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The state of the pores in functioning sieve plates

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Summary

Electron microscopy of Helianthus stem and Saxifraga sarmentosa stolon after first plunging the material into boiling water indicates that the natural condition of the sieve plate pores is to be plugged fairly compactly with slime substance. Electron microscopy of pre-wilted plants demonstrates the same thing. These and other arguments indicate that the slime-filled condition of the pores is not an artifact induced by enzyme action or turgor release, nor is it a consequence of rapid translocation of slime; it is the natural state. This conclusion, very damaging to the pressure-flow hypothesis, is favourable to the electroosmotic theory.

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Authors and Affiliations

  1. Bedford College, London

    A. W. Siddiqui & D. C. Spanner

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  1. A. W. Siddiqui
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  2. D. C. Spanner
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Siddiqui, A.W., Spanner, D.C. The state of the pores in functioning sieve plates. Planta 91, 181–189 (1970). https://doi.org/10.1007/BF00385476

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  • DOI: https://doi.org/10.1007/BF00385476

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