Lima bean (Phaseolus lunatus cv. Pole Sieva) and maize (Zea mays L. cv. Royal Dent) plants were grown in a greenhouse. Each individual plant was grown in a plastic pot in a growth chamber at 25uC with a photoperiod of 16 h (natural+supplemental light), and used for the experiments by the time lima bean and maize were 2- and 1-week old, respectively. A wild-type (WT) or transgenic tobacco plant was grown in a plastic pot in a growth chamber at 25uC (160 mEm 22 s21 during a 16-h photoperiod) for 4–6 weeks until it was ready to be used as an ‘emitter’.