Fig. 2
Differential transcription of the PAL (phenylalanine ammonia-lyase) PR3, PR7 and PR11 genes (pathogenesis-related protein) measured by RT-qPCR according to the treatments: untreated plants (control); humic substances (HS); humic substances plus plant growth-promoting bacteria (HS + PGPB). The expression was normalised concerning the control treatment (control = 0). The data represent the mean; the bars are the three independent plants' standard deviation (n = 3)