Two-dimensional gel analysis of 45 ku heat shock proteins from a drought and heat resistant maize line

In a previous study, Ristic et al. (1991) described a band of heat-shock pr otein(s) [HSP(s)] of 45 ku (kDa) in the leaf tissue of a drought and heat r esistant maize line, ZPBL 1304. This band had not been previously described in the leaves of maize and does not appear to be common in higher plants. It was not known how many polypeptides comprised this 45 ku band, and wheth er drought stress can induce the synthesis of proteins of 45 ku. The object ives of this study were two fold: 1) to analyze the 45 ku HSP band from lea f tissue of the ZPBL 1304 line using two-dimensional gel electrophoresis (h eat-shock polypeptide study), and 2) to investigate the possible synthesis of 45 ku protein(s) in ZPBL 1304 line under dry conditions. For heat-shock polypeptide study, plants were exposed to two environmental stress treatmen ts: soil drying and high temperature (45 degrees C) and high temperature al one (45 degrees C). Generally, the pattern of heat shock (HS) polypeptide s ynthesis under soil drying and high-temperature conditions was similar to t hat under high temperature conditions. Two dimensional gel electrophoresis revealed three HS polypeptides of 45 ku with isoelectric points (p/) rangin g from 5.0 to 5.5 and two HS polypeptides of 46 ku with p/slightly above 5. 5. Drought stress: alone did not induce the synthesis of proteins of 45 ku. The possible role of the 45/46 ku HSPs in the development of heat resistan ce is discussed.