obtained. For the arabinogalactan, evidence was obtained for an interesting structure having a backbone chain of (l→3)-linked β-d-galactopyranosyl residues to which the terminal arabinose residues were attached at the C–6 position as the most prevalent side chains.     

Isolation and Fractionation of Water-soluble Polysaccharides from Bamboo Shoot

It was established that the water-soluble polysaccharides of bamboo shoot other than starch consisted of a water-soluble xylan, an arabinogalactan and an α-glucan by isolation and fractionation of the water-soluble polysaccharides extracted with dimethyl sulfoxide from a preparative meal of bamboo shoot. On the basis of the examination of several properties of these polysaccharides, the presence of a galactan first isolated from bamboo shoot was discussed from points of plant biogenesis.     

应用超声波技术强化提取余甘多糖

通过单因素和正交实验研究了超声波时间、超声波功率、超声波提取温度和料液比对余甘(Phyllanthus emblica L.)多糖收率的影响。结果表明,多糖收率的主要影响因素为超声波功率、超声波时间、料液比、超声波提取温度。余甘多糖的最佳提取工艺条件为:超声波功率475W、超声波时间70min、料液比1:20、超声波提取温度80℃,余甘多糖收率为95.86mgg-1DW。紫外和红外光谱分析表明,余甘多糖是含有糖醛酸的α型吡喃酸性杂多糖,超声波处理没有改变多糖结构。     

褐蘑菇水溶性多糖抗氧化活性研究

采用水提醇沉以及sevag去蛋白的方法获得褐蘑菇水溶性多糖(WPPA)。通过测定还原力、超氧阴离子清除率、羟基自由基清除率和抑制H2O2诱导红细胞氧化溶血实验评价WPPA抗氧化活性。结果表明:WPPA具有较强的还原力,对O2-.和.OH具有较强的清除作用,IC50分别为527μg/mL、310μg/mL;对H2O2诱导红细胞氧化溶血及MDA生成有很强的抑制作用,IC50分别为700μg/mL和541μg/mL。说明WPPA在一定浓度内具有较强的抗氧化能力。     

Changes in Cell Wall Composition and Water-soluble Polysaccharides During Kiwifruit Development

Changes in both cell wall and water-soluble polysaccharide compositionduring the growth of kiwifruits [Actinidia deliciosa (A. chev.) C. F. Liang and A. R. Ferguson var. deliciosa ‘Hayward’]were investigated. Cellulose was the major wall polysaccharide,with galactose and uronics the main non-cellulosic sugars. Muchsolubilization of cell wall pectic polysaccharides was detected.While wall-galactose solubilization started 3 months after anthesis,polyuronide degradation did not start until the fifth month,1 month prior to the harvest date. Parallel to these processes,a linear increase in water-soluble polysaccharides was detected.These mainly comprised galactose-rich polymers in the first3 months and little-branched polyuronides after the fifth month.Two different mechanisms for galactose and uronic acid solubilizationfrom kiwifruit cell walls during fruit development are proposed. Actinidia deliciosa ; cell wall; fruit growth; kiwifruit; water-soluble polysaccharides     

The Structure of an Arabinogalactan Isolated from Bamboo Shoot

It was found that azide bound to alcohol oxidase non-covalently and caused a color change from yellow to red. Alcohol oxidase was purified with a high yield from methanol-limited chemostat-grown cells of Candida boidinii S2 as an enzyme-azide complex by a simple procedure. That is, a cell-free extract was prepared from cells treated with a cationic detergent, Cation M2, and alcohol oxidase amounted to more than 80% of the soluble protein. Inactivation of the enzyme by H₂O₂ and aldehydes was decreased in the complex. The results were discussed as to the production of various aldehydes with the yeast cells.     

竹笋深加工及其功能活性研究进展

竹笋是一种高蛋白、低脂肪、富纤维的食品.本文综述了竹笋膳食纤维、活性多糖、含氮化合物等深加工产品的制备方法,比较了不同方法对竹笋深加工产品纯度、得率、功能活性等方面的影响;对竹笋改善肠功能、抗氧化、调节血脂血糖、消炎抗肿等方面的功能活性进行了论述;分析了目前竹笋深加工过程中存在的问题,对今后研究的方向、重点和趋势进行了展望.     

