Leopold A C, Wettlaufer S H
Boyce Thompson Institute, Cornell University, Ithaca, New York 14853.
Plant Physiol. 1988;87(4):803-5. doi: 10.1104/pp.87.4.803.
The diagravitropic behavior of Merit corn (Zea mays L.) roots grown in darkness provides an opportunity for comparison of two qualitatively different gravitropic systems. As with positive gravitropism, diagravitropism is shown to require the presence of the root cap, have a similar time course for the onset of curvature, and a similar presentation time. In contrast with positive gravitropism, diagravitropism appears to have a more limited requirement for calcium, for it is insensitive to the elution of calcium by EGTA and insensitive to the subsequent addition of a calcium/EGTA complex. These results are interpreted as indicating that whereas the same sensing system is shared by the two types of gravitropism, separate transductive systems are involved, one for diagravitropism, which is relatively independent of calcium, and one for positive gravitropism, which is markedly dependent on calcium.
在黑暗中生长的优良玉米（Zea mays L.）根的斜向重力行为为比较两种性质不同的重力系统提供了一个机会。与正向重力性一样，斜向重力性被证明需要根冠的存在，弯曲开始的时间进程相似，呈现时间也相似。与正向重力性相反，斜向重力性对钙的需求似乎更有限，因为它对EGTA洗脱钙不敏感，对随后添加的钙/EGTA复合物也不敏感。这些结果被解释为表明，虽然两种重力性类型共享相同的传感系统，但涉及不同的转导系统，一个用于斜向重力性，相对独立于钙，另一个用于正向重力性，明显依赖于钙。
