ABSTRACT
This chapter summarizes the progress made toward understanding the roles of heat-shock proteins (Hsps) and molecular chaperones in terms of thermotolerance in plants. Thermotolerance in plants is related to the expression of Hsps. The importance of the heat-induction of Hsps/molecular chaperones in cellular thermotolerance comes from the apparent correlation between the level of Hsps/molecular chaperones accumulation and cellular thermotolerance. Transgenic Arabidopsis whose level of Hsp70/Hsc70 was reduced by an Hsp70 antisense gene exhibited less thermotolerance than the wild type. In E. coli, DnaJ which is heat-induced is essential for its viability at high temperature, indicating that J-proteins are involved in thermotolerance. Pioneering works to decipher the role of Hsp100/ClpB for thermotolerance were done with yeast. Molecular chaperones are proteins that accompany and look after proteins that are in non-native/non-functional structural states. They facilitate the proper folding/assembly of proteins by binding to non-native proteins.
