scholarly journals Proteolytic Activity in Meadow Soil after the Application of Phytohormones

Biomolecules ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 507 ◽  
Author(s):  
Holik ◽  
Vranová
Keyword(s):  
Nitrogen Cycle ◽  
Alpine Meadow ◽  
Inhibitory Effect ◽  
Meadow Soil ◽  
Soil Environment ◽  
Chlorocholine Chloride ◽  
Mineral Horizon ◽  
Native Soil ◽  
Similar Inhibitory Effect ◽  
Soil Nitrogen Cycle

Phytohormones, similar to soil enzymes, are synthesized and secreted into the soil environment by fungi and microorganisms. Phytohormones are involved in regulating microbial community activity in the rhizosphere. This paper examines how auxins, cytokinins, ethephon and chlorocholine chloride affect the activity of native soil proteases in the organo-mineral horizon of an alpine meadow. In the meadow habitat, native soil proteases were inhibited by auxins whereas the effect of cytokinins on these enzymes was not statistically significant. A similar inhibitory effect on the activity of proteases was shown for ethephon and chlorocholine chloride, both of which also inhibited the activity of native soil proteases in the alpine meadow soil. Overall, the inhibitory effect of phytohormones on the activity of native protease activity may affect plant nutrition by retarding the nitrogen cycle in the soil. This work contributes to our understanding of the influence of substances produced by the rhizosphere that can actively participate in the activity of soil microorganisms and consequently influence the soil nitrogen cycle.

scholarly journals Alteration in the Native Proteolytic Activity in the Forest Soil after the Application of Phytohormones

2019 ◽  
Author(s):  
Ladislav Holik ◽  
Valerie Vranová
Keyword(s):  
Organic Matter ◽  
Proteolytic Activity ◽  
Inhibitory Effect ◽  
Tree Stand ◽  
Chlorocholine Chloride ◽  
Synthetic Auxins ◽  
Decomposition Of Organic Matter ◽  
Native Soil ◽  
Negative Effect ◽  
Transformation Of Organic Matter

Soil proteases are involved in the transformation of organic matter and thus influence the nutrient turnover in the ecosystem. Phytohormones, similarly to proteases, are synthesized and secreted into the soil by fungi and microorganisms and regulating their activity in the rhizosphere. The aim of our work was to find out how the presence of auxins, cytokinins, ethephone and chlorocholine chloride affects the activity of native soil proteases at the spruce tree stand. Auxins stimulated the native proteolytic activity in the spruce tree stand. Synthetic auxins most stimulated the activity of 2-naphthoxyacetic acid and the naturally occurring auxins of indole-3-acetic acid in the organic horizon of the spruce forest. Cytokinins, ethephone and chlorocholine chloride inhibited the activity of native soil proteases in the spruce tree stand. The highest inhibitory effect was found in ethephone and chlorocholine chloride. Overall, the negative effect of phytohormones on the activity of the native proteolytic activity may slow down the decomposition of organic matter and thus make plant nutrition more difficult. The outcomes of our work assist with understanding of the effect of substances produced by the rhizosphere on the activity of soil microorganisms and the soil nitrogen cycle.

scholarly journals Effect of Plant Growth Regulators on Protease Activity in Forest Floor of Norway Spruce Stand

Forests ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 665
Author(s):  
Ladislav Holik ◽  
Jiří Volánek ◽  
Valerie Vranová
Keyword(s):  
Organic Matter ◽  
Proteolytic Activity ◽  
Protease Activity ◽  
Forest Floor ◽  
Soil Microbial Activity ◽  
Inhibitory Effects ◽  
Chlorocholine Chloride ◽  
Soil Microbial ◽  
Native Soil ◽  
Transformation Processes

