Figure 6.

Liquid chromatography–mass spectrometry (LC–MS) analysis for the identification and quantification of nicotine levels in the leaves of Nicotiana tabacum treated with salicylic acid (SA)-producing endophytic bacteria (EB) or SA sprayed on plant leaves. (a) Completely matched LC–MS chromatograms of the standard sample with the nicotine peak at 4.49 min and the EB-44 sample with the peak at 4.49. (b) Nicotine content in the leaves of N. tabacum. Data represent means ± standard deviations of four independent replications for each treatment. Means with different letters are significantly different at p < 0.05 by Duncan’s multiple range test. FW = fresh weight.