Molecular chaperone involved in heat stress response. May play a role in resolubilization of protein aggregates after heat shock. Expressed in developing embryos and dry seeds, and decreases rapidly during seed germination. Expressed within five minutes of heat shock at 42 and 45 degrees Celsius in one week-old seedlings. Maximal level of expression after 30 minutes and decrease of expression after four hours at 45 degrees Celsius. No induction detected after salt stress, low temperature, desiccation, or abscisic acid (ABA) treatment. Protein expressed up to 72 hours in Indica rice and up to 96 hours in Japonica rice after a 2 hours heat shock at 42 degrees Celsius. Belongs to the ClpA/ClpB family.