Soil proteases are involved in organic matter transformation processes and, thus, influence ecosystem nutrient turnovers. Phytohormones, similarly to proteases, are synthesized and secreted into soil by fungi and microorganisms, and regulate plant rhizosphere activity. The aim of this study was to determine the effect of auxins, cytokinins, ethephon, and chlorocholine chloride on spruce forest floor protease activity. It was concluded that the presence of auxins stimulated native proteolytic activity, specifically synthetic auxin 2-naphthoxyacetic acid (16% increase at added quantity of 5 μg) and naturally occurring indole-3-acetic acid (18%, 5 μg). On the contrary, cytokinins, ethephon and chlorocholine chloride inhibited native soil protease activity, where ethephon (36% decrease at 50 μg) and chlorocholine chloride (34%, 100 μg) showed the highest inhibitory effects. It was concluded that negative phytohormonal effects on native proteolytic activity may slow down organic matter decomposition rates and hence complicate plant nutrition. The study enhances the understanding of rhizosphere exudate effects on soil microbial activity and soil nitrogen cycle.

scholarly journals Cyclic GMP regulates activation of phosphoinositidase C by bradykinin in sensory neurons

1996 ◽  
Vol 316 (2) ◽  
pp. 539-544 ◽  
Author(s):  
Justine S. HARVEY ◽  
Gillian M. BURGESS
Keyword(s):  
Cyclic Gmp ◽  
Inhibitory Effect ◽  
Neonatal Rat ◽  
Drg Neurons ◽  
Rapid Phase ◽  
Surface Receptors ◽  
Similar Inhibitory Effect ◽  
Key Factor ◽  
The Right ◽  
Oxide Synthase

Prior exposure of cultured neonatal rat dorsal root ganglion (DRG) neurons to bradykinin resulted in marked attenuation of bradykinin-induced activation of phosphoinositidase C (PIC). The (logconcentration)–response curve for bradykinin-induced [3H]inositol trisphosphate ([3H]IP3) formation was shifted to the right and the maximum response was reduced. Bradykinin increases cyclic GMP (cGMP) in DRG neurons [Burgess, Mullaney, McNeill, Coote, Minhas and Wood (1989) J. Neurochem. 53, 1212–1218] and treatment of the neurons with dibutyryl cGMP (dbcGMP) had a similar, inhibitory, effect on bradykinin-induced [3H]IP3 formation. NG-Nitro-L-arginine (LNNA) blocked bradykinin-induced formation of cGMP. It prevented the functional uncoupling induced by pretreatment with bradykinin, but not the inhibitory effect of dbcGMP on [3H]IP3 formation. The ability of LNNA to prevent desensitization was reversed by excess L-arginine, indicating that its actions were mediated through inhibition of nitric oxide synthase. In addition to functional desensitization, exposure to bradykinin reduced the number of cell-surface receptors detected with [3H]bradykinin, without affecting its KD value for the remaining sites. In contrast to bradykinin, pretreatment with dbcGMP had no effect on either the KD or Bmax for [3H]bradykinin binding. This implies that the inhibitory effect of dbcGMP was downstream from the binding of bradykinin to its receptor and upstream of IP3 formation. The lack of effect of dbcGMP on [3H]bradykinin binding suggests that the decrease in receptor number induced by bradykinin was mediated by a different mechanism and was not a key factor in the rapid phase of desensitization in these cells.

The diversity of denitrifying bacteria in the alpine meadow soil of Sanjiangyuan natural reserve in Tibet Plateau

2006 ◽  
Vol 51 (10) ◽  
pp. 1245-1254 ◽  
Author(s):  
Yuguang Zhang ◽  
Diqiang Li ◽  
Huimin Wang ◽  
Qiming Xiao ◽  
Xueduan Liu
Keyword(s):  
Alpine Meadow ◽  
Denitrifying Bacteria ◽  
Tibet Plateau ◽  
Meadow Soil ◽  
Natural Reserve

The Reorganization of Tissue Masses of Cordylophora Lacustris and the Effect of Oral Cone Grafts, with Supplementary Observations on Obelia Gelatinosa

1938 ◽  
Vol 15 (3) ◽  
pp. 303-326
Author(s):  
L. C. BEADLE ◽  
F. A. BOOTH
Keyword(s):  
Brackish Water ◽  
No Reduction ◽  
Sea Water ◽  
Magnesium Deficiency ◽  
Inhibitory Effect ◽  
Sodium Cyanide ◽  
Potassium Deficiency ◽  
Complete Suppression ◽  
Oral Cone ◽  
Similar Inhibitory Effect

