The glyoxylate cycle in an arbuscular mycorrhizal fungus. Carbon flux and gene expression

Peter Lammers, J. Jun, J. Abubaker, R. Arreola, A. Gopalan, B. Bago, C. Hernandez-Sebastia, J. W. Allen, D. D. Douds, P. E. Pfeffer, Y. Shachar-Hill

Research output: Contribution to journalArticle

73 Citations (Scopus)

Abstract

The arbuscular mycorrhizal (AM) symbiosis is responsible for huge fluxes of photosynthetically fixed carbon from plants to the soil. Lipid, which is the dominant form of stored carbon in the fungal partner and which fuels spore germination, is made by the fungus within the root and is exported to the extraradical mycelium. We tested the hypothesis that the glyoxylate cycle is central to the flow of carbon in the AM symbiosis. The results of 13C labeling of germinating spores and extraradical mycelium with 13C2-acetate and 13C2-glycerol and analysis by nuclear magnetic resonance spectroscopy indicate that there are very substantial fluxes through the glyoxylate cycle in the fungal partner. Full-length sequences obtained by polymerase chain reaction from a cDNA library from germinating spores of the AM fungus Glomus intraradices showed strong homology to gene sequences for isocitrate lyase and malate synthase from plants and other fungal species. Quantitative real-time polymerase chain reaction measurements show that these genes are expressed at significant levels during the symbiosis. Glyoxysome-like bodies were observed by electron microscopy in fungal structures where the glyoxylate cycle is expected to be active, which is consistent with the presence in both enzyme sequences of motifs associated with glyoxysomal targeting. We also identified among several hundred expressed sequence tags several enzymes of primary metabolism whose expression during spore germination is consistent with previous labeling studies and with fluxes into and out of the glyoxylate cycle.

Original languageEnglish (US)
Pages (from-to)1287-1298
Number of pages12
JournalPlant Physiology
Volume127
Issue number3
DOIs
StatePublished - 2001
Externally publishedYes

Fingerprint

glyoxylate cycle
Carbon Cycle
Spores
mycorrhizal fungi
Symbiosis
Fungi
symbiosis
Gene Expression
gene expression
Carbon
carbon
Mycelium
spore germination
Germination
mycelium
Glyoxysomes
Malate Synthase
spores
Isocitrate Lyase
Fungal Structures

ASJC Scopus subject areas

  • Physiology
  • Genetics
  • Plant Science

Cite this

Lammers, P., Jun, J., Abubaker, J., Arreola, R., Gopalan, A., Bago, B., ... Shachar-Hill, Y. (2001). The glyoxylate cycle in an arbuscular mycorrhizal fungus. Carbon flux and gene expression. Plant Physiology, 127(3), 1287-1298. https://doi.org/10.1104/pp.127.3.1287

The glyoxylate cycle in an arbuscular mycorrhizal fungus. Carbon flux and gene expression. / Lammers, Peter; Jun, J.; Abubaker, J.; Arreola, R.; Gopalan, A.; Bago, B.; Hernandez-Sebastia, C.; Allen, J. W.; Douds, D. D.; Pfeffer, P. E.; Shachar-Hill, Y.

In: Plant Physiology, Vol. 127, No. 3, 2001, p. 1287-1298.

Research output: Contribution to journalArticle

Lammers, P, Jun, J, Abubaker, J, Arreola, R, Gopalan, A, Bago, B, Hernandez-Sebastia, C, Allen, JW, Douds, DD, Pfeffer, PE & Shachar-Hill, Y 2001, 'The glyoxylate cycle in an arbuscular mycorrhizal fungus. Carbon flux and gene expression', Plant Physiology, vol. 127, no. 3, pp. 1287-1298. https://doi.org/10.1104/pp.127.3.1287
Lammers, Peter ; Jun, J. ; Abubaker, J. ; Arreola, R. ; Gopalan, A. ; Bago, B. ; Hernandez-Sebastia, C. ; Allen, J. W. ; Douds, D. D. ; Pfeffer, P. E. ; Shachar-Hill, Y. / The glyoxylate cycle in an arbuscular mycorrhizal fungus. Carbon flux and gene expression. In: Plant Physiology. 2001 ; Vol. 127, No. 3. pp. 1287-1298.
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