Qualitative examples of GUS expression. Histochemical staining of the controls indicates that Adh/GUS was not expressed in these plants (a – b). An increase in magnetic field strength induces expression of the Adh/GUS transgene (e.g. 20 Tesla for 2.5 hours, c – d). The increased magnification of the plants shown in b and d (second row) provide closer inspection of GUS localization in the roots and leaves of these samples. The middle panel (e) provides a top-view of the five 21 day-old plants just prior to insertion into the bore of the magnet. The right hand panel (f) shows the plants from the side.