Quantitative analysis of concentration gradient and ionic currents associated with hyphal tip growth in fungi.
It has been shown previously that the nutrient gradient generated by a tip growing elongated cell induces an ionic current entering the cell tip and looping back in the extracellular medium [L. Limozin, B. Denet and P. Pelcé, Phys. Rev. Lett. 78, 4881 (1997)]. We apply this mechanism to the case of hyphae of fungi, using realistic cell geometries, symport kinetics, proton pump permeabilities, and buffer concentrations. We show that this mechanism contributes to a noticeable part of the external current intensity, related inner electrical field and pH gradient, in agreement with experimental measurements. This provides a good example in biological cells of interaction between shape and field, a common property of growing nonliving systems, such as crystalline dendrites or electrodeposition.
Limozin
L
L
IRPHE-CNRS/Universités Aix-Marseille 1 et 2, Service 252, Faculté St. Jérôme, 13397 Marseille Cedex 20, France. llimozin@ph.tum.de
Denet
B
B
D002021:Buffers; D002455:Cell Division; D004058:Diffusion; D004553:Electric Conductivity; D005246:Feedback; D005658:Fungi / Q000166:cytology* / Q000254:growth & development / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D017136:Ion Transport; D007477:Ions; D007700:Kinetics; D017494:Proton Pumps / Q000378:metabolism
D002021:Buffers; D007477:Ions; D017494:Proton Pumps