A sensitive computer-controlled pH-stat system allows the study of net H+ fluxes related to nitrogen uptake of intact plants in situ
Article first published online: 28 JUN 2008
Plant, Cell & Environment
Volume 20, Issue 3, pages 400–408, March 1997
How to Cite
WOLLENWEBER, B. (1997), A sensitive computer-controlled pH-stat system allows the study of net H+ fluxes related to nitrogen uptake of intact plants in situ. Plant, Cell & Environment, 20: 400–408. doi: 10.1046/j.1365-3040.1997.d01-79.x
- Issue published online: 28 JUN 2008
- Article first published online: 28 JUN 2008
- Received 6 August 1996; received in revised form 1 October 1996; accepted for publication 7 October 1996
- Hordeum vulgare L;
- acid–base balance;
- net proton fluxes;
- nitrogen uptake;
Proton fluxes related to the acid–base balance of intact plants were investigated in detail. A multi-channel titration system was developed in order to regulate the pH in two different sets of nutrient solutions. This system also allowed computation of the dynamics of proton fluxes associated with nutrient uptake in situ.
The pH-stat system presented here has proved to be very reliable and sensitive. By additions of acid or base to the nutrient solutions, the set pH could typically be maintained within 0·01 pH units. Experiments investigating net proton fluxes correlated with nitrogen uptake are described. The results show a rapid response of proton fluxes to changes in the form of nitrogen supplied, indicating that alterations in net proton fluxes are directly induced by the nature of the nitrogen source. The stoichiometry of proton fluxes connected to nitrogen uptake could be followed online, and the results are discussed in relation to the charge and acid–base balances of the whole plant.