Fig. 3

The presence of D₄-SA in D₆-GABA-treated plants. A GC–MS chromatogram of the D₆-GABA-treated plants (a) showing the presence of D₄-SA and the absence of D₄-SA in control plants (b) after derivatization with MCF. The mass spectra of the MCF derivatives of D₄-SA and SA in D₆-GABA-treated (c) and control plants (d)