Heat-shock protein expression in a perennial grass commonly associated with active geothermal areas in western North America

Heat-shock protein (hsp) expression in response to short- (hours) versus long-term (weeks) heat was examined in Dichanthelium lanuginosum. Expression of cytoplasmic class I small hsps (shsps) and hsp 101 was elicited by 2 h above 40°C, along with an increase over basal levels of hsp 70. Elevated levels of heat-induced shsp and hsp 101 persisted for 5–7 days after plants were returned to control temperatures. Protein extracts from roots exposed to 42°C for several weeks displayed increased levels of shsp but decreased hsp 101 levels. This decrease in hsp 101 did not occur in D. lanuginosum from normothermic environments.