Journal article
Sieve Tube Geometry in Relation to Phloem Flow
The Plant cell, Vol.22(3), pp.579-593
03/2010
Handle:
https://hdl.handle.net/2376/105348
PMCID: PMC2861446
PMID: 20354199
Abstract
This work describes a novel method for imaging cell anatomy and cell wall features by scanning electron microscopy. The method was used to image sieve plates and sieve element geometry at high resolution to correlate sieve tube–specific conductivity with phloem flow measurements.
Sieve elements are one of the least understood cell types in plants. Translocation velocities and volume flow to supply sinks with photoassimilates greatly depend on the geometry of the microfluidic sieve tube system and especially on the anatomy of sieve plates and sieve plate pores. Several models for phloem translocation have been developed, but appropriate data on the geometry of pores, plates, sieve elements, and flow parameters are lacking. We developed a method to clear cells from cytoplasmic constituents to image cell walls by scanning electron microscopy. This method allows high-resolution measurements of sieve element and sieve plate geometries. Sieve tube–specific conductivity and its reduction by callose deposition after injury was calculated for green bean (
Phaseolus vulgaris
), bamboo (
Phyllostachys nuda
), squash (
Cucurbita maxima
), castor bean (
Ricinus communis
), and tomato (
Solanum lycopersicum
). Phloem sap velocity measurements by magnetic resonance imaging velocimetry indicate that higher conductivity is not accompanied by a higher velocity. Studies on the temporal development of callose show that small sieve plate pores might be occluded by callose within minutes, but plants containing sieve tubes with large pores need additional mechanisms.
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Details
- Title
- Sieve Tube Geometry in Relation to Phloem Flow
- Creators
- Daniel L Mullendore - School of Biological Sciences, Washington State University, Pullman, Washington 9164-4236Carel W Windt - Forschungszentrum Jülich, ICG-III Phytosphäre, 52428 Jülich, GermanyHenk Van As - Laboratory of Biophysics and Wageningen NMR Centre, Wageningen University, 6703 HA Wageningen, The NetherlandsMichael Knoblauch - School of Biological Sciences, Washington State University, Pullman, Washington 9164-4236
- Publication Details
- The Plant cell, Vol.22(3), pp.579-593
- Academic Unit
- Biological Sciences, School of
- Publisher
- American Society of Plant Biologists
- Identifiers
- 99900546861501842
- Language
- English
- Resource Type
- Journal article