Volatile sesquiterpenes emitted from leaves of Polygonum longisetum treated with jasmonic acid and its amide conjugates

Sesquiterpenes, such as zingiberene, β-elemene, α-bergamotene, β-caryophyllene and (E,E)-α-farnesene were identified as volatile organic compounds (VOCs) from the leaves of Polygonum longisetum treated with jasmonic acid (JA) exogenously. Sesquiterpenes were emitted with 1 μM JA, and their amounts and relative proportions altered according to the concentration. Experiments with silver thiosulfate (STS) suggested that ethylene might be involved in the JA-inducible emission of sesquiterpenes, but the responses of sesquiterpenes against STS were different among them. The conjugate of JA and 1-aminocyclopropane-1-carboxylic acid (JA-ACC) was also active in emitting sesquiterpenes, while conjugates of JA and amino acids, such as Leu, Ile and Val, were inactive. Mevastatin suppressed almost all the sesquiterpenes, but zingiberene and β-elemene were not fully suppressed. It was suggested that JA might stimulate both the mevalonate and methylerythritol pathways in P. longisetum.