Shabala S N, Newman I A
Dept of Physics, Univ. of Tasmania, Australia.
Physiol Plant. 1997 Aug;100(4):917-26.
The involvement of Ca2+ and H+ flux oscillations in root nutation was studied for decapped roots of corn (Zea mays L. cv. Aussie Gold) placed horizontally. Net ion fluxes were measured around the elongation and meristematic regions using a microelectrode ion flux measuring system. High correlation between H+ flux oscillations and root nutations was found in the elongation region. Two oscillatory components of H+ flux, with periods of about 90 min and 7 min, correlated with root circumnutations and micronutations, respectively. The periods of H+ flux oscillations and rhythmical root movements in this region could be modified similarly by external factors including pH. In the meristematic region no association between ion flux behaviour and nutation was apparent. Ion flux oscillations and nutations both decreased in amplitude as the growth rate at the measured location decreased. Possible involvement of ion flux oscillations in root circumnutation is discussed. It is concluded that a model involving an internal oscillator must be developed to explain the H+ flux involvement in root nutations.
研究了水平放置的去顶玉米（Zea mays L. cv. Aussie Gold）根中Ca2+和H+通量振荡在根的回旋转头中的作用。使用微电极离子通量测量系统测量伸长区和分生区周围的净离子通量。在伸长区发现H+通量振荡与根的回旋转头高度相关。H+通量的两个振荡成分，周期分别约为90分钟和7分钟，分别与根的圆周运动和微圆周运动相关。该区域H+通量振荡的周期和有节奏的根运动可被包括pH值在内的外部因素以类似方式改变。在分生区，离子通量行为与回旋转头之间没有明显关联。随着测量位置的生长速率降低，离子通量振荡和回旋转头的幅度均减小。讨论了离子通量振荡在根圆周运动中的可能作用。得出结论，必须建立一个涉及内部振荡器的模型来解释H+通量在根回旋转头中的作用。
