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1.
UDP-glucose pyrophosphorylase from the pollen of Typha latifoliaLinné was purified to homogeneity as judged by polyacrylamidegel electrophoresis. Two affinity chromatographies with UDP-glucoseSepharose 6B and glucose-1-phosphate (G-l-P) Sepharose 6B wereused in the purification. The molecular weight of this enzyme was estimated to be about53,000 by gel filtration and 55,000 by SDS-polyacrylamide gelelectrophoresis, evidence that it consists of a single protein.It had a specific activity of 3,400, a molecular activity of180,000 and an equilibrium constant of 2.1 in the directionof UDP-glucose pyrophosphorolysis. Results of experiments on product inhibition and the initialvelocity of the reaction of the enzyme suggested an orderedBi Bi mechanism. (Received July 8, 1982; Accepted November 12, 1982)  相似文献   

2.
3.
A phytase was isolated and partially purified from pollen of cattail, Typha latifolia. Its maximum activity was at pH 8.0 and its Km value was 1.7 × 10?5 m for phytic acid in the presence of Ca2+. Among divalent cations tested only Ca2+ affected the activity, increasing it by about 120%, but an excess was inhibitory. The enzyme was specific for phytic acid except for 6% activity for p-nitrophenylphosphate. It seems to be a new type of phytase because it cleaved almost 50% of the total phosphate esters in phytic acid and was product-specific, yielding an inositol triphosphate as a final product.  相似文献   

4.
McNaughton SJ 《Plant physiology》1966,41(10):1736-1738
Irreversible thermal denaturation experiments with 3 enzymes from Typha latifolia populations native to distinct thermal climates produced 3 different responses: (1) malate dehydrogenase was much more resistant to high temperature inactivation when obtained from plants native to a hot climate, (2) glutamate-oxaloacetate transaminase was quite resistant to thermal denaturation regardless of origin, and (3) aldolase was rapidly inactivated by heat regardless of origin.  相似文献   

5.
ADPglucose pyrophosphorylase from developing endosperm tissue of starchy maize (Zea mays) was purified 88-fold to a specific activity of 34 micromoles α-glucose-1-P produced per minute per milligram protein. Rabbit antiserum to purified spinach leaf ADPglucose pyrophosphorylase was able to inhibit pyrophosphorolysis activity of the purified enzyme by up to 90%. The final preparation yielded four major protein staining bands following sodium dodecyl sulfate polyacrylamide gel electrophoresis. When analyzed by Western blot hybridization only the fastest migrating, 54 kilodaltons, protein staining band cross-reacted with affinity purified rabbit antispinach leaf ADPglucose pyrophosphorylase immunoglobulin. The molecular mass of the native enzyme was estimated to be 230 kilodaltons. Thus, maize endosperm ADPglucose pyrophosphorylase appears to be comprised of four subunits. This is in contrast to the respective subunit and native molecular masses of 96 and 400 kilodaltons reported for a preparation of maize endosperm ADPglucose pyrophosphorylase (Fuchs RL and JO Smith 1979 Biochim Biophys Acta 556: 40-48). Proteolytic degradation of maize endosperm ADPglucose pyrophosphorylase appears to occur during incubation of crude extracts at 30°C or during the partial purification of the enzyme according to a previously reported procedure (DB Dickinson, J Preiss 1969 Arch Biochem Biophys 130: 119-128). The progressive appearance of a 53 kilodalton antigenic peptide suggested the loss of a 1 kilodalton proteolytic fragment from the 54 kilodalton subunit. The complete conservation of the 54 kilodalton subunit structure following extraction of the enzyme in the presence of phenylmethylsulfonyl fluoride and/or chymostain was observed. The allosteric and catalytic properties of the partially purified proteolytic degraded versus nondegraded enzyme were compared. The major effect of proteolysis was to enhance enzyme activity in the absence of added activator while greatly decreasing its sensitivity to the allosteric effectors 3-P-glycerate and inorganic phosphate.  相似文献   

