Differential regulation of GS-GOGAT gene expression by plant growth regulators in Arabidopsis seedlings
Primary and secondary ammonium assimilation is catalyzed by the glutamine synthetase-glutamate synthase (GS-GOGAT) pathway in plants. The Arabidopsis genome contains five cytosolic GS1 genes (GLN1;1 - GLN1;5), one nuclear gene for chloroplastic GS2 isoform (GLN2), two Fd-GOGAT genes (GLU1 a...
| Main Authors: | , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
University of Belgrade, University of Novi Sad
2016-01-01
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| Series: | Archives of Biological Sciences |
| Subjects: | |
| Online Access: | http://www.doiserbia.nb.rs/img/doi/0354-4664/2016/0354-46641500087D.pdf |
| Summary: | Primary and secondary ammonium assimilation is catalyzed by the glutamine
synthetase-glutamate synthase (GS-GOGAT) pathway in plants. The Arabidopsis
genome contains five cytosolic GS1 genes (GLN1;1 - GLN1;5), one nuclear gene
for chloroplastic GS2 isoform (GLN2), two Fd-GOGAT genes (GLU1 and GLU2) and
a GLT1 gene coding for NADH-GOGAT. Even though the regulation of GS and
GOGAT isoforms has been extensively studied in response to various
environmental and metabolic cues in many plant species, little is known
about the effects of phytohormones on their regulation. The objective of
this study was to investigate the impact of representative plant growth
regulators, kinetin (KIN), abscisic acid (ABA), gibberellic acid (GA3) and
2,4-dichlorophenoxyacetic acid (2,4-D), on the expression of A. thaliana GS
and GOGAT genes. The obtained results indicate that GS and GOGAT genes are
differentially regulated by growth regulators in shoots and roots. KIN and
2,4-D repressed GS and GOGAT expression in roots, with little effect on
transcript levels in shoots. KIN affected all tested genes; 2,4-D was
apparently more selective and less potent. ABA induced the expression of
GLN1;1 and GLU2 in whole seedlings, while GA3 enhanced the expression of all
tested genes in shoots, except GLU2. The observed expression patterns are
discussed in relation to physiological roles of investigated plant growth
regulators and N-assimilating enzymes. [Projekat Ministarstva nauke
Republike Srbije, br. ON173024] |
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| ISSN: | 0354-4664 1821-4339 |