Lipoxygenase activity in fresh, stored, and germinating pearl millet seeds resistant and susceptible to downy mildew disease

1992 ◽  
Vol 70 (10) ◽  
pp. 2028-2031 ◽  
Author(s):  
K. C. Nagarathna ◽  
Sudheer A. Shetty ◽  
H. S. Prakash ◽  
S. G. Bhat ◽  
H. Shekara Shetty
Keyword(s):  
Enzyme Activity ◽  
Key Words ◽  
Downy Mildew ◽  
Pearl Millet ◽  
Lipoxygenase Activity ◽  
High Enzyme ◽  
Pearl Millet Seeds ◽  
Resistant Genotypes ◽  
High Enzyme Activity ◽  
Downy Mildew Disease

Lipoxygenase activity was studied in fresh, stored, and germinating pearl millet seeds of downy mildew resistant and susceptible genotypes. In both fresh and stored seeds, the enzyme activity was greater in resistant genotypes compared with that of the susceptible ones. In seeds stored for a period of 6 months, a significant reduction in the lipoxygenase activity was recorded, the reduction being greater in resistant seeds. Lipoxygenase activity decreased significantly in germinating seedlings of resistant genotypes, whereas it increased significantly in the susceptible seedlings. The high vigour in the resistant seeds of downy mildew resistant genotypes is attributed to their high enzyme activity. Key words: lipoxygenase, pearl millet, downy mildew, resistant, susceptible.

Resistance to downy mildew in pearl millet is associated with increased phenylalanine ammonia lyase activity

2005 ◽  
Vol 32 (3) ◽  
pp. 267 ◽  
Author(s):  
N. P. Geetha ◽  
K. N. Amruthesh ◽  
R. G. Sharathchandra ◽  
H. S. Shetty
Keyword(s):  
Enzyme Activity ◽  
Downy Mildew ◽  
Pearl Millet ◽  
Phenylalanine Ammonia Lyase ◽  
Cultured Cells ◽  
Enzyme Activation ◽  
Sclerospora Graminicola ◽  
Pathogen Infection ◽  
Pal Activity ◽  
Downy Mildew Disease

Phenylalanine ammonia lyase (PAL) activity was studied in pearl millet cultivars with different levels of resistance to the downy mildew disease caused by Sclerospora graminicola, an important oomycete pathogen. PAL activity was elevated in resistant host cultivar and decreased in susceptible cultivars following downy mildew pathogen infection. The enzyme activation varied between cultivars and was correlated with the degree of resistance to downy mildew disease. The induction of PAL as a response to pathogen inoculation was further corroborated by a time-course study in seedlings and cultured cells of pearl millet. The level of PAL activity was highest at 1.5 h in cultured cells and 4 h in seedlings of resistant host cultivar after inoculation with Sclerospora graminicola. Further studies on PAL activity in different tissues of seedlings showed highest enzyme activity in the young growing region of the root of the resistant host cultivars. The accumulation of wall-bound phenolics and lignin was higher in the resistant cultivar seedlings as evidenced by phloroglucinol–HCl staining and p-coumaric acid assay. The temporal changes in lignin concentration and the concentration of soluble phenolics were greater in root tissues of resistant cultivars than in those of susceptible cultivars. Treatment of resistant seedlings with a PAL inhibitor, α-aminooxy-β-phenylpropionic acid, resulted in the enhancement of the enzyme activity, whereas in the presence of 1 mm trans-cinnamic acid the pathogen-induced PAL was completely inhibited. Treatment of pearl millet seedlings with exogenously applied PAL inhibitors induced downy mildew disease susceptibility in the resistant pearl millet cultivar, consistent with direct involvement of PAL in downy mildew resistance. Results are discussed with respect to the presumed importance of host phenolic compounds and lignin accumulation and its relation to PAL activation as a response to the pathogen infection.

Involvement of silicon in pearl millet resistance to downy mildew disease and its interplay with cell wall proline/hydroxyproline-rich glycoproteins

2008 ◽  
Vol 37 (5) ◽  
pp. 498 ◽  
Author(s):  
S. Deepak ◽  
G. Manjunath ◽  
S. Manjula ◽  
S. Niranjan-Raj ◽  
N. P. Geetha ◽  
...  
Keyword(s):  
Cell Wall ◽  
Downy Mildew ◽  
Pearl Millet ◽  
Downy Mildew Disease

scholarly journals Exogenous Trehalose Treatment Enhances the Activities of Defense-Related Enzymes and Triggers Resistance against Downy Mildew Disease of Pearl Millet

2016 ◽  
Vol 7 ◽  
Author(s):  
Sharathchandra R. Govind ◽  
Sudisha Jogaiah ◽  
Mostafa Abdelrahman ◽  
Hunthrike S. Shetty ◽  
Lam-Son P. Tran
Keyword(s):  
Downy Mildew ◽  
Pearl Millet ◽  
Downy Mildew Disease

Su1843 High Enzyme Activity UGT1A1 or Low Activity Ugt1a8 and Ugt2b4 Genotypes Increase Esophageal Cancer Risk

2012 ◽  
Vol 142 (5) ◽  
pp. S-517
Author(s):  
Polat Dura ◽  
Jody Salomon ◽  
Rene te Morsche ◽  
Hennie Roelofs ◽  
Jon Kristinsson ◽  
...  
Keyword(s):  
Esophageal Cancer ◽  
Enzyme Activity ◽  
Cancer Risk ◽  
High Enzyme ◽  
Low Activity ◽  
High Enzyme Activity