6.
Photosynthesis and Photorespiration in Typha latifolia   总被引:1,自引:2,他引:1       下载免费PDF全文
Photosynthetic rates of Typha latifolia, the broad-leaved cattail, are the equivalent of rates reported in tropical grasses and other plants which assimilate carbon by the phosphopyruvate carboxylase reaction, but photosynthesis in T. latifolia proceeds by a typical Calvin cycle. Glycolate oxidase, the photorespiratory enzyme, is present in high concentration in this species, but only minor quantities of the assimilated carbon pass through the photorespiratory pathway. However, continued operation of the pathway is apparently essential in the maintenance of assimilatory capacity. Glycolate oxidase function is not closely coupled to stomatal operation in T. latifolia.  相似文献   

7.
Aging of cattail (Typha latifolia L.) pollen was studied at 24[deg]C under conditions of 40 and 75% relative humidity (RH). The decline of viability coincides with increased leakage at imbibition; both processes develop much faster at the higher humidity condition. During aging phospholipids are deesterified and free fatty acids (FFAs) and lysophospholipids (LPLs) accumulate, again, much more rapidly at 75% RH than at 40% RH. The fatty acid composition of the remaining phospholipids hardly changes during aging, which suggests limited involvement of lipid peroxidation in the degradation process. Tests with phospholipase A2 revealed that the saturated fatty acids occur at the sn-1 position of the glycerol backbone of the phospholipids. The fatty acid composition of the LPLs is similar to that of the phospholipids from which they were formed, indicating that the deesterification occurs at random. This favors involvement of free radicals instead of phospholipases in the deesterification process. Liposome studies were carried out to characterize components in the lipid fraction that might account for the leakage associated with aging. Entrapped carboxyfluorescein leaked much more from liposomes when they were partly made up from total lipids from aged pollen than from nonaged pollen. The components causing the leakage were found in both the polar and the neutral lipid fractions. Further purification and subsequent interchanging of the FFAs and LPLs between extracts from aged and nonaged pollen revealed that in neutral lipid extracts the FFAs are entirely responsible for the leakage, whereas in the phospholipid fraction the LPLs are largely responsible for the leakage. The leakage from the liposomes is not caused by fusion. We suggest that the observed loss of viability and increased leakage during aging are due to the nonenzymic accumulation of FFAs and LPLs in the pollen membranes.  相似文献   

8.
This study follows the outcome of long-term competition between a broad-leaved and a narrowleaved Typha species, T. latifolia and T. angustifolia respectively, in a eutrophic lake. The lake was bordered by a zone of T. latifolia, at one location interrupted by a T. angustifolia stand. Distributional changes of the T. angustifolia stand and the adjacent zone of T. latifolia were measured on aerial photographs (13 years) and along ground-level transects (6 years). A second stand of T. angustifolia was established with transplanted ramets within a formerly homogeneous zone of T. latifolia, and displacement between the two species was measured along ground-level transects after 6 years. Differences between the species in shoot performance were investigated to help explain the relative competitive abilities of the two Typha species. T. angustifolia expanded at the expense of T. latifolia at all water depths where both species occurred, except in very shallow water. Expansion rates suggest that T. angustifolia was not affected by the presence of T. latifolia in water depths exceeding 0.25 m. The Typha species were significantly negatively associated according to rank correlations of shoot densities, and changes of shoot densities, along the transects. These results suggest that T. angustifolia is competitively superior to T. latifolia, contradicting earlier studies. The higher competitive ability of T. angustifolia is consistent with its having taller shoots and a higher standing crop in early summer. Further, shoot height distributions indicated a closer integration of shoot emergence during spring in T. angustifolia than in T. latifolia. A high leaf area/shoot weight ratio suggest that T. latifolia may instead be relatively fast-growing, achieving competitive superiority over narrower-leaved Typha species during a transient period after simultaneous seedling establishment.  相似文献   

