Record ID No. |
164 |
Author(s) |
Breuninger M., Trujillo C. G., Serrano E., Fischer R., Requena N. , 2004 |
Affiliation |
University of Tubingen, Physiol Ecology Plants Department, Morgenstelle 1, D-72076 Tubingen, Germany |
Title |
Different nitrogen sources modulate activity but not expression of glutamine synthetase in arbuscular mycorrhizal |
Source. Vol.(no):Page |
Fungal Genetics and Biology. 41(5): 542-552p. |
Categories |
Arbuscular Mycorrhiza |
Subjects |
Biochemistry Genetics |
Sub-subjects |
Miscellaneous Nitrogen metabolism |
Host |
n.a. |
Organism |
Glomus mosseae, Glomus intraradices |
Country |
Germany, Europe |
Abstracts |
Glutamine synthetase (GS) is a central enzyme of
nitrogen metabolism that allows assimilation of nitrogen and
biosynthesis of glutamine. We isolated the cDNA encoding GS from
two arbuscular mycorrhizal fungi, Glomus mosseae (GmGln1) and
Glomus intraradices (GiGln1). The deduced protein orthologues
have a high degree of similarity (92%) with each other as well
as with GSs from other fungi. GmGln1 was constitutively
expressed during all stages of the fungal life cycle, i.e.,
spore germination, intraradical and extraradical mycelium.
Feeding experiments with different nitrogen sources did not
induce any change in the mRNA level of both genes independent of
the symbiotic status of the fungus. However, GS activity of
extraradical hypahe in G. intraradices was considerably
modulated in response to different nitrogen sources. Thus, in a
N re-supplementation time-course experiment, GS activity
responded quickly to addition of nitrate, ammonium or glutamine.
Re-feeding with ammonium produced a general increase in GS
activity when compared with hyphae grown in nitrate as a sole N
source.
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