Inhibition of the gravitropic response of snapdragon spikes by the calcium-channel blocker lanthanum chloride
Inhibition of the gravitropic response of snapdragon spikes by the calcium-channel blocker lanthanum chloride
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DOI：
10.1104/pp.118.2.483
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发表时间：
1998-10-01
期刊：
影响因子：
7.4
通讯作者：
Philosoph-Hadas, S
中科院分区：
文献类型：
--
作者：
Friedman, H;Meir, S;Philosoph-Hadas, S
Ca2+通道阻断剂LaCl3抑制金鱼草（Antirrhinum majus L.）spikes（S. Philosoph-Hadas，S.梅尔岛罗森伯格，A.H. Halevy [1996] Plant Physiol 110：301 - 310），并且在弯曲区抑制茎弯曲的程度大于抑制垂直和水平茎伸长的程度。这可能表明，氯化镧，调节胞质Ca 2+，不影响一般的茎生长过程，但可能会特别影响其他重力相关的过程中发生的茎弯曲区。两个这样的特定的重力依赖性事件被发现发生在金鱼草穗的弯曲区：含淀粉的叶绿体在干皮层细胞的底部沉积，如在横截面中所见，并建立一个乙烯梯度在整个干。我们的研究结果表明，横向沉降的叶绿体与重力感应被阻止在横截面从弯曲区的氯化镧处理，随后gravistimated穗和氯化镧完全防止重力诱导的，不对称的乙烯生产建立在整个茎弯曲区。这些数据表明，氯化镧抑制茎弯曲金鱼草穗阻止几个重力依赖的过程。因此，我们建议，向重力反应的芽可以介导的钙依赖性途径，涉及在不同阶段的胞质钙的调制。
The putative Ca2+-channel blocker LaCl3 prevented the gravitropic bending of cut snapdragon (Antirrhinum majus L.) spikes (S. Philosoph-Hadas, S. Meir, I. Rosenberger, A.H. Halevy [1996] Plant Physiol 110: 301-310) and inhibited stem curvature to a greater extent than vertical and horizontal stem elongation at the bending zone. This might indicate that LaCl3, which modulates cytosolic Ca2+, does not influence general stem-growth processes but may specifically affect other gravity-associated processes occurring at the stem-bending zone. Two such specific gravity-dependent events were found to occur in the bending zone of snapdragon spikes: sedimentation of starch-containing chloroplasts at the bottom of stem cortex cells, as seen in cross-sections, and establishment of an ethylene gradient across the stem. Our results show that the lateral sedimentation of chloroplasts associated with gravity sensing was prevented in cross-sections taken from the bending zone of LaCl3-treated and subsequently gravistimulated spikes and that LaCl3 completely prevented the gravity-induced, asymmetric ethylene production established across the stem-bending zone. These data indicate that LaCl3 inhibits stem curvature of snapdragon spikes by preventing several gravity-dependent processes. Therefore, we propose that the gravitropic response of shoots could be mediated through a Ca2+-dependent pathway involving modulation of cytosolic Ca2+ at various stages.