9.
Using epifluorescent and histochemical techniques, we examined anatomical differences in the shoot organs of Typha latifolia, T. angustifolia and T. glauca. The leaf lamina of T. latifolia and T. glauca had enlarged epidermal cells and a thickened cuticle above the subepidermal vascular bundles; that of T. angustifolia lacked these characteristics. Leaf sheaths were similar among the species and all lacked the epidermal thickenings found in the lamina. The fertile stems had typical scattered vascular bundles with a band of fibres that was most prominent in T. glauca. The sterile stems were only 1 cm in length and contained a multiseriate hypodermis and a uniseriate endodermis over part of their length. The rhizomes were similar except for a pronounced band of fibres surrounding the central core in T. angustifolia. The rhizome was also characterized by an outer cortical region with a large multiseriate hypodermis/exodermis and a uniseriate endodermis with Casparian bands, suberin lamellae and secondarily thickened walls.  相似文献   

10.
Analysis of the proton-decoupled 31P-nuclear magnetic resonance (NMR) spectrum of fully hydrated Typha latifolia pollen revealed the presence of two main peaks: A broad asymmetrical component of a `bilayer' lineshape and a much narrower symmetrical component originating from phosphorus compounds undergoing rapid isotropic motion. From (a) 31P-NMR experiments on the hydrated total pollen phospholipids, (b) saturation transfer 31P-NMR experiments, and (c) the fraction of lipid phosphate in the pollen, it can be concluded that the great majority of the endogenous phospholipids are arranged in extended bilayers in which the lipid phosphates undergo fast (τc < 10−6 second) long axis rotation. This bilayer arrangement of phospholipids was observed in the pollen down to hydration levels of at least 10.9% moisture content. At the lowest level of pollen hydration examined (5.2%) the 31P-NMR spectrum had a solid state lineshape demonstrating that all the phosphorus-containing compounds (including the phospholipids) were virtually immobile.  相似文献   

11.
Abstract

Landfilling has been widely used for solid waste disposal; however, the generation of leachate can pose a major threat to the surrounding environment in the form of soil salinity. Two native plants of North America Puccinellia nuttalliana (alkaligrass) and Typha latifolia (cattail) were selected in this study to investigate bioaccumulation of sodium (Na+) and chloride (Cl?) under controlled greenhouse conditions. The treatments include irrigation of the plants using fertilizer (F), landfill leachate (LL), and tap water (control, C). Plants cultivated after one season (12?weeks) were harvested by separating aboveground tissues and roots, and soil from each treatment was collected for analysis. The results show that alkaligrass irrigated with LL had 2.13% more biomass yield than control, but 17.63% less than that with F. However, cattail yielded 19.70% more biomass with the irrigation of LL than C and 3.04% less compared to F. Alkaligrass and cattail accumulated 6.85 and 7.00?g Na+/Kg biomass with the irrigation of LL, respectively. Alkaligrass and cattail irrigated with LL accumulated 120.14% and 94.47% more Cl? than C. When alkaligrass and cattail were irrigated with LL, the electrical conductivity of soil was reduced by 71.70% and 45.36%, respectively. This study demonstrated that using North American native halophytes could be a cost-effective and promising approach for phytoremediation of landfill leachate.  相似文献   

12.
The depth distribution of the aquatic macrophyte Typha orientalis Presl was examined in comparison with two other Typha species: Typha angustifolia L. and Typha latifolia L. Vegetation surveys mapping the depth distributions were conducted at Ushigafuchi Pond, Tokyo, Japan, in autumn 2004 and 2005. All vegetation had been cleared from this artificial pond in spring 2003. In 2004 T. orientalis was distributed in shallow to deep water habitats between T. latifolia (shallow water regions) and T. angustifolia (shallow to deep water regions). However, by 2005 T. orientalis had almost disappeared from the pond. It had been replaced by Leersia japonica Makino at depths of 0–30 cm, by Schoenoplectus validus (Vahl) at depths of 30–60 cm and by T. angustifolia at depths of 60–100 cm. It appears that T. orientalis is not a strong competitor, particularly with taller species, but rather a pioneer species.  相似文献   

