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881.
Herbicide tolerance in maize is related to increased levels of glutathione and glutathione-associated enzymes 总被引:1,自引:0,他引:1
Mamdouh M. Nemat Alla Abdel-Hakeem M. Badawi Nemat M. Hassan Zeinab M. El-Bastawisy Enas G. Badran 《Acta Physiologiae Plantarum》2008,30(3):371-379
Treatment of 10 days old maize seedlings with metribuzin and pretilachlor near the recommended field-dose resulted in differential
reductions in shoot fresh and dry weights during the following 16 days. Metribuzin showed great and consistent reductions,
however, the reduction induced by pretilachlor, mostly nullified by the end of the experiment. Moreover, there were differential
accumulations of lipid peroxides, carbonyl groups and H2O2 in maize leaves; metribuzin caused the greatest accumulation. Meanwhile, levels of thiol forms and reduced glutathione (GSH)
were much more induced by pretilachlor than metribuzin; the contrary was true regarding oxidized glutathione (GSSG). The ratio
of GSH/GSSG was highest following pretilachlor treatment and least by metribuzin. On the other hand, activities of glutathione-S-transferases (GSTs, EC 2.5.1.18), γ-glutamyl-cysteine synthetase (γ-GCS, EC 6.3.2.2), glutathione synthetase (GS, EC 6.3.2.3),
glutathione peroxidase (GPX, EC 1.15.1.1) and glutathione reductase (GR, EC 1.6.4.2) were more enhanced in maize leaves by
pretilachlor than metribuzin. These findings suggest the occurrence of an oxidative stress differentially induced in maize
by the herbicides, a state that was most pronounced with metribuzin. Pretilachlor was concluded to be the least phytotoxic
to maize, while metribuzin was the most, this differential tolerance seemed to be related to the induction of GSH and GSH-associated
enzymes. 相似文献
882.
Elevated CO2 stimulates plant growth and affects quantity and composition of root exudates, followed by response of its microbiome. Three scenarios representing nitrate fertilization regimes: limited (30 ppm), moderate (70 ppm) and excess nitrate (100 ppm) were compared under ambient and elevated CO2 (eCO2, 850 ppm) to elucidate their combined effects on root-surface-associated bacterial community abundance, structure and function. Wheat root-surface-associated microbiome structure and function, as well as soil and plant properties, were highly influenced by interactions between CO2 and nitrate levels. Relative abundance of total bacteria per plant increased at eCO2 under excess nitrate. Elevated CO2 significantly influenced the abundance of genes encoding enzymes, transporters and secretion systems. Proteobacteria, the largest taxonomic group in wheat roots (~ 75%), is the most influenced group by eCO2 under all nitrate levels. Rhizobiales, Burkholderiales and Pseudomonadales are responsible for most of these functional changes. A correlation was observed among the five gene-groups whose abundance was significantly changed (secretion systems, particularly type VI secretion system, biofilm formation, pyruvate, fructose and mannose metabolism). These changes in bacterial abundance and gene functions may be the result of alteration in root exudation at eCO2, leading to changes in bacteria colonization patterns and influencing their fitness and proliferation.Subject terms: Microbiome, Microbial ecology, Metagenomics, Microbial ecology 相似文献
883.
884.
Nemat M. Hassan Ahmed K. A. El-Sayed Heba T. Ebeid Mamdouh M. Nemat Alla 《Acta Physiologiae Plantarum》2011,33(2):593-600
Sunflower (Helianthus annuus L.) hybrid Hysun 333 (black seeded) was cultivated in a greenhouse and subjected during flowering stage to drought with or
without the application of boron (B) and calcium (Ca) foliar sprays alone or in combination. The results revealed that drought
induced a sharp decrease in seed fresh weight, seed protein and lipid contents. Application of B and Ca combined sprays overcame
the drought effects on seed weight and seed lipid contents. Catalase expression was detected as a single band for all treatments
where peroxidase isozymes were increased to seven, six of them were expressed when B sprays were applied with drought indicating
that B has a major role in peroxidase up-regulation under drought conditions. SDS-PAGE analysis showed differential changes
in protein profile with an appearance and/or disappearance of polypeptide protein bands, some of which were concluded to be
drought-related proteins. The combined sprays of B and Ca seemed to overcome the effects of drought through minimizing band
alterations (disappearance and/or appearance). The DD-RT PCR showed a variation in gene expression between the control and
the other treatments. Sprays of B and Ca in combination seemed to be the most effective in band up-regulation and/or down-regulation
that might play a possible role in improving tolerance of sunflower to overcome the drought deleterious effects. 相似文献
885.