Thidiazuron-induced Shoot Multiplication and Plant Regeneration in Bamboo (Dendrocalamus strictus Nees)

Thidiazuron (TDZ) stimulated shoot proliferation from different seedling explants (i.e., shoot, basal node, node and apical segment) of bamboo (Dendrocalamus strictus) when incorporated in half-strength Murashige and Skoog (MS) medium having 2% (w/v) sucrose. All the concentrations of TDZ (0.01 to 1.0 mg l^?1) tried were effective in shoot proliferation. Maximum shoots (14.8 ± 1.0) were obtained from the shoot explants cultured in 0.5 mg l^?1 TDZ supplemented halfstrength MS liquid medium for 21 days and subsequently transferred to the same medium devoid of TDZ. The longer culture period (i.e. 28 and 35 days) in TDZ medium caused reduction in shoot proliferation. The shoots regenerated with lower concentrations of TDZ treatment (i.e. 0.01 to 0.1 mg l^?1) rooted in half-strength MS liquid medium. The shoots formed with 0.5 mg l^?1 TDZ treatment did not root in basal medium and required auxin supplementation in the medium for rooting and about 55% shoots produced roots in 1.0 mg l^?1 IBA supplemented medium. The shoots formed with 1.0 mg l^?1 TDZ did not root even after auxin treatment. The well rooted shoots transplanted to plastic pots filled with sand and garden soil (1:1) mixture showed 98% establishment.     

Purification and Characterization of Sucrose Synthetase from the Shoot of Bamboo Leleba oldhami

A 108-fold purification of the sucrose synthetase from the extract of the shoot of bamboo Lelaba oldhami was achieved by ammonium sulfate fractionation, calcium phosphate gel adsorption, and chromatographic separations on Sephadex G-100 and diethylaminoethyl-cellulose columns. Some properties of this enzyme, namely thermal and pH stabilities, stabilization by aqueous glycerol, pH optimum, substrate specificities, effects of metallic ions, effects of sulfhydryl reagents, molecular weight, sedimentation constants, isoelectric point, and substrate saturation kinetics had been investigated.     

水溶性甘草多糖的分离纯化、结构及生物活性研究进展

甘草是广泛使用的中药材之一.甘草中含有多种活性物质,甘草多糖作为主要的活性大分子,具有抗肿瘤、抗病毒、抗氧化、抗补体以及免疫调节等生物活性.本文对近年来水溶性甘草多糖的分离纯化、结构解析以及生物活性研究的最新进展进行综述.     

Enzymic Dissociation of Zea Shoot Cell-Wall Polysaccharides V. Dissociation of Xyloglucan by Urea

A procedure has been devised to extract and identify structuralcomponents of the xyloglucan of Zea mays L. (hybrid B73 ? Mo17) shoot cell-walls. A water-insoluble fraction of Zea shootcell-walls, after pretreatment with purified Bacillus subtilis(1 3),(1 4)-ß-D-glucan 4-glucanohydrolase, purifiedB. subtilis endo-(l 4)-ß-xylanase and an enzyme preparationfrom B. subtilis enriched in glucuronoxylanase (Kato and Nevins1984a, Nishitani and Nevins 1991), was subsequently treatedwith 7 M urea. The carbohydrates (0.8% of the water-insolublefraction of Zea shoot cell-walls) liberated by the urea treatment,were comprised of xyloglucan polymers with molecular weightswhich varied from 1.0 ? 10⁴ to 4.0 7times; 10⁴ Da. Other wallfragments associated with the isolated polymer suggest covalentbonding of xyloglucan to other polysaccharides. Structural analysesof the xyloglucan polymers reveal a cellulose-like backbonewith about 35% of the C-6 positions substituted with xyloseand other sugars. About 80% of xyloglucan present in the enzyme-pretreatedwater-insoluble fraction of Zea shoot cell-walls was liberatedby the urea treatment. The procedure avoids the use of alkaliin the solubilization of xyloglucan. ¹Supported in part by National Science Foundation research grantsPCM 7818588 and DMB 8505901. (Received September 10, 1990; Accepted May 15, 1991)     

采后预冷处理和贮藏温度对台湾绿竹笋鲜笋老化的影响

研究采后预冷处理和贮藏温度对台湾绿竹笋鲜笋老化的影响。结果表明,采后预冷处理和贮藏温度对台湾绿竹笋的老化速度、保鲜期和失重率有显著影响。采后预冷处理抑制鲜笋的老化,降低其老化率,延长保鲜期。(5±0.5) ℃恒温箱贮藏下,鲜笋的老化率、失重率低于(30±0.5) ℃恒温箱贮藏,贮藏期则相反。贮藏3、6、9、12 d,(5±0.5) ℃恒温贮藏下的鲜笋失重率均低于1%;(30±0.5) ℃恒温贮藏下,鲜笋失重率分别为26.32%、38.10%、48.04%、55.23%。     

Interactions Between Shoot Age Structure, Nutrient Availability and Physiological Integration in the Giant Bamboo Phyllostachys pubescens

