Asset Details
Do you wish to reserve the book?
Concerted modulation of alanine and glutamate metabolism in young Medicago truncatula seedlings under hypoxic stress
Hey, we have placed the reservation for you!
By the way, why not check out events that you can attend while you pick your title.
Oops! Something went wrong.
Looks like we were not able to place the reservation. Kindly try again later.
Are you sure you want to remove the book from the shelf?
Concerted modulation of alanine and glutamate metabolism in young Medicago truncatula seedlings under hypoxic stress
Do you wish to request the book?
Concerted modulation of alanine and glutamate metabolism in young Medicago truncatula seedlings under hypoxic stress
Please be aware that the book you have requested cannot be checked out. If you would like to checkout this book, you can reserve another copy
We have requested the book for you!
Your request is successful and it will be processed during the Library working hours. Please check the status of your request in My Requests.
Oops! Something went wrong.
Looks like we were not able to place your request. Kindly try again later.
Journal Article
Concerted modulation of alanine and glutamate metabolism in young Medicago truncatula seedlings under hypoxic stress
2008
Overview
The modulation of primary nitrogen metabolism by hypoxic stress was studied in young Medicago truncatula seedlings. Hypoxic seedlings were characterized by the up-regulation of glutamate dehydrogenase 1 (GDH1) and mitochondrial alanine aminotransferase (mAlaAT), and down-regulation of glutamine synthetase 1b (GS1b), NADH-glutamate synthase (NADH-GOGAT), glutamate dehydrogenase 3 (GDH3), and isocitrate dehydrogenase (ICDH) gene expression. Hypoxic stress severely inhibited GS activity and stimulated NADH-GOGAT activity. GDH activity was lower in hypoxic seedlings than in the control, however, under either normoxia or hypoxia, the in vivo activity was directed towards glutamate deamination. 15NH4 labelling showed for the first time that the adaptive reaction of the plant to hypoxia consisted of a concerted modulation of nitrogen flux through the pathways of both alanine and glutamate synthesis. In hypoxic seedlings, newly synthesized 15N-alanine increased and accumulated as the major amino acid, asparagine synthesis was inhibited, while 15N-glutamate was synthesized at a similar rate to that in the control. A discrepancy between the up-regulation of GDH1 expression and the down-regulation of GDH activity by hypoxic stress highlighted for the first time the complex regulation of this enzyme by hypoxia. Higher rates of glycolysis and ethanol fermentation are known to cause the fast depletion of sugar stores and carbon stress. It is proposed that the expression of GDH1 was stimulated by hypoxia-induced carbon stress, while the enzyme protein might be involved during post-hypoxic stress contributing to the regeneration of 2-oxoglutarate via the GDH shunt.
Publisher
Oxford University Press (OUP),CCSD,Oxford University Press,Oxford Publishing Limited (England)
Subject
/ Alanine Transaminase - genetics
/ Alanine Transaminase - metabolism
/ Alfalfa
/ ammonia
/ Biological and medical sciences
/ Botanics
/ carbon
/ Embryos
/ Ethanol
/ Fundamental and applied biological sciences. Psychology
/ Gene Expression Regulation, Plant
/ genetics
/ Glutamate Dehydrogenase - genetics
/ Glutamate Dehydrogenase - metabolism
/ Glutamate Synthase (NADH) - genetics
/ Glutamate Synthase (NADH) - metabolism
/ Hypoxia
/ Isocitrate Dehydrogenase - genetics
/ Isocitrate Dehydrogenase - metabolism
/ Lactates
/ Medicago truncatula - enzymology
/ Medicago truncatula - metabolism
/ Nitrogen
/ Oxygen
/ Plant physiology and development
/ Plants
/ proteins
/ Quaternary Ammonium Compounds
/ Quaternary Ammonium Compounds - metabolism
/ Reverse Transcriptase Polymerase Chain Reaction
/ sugars
ISBN
0002567604000
