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פותח על ידי קלירמאש פתרונות בע"מ -
Effects of salts on NADH-malate dehydrogenase activity in celery leaves during their maturation and senescence
Year:
1981
Source of publication :
Plant Science Letters
Authors :
אלוני, בנימין
;
.
פרסמן, איתן
;
.
שקד, רחל
;
.
Volume :
20
Co-Authors:
Aloni, B., Institute of Field and Garden Crops, Agricultural Research Organization, The Volcani Center, Bet Dagan, Israel
Pressman, E., Institute of Field and Garden Crops, Agricultural Research Organization, The Volcani Center, Bet Dagan, Israel
Shaked, R., Institute of Field and Garden Crops, Agricultural Research Organization, The Volcani Center, Bet Dagan, Israel
Facilitators :
From page:
239
To page:
250
(
Total pages:
12
)
Abstract:
The effect of several inorganic salts on the activity of NADH-malate dehydrogenase (MDH) from the petiole and the blade of celery leaves of different age, was investigated. KCl and NaCl, in a concentration range of 100-180 mM, activated the enzyme similarly when given in the assay medium. At higher concentrations, both salts became inhibitory. CaCl2 and MgCl2 activated the enzyme at a much lower concentration, with MgCl2 being the weaker activator. The activation of celery leaf MDH by KCl was found to vary with the leaf age. As the leaf matured, the extracted enzyme exhibited increased activation by KCl. However, the transition from maturity to senescence was accompanied by a decline in the activation of the enzyme by the salt. During senescence of detached leave blades in the dark, the MDH activation by KCl undergoes the same changes found in the intact plant. The changes in MDH activity due to either age or KCl, were a result of changes in the Vmax and not of the Km-value for oxaloacetate. Acceleration of senescence by transient water stress or flooding induced a marked increase in the MDH activation by KCl in vitro. It is suggested that the change in the enzyme response to ions is part of a regulation mechanism by which MDH activity is maintained during various developmental stages of the leaf. However, in accelerated senescence situations, this regulation mechanism is disrupted. © 1981.
Note:
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More details
DOI :
10.1016/0304-4211(81)90268-6
Article number:
0
Affiliations:
Database:
סקופוס
Publication Type:
מאמר
;
.
Language:
אנגלית
Editors' remarks:
ID:
21684
Last updated date:
02/03/2022 17:27
Creation date:
16/04/2018 23:46
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Scientific Publication
Effects of salts on NADH-malate dehydrogenase activity in celery leaves during their maturation and senescence
20
Aloni, B., Institute of Field and Garden Crops, Agricultural Research Organization, The Volcani Center, Bet Dagan, Israel
Pressman, E., Institute of Field and Garden Crops, Agricultural Research Organization, The Volcani Center, Bet Dagan, Israel
Shaked, R., Institute of Field and Garden Crops, Agricultural Research Organization, The Volcani Center, Bet Dagan, Israel
Effects of salts on NADH-malate dehydrogenase activity in celery leaves during their maturation and senescence
The effect of several inorganic salts on the activity of NADH-malate dehydrogenase (MDH) from the petiole and the blade of celery leaves of different age, was investigated. KCl and NaCl, in a concentration range of 100-180 mM, activated the enzyme similarly when given in the assay medium. At higher concentrations, both salts became inhibitory. CaCl2 and MgCl2 activated the enzyme at a much lower concentration, with MgCl2 being the weaker activator. The activation of celery leaf MDH by KCl was found to vary with the leaf age. As the leaf matured, the extracted enzyme exhibited increased activation by KCl. However, the transition from maturity to senescence was accompanied by a decline in the activation of the enzyme by the salt. During senescence of detached leave blades in the dark, the MDH activation by KCl undergoes the same changes found in the intact plant. The changes in MDH activity due to either age or KCl, were a result of changes in the Vmax and not of the Km-value for oxaloacetate. Acceleration of senescence by transient water stress or flooding induced a marked increase in the MDH activation by KCl in vitro. It is suggested that the change in the enzyme response to ions is part of a regulation mechanism by which MDH activity is maintained during various developmental stages of the leaf. However, in accelerated senescence situations, this regulation mechanism is disrupted. © 1981.
Scientific Publication
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