Upper panel: Recombinant AtGCL protein at different dilutions (0.011, 0.042, 0.168 and 0.67 pmol) when compared with root protein extract dilutions. Diluted extract (0.063) is equivalent to 0.078 mg fresh weight. The comparison indicates that the amount of endogenous AtGCL protein in 0.078 mg of root tissue approximately equals 0.042 pmol of recombinant AtGCL protein, corresponding to 538 nmol endogenous AtGCL protein per kilogram fresh weight. Lower panel: Comparison of leaf and root extracts at different dilutions. As in leaf extracts, Rubisco Large SU tends to distort GCL immune signals, the root part was used for quantification. Numbers indicate the dilution factors, factor 1 corresponds to 90 mg fresh weight equivalent.