Dietrich P (2001)
Publication Language: English
Publication Status: Published
Publication Type: Journal article, Original article
Publication year: 2001
Book Volume: 126
Pages Range: 397-410
Journal Issue: 1
DOI: 10.1104/pp.126.1.397
Open Access Link: http://www.plantphysiol.org/content/126/1/397.long
In search for the cellular and molecular basis for differences in aluminum (Al) resistance between maize (Zea mays) cultivars we applied the patch-clamp technique to protoplasts isolated from the apical root cortex of two maize cultivars differing in Al resistance. Measurements were performed on protoplasts from two apical root zones: The 1- to 2-mm zone (DTZ), described as most Al-sensitive, and the main elongation zone (3-5 mm), the site of Al-induced inhibition of cell elongation. Al stimulated citrate and malate efflux from intact root apices, revealing cultivar differences. In the elongation zone, anion channels were not observed in the absence and presence of Al. Preincubation of intact roots with 90 microM Al for 1 h induced a citrate- and malate-permeable, large conductance anion channel in 80% of the DTZ protoplasts from the resistant cultivar, but only 30% from the sensitive cultivar. When Al was applied to the protoplasts in the whole-cell configuration, anion currents were elicited within 10 min in the resistant cultivar only. La3+ was not able to replace or counteract with Al3+ in the activation of this channel. In the presence of the anion-channel blockers, niflumic acid and 4, 4'-dinitrostilbene-2, 2'disulfonic acid, anion currents as well as exudation rates were strongly inhibited. Application of cycloheximide did not affect the Al response, suggesting that the channel is activated through post-translational modifications. We propose that the Al-activated large anion channel described here contributes to enhanced genotypical Al resistance by facilitating the exudation of organic acid anions from the DTZ of the maize root apex.
APA:
Dietrich, P. (2001). Aluminum activates a citrate-permeable anion channel in the aluminum-sensitive zone of the maize root apex. A comparison between an aluminum- sensitive and an aluminum-resistant cultivar. Plant Physiology, 126(1), 397-410. https://doi.org/10.1104/pp.126.1.397
MLA:
Dietrich, Petra. "Aluminum activates a citrate-permeable anion channel in the aluminum-sensitive zone of the maize root apex. A comparison between an aluminum- sensitive and an aluminum-resistant cultivar." Plant Physiology 126.1 (2001): 397-410.
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