Nutritional Requirements and Invertase Activity of Rhizobium Nodulating Sesbania sesban Roots

1993 ◽  
Vol 148 (8) ◽  
pp. 582-587
Author(s):  
F.A. Helemish ◽  
M.T. El Mokadem ◽  
S.H. Abou Zekry

On the grey forest medium-loamy soil of Vladimir Opolye region we have studied the impact of various methods of basic cultivation and fertilizer systems on the activity of redox and hydrolytic enzymes: ure-ase (nitrogen cycle), invertase (carbon cycle), phosphatase (phosphorus cycle), and catalase, involved in the cycle of carbon in the soil. The second humus horizon with capacity of 19-24cm was found at the depth of 20 - 21 cm on the experimental field. We have studied three modes of basic soil cultivation: an-nual shallow flat plowing (6-8 cm), annual deep flat plowing (20-22 cm), and annual moldboard plowing (20-22 cm) with normal and intensive application of fertilizers. The most enzymatically active layer is 0-20 cm. No relevant difference has been found in the level of enzymes activity between variants of basic soil treatment. Activity of enzymes increases with application of fertilizers on the intensive background. In agrogenic soils, soil enzymatic activity is lower on average by 16-22% compared to the soil of the res-ervoir. The biggest negative transformation of activity has been observed at the urease enzyme (up to 50%). With annual moldboard plowing on the intensive backgroung, enzyme activity has been close to the natural level – 98.4%. Catalise and invertase activity in this case were found to be higher (105 and 116% respectively) than that of natural analogues. Activity of enzymes increases with intensive application of fertilizers as compared with normal background. This is particularly evident with 6-8cm deep beardless plowing and 20-22cm deep moldboard plowing. In general, the obtained biochemical indicators charac-terize the highest environmental sustainability of this variation within our research.


HortScience ◽  
1990 ◽  
Vol 25 (9) ◽  
pp. 1091G-1091
Author(s):  
Anne K. Hurley ◽  
B. Greg Cobb

Cucumis sativus, L., `Poinsett' seedlings were grown under artificial light in 40% modified Hoagland's solution until an average plant plastochron index of 4.73 was reached. Plants were then placed in solutions of (1) 0 mM NaCl, (2) 80 mM NaCl (salt-shock), or (3) placed in a dropwise gradient solution of NaCl and Hoagland's until the final concentration of 80 mM NaCl was reached at 41 hours. Leaves of the 80 mM shock treatment wilted immediately, but recovered turgor within 6 hours. Leaves of 80 mM gradient did not wilt at anytime. The control and gradient treatments had relative growth rates which were similar to each other, but RGR decreased in the shock treatment. Invertase activity was measured in the roots at 24, 41, and 48 hours after initial treatment. Invertase activity of shock treatment increased significantly over the controls at 24 hours. The 80mM gradient was not significantly different than either treatment. Four isozymes of α– galactosidase were detected. The relative intensities of the bands varied with time and treatment. One invertase band was resolved in roots on 8% native acrylamide gels. SDS gels indicated increases in proteins in the gradient treatment compared to the control and the 80 mM shock treatment.


HortScience ◽  
1994 ◽  
Vol 29 (5) ◽  
pp. 539f-539
Author(s):  
Kirk W. Pomper ◽  
Patrick J. Breen

Invertase (INV) may influence sugar levels and assimilate transport in strawberry fruit. Several groups, including our own, have only detected acid INV (optimum pH 4.6) in strawberry fruit, however, recently Hubbard et al. (Physiol. Plant. 82:191-196, 1991) reported the presence of a neutral INV (pH 7.5). Since dissimilar isolation protocols may have contributed to the different findings, we re-examined our work with developing `Brighton' strawberry using the extraction procedure of Hubbard et al. Neutral INV activity per gFW (pH 7.5-8.0) increased many fold as fruit developed from green to the red ripe stage. Acid INV activity decreased markedly from green-white to the red stage. In addition, when fruit extracts were precipitated with cold acetone, a pellet contained 60% of the acid INV activity, and a surface coagulation of protein contained 60% of the neutral INV activity. This allowed easy separation of these two enzymes. Extraction methodologies affect isolation of neutral INV activity from strawberry fruit.


