To investigate the resistance phenotypes of our F1 populations against stresses other than the parental stress (mismatched environments), we used a reciprocal experimental design based on the three parental stress treatments (Fig. 1). We have previously reported that Pst-elicited TAR is associated with increased susceptibility to the necrotrophic fungus A. brassicicola (Luna et al., 2012). In agreement with this finding, F1 progeny from Pst-infected plants developed larger lesions after inoculation with the necrotrophic Pc (Fig. 6a and Fig. S5a). Furthermore, F1 progeny from Pst-exposed parents showed a statistically significant increase in root growth inhibition by 50 mM NaCl (Fig. 6b and Fig. S5b,c), indicating increased sensitivity to salt stress. Next, we investigated F1 progeny from Pc-infected parents for resistance against biotrophic Hpa and salt stress. F1 populations from parents exposed to the two highest severities of Pc disease showed increased susceptibility to Hpa (Fig. 6c and Fig. S6a) but were unaffected in salt tolerance (Fig. 6d and Fig. S6b,c). Together, these results indicate that the potential benefits of pathogen-induced TAR are traded off against costs of increased susceptibility to other stresses that become apparent in mismatched environments.