The purpose of this study was to examine the influence of phosphorus soil level on the development and on the activities of key enzymes (i.e. nitrate reductase (NR) and glutamine synthetase (GS)) involved in nitrogen metabolism in mycorrhized plant. NR and GS activities in leaf and root tissues were correlated with the P soil availability under the optimal soil nitrogen conditions in mycorrhized plants (MP) and non-mycorrhized plants (NMP). The micorrhizal treatment increased nitrate reductase activity in roots more markedly than in leaf under the different soil phosphorus conditions tested (0-10-20 and 40 ppm). In particular under phosphorus limitation the efficiency of mycorrhizal-colonization on NR activity in plant was widely increased. Our data showed that also GS activity in same conditions above reported, was higher in MP than NMP mainly in the leaf tissue to indicate that the fundamental leaf role in the nitrogen organication was particularly pronounced in micorrhizal plant condition. In apparent contrast the few important amino acid found in MP root showed an N/C ratio higher than MP leaf where was found a more large content of amino acid pool.
Effect of phosphorus availability on nitrogen assimilation in durum wheat mycorrhized plants
DI MARTINO, Catello;PALLOTTA, Maria Luigia;
2010-01-01
Abstract
The purpose of this study was to examine the influence of phosphorus soil level on the development and on the activities of key enzymes (i.e. nitrate reductase (NR) and glutamine synthetase (GS)) involved in nitrogen metabolism in mycorrhized plant. NR and GS activities in leaf and root tissues were correlated with the P soil availability under the optimal soil nitrogen conditions in mycorrhized plants (MP) and non-mycorrhized plants (NMP). The micorrhizal treatment increased nitrate reductase activity in roots more markedly than in leaf under the different soil phosphorus conditions tested (0-10-20 and 40 ppm). In particular under phosphorus limitation the efficiency of mycorrhizal-colonization on NR activity in plant was widely increased. Our data showed that also GS activity in same conditions above reported, was higher in MP than NMP mainly in the leaf tissue to indicate that the fundamental leaf role in the nitrogen organication was particularly pronounced in micorrhizal plant condition. In apparent contrast the few important amino acid found in MP root showed an N/C ratio higher than MP leaf where was found a more large content of amino acid pool.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
