Figure 2.

Electron micrographs of leaf mesophyll cells of 15-day hydroponically grown seedlings of Brassica napus cv. ZS 758. (a-b) TEM micrographs of mesophyll cells of leaves of ZS 758 at control level at low and high magnifications, respectively, show a clear cell wall (CW) and cell membrane (CM), well-developed chlorophyll (Chl) with thylakoids, grana, and starch grain (S). (c-d) TEM micrographs of mesophyll cells of ZS 758 at 25 mg L⁻¹ 5-aminolevulinic acid (ALA) alone at low and high magnifications, respectively, show a small nucleus (N) with developed nucleolus (Nue) and nuclear membrane (NM), well-developed chloroplast (Chl) with thylakoids, grana, and starch grains (S). Cell wall (CW) and cell membrane (CM) are present. Moreover, intercellular spaces are found.