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101.
Summary The cellular structures of acid rain-irrigated needles of several provenances of Norway spruce (Picea abies L. Karst) seedlings were studied after winter experimental freezing. Frost injuries and recovery were characterized by visual damage scoring and classification of mesophyll cell alterations, also using histochemical methods for carbohydrate fluorescent staining. The treatment with-30° C during the late dormancy period was sufficient to cause significant injuries and intracellular degradation in the tissues of the green needles. The most affected seedlings in terms of visual injury scoring were found among those treated with clean water or at pH 3, while freezing injury, defined as an occlusion of phenolic substances in the central vacuole of the mesophyll cells, was most abundant in the needles from spruces irrigated either with clean water or at pH 4 or pH 3. Electron microscopy revealed the details of the injury, e. g. thinning out of the cytoplasm and chloroplast stroma, darkening of the chloroplasts and eventually swelling of the chloroplasts and protoplast. PAS and ConA reactions in the needle tissue revealed intense starch accumulation in the mesophyll and transfusion tissues as early as in March, with a tendency to increase, especially in the untreated needles during the recovery period. Plasma membrane disturbances were indicated by histochemical identification of callose deposits in the mesophyll cell walls, these being most abundant in the acid rain-treated needles. All these findings suggest that freezing at –30° C was more deleterious to the seedlings pretreated with acid or clean water than to those not given additional irrigation. 相似文献
102.
Microbial lipids produced by oleaginous microorganisms, also called microbial oils and single cell oils (SCOs), are very promising sources for several oil industries. The exploration of efficient oleaginous yeast strains, meant to produce both high-quantity and high-quality lipids for the production of biodiesel, oleochemicals, and the other high value lipid products, have gained much attention. At present, the number of oleaginous yeast species that have been discovered is 8.2% of the total number of known yeast species, most of which have been isolated from their natural habitats. To explore high lipid producing yeasts, different methods, including high-throughput screening methods using colorimetric or fluorometric measures, have been developed. Understanding of the fatty acid composition profiles of lipids produced by oleaginous yeasts would help to define target lipid-related products. For lipid production, the employment of low-cost substrates suitable for yeast growth and lipid accumulation, and efficient cultivation processes are key factors for successfully increasing the amount of the accumulated lipid yield while decreasing the cost of production. 相似文献
103.
Muhammad ASHFAQ Shahid Mehmood KHALID Waseem AKRAM Riaz HUSSAIN Jong-Jin LEE 《Entomological Research》2004,34(1):43-46
Biochemical effects of sub lethal doses LC10 and LC20 of cypermethrin were studied on some enzymes and macromolecule activities of adult beetles of Tribolium castaneum (Herbst.). Cypermethrin caused disturbances in levels of all biochemical components under study. The dose of 0.78 ppm caused abnormalities in α‐amylase and FAA by increasing their activities i.e., 45.45% and 21.97% significantly. The higher sub lethal dose of 2.62 ppm disturbed all the parameters (AcP, α‐amylase, soluble protein and FAA) except AkP, which was decreased by 93.06%. Moreover, sub lethal doses either increased or decreased the levels of all parameters non‐significantly except AkP and FAA which were effected significantly by 87.92% and 14.29% at lower and higher doses, respectively. In the present studies, cypermethrin significantly enhanced the activity of AkP in both susceptible and resistant strains of T. castaneum adult beetles while FAA contents were increased significantly in resistant strain only. The activity of α‐amylase was significantly lowered in susceptible strain only. 相似文献
104.
The soil algal communities of forested and reforested, limed and unlimed plots were compared in the acid rain impacted Kru sné hory Mountains. The floristic composition of unlimed plots is similar to that found in acid forest soils with a naturally low pH and no effect of the acid rain on these communities can be detected. Chlorophyceae are the only group present in these soils. In limed areas with a higher soil pH, algal diversity is significantly increased while algal densities remain similar. Chlorophyceae, while still the dominant group, are accompanied in these soils by Bacillariophyceae, Xanthophyceae, Eustigmatophyceae and Cyanophyceae. Total vegetation cover and thus light hitting the soil surface seems to be most important in determining the algal biomass. 相似文献
105.
R.S. Percival P.D. Marsh S.J. Challacombe 《FEMS immunology and medical microbiology》1996,15(1):35-42
Abstract Pyelonephritis is the most common urinary tract infection affecting females of all age groups. Despite concerted efforts the mechanism of renal injury in pyelonephritis is not clearly understood. In the present study we have made an attempt to characterise the mediators of inflammatory insult in an experimental model of ascending pyelonephritis. Mice infected with Escherichia coli O6:K13:H1 were sacrificed at 2, 7 and 14 days post-infection. Luminol-dependent chemiluminescence response, NADPH oxidase, acid phosphatase, β-glucuronidase and N -acetyl-β- d -glucosaminidase activities were monitored in circulating as well as renal phagocytic cells in order to determine the role of reactive oxygen species and lysosomal enzymes in genesis of renal injury. We have demonstrated that reactive oxygen species are generated at the initiation of infection and the levels increase progressively during the course of infection. While intracellular release of lysosomal enzymes was seen in all groups, extracellular release was primarily observed at 7 and 14 days post-infection only. The results indicate that while reactive oxygen species play a significant role in tissue injury during all stages of infection, lysosomal enzyme release in extracellular milieu augments tissue destruction at later stages only. 相似文献
106.
