Tissue-type-specific heat-shock response and immunolocalization of class I low-molecular-weight heat-shock proteins in soybeans.

摘要

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 soyabeans under different heat-shock regimes. In etiolated soyabean 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鳦 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鳦 28鳦 treatment, a large proportion of the class I LMW HSPs that originally localized in the cytoplasm were translocatedinto 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.