Metabolic and miR Profiling of TMV Infected Plants Figure 2. Relative metabolite content of TMV infected plants detected by GC-MS. A) Heat map representing changes in relative metabolite contents of TMV-inoculated and control plants detected by GC-MS experiments. The average accumulation of each metabolite was calculated in each time point and treatment (n$6, per time/treatment). TMV panel shows the average metabolites level ratios calculated between TMV- and mock- inoculated plants (TMV panel) for each time point. Mock-inoculated panel shows the relative average metabolites logarithmic ratios with respect to 1 dpi data at different time points. Asterisks indicate statistically significant differences (P,0.01) by Student’s t test. B) Number of metabolites with significant changes along TMV infection extracted from figure 2A (TMV panel). Dpi = days post inoculation. doi:10.1371/journal.pone.0028466.g002 levels. The early phase spanned the first 24 hours of infection when viral accumulation was undetectable in the sampled leaf (Figures 1B and 2). By contrast, in the second phase the number of statistically significant changes correlated with the increasing accumulation of the virus along the infection progress (Figures 1B and 2B). PLoS ONE | www.plosone.org 3 December 2011 | Volume 6 | Issue 12 | e28466