Effectivity of copper and cadmium sulphide nanoparticles in mitotic and meiotic cells of Nigella sativa L. (black cumin) – can nanoparticles act as mutagenic agents?

Figures & data

Figure 1. ( a–g) Characterisation of copper and cadmium sulphide nanoparticles. (a–b) UV--vis spectra of (a) Cu-NPs and (b) CdS-NPs. (c) FTIR spectra of CdS-NPs. (d–e) XRD patterns of powdered NPs ((d) Cu; (e) CdS). (f–g) DLS pattern of size distribution of (e) Cu-NPs and (f) CdS- NPs.

Figure 2. FESEM ((a) Cu-NPs; (b) CdS-NPs) images showing nanoclusters and TEM ((c) Cu-NPs; (d) CdS-NPs) images of NPs (right-handed arrow – gelatin envelop; dotted arrow – metallic core).

Table 1. Accumulation Cu- and CdS-NPs in controls and treatments.

	Treatments
	Dose (µg/ml)	Duration (h)	Amount of copper (Cu^2+)/cadmium (Cd^2+) ions detected in seedling ash (µg/g)
Bulk Cu	0.25	3	0.36
Cu-NPs	0.25	3	3.02
	0.50	3	8.62
	1.00	3	10.12
	0.25	6	4.94
	0.50	6	9.80
	1.00	6	10.76
Bulk CdS	0.25	3	0.43
CdS-NPs	0.25	3	6.44
	0.50	3	9.84
	1.00	3	13.49
	0.25	6	8.37
	0.50	6	9.07
	1.00	6	19.11

Figure 3. ( a–g) Mitotic index and frequency of abnormal dividing cells in relation to respective controls of N. sativa. (a–b) Cu-NPs. (c–d) CdS-NPs. (e–f) EMS. (g) Gamma irradiations. (A) Frequency of abnormal cells; (B) mitotic index.

Figure 4. ( a–h) Mitotic cells ((a–e) metaphase, (f–h) anaphase) of N. sativa in (a) control and (b–i) Cu- and CdS-NPs treated material. (a) 2n = 12. (b) Differentially condensed chromosome with a fragment (right-handed arrow) and a ring (dotted arrow). (c) Diplochromatid nature of chromosomes with unoriented chromosomes. (d) Cell with >2n = 12 chromosomes. (e) Differential condensation and fragmentation of chromosomes. (f) Anaphase with lagging fragments. (g) Chromosome bridge formation. (h) I: Anaphasic bridge with two equal size fragment, II: Double bridge with two minute fragments. (i) Cells without or with depleted chromatin. (j) Cell with fragmented chromatin mass. (k) Interphase cell with two unequal sized micronuclei. (l) Giant cell. Scale bar = 20 µm.

Table 2. Pooled data across doses of treated materials in root tip mitosis of N. sativa.

				Dividing cells
Treatments	Total no. of cells	No. of dividing cells	No. of resting cells	Mitotic index (%)	Fragments (%)	Rings (%)	Bridges (%)	Bridges and fragments (%)	Total no. of abnormal dividing cells (%)	Micronuclei (%)
Control	905	201	704	22.21	0.00	0.00	0.00	0.00	0.00	0.00
Bulk Cu control (µg/ml)	712	158	554	22.19	0.00	0.00	0.00	0.00	3.16	0.00
Bulk CdS control (µg/ml)	1213	217	996	17.89	0.00	0.00	0.00	0.00	2.30	0.00
EMS (%)	6977	580	6397	8.31	6.38	0.00	1.90	0.00	19.32	1.33
Gamma irradiation (Gy)	8093	865	7228	10.69	14.34	0.35	6.59	2.43	46.67	6.95
Cu-NPs (µg/ml)	10,222	884	9338	8.65	5.88	0.11	0.45	1.40	17.84	1.29
CdS-NPs (µg/ml)	6072	874	5198	14.34	0.69	0.00	0.23	0.00	3.01	3.19
CD at 5%				1.28	0.66	–	0.40	–	0.58	0.40
p-Value at 6 DF				<0.001	<0.001	<0.001	<0.001	<0.001	<0.001	<0.001

Table 3. Meiotic configurations and pollen fertility in treated materials.

		Mean chromosome/cell
Treatments	Total no. of MI cells scored	II	I	Total no. of AI cells scored	Balanced AI cells (%)	Total no. of AII cells scored	Balanced AII cells (%)	Total no. of pollen grains	Pollen fertility (%)
Control	300	6.00	0.00	400	100.00	200	100.00	2158	95.80
Bulk Cu control (µg/ml)	225	6.00	0.00	337	100.00	892	99.78	712	95.79
Bulk CdS control (µg/ml)	556	5.88	0.24	612	100.00	377	100.00	681	89.87
EMS (%)	1560	5.89	0.23	1668	71.95	1440	76.09	2754	59.37
Gamma irradiation (Gy)	2341	5.64	0.49	1150	84.78	821	94.52	16,290	69.12
Cu-NPs (µg/ml)	1990	5.96	0.07	3930	77.35	1982	76.03	8768	75.58
CdS-NPs (µg/ml)	2450	5.83	0.32	1974	95.94	2742	89.46	6784	76.34
χ^2 test of heterogeneity		24.08	889.99
p-Value at 6 DF		<0.001	<0.001

Figure 5. Meiosis in (a) control and (b–x) nanoparticles treated plants. (a) 6II. (b) Pachytene stage with two fragments. (c) Diakinesis cell showing breakage of an arm (dotted arrow) in a bivalent. (d) MI with 5II + 2I + 3 fragments (right-handed arrow). (e–f) Chromosomal grouping (4II + 2II) at MI. (g) Fragments in association to bivalent and univalent at MI possibly 2n > 12. (h) Intense chromosomal fragmentation at MI. (i) Cytomictic behaviour involving two meiocytes. (j) Hyperploid PMC – 7II at MI. (k) Hypoploid cell with condensed type chromosomal fragments. (l) Agglutination of chromatin and fragments. (m) Differential condensation of chromosomes at MI. (n) 6/6 separation at AI. (o) 3/5/4 separation of chromosomes at AI. (p) 5/7 AI separation with interchromosomal connections. (q) 2n > 12 with sticky chromosomes at AI. (r) Dicentric chromatid bridge with an acentric fragment. (s) 2n = 24; AI showing tripolar organisation of chromosomes. (t) AII with one disorganised pole. (u) AII with bridge. (v) Unequal tripolarity. (w,x) AII with multiple groups and fragments. Scale bar = 10 µm.

Figure 6. Frequency (%) of seedless plant at MI. (a) Cu-NPs. (b) CdS-NPs. (c) EMS. (d) Gamma irradiations.