Aspen Bibliography

Bioelectric currents and oxidant levels in plant systems

W.C. Levengood

Document Type

Article

Journal/Book Title/Conference

Journal of Experimental Botany

Volume

24

Issue

81

First Page

626

Last Page

639

Publication Date

1973

Abstract

A bioelectric current measured with a polarized electrode system in the bole of a tree or the stem of an herbaceous plant may indicate altered intertissue redox levels. Circumference-height ratio along the stem is shown to be exponentially related to the current level. This empirical relationship was used to evaluate quantitatively the internal perturbations. Defoliation, foliage density, water stress, girdling, and neoplastic growth change the current gradient in the plant. Changes following defoliation and girdling strongly suggest altered levels of oxidation products. Under water stress both the current level and gradient are reduced and the implications of these changes are discussed.

Transverse stem sections from a tree bole disclosed dark-coloured proteinaceous compounds at the site of an iron cathode. These complexes are translocated from the reaction site by ray parenchyma and stored in the secondary xylem and pith regions. Newly formed xylem and phloem are free of these complexes, indicating that metabolically active tissue rapidly translocates reaction products, preventing them from accumulating and interfering with electrode oxidation reactions.

Link to Full Text

Share

 
COinS