Effects of ethylene on the kinetics of curvature and auxin redistribution in gravistimulated roots of Zea mays.
Effects of ethylene on the kinetics of curvature and auxin redistribution in gravistimulated roots of Zea mays.
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DOI：
10.1104/pp.94.4.1770
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发表时间：
1990-12
期刊：
影响因子：
7.4
通讯作者：
J. S. Lee;Chang W-K;M. Evans
中科院分区：
文献类型：
--
作者：
J. S. Lee;Chang W-K;M. Evans
我们通过测量在乙烯、乙烯合成抑制剂或乙烯作用抑制剂处理下的根的弯曲和横向生长素运动动力学来测试乙烯在玉米（Zea mays L.）根向地性中的作用。乙烯的存在使地向曲率潜伏期有所增加。然而，乙烯处理的根在对照根达到最终弯曲角度后继续弯曲。因此，乙烯处理过的根在乙烯存在下的最大曲率比对照大得多。乙烯生物合成抑制剂或作用抑制剂对弯曲动力学的影响与乙烯相反，即潜伏期比对照有所缩短，总弯曲比对照有所减小。3h -吲哚-3-乙酸的标签优先向受刺激根的下侧运输。与对弯曲度的影响平行，乙烯处理延缓了重力诱导的生长素跨根不对称运动的发展，但一旦开始就延长了其持续时间。生长素运输抑制剂1- n -萘酞酸降低了向地性曲率和乙烯对曲率的影响。由于乙烯和乙烯生物合成抑制剂或作用都不能阻止弯曲，我们得出结论，乙烯不介导引起弯曲的主要差异生长反应。由于乙烯影响曲率和生长素的平行运输，我们认为乙烯通过影响重力诱导的生长素的横向运输来改变曲率，可能是通过干扰生长素运输系统对重力刺激的适应。
We tested the involvement of ethylene in maize (Zea mays L.) root gravitropism by measuring the kinetics of curvature and lateral auxin movement in roots treated with ethylene, inhibitors of ethylene synthesis, or inhibitors of ethylene action. In the presence of ethylene the latent period of gravitropic curvature appeared to be increased somewhat. However, ethylene-treated roots continued to curve after control roots had reached their final angle of curvature. Consequently, maximum curvature in the presence of ethylene was much greater in ethylene-treated roots than in controls. Inhibitors of ethylene biosynthesis or action had effects on the kinetics of curvature opposite to that of ethylene, i.e. the latent period appeared to be shortened somewhat while total curvature was reduced relative to that of controls. Label from applied 3H-indole-3-acetic acid was preferentially transported toward the lower side of stimulated roots. In parallel with effects on curvature, ethylene treatment delayed the development of gravity-induced asymmetric auxin movement across the root but extended its duration once initiated. The auxin transport inhibitor, 1-N-naphthylphthalamic acid reduced both gravitropic curvature and the effect of ethylene on curvature. Since neither ethylene nor inhibitors of ethylene biosynthesis or action prevented curvature, we conclude that ethylene does not mediate the primary differential growth response causing curvature. Because ethylene affects curvature and auxin transport in parallel, we suggest that ethylene modifies curvature by affecting gravity-induced lateral transport of auxin, perhaps by interfering with adaptation of the auxin transport system to the gravistimulus.