Premium
Contribution of mineral nutrition to the response of barley seedlings to polyethylene glycol–induced mild water stress
Author(s) -
Kocheva Konstantina V.,
Georgiev Georgi I.,
VunkovaRadeva Reneta V.
Publication year - 2007
Publication title -
journal of plant nutrition and soil science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.644
H-Index - 87
eISSN - 1522-2624
pISSN - 1436-8730
DOI - 10.1002/jpln.200625182
Subject(s) - polyethylene glycol , nitrate reductase , osmolyte , chemistry , glutamine synthetase , osmotic shock , glutamine , proline , biochemistry , amino acid , nitrate , polyphenol oxidase , food science , enzyme , organic chemistry , peroxidase , gene
Abstract The effect of polyethylene glycol–induced osmotic stress on the activity of nitrate reductase, glutamine synthetase, and glycolate oxidase in leaves of young barley plants grown under two nutrient‐supply regimes was studied. The activity of nitrate reductase gradually decreased after polyethylene glycol (PEG) application, while glutamine synthetase and glycolate oxidase were increased. It is speculated that the enhanced glutamine synthetase and glycolate oxidase activities are due to increased flux of metabolites through the photorespiratory cycle. Prominent increase in concentrations of free proline, reducing sugars, and free amino acids was observed. The possible contribution of these cellular solutes to the process of osmotic adjustment and the role of mineral supply is discussed. It is suggested that low N supply in combination with stress conditions switched the preferred osmolyte type from amino acids (N‐containing) to sugars (C‐containing).