Premium
Cytokinin biochemistry in relation to leaf senescence. VI. Effect of nitrogenous nutrients on cytokinin levels and senescence of tobacco leaves
Author(s) -
Singh Santokh,
Letham D. S.,
Zhang Xuedong,
Palni L. M. S.
Publication year - 1992
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.1399-3054.1992.tb04663.x
Subject(s) - cytokinin , senescence , ammonium , nitrate , ammonium nitrate , botany , nutrient , biology , endogeny , chemistry , horticulture , biochemistry , auxin , microbiology and biotechnology , ecology , organic chemistry , gene
The effect of nitrogenous nutrients on endogeneous cytokinins and senescence of tobacco leaves was investigated. Ammonium nitrate was the most effective in retarding senescence and its activity was attributed principally to NH 4 + ions. Repeated applications or a continuous supply of ammonium nitrate was required for maximal retardation of tobacco leaf senescence. Ammonium nitrate solution supplied via the petioles reduced the senescence retarding effect of dihydrozeatin applied directly to the laminae of detached tobacco leaves. Ammonium nitrate also elevated the endogenous levels of cytokinins (especially zeatin and dihydrozeatin) particularly in growing tobacco leaves excised from near the apex of the plant. Ammonium nitrate induced retardation of leaf senescence may be mediated at least partly by its effect on foliar cytokinin content.