scholarly journals Changes in the Activities of Protective Enzymes Induced by Mepiquat Chloride (DPC) in Cotton to Defend Against Aphids

2021 ◽  
Author(s):  
Quancheng Zhang ◽  
Xiaoxia Deng ◽  
Jungang Wang
Keyword(s):  
Population Density ◽  
Soluble Protein ◽  
Defense Mechanism ◽  
Specific Activity ◽  
Induced Defense ◽  
Insect Population ◽  
Detoxification Enzymes ◽  
Sod Activity ◽  
Mepiquat Chloride ◽  
Protective Enzymes

Abstract Background: Mepiquat chloride (DPC) enhances the resistance of cotton plants, and it is widely used as a growth regulator. DPC can stimulate photosynthesis, stabilize the structure of cotton leaves, and affect population reproduction and energy substances in cotton aphids, but interactions between DPC and cotton aphids remain unclear. In this study, we analyzed the physiological responses of cotton to DPC, and the toxicity of DPC toward cotton aphids, before and after feeding, to explore the DPC-induced defense mechanism against cotton aphids.Results: Measurements of protective enzyme activity in cotton showed that the soluble protein contents, peroxidase (POD) activity, and catalase (CAT) activity in cotton treated with different concentrations of DPC were higher than in the control. Superoxide dismutase (SOD) activity was higher than that of controls when the concentration of DPC was <0.1 g/L. Under aphid stress, POD activity of cotton treated with a low insect population density was significantly lower than that of controls, but the reverse was true for cotton treated with a high insect population density, and SOD activity was positively correlated with population density. The activities of detoxification enzymes in field and laboratory experiments showed that DPC promoted the specific activity of glutathione S-transferase (GST) in cotton aphids, while the specific activities of carboxylesterase and acetylcholinesterase were decreased.Conclusions: DPC enhanced the resistance of cotton by increasing the activity of protective enzymes. It also had a toxic effect on cotton aphids by increasing GST activity (the main DPC target) and lowering carboxylesterase and acetylcholinesterase activities. DPC increased the soluble protein content and SOD activity in cotton under aphid stress, and thereby enhanced tolerance to cotton aphids.

scholarly journals Gibberellic acid and nitrogen efficiently protect early seedlings growth stage from salt stress damage in Sorghum

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Adam Yousif Adam Ali ◽  
Muhi Eldeen Hussien Ibrahim ◽  
Guisheng Zhou ◽  
Nimir Eltyb Ahmed Nimir ◽  
Aboagla Mohammed Ibrahim Elsiddig ◽  
...  
Keyword(s):  
Chlorophyll Content ◽  
Seedling Growth ◽  
Soluble Protein ◽  
Dry Weight ◽  
Sod Activity ◽  
Seedling Length ◽  
Relative Water ◽  
Emergence Percentage ◽  
Negative Impacts ◽  
Stress Damage

AbstractSalinity one of environmental factor that limits the growth and productivity of crops. This research was done to investigate whether GA3 (0, 144.3, 288.7 and 577.5 μM) and nitrogen fertilizer (0, 90 and 135 kg N ha−1) could mitigate the negative impacts of NaCl (0, 100, and 200 mM NaCl) on emergence percentage, seedling growth and some biochemical parameters. The results showed that high salinity level decreased emergence percentage, seedling growth, relative water content, chlorophyll content (SPAD reading), catalase (CAT) and peroxide (POD), but increased soluble protein content, superoxide dismutase (SOD) activity and malondialdehyde (MDA) content. The SOD activity was decreased by nitrogen. However, the other measurements were increased by nitrogen. The interactive impact between nitrogen and salinity was significant in most parameters except EP, CAT and POD. The seedling length, dry weight, fresh weight, emergence percentage, POD, soluble protein and chlorophyll content were significantly affected by the interaction between GA3 and salinity. The GA3 and nitrogen application was successful mitigating the adverse effects of salinity. The level of 144.3 and 288.7 μm GA3 and the rate of 90 and 135 kg N ha−1 were most effective on many of the attributes studied. Our study suggested that GA3 and nitrogen could efficiently protect early seedlings growth from salinity damage.

