Abstract Our previous work has indicated that salicylic acid (SA) is involved in the development of pea plant thermotolerance and induces the gene expression of phenylalanine ammonia-lyase (PAL; EC 4.3. 1.5), a key enzyme in phenylpropanoid metabolism of grape berry. However, the relationship between SA and PAL during high temperature stress remains obscure. The present experiment, using the technique of in ...