Ecotoxicological and Interactive Effects of Copper and Chromium on Physiochemical, Ultrastructural, and Molecular Profiling in Brassica napus L.

Figure 6

Electron micrographs of root tip cells of 10-day grown seedlings of two rapeseed cultivars (ZS 758 and ZD 622) under control (CK) and treatment (Cu 200 μM, Cr 200 μM, and Cu 200 μM + Cr 200 μM). (a, b) TEM micrograph of root tips of ZS 758 and ZD 622 under control showing large sized nucleus (N) with a round nucleolus (Nue) and well-shaped nuclear membrane (NM), clear cell wall (CW) and cell membrane (CM), oval shape mitochondria (MC), and endoplasmic reticulum (ER). (c) TEM micrograph of root tips of ZS 758 under Cu treatment showing clear cell wall (CW) and cell membrane (CM), round-shaped nucleolus (Nue) and well-developed nucleus (N), and oval shape mitochondria (MC). (d) TEM micrograph of root tips of ZD 622 under Cu treatment showing clear cell wall (CW) and cell membrane (CM), distorted nucleolus (Nue), and oval shape mitochondria (MC). (e) TEM micrograph of root tips of ZS 758 under Cr treatment showing rough cell wall (CW), scattered nucleolus (Nue), and bigger vacuole (V). (f) TEM micrograph of root tips of ZD 622 under Cr treatment showing rough cell wall (CW) and cell membrane (CM) and reputed nucleolus (Nue). (g) TEM micrograph of root tips of ZS 758 under Cu+Cr treatment showing undeveloped nucleus (N) with a roundish nucleolus (Nue), rough cell wall (CW) and cell membrane (CM), and electron dense granules (ED). (h) TEM micrograph of root tips of ZD 622 under Cu+Cr treatment showing thick and rough cell wall (CW), ruptured nucleus (N) and broken nuclear membrane (NM), and electron dense granules (ED).

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