Home | Legals | Sitemap | KIT

Karlsruhe Institute of Technology - KIT
Botanical Institute
Molecular Phytopathology

 

Hertzstraße 16

Geb. 06.40

D-76187 Karlsruhe

 

Phone:  +49 721 608-44626

Secret.: +49 721 608-44632

Fax:      +49 721 608-44509

 

E-mail: 

natalia requenaLuw2∂kit edu

 

Breuninger et al. 2004

2004_Breuninger
Fungal Gen. Biol. 41: 542-552.

Different N sources modulate activity but not expression of glutamine synthetase in two arbuscular mycorrhizal fungi. Fungal Gen. Biol. 41: 542-552.

Breuninger M., Trujillo C.G., Serrano E., Ecke M., Fischer R. and Requena N.

 

Abstract

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.

 

üubmed

 

pdf