You are not currently logged in.
Access your personal account or get JSTOR access through your library or other institution:
If You Use a Screen ReaderThis content is available through Read Online (Free) program, which relies on page scans. Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.
Noncircadian Oscillations in Amino Acid Transport Have Complementary Profiles in Assimilatory and Foraging Hyphae of Phanerochaete velutina
M. Tlalka, D. Hensman, P. R. Darrah, S. C. Watkinson and M. D. Fricker
The New Phytologist
Vol. 158, No. 2 (May, 2003), pp. 325-335
Stable URL: http://www.jstor.org/stable/1513991
Page Count: 11
Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.
Preview not available
• Cord-forming woodland basidiomycete fungi form extensive, interconnected mycelial networks that scavenge nitrogen (N) efficiently. We have developed techniques to study N dynamics in such complex mycelial systems in vivo. • Uptake and distribution of the nonmetabolised, 14 C-labelled amino-acid analogue, α-aminoisobutyrate (14 C- AIB) was continuously imaged in Phanerochaete velutina growing across scintillation screens using an enhanced photon-counting camera. • Oscillations in the 14 C- AIB signal were observed for both the assimilatory hyphae in the inoculum and the foraging hyphae, but with complementary profiles. Pulses were asymmetric, with an abrupt switch between each exponential decay phase and the next rising phase. The period of the oscillations was 16 h at 21°C, but showed a strong temperature dependence with a temperature coefficient of 2.1. Oscillations occurred in the absence of obvious pulses in growth. • Some, but not all, of the features of the oscillations were simulated using a model of amino acid accumulation and transport that included both vacuolar uptake, and release once an intravacuolar concentration threshold was exceeded. The combination of imaging and modelling provides a useful framework to understand N fluxes in vivo.
The New Phytologist © 2003 New Phytologist Trust