The microtubule plus-end binding protein EB1 functions in root responses to touch and gravity signals in Arabidopsis
The microtubule plus-end binding protein EB1 functions in root responses to touch and gravity signals in Arabidopsis
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DOI：
10.1105/tpc.107.056846
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发表时间：
2008-02-01
期刊：
影响因子：
11.6
通讯作者：
Kropf, Darryl L.
中科院分区：
文献类型：
--
作者：
Bisgrove, Sherryl R.;Lee, Yuh-Ru Julie;Kropf, Darryl L.
微管与相关的蛋白质一起发挥作用，这些蛋白质改变微管的行为和/或传递影响生长变化的信号。为了更好地了解微管及其相关蛋白如何影响生长，我们分析了一个微管相关蛋白家族，即拟南芥中的END BINDING 1（EB 1）蛋白（EB 1a，EB 1b和EB 1c）。我们发现，针对EB 1蛋白的抗体与根中的微管共定位，这一观察结果证实了先前使用EB 1-GFP融合的报道。我们还发现，T-DNA插入突变体与EB 1基因的表达减少有根，偏离向左垂直或倾斜板。突变体的根也表现出延长的水平生长，然后它们在围绕障碍物跟踪或根的908顺时针重新定向后向下弯曲。这些观察结果表明，根生长的延迟偏差可能是对触摸和/或重力信号的延迟响应的结果。根部长度和宽度正常，表明弯曲形成的延迟不是由于总体生长速率的变化。此外，最严重的缺陷的基因型响应于低剂量的微管抑制剂的方式与野生型难以区分，表明微管的完整性是不是一个主要的贡献者突变体根生长的微偏差。
Microtubules function in concert with associated proteins that modify microtubule behavior and/or transmit signals that effect changes in growth. To better understand how microtubules and their associated proteins influence growth, we analyzed one family of microtubule-associated proteins, the END BINDING1 (EB1) proteins, in Arabidopsis thaliana (EB1a, EB1b, and EB1c). We find that antibodies directed against EB1 proteins colocalize with microtubules in roots, an observation that confirms previous reports using EB1-GFP fusions. We also find that T-DNA insertion mutants with reduced expression from EB1 genes have roots that deviate toward the left on vertical or inclined plates. Mutant roots also exhibit extended horizontal growth before they bend downward after tracking around an obstacle or after a 908 clockwise reorientation of the root. These observations suggest that leftward deviations in root growth may be the result of delayed responses to touch and/or gravity signals. Root lengths and widths are normal, indicating that the delay in bend formation is not due to changes in the overall rate of growth. In addition, the genotype with the most severe defects responds to low doses of microtubule inhibitors in a manner indistinguishable from the wild type, indicating that microtubule integrity is not a major contributor to the leftward deviations in mutant root growth.