Testing the Munch hypothesis of long distance phloem transport in plants
Testing the Munch hypothesis of long distance phloem transport in plants
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DOI：
10.7554/elife.15341
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发表时间：
2016-06-02
期刊：
影响因子：
7.7
通讯作者：
Holbrook, N. Michele
中科院分区：
文献类型：
--
作者：
Knoblauch, Michael;Knoblauch, Jan;Holbrook, N. Michele
植物体内的长距离运输发生在韧皮部的筛管中。Ernst Munch在1930年提出的压力流假说描述了一种由热力学产生的压差的机制，该压差应该驱动韧皮部中的糖和其他溶质的运动，但该假说长期以来一直面临重大挑战。关键问题是筛管（包括筛板孔）的传导性是否足以允许压力流。我们发现，随着源和库之间的距离增加，筛管的电导率和膨压显着增加，在Ipomoea nil。我们的研究结果为蒙克假说提供了强有力的支持，同时为研究最不了解的植物组织之一提供了新的工具。
Long distance transport in plants occurs in sieve tubes of the phloem. The pressure flow hypothesis introduced by Ernst Munch in 1930 describes a mechanism of osmotically generated pressure differentials that are supposed to drive the movement of sugars and other solutes in the phloem, but this hypothesis has long faced major challenges. The key issue is whether the conductance of sieve tubes, including sieve plate pores, is sufficient to allow pressure flow. We show that with increasing distance between source and sink, sieve tube conductivity and turgor increases dramatically in Ipomoea nil. Our results provide strong support for the Munch hypothesis, while providing new tools for the investigation of one of the least understood plant tissues.