2019 ◽  
Vol 16 (4) ◽  
pp. 386-391 ◽  
Author(s):  
Kenneth Lundstrom

Epigenetic mechanisms comprising of DNA methylation, histone modifications and gene silencing by RNA interference have been strongly linked to the development and progression of various diseases. These findings have triggered research on epigenetic functions and signal pathways as targets for novel drug discovery. Dietary intake has also presented significant influence on human health and disease development and nutritional modifications have proven important in prevention, but also the treatment of disease. Moreover, a strong link between nutrition and epigenetic changes has been established. Therefore, in attempts to develop novel safer and more efficacious drugs, both nutritional requirements and epigenetic mechanisms need to be addressed.


2017 ◽  
Vol 10 (1) ◽  
pp. 35-45
Author(s):  
N.F. Lunkova ◽  
N.A. Burmistrova ◽  
M.S. Krasavina

Background:A growing part of the root is one of the most active sinks for sucrose coming from source leaves through the phloem. In the root, sucrose is unloaded from conducting bundles and is distributed among the surrounding cells. To be involved in the metabolism, sucrose should disintegrate into hexoses by means of degrading enzymes.Aims:The aim of this research was to explore the possibility of the involvement of one such enzymes, invertase, in phloem unloading as well as distribution of its activity in the functionally different tissues of the plant root tips.Method:To estimate the enzyme activities in root tissues, we applied two techniques: the histochemical method using nitro blue tetrazolium. The localization of phloem unloading was studied with carboxyfluorescein, a fluorescent marker for symplastic transport.Results:Invertase activity was not detected in the apical part of the meristem. It appeared only between the basal part of this zone and the beginning of the elongation zone. There is the root phloem unloading in that area. Invertase activity increased with increasing the distance from the root tip and reached the highest values in the region of cell transition to elongation and in the elongation zone. The activities of the enzyme varied in different tissues of the same zone and sometimes in the neighboring cells of the same tissue. Biochemical determination of invertase activity was made in the maize root segments coincident to the zones of meristem, cell elongation and differentiation. The results of both methods of determination of invertase activity were in agreement.Conclusion:It was concluded that phloem unloading correlated with invertase activity, possibly because of the activation of invertase by unloaded sucrose. Invertase is one of the factors involved in the processes preparing the cells for their transition to elongation because the concentration of osmotically active hexoses increases after cleavage of sucrose, that stimulates water entry into the cells, which is necessary for elongation growth.


2017 ◽  
Vol 6 (8) ◽  
pp. 5459
Author(s):  
Chandra Teja K. ◽  
Rahman S. J.

Entomopathogenic fungi like Beauveria bassiana, Metarhizium anisopliae and Lecanicillium lecanii are used in biological control of agricultural insect pests. Their specific mode of action makes them an effective alternative to the chemical Insecticides. Virulent strains of Entomopathogenic fungi are effectively formulated and used as bio-insecticides world-wide. Amenable and economical multiplication of a virulent strain in a large scale is important for them to be useful in the field. Culture media plays a major role in the large-scale multiplication of virulent strains of Entomopathogens. Different substrates and media components are being used for this purpose. Yet, each strain differs in its nutritional requirements for the maximum growth and hence it is necessary to standardize the right components and their optimum concentrations in the culture media for a given strain of Entomopathogen. In the current study, three different nitrogen sources and two different carbon sources were tried to standardize the mass multiplication media for seven test isolates of Entomopathogenic fungi. A study was also conducted to determine the ideal grain media for the optimum conidial yields of the test isolates. Yeast extract was found to be the best Nitrogen source for the isolates. The isolates tested, differed in their nutritional requirements and showed variation in the best nitrogen and carbon sources necessary for their growth. Variation was also found in the optimum concentration of both the ingredients for the growth and sporulation of the isolates. In the solid-state fermentation study, rice was found to be the best grain for the growth of most of the fungi followed by barley. The significance of such a study in the development of an effective Myco-insecticide is vital and can be successfully employed in agriculture is discussed.


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