Abstract: The age structure of adult shoots, the nutrient availability of the habitat, and their interaction, are important factors influencing the productivity of bamboo groves. In a field fertilization experiment over two years we examined the impact of physiological integration on the emergence, growth, and survival of new shoots of Phyllostachys pubescens, a giant woody bamboo. Impacts of physiological integration were compared using uniform and patchy fertilization treatments. The number of new shoots emerging per plot significantly increased with the application of fertilizer (NPK), but the increase was constrained by the age structure of adult shoots. In a year with a high proportion of shoots with new (first-year) leaves many more new shoots emerged than in a year with a low proportion of new leaves. Mean survivorship of the new shoots was constant at 20 % for all treatments in both years of study. Surprisingly, fertilization did not increase DBH or height of the new shoots, suggesting that shoot size was fixed early in ontogeny. The pattern of fertilizer application, either uniform or patchy, did not affect the total number of new shoots produced. In the case of patchy application, more new shoots developed in unfertilized patches in comparison to uniformly unfertilized plots, probably because these parts of the clone received resources via the rhizomes from the adult shoots in adjacent fertilized patches. The production of new shoots in fertilized patches, in turn, was lower than that in uniformly fertilized plots as a result of this physiological integration. The results are discussed in the general context of the impact of integration on clonal plant performance in dense stands.     

麻黄水溶性多糖的提取及其清除氧自由基作用的研究

采用热水提取法 ,从麻黄中提取到水溶性多糖 ,其收率为 2 .8%左右。经SephadexG -1 0 0柱层析得到较纯的麻黄多糖样品。该样品具有清除O -2 的作用。     

竹笋采后木质化与多酚氧化酶，过氧化物酶和苯丙氨酸解氨酶活性的关系（简报）

竹笋采后10d内,PPO,POD和PAL活性呈迅速上升趋势,之后缓慢下降,木质素含量在采后10d内迅速增加,随后缓慢增加,1℃和10℃之间的PPO,POD和PAL活性的差异都达显著水平（P＜0．05）,木质素含量的差异达极显著水平（P＜0．01）。     

Endogenous Shoot Growth Rhythms and Indeterminate Shoot Growth in Oak

Wide variations of shoot growth patterns in saplings of pin oak (Quercus palustris Muenchh.) have been observed as a consequence of varying environmental conditions, experimental manipulations, and vigor of trees. Shoot growth patterns range from a series of recurrent, determinate flushes, constituting a genuine endogenous rhythm, to continuous, indeterminate growth. Observed growth patterns agree well with those predicted by a model of rhythmic growth which assumes the dependence of shoot growth on the functional equilibrium between shoot and root system. Indirect evidence suggests that cessation of shoot growth under favorable environmental conditions might be a consequence of internal water deficits. Observed differences in shoot growth patterns between young and mature trees are discussed as logical consequences of the model.     

Connective Auxin Transport in the Shoot Facilitates Communication between Shoot Apices

The bulk polar movement of the plant signaling molecule auxin through the stem is a long-recognized but poorly understood phenomenon. Here we show that the highly polar, high conductance polar auxin transport stream (PATS) is only part of a multimodal auxin transport network in the stem. The dynamics of auxin movement through stems are inconsistent with a single polar transport regime and instead suggest widespread low conductance, less polar auxin transport in the stem, which we term connective auxin transport (CAT). The bidirectional movement of auxin between the PATS and the surrounding tissues, mediated by CAT, can explain the complex auxin transport kinetics we observe. We show that the auxin efflux carriers PIN3, PIN4, and PIN7 are major contributors to this auxin transport connectivity and that their activity is important for communication between shoot apices in the regulation of shoot branching. We propose that the PATS provides a long-range, consolidated stream of information throughout the plant, while CAT acts locally, allowing tissues to modulate and be modulated by information in the PATS.     

Shoot branching

The mature form of a plant shoot system is an expression of several genetically controlled traits, many of which are also environmentally regulated. A major component of this architectural variation is the degree of shoot branching. Recent results indicate conserved mechanisms for shoot branch development across the monocots and eudicots. The existence of a novel long-range branch-inhibiting signal has been inferred from studies of branching mutants in pea and Arabidopsis.     

Water-soluble phenolic compounds in lichens

The quantity and the qualitative composition (for some species) of phenolic compounds (PC) washed out of the intact thalli of lichens of the orders Peltigerales (the genera Peltigera, Solorina, and Nephroma) and Lecanorales (the genera Cladonia, Alectoria, and Cetraria) were studied. It was shown that the quantity of leachable PCs in Peltigerales was on average 2–3 times higher than in Lecanorales. At the same time, the extractability of PC from intact thalli by water was higher in Lecanorales than in Peltigerales: 48–88% and 34–70%, respectively, of the PC content in ethanol extracts from crushed thalli (i.e., of the total content of soluble PC). Water-soluble PC in the lichens Peltigera aphthosa, Solorina crocea, Cetraria islandica, Flavocetraria nivalis, Cladonia uncialis, and Cladonia arbuscula were represented by 7–12 phenolic compounds with similar qualitative composition in the species of the same order. The most part of water soluble PC were phenylpropanoids. All of the studied species showed the presence of p-hydroxybenzoic acid derivatives; vanillic and protocatechuic acid derivatives were found in Cetraria and Cladonia species, respectively.