Abscisic acid (ABA) treatment had no direct effect on Plasmodium falciparum asexual growth or gametocyte formation. (A) Mean fold-changes in growth of asexual stage parasites as counted by flow cytometry 48 hours and 96 hours after treatment with 10 nM ABA, 100 nM ABA, or a diluent control; controls are set at one. Growth assays were performed with three different parasite culture passages. Data were analyzed by one-sample t tests. (B) Mean fold-changes in gametocyte density, counted using flow cytometry, at days 6, 8, and 10 postculture synchronization. Gametocyte assays were performed with continuous treatment with 10 nM ABA, 100 nM ABA or a diluent control using four different parasite culture passages; controls are set at one. Data were analyzed by one-sample t tests.