离子导入法和渗透促进剂并用对裸鼠皮肤角质层影响的ESR研究 总被引:8,自引:0,他引:8
通过测定5-唑烷氮氧自由基硬脂酸(5-DSA)标记裸鼠皮肤角质层的ESR谱,研究离子导入法与渗透促进剂100%月桂氮酮(100%AZ)、5%月桂氨 酮/丙二醇溶液(5% AZ/PG)和10%油酸/丙二醇溶液(10%OA/PG)并用对裸鼠皮肤角质层的影响。离子导入法处理皮肤后,标记物序参数降低,各向同性超精细分裂偶合常数增大,表明低密度电流能够引起皮肤角质层细胞间脂质排列有序性降低,流动性增大,极性增大;离子导入法与渗透促进剂并用处理皮肤后,序参数进一步降低,各向同性超精细分裂偶合常数进一步增大,表明二者对皮肤角质层的影响具有协同作用。 相似文献
107.
植酸对稻米品质影响的研究(Ⅰ) 总被引:2,自引:0,他引:2
本文报道在水稻生长的抽穗期、齐穗期、灌浆期和蜡熟期喷施不同浓度植酸改良稻米品质的研究。结果表明,在水稻生长的不同阶段,控制喷施植酸浓度可提高糙米率,降低稻米垩白。 相似文献
108.
本文对特种油料植物的种质资源研究进行综述,这些植物包括含长链脂肪酸的Crambe,Limnanthes,Lunaria,短链脂肪酸的Cuphea,Lauraceae,羟基脂肪酸的Lesquerella,环氧脂肪酸的Vernonia,Stokesia,以及液体蜡酯的simmondsia等科、属的植物。 相似文献
109.
We have purified for the first time from green leaves a multifunctional protein (MFP) involved in fatty acid -oxidation. The protein, designated MFP IV, was extracted from green leaves of three-week-old cucumber (Cucumis sativus L.) plants. Chromatography on cation exchanger, separation on hydroxylapatite, and fast-protein liquid chromatography on Phenylsuperose led to a more than 7000-fold purification and to the isolation of an apparently homogeneous 80-kDa monomeric protein. This protein is immunologically related to the glyoxysomal MFP II, as evidenced by immunodecoration with antiserum raised against MFP II. Comparison of molecular masses of all MFPs presently known revealed that the MFP prepared from green leaves (MFP IV) is distinct from MFP II (76.5 kDa) and MFP I (74 kDa) from dark-grown cotyledons. By including other properties in this comparison, we demonstrated that MFP IV can also be distinguished from the glyoxysomal MFP III (81 kDa) and the bacterially expressed MFP-a (80 kDa). Moreover, MFP IV is a constituent of leaf peroxisomes and contains the activities of 2-enoyl-CoA hydratase (EC 4.2.1.17),l-3-hydroxyacyl-CoA dehydrogenase (EC 1.1.1.35) and 3-hydroxyacyl-CoA epimerase.Abbreviation MFP
multifunctional protein
This work was supported by grants from the Deutsche Forschungsgemeinschaft and the Fonds der Chemischen Industrie. 相似文献
110.
Fatty acids of the scleractinian coral Galaxea fascicularis: effect of light and feeding 总被引:3,自引:0,他引:3
S. Al-Moghrabi D. Allemand J. M. Couret J. Jaubert 《Journal of comparative physiology. B, Biochemical, systemic, and environmental physiology》1995,165(3):183-192
In order to investigate nutritional interactions in the symbiotic scleractinian coral-zooxanthella association, fatty acids of the coral Galaxea fascicularis were analysed in two groups of cultured microcolonies. The first group was fed with Artemia sp., while the second group was starved. After an initial 1-month period during which both groups were subjected to the same normal light conditions (constant irradiance of 125 E·cm-2·s-1 and 14:10 h light:dark), a light cap was used to cover the aquarium and keep all the microcolonies in permanent darkness for 20 days. During the light phase of the experiment it was shown that the nutritional status lead to large variations in the percentage of saturated, mono-unsaturated and polyunsaturated fatty acids. Palmitic acid (C16:0) was the most abundant fatty acid in both groups. Important differences between fed and starved microcolonies occurred during the dark phase of the experiment. In the fed group the dark phase was characterized by a significant increase in polyunsaturated fatty acids. Particularly arachidonic acid (C20:4 n-6) became the most important fatty acid followed by docosatrienoic acid (C22:3 n-3). A slight increase in these two fatty acids was also found in the starved group but the bulk of polyunsaturated fatty acids was significantly decreased. In this group, palmitic acid remained the most important fatty acid while an increased concentration of cis-vaccenic acid (C18:1 n-7) was found at the end of the experiment. The increased concentration of cis-vaccenic acid might indicate that bacteria serve as a source of energy. While the number of zooxanthellae per milligram of protein and the chlorophyll a to protein ratio strongly decreased in the starved microcolonies immediately after the beginning of the dark period, the decrease in fed microcolonies was delayed for about 10 days. Furthermore, after 20 days of dark incubation the chlorophyll a to protein ratio was the same as measured at the beginning of the dark period. This suggests that in the dark the metabolic requirements of the zooxanthellae are in part met from the animal host through a heterotrophic mode of nutrition.Abbreviations
CZ
cultured zooxanthellae
-
FAME
fatty acid methylester(s)
-
FDM
fed dark microcolonies
-
FLM
fed light microcolonies
-
MUFA
monounsaturated fatty acid(s)
-
PUFA
polyunsaturated fatty acid(s)
-
SDM
starved dark microcolonies
-
SFA
saturated fatty acids
-
SLM
starved-light microcolonies
-
SW
sea water
-
TFA
total fatty acids 相似文献