This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via CrossRef Citing Articles via Google Scholar Google Scholar Articles by Gardner, J. M. Articles by Higinbotham, N. Search for Related Content PubMed PubMed Citation Articles by Gardner, J. M. Articles by Higinbotham, N. Agricola Articles by Gardner, J. M. Articles by Higinbotham, N.

Articles

Effects of Host-Specific Toxins on Electropotentials of Plant Cells ^1,2,3

Robert P. Scheffer^b

Noe Higinbotham^c

^a Department of Biological Chemistry, University of California, Davis, California 95616, Department of Botany and Plant Pathology, Michigan State University, East Lansing, Michigan 48824, Department of Botany, Washington State University, Pullman, Washington 99163

Host-specific toxins from Helminthosporium victoriae (HV) and Periconia circinata (PC) caused gradual decreases in the negative electropotentials of single cells of susceptible but not of resistant plants. When tissues were held in a standard nutrient solution, the decrease (depolarization) induced by HV toxin was approximately 50 mv/hr; the decrease induced by PC toxin was even more gradual. Changes in ion efflux were detected before changes in electropotential. In contrast, toxin from H. carbonum caused a rapid but transient increase in negative electropotential of cells. Carbonyl cyanide m-chlorophenylhydrazone, which (like other metabolic inhibitors) blocks electrogenic pumps, caused cell electropotentials to decrease by approximately 50 mv within a few minutes. This suggests that HV and PC toxins do not have direct effects on electrogenic pumps, but do affect passive efflux of ions, or electrically neutral ion exchange systems, across the plasma membrane.

² Journal Article No. 6782, Michigan Agricultural Experimental Station.

³ This paper is dedicated to the memory of Solon A. Gordon in honor of his contributions to Plant Physiology.

This article has been cited by other articles:

				R. P. Scheffer and R. S. Livingston Host-Selective Toxins and Their Role in Plant Diseases Science, January 6, 1984; 223(4631): 17 - 21. [Abstract] [PDF]