Gramicidin-D-stimulated influx of monovalent cations into plant roots
✍ Scribed by T. K. Hodges; R. L. Darding; T. Weidner
- Book ID
- 104751202
- Publisher
- Springer-Verlag
- Year
- 1971
- Tongue
- English
- Weight
- 618 KB
- Volume
- 97
- Category
- Article
- ISSN
- 0032-0935
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✦ Synopsis
Gramicidin D and nigericin were found to stimulate K + influx into oat roots. Valinomycin and nonaetin had little effect on K + influx. The region of the root most sensitive to gramieidin was the elongation zone. Monoeot roots were more sensitive to gramicidin than dicot roots. At 0.2 mM KC1, gramicidin stimulated K+ influx by 4-to 8fold over a 30-min absorption period. Although a gramicidin response is detectable within one minute, maximum stimulation occurred after a slight (approximately 2-min) lag period. The gramicidin effect was much greater at 0.2 mM KC1 than at 20 mM KC1. Respiratory inhibitors reduced the gramicidin-stimulated K + influx by 50-80%. The results are discussed in terms of possible mechanisms of action of the various ionophores on ion transport in roots.