Fig. 1: Development of Beauveria bassiana on cabbage aphids is affected by the glucosinolates (GSLs) of their Brassicales host plants.

A–D Cabbage aphids were fed on Brassica napus, B. nigra, B. oleracea, or Nasturtium officinale as host plants. A Number of living aphids, including both surviving adults and their offspring, for aphids infected by B. bassiana compared to non-infected ones (n = 6). B Relative abundance of B. bassiana infecting aphids (measured as the transcript level of the B. bassiana actin gene (actin) relative to the cabbage aphid elongation factor 1 alpha gene (ef1α), n = 5). C GSL content of host plants and cabbage aphids (n = 5, detailed GSL contents are listed in Table S1). D Principal component analysis (PCA) plot showing the variation among GSL accumulation by the cabbage aphid on different Brassicales plants. Vectors indicate the direction and strength of the GSLs accumulated by aphids on different host plants in relation to the overall GSL distribution. E–H Cabbage aphids were fed on Arabidopsis thaliana with aliphatic GSLs (wild type Col-0 plants) and without aliphatic GSLs (myb28myb29 mutant plants). E GSL content of A. thaliana plants and cabbage aphids (n = 5). F Number of living aphids after infection by B. bassiana (n = 6). G Relative abundance of B. bassiana infecting aphids (measured as the transcript level of the B. bassiana actin gene relative to the cabbage aphid ef1α gene, n = 5). H Photographs of B. bassiana-infected aphids from an A. thaliana wild-type plant (left) and a myb28myb29 plant (right) taken on the 6th day after infection. 3MSOP-GSL, 3-methylsulfinylpropyl GSL; 4MSOB-GSL (1), 4-methylsulfinylbutyl GSL; 5MSOP-GSL, 5-methylsulfinylpentyl GSL; 8MSOO-GSL, 8-methylsulfinyloctyl GSL; 4MTB-GSL (5), 4-methylthiobutyl GSL; I3M-GSL, indolyl-3-methyl GSL; 4MOI3M-GSL, 4-methoxyindolyl-3-methyl GSL. The statistical methods are listed in the figures. Asterisks and lowercase letters denote statistically significant differences.