scholarly journals Engineering a Pseudo-26-kDa Schistosoma Glutathione Transferase from bovis/haematobium for Structure, Kinetics, and Ligandin Studies

Biomolecules ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1844
Author(s):  
Neo Padi ◽  
Blessing Oluebube Akumadu ◽  
Olga Faerch ◽  
Chinyere Aloke ◽  
Vanessa Meyer ◽  
...  
Keyword(s):  
Glutathione Transferase ◽  
Specific Activity ◽  
Enzyme Stability ◽  
Competitive Inhibitor ◽  
Spectroscopic Studies ◽  
Complete Sequence ◽  
Detoxification Enzymes ◽  
Ligand Docking ◽  
Sequence Information ◽  
Dimer Interface

Glutathione transferases (GSTs) are the main detoxification enzymes in schistosomes. These parasitic enzymes tend to be upregulated during drug treatment, with Schistosoma haematobium being one of the species that mainly affect humans. There is a lack of complete sequence information on the closely related bovis and haematobium 26-kDa GST isoforms in any database. Consequently, we engineered a pseudo-26-kDa S. bovis/haematobium GST (Sbh26GST) to understand structure–function relations and ligandin activity towards selected potential ligands. Sbh26GST was overexpressed in Escherichia coli as an MBP-fusion protein, purified to homogeneity and catalyzed 1-chloro-2,4-dinitrobenzene-glutathione (CDNB-GSH) conjugation activity, with a specific activity of 13 μmol/min/mg. This activity decreased by ~95% in the presence of bromosulfophthalein (BSP), which showed an IC50 of 27 µM. Additionally, enzyme kinetics revealed that BSP acts as a non-competitive inhibitor relative to GSH. Spectroscopic studies affirmed that Sbh26GST adopts the canonical GST structure, which is predominantly α-helical. Further extrinsic 8-anilino-1-naphthalenesulfonate (ANS) spectroscopy illustrated that BSP, praziquantel (PZQ), and artemisinin (ART) might preferentially bind at the dimer interface or in proximity to the hydrophobic substrate-binding site of the enzyme. The Sbh26GST-BSP interaction is both enthalpically and entropically driven, with a stoichiometry of one BSP molecule per Sbh26GST dimer. Enzyme stability appeared enhanced in the presence of BSP and GSH. Induced fit ligand docking affirmed the spectroscopic, thermodynamic, and molecular modelling results. In conclusion, BSP is a potent inhibitor of Sbh26GST and could potentially be rationalized as a treatment for schistosomiasis.

scholarly journals Effects of Water Particles in the Jinjiang River Estuary on the Physiological and Biochemical Characteristics of Microcystit Flos-Aquae

2021 ◽  
Author(s):  
Yiting Nan ◽  
Peiyong Guo ◽  
Hui Xing ◽  
Sijia Chen ◽  
Bo Hu ◽  
...  
Keyword(s):  
Particle Size ◽  
Particulate Matter ◽  
Protein Content ◽  
Suspended Particulate Matter ◽  
Soluble Protein ◽  
Suspended Particles ◽  
Dose Effect ◽  
Soluble Protein Content ◽  
Sod Activity ◽  
Suspended Particulate

