Monitoring of [Ca2+]
in soybean cells challenged with fungal metabolite mixtures. Cells were treated with: the whole culture filtrate of Trichoderma (black trace) or non-inoculated culture medium (grey trace) (a); >3 kDa (black trace) and <3 kDa (grey trace) fractions from culture filtrates of Trichoderma (b), Botrytis (c), and Trichoderma grown in the presence of Botrytis (d). In c, the first peak of the Ca2+ transient induced by the >3 kDa metabolites is represented out of scale. In d, the inset shows the [Ca2+]cyt changes induced by the simultaneous application of the metabolite fractions (>3 kDa, black trace; <3 kDa, grey trace) from separately grown Trichoderma and Botrytis. Fungal filtrates were applied to cells after 100 s. These and the following traces have been chosen to best represent the mean results from at least three repetitions.