13.
Purification of Spinach Leaf ADPglucose Pyrophosphorylase   总被引:13,自引:11,他引:2       下载免费PDF全文
ADPglucose pyrophosphorylase from spinach leaves has been purified to homogeneity by hydrophobic chromatography carried out in 1 molar phosphate buffer. After polyacrylamide gel electrophoresis, the preparation showed only one protein staining band that coincided with a single activity stain. The enzyme appears to be composed of two subunits with molecular weights of 44,000 and 48,000, respectively, as determined by SDS polyacrylamide gel electrophoresis. Thus ADPglucose pyrophosphorylase of spinach appears to be comprised of subunits which are similar in size to the subunits of ADPglucose pyrophosphorylase isolated from bacterial sources. In contrast, a subunit molecular weight of 96,000 has been reported for the maize endosperm ADPglucose pyrophosphorylase (Fuchs RL and JO Smith 1979 Biochim Biophys Acta 556: 40-48). The purified enzyme retains similar allosteric and catalytic properties as reported previously and is more sensitive to phosphate inhibition under “dark”-simulated conditions than under “light”-simulated conditions.  相似文献   

14.
Summary The whitespotted swayer Monochamus scutellatus (Say) (Coleoptera: Cerambycidae) breeds in recently killed conifers in northeastern North America, especially white pine Pinus strobus L. We cut down 4 white pines in Pocahontas County, West Virginia, in June 1981, in order to study the behavior of sawyers attracted to the trees. Far greater numbers of both male and female sawyers were attracted to the largest of the trees cut. At all trees, females preferred the parts of the tree of greater circumference. These preferences may be related to greater larval survival in large-circumference regions. Male and female numbers at breeding site peaked at about 1200–1500 h EST; at this time, males generally outnumbered females by about 2:1. We placed males in 3 size classes: L (>2.0 cm), M (2.0 cm, 1.8 cm), and S (<1.8 cm). At the largest of our 4 trees, L males disproportionately frequented the portion of the trunk preferred by females. L males were far more successful than M and S males in mating and in agonistic encounters with other males. L males were thus apparently able to exclude smaller males from the preferred region to some extent.  相似文献   

15.
采用温室盆栽方法,研究添加外源铁对不同铅浓度(0、100、500和1000 mg·kg-1)污染土壤中宽叶香蒲铅积累的影响.结果表明:各铅浓度条件下,与添加100 mg Fe·kg-1相比,添加500 mg Fe·kg-1处理的宽叶香蒲地上部和根的铅含量均增高.土壤铅浓度为1000mg·kg-1时,添加500 mg Fe·kg-1处理根的铅含量比100 mg Fe·kg-1处理增加33.7%,地上部铅含量增加50.5%.添加500 mg Fe·kg-1处理的根际土壤中可交换态铅比100mg Fe·kg-1处理增加77.0%~114.6%.除500 mg·kg-1铅浓度外,各铅浓度条件下添加500mg Fe·kg-1处理根干质量均显著低于100 mg Fe·kg-1处理.在铅污染的湿地环境中添加适量铁可以提高铅的有效性,促进铅积累.  相似文献   

16.
We measured the flow of methane in Typha latifolia L. (cattail)-dominated wetlands from microbial production in anoxic sediment into, through, and out of emergent T. latifolia shoots (i.e. plant transport). The purpose was to identify key environmental and plant factors that might affect rates of methane efflux from wetlands to the Earth's atmosphere. Methane accumulated in leafy T. latifolia shoots overnight, reaching concentrations up to 10000 μl l−1 (vs. atmospheric concentrations <4 μl l−1), suggesting that lower stomatal conductance at night limits methane efflux from the plant into ambient air. Daytime light and (or) lower atmospheric humidity that induce convective gas flow through the plant coincided with ( a ) an increase in the rate of methane efflux from T. latifolia leaves to ambient air (from <0·1 to >2·0 μmol m−2 (leaf) s−1) and ( b ) a decrease in shoot methane concentration to <70 μl l−1. Very short fluctuation in stomatal conductance during the day did not affect the methane efflux rate unless, possibly, the rate of photosynthesis decreased. A strong relationship between the maximum daily rate of methane efflux and shoot methane concentration (measured before the onset of convective gas flow) suggests T. latifolia plants behave like a capacitor (filling with methane at night, emitting the stored methane during the day). Experimentally cutting leaves (to prevent pressurization) reduced plant capacitance for methane.  相似文献   

