PLANT PHYSIOLOGY , Vol 114, Issue 2 429-438, Copyright © 1997 by American Society of Plant Biologists
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WHOLE PLANT, ENVIRONMENTAL, AND STRESS PHYSIOLOGY |
Tissue-Type-Specific Heat-Shock Response and Immunolocalization of Class I Low-Molecular-Weight Heat-Shock Proteins in Soybean
T. L. Jinn, PFL. Chang, Y. M. Chen, J. L. Key and C. Y. Lin
Department of Botany, National Taiwan University, Taipei 106, Taiwan, Republic of China (T.-L.J., P.-F.L.C., Y.-M.C., C.-Y.L.)
A monospecific polyclonal antibody was used to study the tissue-type
specificity and intracellular localization of class I low-molecular-weight
(LMW) heat-shock proteins (HSPs) in soybean (Glycine max) under different
heat-shock regimes. In etiolated soybean seedlings, the root meristematic
regions contained the highest levels of LMW HSP. No tissue-type-specific
expression of class I LMW HSP was detected using the tissue-printing
method. In immunolocalization studies of seedlings treated with HS
(40[deg]C for 2 h) the class I LMW HSPs were found in the aggregated
granular structures, which were distributed randomly in the cytoplasm and
in the nucleus. When the heat shock was released, the granular structures
disappeared and the class I LMW HSPs became distributed homogeneously in
the cytoplasm. When the seedlings were then given a more severe heat shock
following the initial 40[deg]C -> 28[deg]C treatment, a large proportion
of the class I LMW HSPs that originally localized in the cytoplasm were
translocated into the nucleus and nucleolus. Class I LMW HSPs may assist in
the resolubilization of proteins denatured or aggregated by heat and may
also participate in the restoration of organellar function after heat
shock.