Internodal invertases and stalk maturity in sugarcane

1991 ◽  
Vol 116 (2) ◽  
pp. 239-243 ◽  
Author(s):  
H. L. Sehtiya ◽  
J. P. S. Dendsay ◽  
A. K. Dhawan
Keyword(s):  
Enzyme Activity ◽  
Cell Expansion ◽  
Reducing Sugars ◽  
Sucrose Solution ◽  
Invertase Activity ◽  
Neutral Invertase ◽  
High Enzyme ◽  
Stem Slices ◽  
High Enzyme Activity

SUMMARYAcid and neutral invertase activities in the stem of an early (CoJ 64) and a late cultivar (Col 148) of sugarcane were estimated by incubating stem slices in buffered sucrose solution and measuring the production of reducing sugars. High enzyme activity occurred in young tissue but the activity of both enzymes was considerably lower in the mature internodes. Acid and neutral invertase activity was highest in the midinternode position, corresponding to the region of cell expansion.

scholarly journals Isolation and evaluation of proteolytic actinomycete isolates as novel inducers of pearl millet downy mildew disease protection

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Sudisha Jogaiah ◽  
Mahantesh Kurjogi ◽  
Sharathchandra Ramasandra Govind ◽  
Shekar Shetty Huntrike ◽  
Vedamurthy Ankala Basappa ◽  
...  
Keyword(s):  
Downy Mildew ◽  
Pearl Millet ◽  
Downy Mildew Disease

Preparation of enzymatically highly active pegylated-D-amino acid oxidase and its application to antitumor therapy

2021 ◽  
Vol 18 ◽  
Author(s):  
Hideaki Nakamura ◽  
Appiah Enoch ◽  
Shotaro Iwaya ◽  
Sakura Furusho ◽  
Shoko Tsunoda ◽  
...  
Keyword(s):  
Enzyme Activity ◽  
Antitumor Effect ◽  
Tumor Tissue ◽  
Acid Oxidase ◽  
Antitumor Therapy ◽  
Amino Acid Oxidase ◽  
Tumor Bearing ◽  
Highly Active ◽  
High Enzyme ◽  
High Enzyme Activity

Background: D-amino acid oxidase (DAO) is an H2O2-generating enzyme, and tumor growth suppression by selective delivery of porcine DAO in tumors via the cytotoxic action of H2O2 has been reported. DAO isolated from Fusarium spp. (fDAO) shows much higher enzyme activity than porcine DAO, although the application of fDAO for antitumor treatment has not yet been determined. Objective: The purpose of this study was to prepare enzymatically highly active pegylated-fDAO, and to determine whether it accumulates in tumors and exerts a potent antitumor effect in tumor-bearing mice. Methods: Polyethylene glycol (PEG; Mw. 2000) was conjugated to fDAO to form PEGylated fDAO (PEG-fDAO). PEGfDAO was intravenously administered into S180 tumor-bearing mice, and the body distribution and antitumor activity of PEG-fDAO was determined. Results: The enzyme activity of PEG-fDAO was 26.1 U/mg, which was comparable to that of fDAO. Intravenously administered PEG-fDAO accumulated in tumors with less distribution in normal tissue except in the plasma. Enzyme activity in the tumor was 60–120 mU/g-tissue over 7–20 h after i.v. injection of 0.1 mg of PEG-fDAO. To generate the H2O2 in the tumor tissue, PEG-fDAO was intravenously administered, and then, D-phenylalanine was intraperitoneally administered after a lag time. No remarkable tumor suppression effect was observed under conditions used in this study, compared to the non-treated group. Conclusion: The results suggest that PEG-fDAO maintained high enzymatic activity after pegylation. Treatment with PEGfDAO conferred high enzyme activity on tumor tissue; 3–6 fold higher than that of previously reported pDAO; however, high enzyme activity in the plasma limited repeated treatment owing to lethal toxicity, which seemingly led to poor therapeutic outcome. Overall, the use of PEG-fDAO is promising for antitumor therapy, although the suppression of DAO activity in the plasma would also be required rather than only the increase in DAO activity in the tumor for an antitumor effect.

A Study of the Colorimetric Dinitrophenylhydrazine Method for the Determination of Serum Glutamic Oxalacetic Transaminase Activity

1966 ◽  
Vol 12 (4) ◽  
pp. 217-225 ◽  
Author(s):  
J S Annino
Keyword(s):  
Enzyme Activity ◽  
Transaminase Activity ◽  
Reagent Blank ◽  
Glutamic Oxalacetic Transaminase ◽  
Color Development ◽  
High Enzyme ◽  
Serum Glutamic Oxalacetic Transaminase ◽  
The Relationship ◽  
High Enzyme Activity

Abstract Study of the colorimetric transaminase method of Reitman and Frankel for the determination of serum glutamic oxalacetic transaminase activity revealed the following: (1) although maximum absorption occurs at 444 mµ, absorbance readings at 505 mµ gave satisfactory results; (2) color development is immediate and the color is stable for at least 1 hr.; (3) a pyruvate calibration standard may be used; (4) sample blanks are not usually necessary; (5) a reagent blank should accompany each group of analyses and should be used as a photometric reference; (6) the relationship between dilution and enzyme activity is linear; and (7) although the relationship between incubation time and activity is not exactly linear, a factor has been determined to permit the use of a 12-min. incubation period with samples showing high enzyme activity.

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