Abstract
Using standard microelectrode techniques, we measured the effects of fusaric acid (FA) on the membrane potential of tomato (Lycopersicon esculentum Mill. cv New Yorker 870) incipient root hair cells. At pH 5.3, FA caused a hyerpolarization, the magnitude of which increased with FA concentrations from 0.05 to 0.50 millimolar. A depolarization followed, the rate and magnitude of which increased with the concentration of FA and exposure to FA. Partial repolarizations occurred after exposures to 1.0 millimolar FA for less than 8 to 10 minutes, after longer exposures to lower FA concentrations, or after longer exposures to 1.0 millimolar FA in a less concentrated nutrient solution. The amount of ATP in tomato root tips decreased by about 85% after incubation for 80 min in 1.0 millimolar FA.
At pH 7.2 and 8.2, the depolarization caused by an 8-minute exposure to 1.0 millimolar FA was immediate and much more rapid than at pH 5.2 and 6.3, but its magnitude was not as great. At pH 6.3, 7.2, and 8.2, the depolarization was at least partially reversible. The data are consistent with FA having at least three effects that elicited changes in tomato root cell electrical potential differences between the cell's interior and the external solution.
Full text
PDF
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Bochner B. R., Huang H. C., Schieven G. L., Ames B. N. Positive selection for loss of tetracycline resistance. J Bacteriol. 1980 Aug;143(2):926–933. doi: 10.1128/jb.143.2.926-933.1980. [DOI] [PMC free article] [PubMed] [Google Scholar]
- ETHERTON B., HIGINBOTHAM N. Transmembrane potential measurements of cells of higher plants as related to salt uptake. Science. 1960 Feb 12;131(3398):409–410. doi: 10.1126/science.131.3398.409. [DOI] [PubMed] [Google Scholar]
- Etherton B. Relationship of Cell Transmembrane Electropotential to Potassium and Sodium Accumulation Ratios in Oat and Pea Seedlings. Plant Physiol. 1963 Sep;38(5):581–585. doi: 10.1104/pp.38.5.581. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Kinraide T. B., Etherton B. Energy Coupling in H-Amino Acid Cotransport : ATP DEPENDENCE OF THE SPONTANEOUS ELECTRICAL REPOLARIZATION OF THE CELL MEMBRANES IN OAT COLEOPTILES. Plant Physiol. 1982 Mar;69(3):648–652. doi: 10.1104/pp.69.3.648. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Suda H., Takeuchi T., Nagatsu T., Matsuzaki M., Matsumoto I., Umezawa H. Inhibition of dopamine beta-hydroxylase by 5-alkylpicolinic acid and their hypotensive effects. Chem Pharm Bull (Tokyo) 1969 Nov;17(11):2377–2380. doi: 10.1248/cpb.17.2377. [DOI] [PubMed] [Google Scholar]