Effect of inorganic nitrogen source on ammonium assimilation enzymes of Catharanthus roseus plants
The activities of the enzymes glutamate dehydrogenase (EC 1.4.1.2), glutamine synthetase (EC 6.3.1.2) and glutamate synthase (EC 1.4.1.14) were measured in leaves, roots and leaf explants of Catharanthus roseus grown in different N sources: water (control), 20 mM KNO3, 2 mM NH4Cl and a mixture of the latter two. In the roots, glutamate dehydrogenase activity is fourfold higher than in leaves and it is also higher than the activities of glutamine synthetase and glutamate synthase. The aminative and deaminative GDH activities are regulated differentially depending on the nitrogen source and the tissue studied. Ferredoxin dependent glutamate synthase was detected only in photosynthetic tissues but not in the roots, where the NADH dependent enzyme was found. The N sources substantially modified the total alkaloid content with respect to the control (water): with nitrate producing an increment of 50%, while a mixture of nitrate and ammonium produced a decrease of 45%.
| Main Authors: | , , |
|---|---|
| Format: | info:eu-repo/semantics/article biblioteca |
| Language: | eng |
| Subjects: | info:eu-repo/classification/Autores/GLUTAMATE DEHYDROGENASE, info:eu-repo/classification/Autores/GLUTAMATE SYNTHASE, info:eu-repo/classification/Autores/GLUTAMINE SYNTHETASE, info:eu-repo/classification/Autores/NITROGEN SOURCE, info:eu-repo/classification/cti/2, info:eu-repo/classification/cti/24, info:eu-repo/classification/cti/2415, info:eu-repo/classification/cti/241502, |
| Online Access: | http://cicy.repositorioinstitucional.mx/jspui/handle/1003/1684 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|