1. A method is described for the preparation of reconstitution masses from the expressed coenosarc tissues of Cordylophora lacustris. This brackish water hydroid is more suitable for the purpose than others which have so far been used. 2. Under normal conditions (50% sea water at 16-17° C.) such masses produce one or more hydranths within about 2 days and often additional unorganized outgrowths. 3. The main histological features of the reconstitution masses as seen in sections are described. From these observations and from experiments with masses made from isolated ectoderm and endoderm it is concluded that there is no reduction of the cells to a pleuripotent condition. The cells of each original layer can form only the layer from which they were derived. 4. Masses made from endoderm cells only are incapable of holding together for long and soon disintegrate. Pure ectoderm masses, however, rapidly round up and form hollow vesicles but do not produce hydranths. 5. No signs of cell division during reconstitution were detected. 6. The "interstitial" cells observed in the coenosarc ectoderm are thus not able to differentiate into endoderm when this is absent and there is no indication that they perform any essential part in the process of reconstitution. 7. An oral cone when grafted into a mass will determine the position of the regenerated hydranth which develops in relation to the graft. 8. Evidence is given to prove that the action of the cone is one of pure induction and that it does not supply cells to the induced hydranth. 9. The action of the cone is independent of its orientation and it will produce its effect even after previous chopping up and reuniting. Attempts to graft killed oral cones have so far failed. 10. Grafts of distal halves of young gonophores do not induce hydranths. 11. Calcium or magnesium deficiency in the medium results in complete suppression of hydranth formation from masses but not always of unorganized outgrowths. Oral cone grafts, however, can overcome this inhibition and tentacles are formed. A similar inhibitory effect is produced by potassium deficiency, but is not overcome by an oral cone graft. 12. The quantity of calcium required to permit tentacle formation in plain masses is very small (c. 0.00006 M). 13. Sodium cyanide (c. M/30,000), phenyl urethane (c. M/3000) and low temperature (5.5-6.5° C.) can inhibit hydranth formation in plain masses, but oral cone grafts overcome this inhibition and induce the formation of tentacles. 14. Reconstitution masses which produced hydranths were also made from the coenosarc of another brackish water hydroid Obelia gelatinosa. Isolated ectoderm and endoderm were incapable of reorganization. 15. Mixed masses of Cordylophora and Obelia coenosarc separated into regions composed of tissue from one species only and each produced hydranths independently.

Tumor-promoting phorbol esters inhibit monocyte adherence to endothelial cells

1989 ◽  
Vol 66 (1) ◽  
pp. 437-442 ◽  
Author(s):  
D. W. Kamp ◽  
K. D. Bauer ◽  
D. B. Rubin ◽  
M. M. Dunn
Keyword(s):  
Endothelial Cells ◽  
Phorbol Esters ◽  
Kinetic Studies ◽  
Inhibitory Effect ◽  
Adhesive Interaction ◽  
Kinase C ◽  
Inflammatory Stimuli ◽  
Similar Inhibitory Effect ◽  
Monocyte Adherence ◽  
Activate Protein Kinase

Monocyte adherence to endothelial cells (EC) is an important event in the development of a monocytic inflammatory response, yet the effects of inflammatory mediators on monocyte adherence to EC are not well described. We compared the effects of phorbol esters known to activate protein kinase C, including phorbol myristate acetate (PMA) and phorbol 12,13-dibutyrate (PDA), on monocyte adherence to bovine aortic EC. Human monocytes (purity 90 +/- 1% SE) were isolated by centrifugal elutriation to obtain monocytes not previously exposed to a surface. Kinetic studies revealed that 51Cr-labeled monocyte adherence to EC reached a plateau after a 45-min incubation. Concentrations of PMA between 10 and 1,000 ng/ml significantly decreased monocyte adherence to EC (26 +/- 10 and 35 +/- 8% decrease compared with control, respectively). Concentrations of PDA of 100 and 1,000 ng/ml had a similar inhibitory effect. In contrast, the chemotactic stimulus, zymosan-activated serum, significantly increased monocyte adherence (40 +/- 14% increase compared with control). Thus inflammatory stimuli have different effects on the adhesive interaction of monocytes to EC. This may provide a mechanism to selectively modulate monocyte egress from the circulation into extravascular inflammatory sites.

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