Effect of Heat Shock on the mRNA-Directed Disease Resistance Response of Peas.

Pea tissue ;heat shocked' for 2 hours at 40 degrees C accumulates mRNAs that code for a series of new proteins called heat shock proteins. A different messenger RNA population, which codes for a high level of 20 or more ;resistance proteins,' accumulates in pea tissue as it resists plant pathogenic fungi. Heat shock treatment applied prior to fungal inoculation prevents the high level accumulation of messenger RNA coding for the 20 resistance proteins and blocks disease resistance. If the resistance response is initiated before the heat shock treatment or after heat shock recovery, messenger RNA accumulates for the resistance proteins and disease resistance develops.