The Fern Sporangium: A Unique Catapult
The Fern Sporangium: A Unique Catapult
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DOI：
10.1126/science.1215985
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发表时间：
2012-03-16
期刊：
影响因子：
56.9
通讯作者：
Dumais, J.
中科院分区：
文献类型：
--
作者：
Noblin, X.;Rojas, N. O.;Dumais, J.
各种植物和真菌都进化出了巧妙的装置来传播它们的孢子。其中一种机制是蕨类孢子囊的空泡触发弹射。球形孢子囊内有一排12 ~ 13个特化细胞，称为环带。当脱水时，这些细胞诱导孢子囊中的曲率的急剧变化，其在环带细胞的空化之后突然释放。整个弹射过程让人想起人造弹射器，但有一个明显的例外：孢子囊缺少在弹射臂返回时阻止弹射臂的横杆。我们发现，弹射机制的复杂性和效率在于与瓣环闭合相关的两个非常不同的时间尺度。
Various plants and fungi have evolved ingenious devices to disperse their spores. One such mechanism is the cavitation-triggered catapult of fern sporangia. The spherical sporangia enclosing the spores are equipped with a row of 12 to 13 specialized cells, the annulus. When dehydrating, these cells induce a dramatic change of curvature in the sporangium, which is released abruptly after the cavitation of the annulus cells. The entire ejection process is reminiscent of human-made catapults with one notable exception: The sporangia lack the crossbar that arrests the catapult arm in its returning motion. We show that much of the sophistication and efficiency of the ejection mechanism lies in the two very different time scales associated with the annulus closure.