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121.
Barley plants (Hordeum vulgare L.) received foliar applications of 10?4 M gibberellic acid (GA3) and Kinetin (KN) individually and in combination at one or more of three growth stages: flag leaf appearance (I), ear emergence (II), and the first stage of senescence initiation in the flag leaf (III). Both plant growth regulators (PGR) hastened onset of senescence when sprayed at Stage I and/or Stage II. Treatment at Stage III, either alone or in combination with treatments at the other stages, tended to postpone senescence. Yield components also showed stage-dependent response: Stage I treatment increased the formation of total and bearing tillers, and Stage III treatment improved grain number and weight. However, while GA3 proved more effective than KN, the two together acted antagonistically. 相似文献
122.
Aparna Banerjee Shalini Gaur Rudra Koushik Mazumder Vinod Nigam Rajib Bandopadhyay 《Indian journal of microbiology》2018,58(1):39-50
Exopolysaccharide produced by a unique avirulent Bacillus anthracis strain PFAB2 of hot spring origin has been characterized and its functional properties are investigated which is a first report. Maximum yield of EPS is 7.66 g/l with 2% glucose and 1% peptone as optimum carbon and nitrogen source respectively. The EPS is found to be a homopolymer consisting of only glucose as principle monosaccharide component. Through 1H NMR study, different dextran-like proton peaks are observed. Molecular weight of the EPS resembles low molecular weight bacterial origin polysaccharides. Melting transition of the EPS has started after 276 °C which indicates good thermal stability. The EPS also shows potent antioxidant activity in terms of DPPH and ABTS mediated free radical scavenging property compared to standard ascorbic acid. Emulsifying property of the EPS is also observed and has shown good emulsification of vegetable oils. The polysaccharide forms a thermo resistant gel during the heating phase, with G′ higher than G″ indicating excellent shear-thinning behaviour and viscoelastic nature of the EPS. 相似文献
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125.
Cations, including calcium, magnesium, potassium, sodium, copper, iron, nickel and zinc, inhibited (up to 40%) extracellular binding and intracellular uptake of cadmium by Lemna polyrhiza in solution culture. Test plants showed a high capacity of extracellular cadmium binding which was competitively inhibited by copper, nickel and zinc; however, calcium, magnesium and potassium caused non-competitive inhibition. Iron and sodium increased K
m and decreased V
max, thereby causing mixed inhibition of extracellular binding. Intracellular cadmium uptake displayed Michaelis-Menten kinetics. It was competitively inhibited by calcium, magnesium, iron, nickel and zinc. Monovalent cations (sodium and potassium) caused non-competitive and copper caused mixed inhibition of intracellular cadmium uptake. Thus, high levels of cations and metals in the external environment should be expected to lower the cadmium accumulation efficiency of L. polyrhiza. 相似文献
126.
Functional group substitutions of the branchpoint adenosine in a nuclear pre-mRNA and a group II intron. 总被引:2,自引:0,他引:2
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Splicing of nuclear mRNA precursors (pre-mRNAs) takes place in the spliceosome, a large and complex ribonucleoprotein. Nuclear pre-mRNA splicing and group II intron self-splicing occur by a chemically identical pathway involving recognition of a specific branchpoint adenosine and nucleophilic activation of its 2'-hydroxyl group. The chemical similarity between these two splicing reactions, as well as other considerations, have suggested that the catalytic core of the spliceosome and group II introns may be related. Here we test this hypothesis by analyzing splicing and RNA branch formation of a pre-mRNA and a group II intron in which the branchpoint adenosine was substituted with purine base analogues. We find that replacement of the branchpoint adenosine with either of two modified adenosine analogues or guanosine leads to remarkably similar patterns of splicing and RNA branch formation in the two systems. 相似文献
127.
The responses of Acacia nilotica L. var. cupriciformis to phosphorus application and inoculation with the indigenous consortium of arbuscular mycorrhizal
(AM) fungi were evaluated in a nursery experiment using soil from a marginal wasteland. A positive growth response to mycorrhizal
inoculation was observed at an Olsen-P level of 20 ppm in the presence of the natural population of AM fungi. There was growth
stimulation by either inoculation or additional P at the highest soil P of 40 ppm. Colonization was negatively correlated
to soil P but P content of both shoot and root were positively correlated. Inoculation with the indigenous AM consortium significantly
increased the uptake of P at all levels of applied P. Acacia is moderately dependent upon the AM symbiosis and exhibited a maximal mycorrhizal dependence (MD) of 18.25% at 20 ppm Olsen-P
level under the conditions studied. A sharp and considerable reduction in MD and dry matter yield observed at 40 ppm P suggests
that the external P requirement for maximal production of biomass was met at approximately 20 ppm Olsen-P.
Accepted: 25 June 1996 相似文献
128.
The surface of eukaryotic cells is a multi-component fluid bilayer in which glycosylphosphatidylinositol (GPI)-anchored proteins are an abundant constituent. In this review, we discuss the complex nature of the organization and dynamics of GPI-anchored proteins at multiple spatial and temporal scales. Different biophysical techniques have been utilized for understanding this organization, including fluorescence correlation spectroscopy, fluorescence recovery after photobleaching, single particle tracking, and a number of super resolution methods. Major insights into the organization and dynamics have also come from exploring the short-range interactions of GPI-anchored proteins by fluorescence (or Förster) resonance energy transfer microscopy. Based on the nanometer to micron scale organization, at the microsecond to the second time scale dynamics, a picture of the membrane bilayer emerges where the lipid bilayer appears inextricably intertwined with the underlying dynamic cytoskeleton. These observations have prompted a revision of the current models of plasma membrane organization, and suggest an active actin-membrane composite. 相似文献
129.
Anupama Reddy Joseph D. Growney Nick S. Wilson Caroline M. Emery Jennifer A. Johnson Rebecca Ward Kelli A. Monaco Joshua Korn John E. Monahan Mark D. Stump Felipa A. Mapa Christopher J. Wilson Janine Steiger Jebediah Ledell Richard J. Rickles Vic E. Myer Seth A. Ettenberg Robert Schlegel William R. Sellers Heather A. Huet Joseph Lehár 《PloS one》2016,11(1)
130.
The isolation of Blastomyces dermatitidis in India is reported from the bronchial aspirate of a female asthmatic patient who had never travelled abroad. The patient was a resident of Rodhain, a small town in the District of Badaun (Uttar Pradesh), situated about 250 km south-east of Delhi. Apart from its demonstration by culture and direct microscopy of a bronchial aspirate, B. dermatitidis was seen microscopically on two occasions in KOH wet mounts and smears of sputum stained with periodic acid-Schiff's reagent. Anti-B. dermatitidis serum precipitins were shown by immunodiffusion in 3 of 4 serum samples from the patient. The identity of the fungus was based on its characteristic morphology in clinical specimens and in culture, conversion of the mold form to the yeast from in vitro and vice versa, and by verification of its pathogenicity in white mice. A detailed clinical and laboratory evaluation of the patient indicated that she had suffered from an episode of self-limited acute pulmonary blastomycosis that required no antifungal therapy. This is believed to be the first authentic report of the isolation of B. dermatitidis from clinical material in India. 相似文献