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Pizzaia D, Nogueira ML, Mondin M, Carvalho MEA, Piotto FA, Rosario MF, Azevedo RA. Cadmium toxicity and its relationship with disturbances in the cytoskeleton, cell cycle and chromosome stability. ECOTOXICOLOGY (LONDON, ENGLAND) 2019; 28:1046-1055. [PMID: 31502144 DOI: 10.1007/s10646-019-02096-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 08/02/2019] [Indexed: 06/10/2023]
Abstract
This study aimed to investigate the mode of action of cadmium (Cd) toxicity at cell level, especially at early stages of plant exposure. Tomato seedlings were cultivated in growth media containing from 0.1 to 70 µM CdCl2 for 24 h. Mitotic index, chromosome abnormality, DNA integrity and organization of tubulin-based structures were assessed in root cells. As higher the Cd concentration in the growth media, higher was the DNA damage intensity and the occurrence of chromosomal abnormalities that included chromosome lost, bridges, stickiness, C-metaphase and polyploidy. The profile of chromosomal aberrations also varied with elevated Cd concentration, being observed increases in the frequency of chromosome stickiness. The mitotic index was reduced at the lowest Cd concentration, but such reduction was statistically similar to that detected at the highest concentration, suggesting that mitotic depression is a rapid outcome and, at same time, a Cd-induced effect that is limited at the first 24 h of direct root exposure to this metal. Under exposure to 20 µM CdCl2, heterogenous distribution of the spindle fibers, formation of two spindle complexes in both of the cell poles, absence of centrosome center, polarization of the spindle fibers during cell division, and non-uniform tubulin deposition in microtubule and phragmoplast were noticed. The results indicate that the tubulin-dependent components of cytoskeleton are Cd targets, and the sensitivity of tubulin-based structures to Cd exposure depends on cell cycle phase. Moreover, DNA damage intensity and chromosomal abnormality profile can be employed as markers of Cd toxicity level.
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Affiliation(s)
- Daniel Pizzaia
- Departamento de Genética, Escola Superior de Agricultura "Luiz de Queiroz", Universidade de São Paulo, Av. Pádua Dias, 11, Piracicaba, SP, 13418-900, Brazil
| | - Marina Lima Nogueira
- Departamento de Genética, Escola Superior de Agricultura "Luiz de Queiroz", Universidade de São Paulo, Av. Pádua Dias, 11, Piracicaba, SP, 13418-900, Brazil
| | - Mateus Mondin
- Departamento de Genética, Escola Superior de Agricultura "Luiz de Queiroz", Universidade de São Paulo, Av. Pádua Dias, 11, Piracicaba, SP, 13418-900, Brazil
| | - Marcia Eugenia Amaral Carvalho
- Departamento de Genética, Escola Superior de Agricultura "Luiz de Queiroz", Universidade de São Paulo, Av. Pádua Dias, 11, Piracicaba, SP, 13418-900, Brazil
| | - Fernando Angelo Piotto
- Departamento de Produção Vegetal, Escola Superior de Agricultura "Luiz de Queiroz", Universidade de São Paulo, Av. Pádua Dias, 11, Piracicaba, SP, 13418-900, Brazil
| | - Millor Fernandes Rosario
- Universidade Federal de São Carlos, Campus Lagoa do Sino, Rodovia Lauri Simões de Barros, km 12, SP 189, Buri, SP, 18290-000, Brazil
| | - Ricardo Antunes Azevedo
- Departamento de Genética, Escola Superior de Agricultura "Luiz de Queiroz", Universidade de São Paulo, Av. Pádua Dias, 11, Piracicaba, SP, 13418-900, Brazil.
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Lima MGF, Rocha LC, Silveira GL, Alvarenga IFS, Andrade-Vieria LF. Nucleolar alterations are reliable parameters to determine the cytogenotoxicity of environmental pollutants. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2019; 174:630-636. [PMID: 30875556 DOI: 10.1016/j.ecoenv.2019.03.033] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2018] [Revised: 03/06/2019] [Accepted: 03/07/2019] [Indexed: 06/09/2023]
Abstract
Pollution generated by deposition of industrial activity waste in the environment without due care can lead to serious environmental consequences. Bioassays in higher plants are means of understanding the cytogenotoxic effects of these substances. In the present work, Allium cepa L. was used as a model species to assess nucleolar changes induced by environmental pollutants. The substances used were Methyl Methane Sulfonate (MMS), cadmium (Cd), Spent Potliner (SPL) and the herbicide Atrazine. Water was used as a negative control. The silver-stained nucleolar organizer region (AgNOR) assay was used making it possible to evaluate how nucleolar parameters (number of nucleoli per nucleus and nucleoli area) behave when facing stress caused by such pollutants. The results obtained showed a variation in the observed parameters: an increase in the number of nucleoli in the treated cells and tendency to a reduction in nucleolar area, indicating that the tested pollutants may have impaired nucleolar activity. In addition, it was possible to establish a relationship between the behavior of the nucleolus with other changes as plantlet growth, cell proliferation, and DNA damage.
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Affiliation(s)
| | - Laiane Corsini Rocha
- Biology Department, Federal University of Lavras (UFLA), ZIP: 37.200-000 Lavras, MG, Brazil
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