Krylov Victor Shaburova Olga Pleteneva Elena Krylov Sergey Kaplan Alla Burkaltseva Maria Polygach Olga Chesnokova Elena 《中国病毒学》2015,30(1):33-44
Virologica Sinica - The emergence of multidrug-resistant bacterial pathogens forced us to consider the phage therapy as one of the possible alternative approaches to treatment. The purpose of this... 相似文献
886.
We consider a situation in which individual features of the input are represented in the neural system by different frequencies of periodic firings. Thus, if two of the features are presented concurrently, the input to the system will consist of a superposition of two periodic trains. In this paper we present an algorithm that is capable of extracting the individual features from the composite signal by separating the signal into periodic spike trains with different frequencies. We show that the algorithm can be implemented in a biophysically based excitatory-inhibitory network model. The frequency separation process works over a range of frequencies determined by time constants of the model’s intrinsic variables. It does not rely on a “resonance” phenomenon and is not tuned to a discrete set of frequencies. The frequency separation is still reliable when the timing of incoming spikes is noisy. 相似文献
887.
Laining Zhang Tetyana Smertenko Deirdre Fahy Nuria Koteyeva Natalia Moroz Anna Kuchaov Dominik Novk Eduard Manoilov Petro Smertenko Charitha Galva Jozef amaj Alla S. Kostyukova John C. Sedbrook Andrei Smertenko 《Plant physiology》2021,186(2):945
The phragmoplast separates daughter cells during cytokinesis by constructing the cell plate, which depends on interaction between cytoskeleton and membrane compartments. Proteins responsible for these interactions remain unknown, but formins can link cytoskeleton with membranes and several members of formin protein family localize to the cell plate. Progress in functional characterization of formins in cytokinesis is hindered by functional redundancies within the large formin gene family. We addressed this limitation by employing Small Molecular Inhibitor of Formin Homology 2 (SMIFH2), a small-molecule inhibitor of formins. Treatment of tobacco (Nicotiana tabacum) tissue culture cells with SMIFH2 perturbed localization of actin at the cell plate; slowed down both microtubule polymerization and phragmoplast expansion; diminished association of dynamin-related proteins with the cell plate independently of actin and microtubules; and caused cell plate swelling. Another impact of SMIFH2 was shortening of the END BINDING1b (EB1b) and EB1c comets on the growing microtubule plus ends in N. tabacum tissue culture cells and Arabidopsis thaliana cotyledon epidermis cells. The shape of the EB1 comets in the SMIFH2-treated cells resembled that of the knockdown mutant of plant Xenopus Microtubule-Associated protein of 215 kDa (XMAP215) homolog MICROTUBULE ORGANIZATION 1/GEMINI 1 (MOR1/GEM1). This outcome suggests that formins promote elongation of tubulin flares on the growing plus ends. Formins AtFH1 (A. thaliana Formin Homology 1) and AtFH8 can also interact with EB1. Besides cytokinesis, formins function in the mitotic spindle assembly and metaphase to anaphase transition. Our data suggest that during cytokinesis formins function in: (1) promoting microtubule polymerization; (2) nucleating F-actin at the cell plate; (3) retaining dynamin-related proteins at the cell plate; and (4) remodeling of the cell plate membrane.Formins regulate phragmoplast expansion, microtubule turnover rate, actin nucleation, and cell plate membrane remodeling during cytokinesis. 相似文献
888.
