-PIXE analysis of BJ and MS stem and root show the presence of Au in all three tissue systems.A series of typical in situ, Au elemental maps for BJ root after 24 h exposure at 1000ppm and MS stem after 24 h of exposure at 40ppm are given in Fig. 6. Fig. 6 also indicates the elemental maps achieved by varying the exposure time for MS root at 80ppm and BJ root at 1000 ppm.