Repeated exposure to Z -3-hexenyl acetate does not induce more jasmonic acid. Maize seedlings were exposed to Z-3-hexenyl acetate (Z-3-HAC) at time point 0 and jasmonic acid accumulation monitored over 90 min (grey bars). After reaching baseline levels seedlings were again exposed to Z-3-HAC and JA measured 30 min later (dotted grey bar). No further accumulation was measured. At the same time control seedlings (white bars) did respond normally to Z-3-HAC exposure (white bar with dots). Error bars represent standard deviation. An * indicates a significant difference between Z-3-HAC-treated and control plants (t-test, p ≤ 0.05).