Abstract The effects of different concentrations (100,150,200,250 mg/L) and different particle sizes (0–75µm, 75–120µm, 120–150µm, 150–500µm) on soluble protein content, SOD and CAT activity, MDA content, chlorophyll a content and photosynthetic parameters of Microcystis flos-aquae were studied, the mechanism of the effect of suspended particulate matter on the physiology and biochemistry of Microcystis flos-aquae was discussed. The results showed that the soluble protein content of Microcystis flos-aquae did not change obviously after being stressed by suspended particles of different concentration/diameter. The SOD activity of Microcystis flos-aquae increased at first and then decreased with the increase of the concentration of suspended particulate matter. The SOD activity of Microcystis flos-aquae reached 28.03 U/mL when the concentration of suspended particulate matter was 100 mg/L. The CAT activity of Microcystis flos-aquae increased with the increase of the concentration of suspended particles, and reached the maximum value of 12.45 U/mgprot in the concentration group of 250 mg/L, showing a certain dose-effect. The effect of small particle size on SOD, CAT and MDA of Microcystis flos-aquae was more significant than that of large particle size. The larger the concentration and the smaller the particle size, the stronger the attenuation of light and the lower the content of chlorophyll a. Both Fv/Fm and Fv/F0 of Microcystis flos-aquae increased at first and then decreased under different concentration/size of suspended particles. The relative electron transfer rate gradually returned to the normal level with the passage of time. There was no significant difference in α value between treatment group and control group, ETRmax and Ik decreased.

Amino Acid Metabolism in Plants. III. Purification and Some Properties of a Multispecific Aminotransferase Isolated from Bushbean Seedlings (Phaseolus vulgaris L.)

1972 ◽  
Vol 50 (7) ◽  
pp. 813-829 ◽  
Author(s):  
J. C. Forest ◽  
F. Wightman
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Aspartic Acid ◽  
Aspartate Aminotransferase ◽  
Soluble Protein ◽  
Specific Activity ◽  
Aromatic Amino Acids ◽  
Total Activity ◽  
Aminotransferase Activity ◽  
Aromatic Aminotransferase

The development of aromatic aminotransferase activity was examined in cotyledons, roots, and shoots of bushbean seedlings growing under light or dark conditions for the first 2 weeks after germination. All three aromatic amino acid – α-ketoglutarate aminotransferase activities were found to have similar patterns of development in comparable organs grown under the two environmental conditions, and the changes in levels of activity appeared unrelated to variations in the endogenous amounts of free aromatic amino acids in the organs of these seedlings. The highest total activity for all three transamination reactions was found in the shoots of light-grown seedlings after 14 days, whereas the aminotransferases showing highest specific activity were found in roots of both kinds of seedlings after 8 days of growth. The intracellular distribution of the three aromatic aminotransferase activities and of aspartate aminotransferase activity was investigated by differential centrifugation of root homogenates. Only a total of 10% of these two activities was found in the two particulate fractions; the soluble protein in the final supernatant fraction accounted for almost 90% of the total aromatic and aspartate aminotransferase activities.The aromatic aminotransferase in the soluble protein fraction from seedling roots was purified about 600-fold by pH precipitation, ammonium sulfate fractionation, and Sephadex chromatography, and the recovery obtained was 30–35% based on total activity. It was observed that the specific activity for aspartate–α-ketoglutarate aminotransferase increased proportionally to the increase in aromatic aminotransferase activities during the different steps of purification. Gel electrophoresis of the purified fraction revealed only one protein band which corresponded to the product-specific stained band for the three aromatic aminotransferase activities assayed on other gels. The molecular weight of the purified aminotransferase was found to be about 128 000 daltons and its Stokes radius was calculated to be 43 ± 3 Å. The pH optima for the three aromatic aminotransferase activities and for aspartate aminotransferase activity were all found to be 8.5. The purified enzyme showed no specific requirement for pyridoxal phosphate and an examination of its amino acid substrate specificity revealed that it was able to catalyze transamination of L-aspartic acid, L-phenylalanine, L-tyrosine, and L-tryptophan when α-ketoglutarate was provided as amino group acceptor. The enzyme was also found to catalyze transamination of L-glutamic acid when oxaloacetate was used as amino group acceptor, but neither pyruvate nor glyoxylate were utilized as amino acceptors for transamination of any of the amino acids examined. The enzyme was found to catalyze transamination of aspartic acid with much greater velocity than its rate of reaction with any of the three aromatic amino acids, and the inclusion of aspartic acid in a reaction medium at equimolar concentration with any one of the three aromatic amino acids resulted in strong inhibition of the aromatic aminotransferase activity of the enzyme. All the evidence indicates that the soluble protein fraction purified from bushbean roots contained only one aminotransferase which was able to catalyze the transamination of five L-amino acids. The demonstration of the substrate multispeciftcity of this pure enzyme represents the first evidence for a multispecific aminotransferase in plants.

