Microscopic analysis of roots from T2 homozygous transgenic plants (p BjMTP1::mRFP1 and GUSPlus) after exposure to 50 μM Ni2+ for 48 h. Images of cross sections taken from the top of the main root under bright field illumination, using diascopic filters at 10× (A) and 20× (B) magnification, and fluorescent images of the same sections using a Rhodamine – Texas red filter at 10× (C) and 20× (D) magnification.. Root morphology in (A) and (B) labeled as follows. (1) periderm, (2) pericycle, (3) secondary phloem, (4) cambial zone, (5) secondary xylem and (6) secondary xylem parenchyma. Lateral root showing an overlay of a bright field and fluorescent image (E) and fluorescent image alone (F). Image of a root cross section showing GUS activity at 20× magnification. Scale bar = 40 μm for B, D, E, F, G and 120 μm for A and C.