THE BIO-ELECTRIC POTENTIALS OF PLANTS AND THEIR FUNCTIONAL SIGNIFICANCE: III. THE PRODUCTION OF CONTINUOUS POTENTIALS ACROSS MEMBRANES IN PLANT TISSUE BY THE CIRCULATION OF THE HYDROGEN ION

Abstract

Of the three types of membranes which occur generally in plant cells, lipoid, protein, and cellulose, it would seem that a protein-coated grid of cellulose can be envisaged as surrounding the cells. Such a membrane would appear to have the right pore size and properties to allow almost unfettered hydrogen ion diffusion but yet permit intercell biopotentials to be built up. It is pointed out that the most important ion involved in diffusion and in subsequent ion exchange would seem to be the hydrogen (as hydronium) ion, and that tissue can conveniently be divided into general areas of hydrogen ion production or hydrogen ion absorption. The resulting circulation of this ion is explored and discussed in relation to photosynthesis, respiration, protoplasmic streaming, and transport. These ideas are shown to give reasonable explanations for the results obtained in experiments and to resolve certain difficulties related to biopotential studies. They are considered to be useful since they predict some important results which can be experimentally tested, some of which are here given.