Plastids and gravitropic sensing
Plastids and gravitropic sensing
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DOI：
10.1007/pl00008116
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发表时间：
1997-01-01
期刊：
影响因子：
4.3
通讯作者：
Sack, FD
中科院分区：
文献类型：
--
作者：
Sack, FD
综述了有关地向感测质量同一性的数据和理论。在植物和藻类中，重力感应可能在器官和尖端生长细胞的向重力性、重力形、重力轴和Chara节间细胞的细胞质流调节等过程中进化了几次。在后者和重力轴中，整个细胞的质量可能起传感作用。但向地性感应似乎依赖于沉积的淀粉体的质量，因为(i)有沉降的细胞的位置受到高度调节，（ii）这些细胞含有其他有利于沉降的形态特化，（iii）在野生型植物中，沉降总是与向地性能力相关，（iv）根帽淀粉体的磁泳运动模仿向地性，(v)无淀粉和中间淀粉突变体表现出较低的向地性敏感性。对这些数据最简单的解释是，地向感测是基于质体的。
Data and theories about the identity of the mass that acts in gravitropic sensing are reviewed. Gravity sensing may have evolved several times in plants and algae in processes such as gravitropism of organs and tip-growing cells, gravimorphism, gravitaxis, and the regulation of cytoplasmic streaming in internodal cells of Chara. In the latter and in gravitaxis, the mass of the entire cell may function in sensing. But gravitropic sensing appears to rely upon the mass of amyloplasts that sediment since (i) the location of cells with sedimentation is highly regulated, (ii) such cells contain other morphological specializations favoring sedimentation, (iii) sedimentation always correlates with gravitropic competence in wild-type plants, (iv) magnetophoretic movement of rootcap amyloplasts mimics gravitropism, and (v) starchless and intermediate starch mutants show reduced gravitropic sensitivity. The simplest interpretation of these data is that gravitropic sensing is plastid-based.