17.
Typha latifolia is a plant species widely used for phytoremediation. Accumulation, localization and distribution of Pb and mineral nutrients were investigated in roots, rhizomes and leaves of Typha latifolia grown at 0, 50, 100 and 250 μM Pb concentrations in a pot experiment under controlled conditions. Bulk elemental concentrations were determined by X-ray fluorescence (XRF) spectroscopy whereas micro-proton-induced X-ray emission (micro-PIXE) was used for element localization in root and rhizome tissues. Gradual increase in bulk Pb concentrations was observed in Typha latifolia roots and rhizomes treated with increasing Pb concentrations, however in rhizomes Pb concentrations were an order of magnitude lower than in roots. In leaves Pb concentrations were around the limit of detection for XRF (~20 μg g(-1)). An increase in concentration of K and Ca in roots, rhizomes and leaves, of iron and zinc in roots and leaves, and of Mn in rhizomes was observed either at 50 and/or 100 μM Pb treatments, whereas for K and Ca in roots, rhizomes and leaves, Fe and Zn in roots and leaves and Mn in rhizomes, or at 250 μM Pb treatment the increase was seen for concentrations of Fe and Zn in rhizomes and Cu in roots. Mn concentrations decreased with Pb treatments in roots and leaves. Element localization using micro-PIXE analysis demonstrated Pb accumulation in epidermal and cortical tissues of treated roots and rhizomes, while in endodermis and vascular tissues Pb was not detected. A displacement of Ca from epidermal to cortical tissues was observed in Pb treated roots and rhizomes, pointing to cell wall immobilization of Pb as one of the tolerance mechanisms in Typha latifolia. High level of colocalization of Pb with P (r = 0.60), S (r = 0.37) and Zn (r = 0.70) was observed in Pb treated roots, while in rhizomes colocalization with the mentioned elements was still positive, but not that prominent. These results indicate that Pb may form complexes with phosphorus and sulfur compounds in roots and rhizomes, which may also represent attraction sites for binding Zn. Because of its large root and rhizome surface area acting as main sites for Pb adsorption, Typha latifolia may represent potentially efficient plant species for phytoremediation of Pb contaminated soils and waters.  相似文献   

18.
The full effects of biological invasions may be underestimated in many areas because of cryptogenic species, which are those that can be identified as neither native nor introduced. In North America, the cattails Typha latifolia, T. angustifolia, and their hybrid T. × glauca are increasingly aggressive invaders of wetlands. There is a widespread belief that T. latifolia is native to North America and T. angustifolia was introduced from Europe, although there has so far been little empirical support for the latter claim. We used microsatellite data and chloroplast DNA sequences to compare T. latifolia and T. angustifolia genotypes from eastern North America and Europe. In both species, our data revealed a high level of genetic similarity between North American and European populations that is indicative of relatively recent intercontinental dispersal. More specifically, the most likely scenario suggested by Approximate Bayesian Computation was an introduction of T. angustifolia from Europe to North America. We discuss the potential importance of our findings in the context of hybridization, novel genomes, and increasingly invasive behaviour in North American Typha spp.  相似文献   

19.
经丙酮粉、硫酸铵分级沉淀和阴离子交换层析等方法,首次从玉米花粉细胞质粗提物中纯化了一种具有ATPase活性的可溶性蛋白。SDS-PAGE测得分子量为28kD,IEF-PAGE测得等电点为8.3。免疫印迹鉴定结果表明该酶蛋白与抗牛脑动蛋白或动力蛋白的抗体无免疫交叉反应。最大紫外吸收波长为278nm,并作了CD谱分析。底物特异性研究表明:ATPase水解活性最高。药理学研究表明:该酶蛋白可被矾酸钠强烈抑制,但对NEM基本不敏感,氟化钠可使酶活力丧失50%左右,寡霉素、硝酸钾及乌本苷对酶活力没有抑制作用.  相似文献   

20.
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