Sery Gonedelé Bi Didier P Sokouri Kouakou Tiékoura Oulo Alla N?Nan Marcel Lolo Félix Gnangbé Assanvo SP N?Guetta 《Bioinformation》2014,10(11):671-678
Cête d׳Ivoire continues to have the highest HIV-1 prevalence rate in West Africa, although the infection number is in constant
decline. The external envelope protein of the viruses is a likely site of selection, and responsible for receptor binding and entry into
host cells, and therefore constitutes an ideal region with which to investigate the evolutionary processes acting on HIV-1. In this
study, we analyse 189 envelope glycoprotein V3 loop region sequences of viruse isolates from 1995 to 2009, from HIV-1 untreated
patients living in Cête d׳Ivoire, to decipher the temporal relationship between disease diversity, divergence and selection. Our
analyses show that the nonsynonymous and synonymous ratio (dN/dS) was lower than 1 for viral populations analysed within 15
years, which showed the sequences did not undergo adequate immune pressure. The phylogenetic tree of the sequences analysed
demonstrated distinctly long internal branches and short external branches, suggesting that only a small number of viruses
infected the new host cell at each transmission. In addition to identifying sites under purifying selection, we also identified neutral
sites that can cause false positive inference of selection. These sites presented form a resource for future studies of selection
pressures acting on HIV-1 enν gene in Cête d׳Ivoire and other West African countries. 相似文献
889.
Patrick Ferrand Paulina Gasecka Alla Kress Xiao Wang Fatma-Zohra Bioud Julien Duboisset Sophie Brasselet 《Biophysical journal》2014,106(11):2330-2339
The orientational distribution of fluorophores is an important reporter of the structure and function of their molecular environment. Although this distribution affects the fluorescence signal under polarized-light excitation, its retrieval is limited to a small number of parameters. Because of this limitation, the need for a geometrical model (cone, Gaussian, etc.) to effect such retrieval is often invoked. In this work, using a symmetry decomposition of the distribution function of the fluorescent molecules, we show that polarized two-photon fluorescence based on tunable linear dichroism allows for the retrieval of this distribution with reasonable fidelity and without invoking either an a priori knowledge of the system to be investigated or a geometrical model. We establish the optimal level of detail to which any distribution can be retrieved using this technique. As applied to artificial lipid vesicles and cell membranes, the ability of this method to identify and quantify specific structural properties that complement the more traditional molecular-order information is demonstrated. In particular, we analyze situations that give access to the sharpness of the angular constraint, and to the evidence of an isotropic population of fluorophores within the focal volume encompassing the membrane. Moreover, this technique has the potential to address complex situations such as the distribution of a tethered membrane protein label in an ordered environment. 相似文献
890.
Alla A. Movsesian 《American journal of physical anthropology》2013,152(4):495-505
The population history of the East Slavs is complicated. There are still many unanswered questions relating to the origins and formation of the East Slavic gene pool. The aims of the current study were as follows: (1) to assess the degree of biological affinity in medieval East Slavic tribes and to test the hypothesis that East Slavic peoples have a common origin; (2) to show their genetic connections to the autochthonous populations of the northern part of Eastern Europe (Baltic and Finno‐Ugric tribes); and (3) to identify a genetic continuity between the bearers of Chernyakhov culture and medieval Eastern Slavs. In this study, nonmetric cranial trait data for medieval East Slavic tribes and comparative samples from unrelated groups were examined. Analyzes of phenotypic differentiation were based on Nei's standard genetic distance and hierarchical GST statistics. The results obtained suggest that the genetic affinity of the East Slavic tribes is due not only to inter‐tribal gene flow, but is, more importantly, a result of their common population history. Evidence of gene flow from the Baltic and Finno‐Ugric groups was showed in the gene pool of Eastern Slavs, as was genetic continuity between medieval East Slavic tribes and the populations of the preceding Chernyakhov culture. These findings support a “generalizing” hypothesis of East Slavic origin, in which a Slavic community was formed in some particular ancestral area, and subsequently spread throughout Eastern Europe. Am J Phys Anthropol 152:495–505, 2013. © 2013 Wiley Periodicals, Inc. 相似文献