In vitro and in vivo experiments on human cell lines (breast adenocarcinoma, MCF-7, and liver hepatocellular carcinoma, HepG2), plants (Allium cepa) and bacteria (Staphylococcus aureus and Pseudomonas aeruginosa) displayed cytotoxic and genotoxic impacts of silver nanoparticles (AgNPs). The cell viability assays indicated that AgNPs had inhibitory effects on MCF-7 cell line more effectively than HepG2 cell line. Mitotic indices and distribution of cells in mitotic phases of A. cepa were clearly changed after treatment with three different weight ratios of silver metal (1, 3 and 5%) for 3 and 12 h. With increasing concentration of the nanoparticles a decrease in the mitotic index was detected (from 4.19 to 0.79 after 3 h and from 4.56 to 0.25 after 12 h) and different types of chromosomal aberrations were noticed. Protein electrophoresis results of S. aureus and P. aeruginosa demonstrated the change in the protein profiles of the two bacterial strains and it was more noticeable in P. aeruginosa than S. aureus. RAPD-PCR and ISSR-PCR analyses using different primers (OP-A19, OP-B04, OP-C04, OP-C12, OP-Q18, OP-Z03, 14A, 44B, HB-08, HB-11 and HB-12) demonstrated the impairment of bacterial DNA and induction of genetic variability. The percentage of polymorphism was higher in P. aeruginosa than S. aureus. The present findings revealed an analogous effect of AgNPs induced in in vitro and in vivo experiments, therefore AgNP applications should be given special consideration.

EvEral abiotic stresses including salinity impact plant growth and reduce the productivity of many plants and field crops. Plantlets produced in vitro by tissue culture technique offer a direct and fast approach to investigate the mechanism of stress adaptation. The present study estimated the survival percentage of two potato (Solanum tuberosum l.) cultivars (Spunta and valor) under salt stress as abiotic stresses. Some biochemical alterations and ultrastructural responses of plantlets were examined. Moreover, genetic diversity was also studied using raPD technique. The results showed that, with the increase of external stress there was a significant decrease in the survival percentage, significant accumulation of osmoprotectants (proline) and induction of DNa damages. Furthermore, there were closing of stomatal apertures, changes in chloroplast ultrastructure and cell intercellular spaces markedly decreased. additionally, high salt stress (150 and 200mM NaCl) caused complete inhibition of plantlet growth. The present work provides insight view for the adaptation of potato plantlets to salt stress through accumulating of osmoprotectants and change in molecular and ultrastructure traits.

In this study, we used the Agrobacterium tumefaciens-mediated transformation approach to transfer the activity of the cyanobacterial cyanase enzyme into the microalga, Chlamydomonas reinhardtii. In transgenic C. reinhardtii strains, the recombinant cyanase enzyme was proven to be active. In comparison to wild-type control, transgenic type demonstrated higher rates of ammonia release, reduced loss of pigmentation, and a lower percentage of growth retardation when varied amounts of cyanide (up to 200 ppm) were applied to the growth medium. Moreover, cyanase activity increases as concentration of cyanide increase especially in case of transgenic. The maximum activity was indicated in presence of 100 mg/l cyanide it reached eight folds more than wild activity at the same cyanide concentration. Results of this study provide an effective eco-friendly phytoremediation system for detoxification of cyanide using micro-alga compared to previously reported conventional system for removal of cyanide compounds, Also, some factors are taken in consideration like different pH, contact time and the transgenic type has been the priority for removal cyanide at wide range of pH with two folds more than wild type.

Recombinant DNA technology offered the creation of new combinations of DNA segments that are not found together in nature. The present study aimed to produce an ecofriendly bioremediation model to remediate cyanide pollution from a polluted marine system. Cyanide is a known toxic compound produced through natural and anthropogenic activities. An Agrobacterium-tumefaciens-mediated genetic transformation technique was used to generate transformed Chlamydomonas reinhardtii using plant expression vector pTRA-K-cTp carries isolated coding sequence of the cyanobacterial cyanase gene (CYN) isolated from Synechococcus elongatus (PCC6803). qRT-PCR analysis showed the overexpression of CYN in transgenic C. reinhardtii, as compared with the respective wild type. Growth parameters and biochemical analyses were performed under cyanide stress conditions using transgenic and wild C. reinhardtii for evaluating the effect of the presence of the cyanobacterial cyanase gene in algae. The transgenic C. reinhardtii strain (TC. reinhardtii-2) showed promising results for cyanide bioremediation in polluted water samples. Cyanide depletion assays and algal growth showed a significant resistance in the transgenic type against cyanide stress, as compared to the wild type. Genetically modified alga showed the ability to phytoremediate a high level of potassium cyanide (up to150 mg/L), as compared to the wild type. The presence of the CYN gene has induced a protection response in TC. Reinhardtii-2, which was shown in the results of growth parameter analyses. Therefore, the present study affirms that transgenic C. reinhardtii by the CYN coding gene is a potential effective ecofriendly bioremediator model for the remediation of cyanide pollutants in fresh water.

Mesembryanthemum nodiflorum L. (Aizoaceae) has long been used as food and in traditional medicine. This study was intended to explore the active groups within M. nodiflorum ethanolic extract and to study the cytological effects of M. nodiflorum water extract on Allium cepa L. root tips. Phytochemical analysis of M. nodiflorum ethanolic extract indicated the presence of alkaloids and triterpenes. Tannins, flavonoids and saponins did not found in M. nodiflorum alcoholic extract. Mitotic indices and distribution of cells in mitotic phases of A. cepa root tips were clearly changed after treatment with three different concentration of M. nodiflorum water extract (0.1, 1 and 3%) for 3h, 6h, and 12h. The maximum value of mitotic index 2.68% was observed after treatment with 3% for 6h, while the minimum value 1.35% was scored after 12h exposure to the same concentration. Different types of chromosomal aberrations were noticed. The present study revealed that M. nodiflorum water extract has a potent inhibitory effect on the mitotic activity of A. cepa root tip cells.