Effect of lanthanum on ion absorption in corn roots.
Effect of lanthanum on ion absorption in corn roots.
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DOI：
10.1104/pp.55.3.542
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发表时间：
1975-03
期刊：
影响因子：
7.4
通讯作者：
R. Leonard;G. Nagahashi;W. Thomson
中科院分区：
文献类型：
--
作者：
R. Leonard;G. Nagahashi;W. Thomson
Short term (10 min) influx of (86)Rb-labeled potassium into corn (Zea mays L. WF9 x M14) root segments was inhibited by La (NO(3))(3) or LaCl(3). Half maximal inhibition of K(+) influx from 0.25 mm KCl was obtained with 0.025 mm La(3+). Kinetic analysis indicated the inhibition to be of a competitive nature. With absorption periods exceeding one hour, La(3+) no longer inhibited, but rather stimulated K(+) influx rates. La(3+) was not an inhibitor of (36)Cl or (32)P absorption. Separated cortex and stele absorbed labeled potassium (and phosphate) at comparable rates, and La(3+) inhibited potassium influx in both tissues. The effects of La(3+) on ion absorption were similar to those of Ca(2+), suggesting that the two polyvalent cations act at the same site. Based on this and the observation that La(3+) does not seem to penetrate the plasma membrane, it was concluded that La(3+) and Ca(2+) affect changes in ion transport without entering cells.
