Authors: PLATT K A OLIVER M J THOMSON W W
Publish Date: 1997/11/01
Volume: 80, Issue: 5, Pages: 599-610
Abstract
K A PLATT M J OLIVER W W THOMSON Importance of the Fixative for Reliable Ultrastructural Preservation of Poikilohydric Plant Tissues Observations on Dry Partially and Fully Hydrated Tissues of Selaginella lepidophylla Annals of Botany Volume 80 Issue 5 November 1997 Pages 599–610 https//doiorg/101006/anbo19970476Leaves of desiccated ‘resurrection plants’ Selaginella lepidophylla were hydrated either through the roots of intact plants or as isolated organs Airdry tissue and samples at 1 4 8 and 24 h both detached and intact of hydration were prepared for electron microscopy using aldehyde fixatives of different osmotic strengths Both dry and hydrated tissues were also prepared using freeze substitution Significant differences in the ultrastructural preservation of these different samples were noted There was a direct correlation between the osmolality of both the fixative and the tissue with the quality of ultrastructural preservation When the osmolality of the fixative was slightly or even considerably higher than that of the tissue optimal preservation was achieved Freeze substitution however gave the most faithful preservation of all subcellular compartments despite the frequent presence of small ice crystals Additionally hydration of detached leaves for more than 4 h resulted in swelling damage of the organelles and cytoplasm regardless of the fixation protocolBroadly interpreted the results of this study indicate that an optimal preservation of plant cell and organelle ultrastructure can be achieved by the use of high osmolality fixatives or preferably freeze substitution These results are also important in determining the method of hydration of poikilohydric samples for physiological studies and for interpretation of functional changes as related to the structural condition of the organelles Copyright 1997 Annals of Botany Company
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