The membrane‐permeable zinc chelator N,N,N′,N′‐tetrakis(2‐pyridylmethyl)ethylenediamine (TPEN) causes similar phytotoxicity symptoms in tomato plants to fusaric acid. Leaves of tomato plants were pretreated, or not, with a 0.025% ZnSO4 solution and roots were immersed in sterile water containing 4 µm of the zinc chelator TPEN for 3 and 6 days. Boxed areas are shown at double magnification.