Heat shock proteins in whiteflies, an insect that accumulates sorbitol in response to heat stress

1. The heat shock response was examined in the silverleaf whitefly. Hsp70 and Hsp90 were the major polypeptides synthesized by whiteflies in response to heat stress. 2. The amounts of Hsp70 and Hsp60 protein and Hsp70 mRNA were unchanged in response to a diurnal increase in temperature, whereas sorbitol content increased eight-fold. That steady-state levels of Hsps did not increase with higher rates of synthesis suggests that Hsps turn over faster in heat-stressed whiteflies. 3. Hsp70 transcript levels were highest when nutrient deprivation accompanied heat stress. Thus, Hsps appear to be especially important for heat-stressed whiteflies when sorbitol synthesis is limited nutritionally. (C) 2000 Elsevier Science Ltd. All rights reserved.