Quantification of 18-carbon unsaturated fatty acid levels in PMV- and PMV+SPMV-infected Brachypodium. Levels of free and total 18:1, 18:2, and 18:3 fatty acids in mock-, PMV-, and PMV+SPMV-infected plants at stages II (14 dpi) and III (21 dpi) of infection. The error bars represent standard errors of means (n = 3 and n = 4 for stages II and III, respectively). *, P ≤ 0.05; **, P ≤ 0.01; ***, P ≤ 0.001 between mock- and virus-infected samples as determined by two-sample t test (one-tailed). M, mock; P, PMV; PS, PMV+SPMV.