scholarly journals Developmental regulation of rat lung Cu,Zn-superoxide dismutase

1987 ◽  
Vol 246 (3) ◽  
pp. 697-703 ◽  
Author(s):  
M A Hass ◽  
D Massaro
Keyword(s):  
Superoxide Dismutase ◽  
Half Life ◽  
Specific Activity ◽  
Developmental Regulation ◽  
Progressive Increase ◽  
Enzyme Synthesis ◽  
Enzyme Activation ◽  
Sod Activity ◽  
Adult Rats ◽  
Copper Chelation

In the present investigation we found that lung Cu, Zn-superoxide dismutase (SOD) activity (units/mg of DNA) increases steadily in the rat from birth to adulthood. The specific activity (units/micrograms of enzyme) of Cu, Zn-SOD was unchanged from birth to adulthood, excluding enzyme activation as a mechanism responsible for the increase in enzyme activity. Lung synthesis of Cu, Zn-SOD peaked at 1 day before birth and decreased thereafter to adult values. Calculations, based on rates of Cu, Zn-SOD synthesis and the tissue content of the enzyme, indicated that lung Cu, Zn-SOD activity increased during development owing to the rate of enzyme synthesis exceeding its rate of degradation by 5-10%. These calculations were supported by measurements of enzyme degradation in the neonatal (half-life, t1/2, = 12 h) and adult lung (t1/2 = greater than 100 h); the difference in half-life did not reflect the rates of overall protein degradation in the lung, since these rates were not different in lungs from neonatal and adult rats. We did not detect differences in the Mr or pI of Cu, Zn-SOD during development, but the susceptibility of the enzyme to inactivation by heat or copper chelation decreased with increasing age of the rats. We conclude that the progressive increase in activity of Cu, Zn-SOD is due to a rate of synthesis that exceeds degradation of the enzyme. The data also suggest that increased stabilization of enzyme conformation accounts for the greater half-life of the enzyme in lungs of adult compared with neonatal rats.

Testing Insect Population Density Relative to Critical Densities with 2-SPRT

1993 ◽  
Vol 22 (2) ◽  
pp. 346-351 ◽  
Author(s):  
Madhuri S. Mulekar ◽  
Linda J. Young ◽  
J. H. Young
Keyword(s):  
Population Density ◽  
Insect Population

scholarly journals Modelling the structural response of cotton plants to mepiquat chloride and population density

2014 ◽  
Vol 114 (4) ◽  
pp. 877-887 ◽  
Author(s):  
Shenghao Gu ◽  
Jochem B. Evers ◽  
Lizhen Zhang ◽  
Lili Mao ◽  
Siping Zhang ◽  
...  
Keyword(s):  
Population Density ◽  
Structural Response ◽  
Mepiquat Chloride ◽  
Cotton Plants

PROTEIN SYNTHESIS IN DARK-GROWN BEAN LEAVES

1965 ◽  
Vol 43 (7) ◽  
pp. 817-824 ◽  
Author(s):  
David Racusen ◽  
Murray Foote
Keyword(s):  
Protein Synthesis ◽  
Soluble Protein ◽  
Specific Activity ◽  
Disc Electrophoresis ◽  
Protein Zone ◽  
Bean Leaves

RuDP carboxylase was present in 4-day-old, dark-grown bean leaves. The enzyme increased during subsequent dark growth and in 11 days reached one-third of the specific activity of a light-grown control. Preparative disc electrophoresis of the soluble protein revealed a zone symmetrical with RuDP carboxylase. Increases in RuDP carboxylase during dark growth were matched by corresponding increases in this protein zone. The correlation indicated that the enzyme accounted for 45% of the soluble protein in 11-day-old, light-grown leaves. The formation of peroxidase and catalase was much slower than the formation of RuDP carboxylase during dark growth.

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