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In vivo Characterization of Nitrate Reductase Activity in Cotton
Author(s) -
BILAL I. M.,
RAINS D. W.
Publication year - 1973
Publication title -
physiologia plantarum
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.351
H-Index - 146
eISSN - 1399-3054
pISSN - 0031-9317
DOI - 10.1111/j.1399-3054.1973.tb01182.x
Subject(s) - nitrate reductase , in vivo , nitrate , chemistry , enzyme , enzyme assay , biochemistry , botany , biology , microbiology and biotechnology , organic chemistry
The in vivo nitrate reductase activity in leaf tissue of cotton ( Gossypium hirsutum L.) was characterized. Enzymatic activity was linear with time up to 60 min. The assay for nitrate reductase activity was optimized in leaf slices 400 μm wide incubated in an anaerobic system at 30°C, in a 0.02 M KNO 3 medium at pH 7.0 with 1 % propanol. In vivo activity was highest in recently matured leaves at the top of the plant. Both light and nitrate enhanced in vivo enzymatic activity. The activity was highest after 9 hours in the light and then decreased steadily for several more hours even in the presence of light. The nitrate reductase activity was more strongly correlated to the levels of NO 3 ‐N in the culture solution than to the NO 3 ‐N level in the tissue. The utility of this technique in nitrate reductase assay in a tissue containing large amounts of phenolic compounds is discussed.