Role of ethylenediamine tetraacetic acid and salicylic acid in alleviating cytogenetic toxicity of copper in roots of Allium cepa (L.)
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Umebese, C. E.
Azeez, T. A.
Adekoya, K. O.
Institute of Plant Physiology and Genetics – Bulgarian Academy of Sciences
The ameliorative impact of salicylic acid (SA) and ethylene diamine tetraacetic acid (EDTA) on cytogenetic and growth changes induced in Allium cepa by toxic concentration of copper (Cu) was investigated. Onion bulbs were treated with solutions prepared from different combinations of these substances: Cu (100.79 mmol l-1), Cu + EDTA (1273.75 mmol l-1), Cu + SA (1000.00 mmol l-1), Cu + EDTA + SA for 5 days. It was observed that Cu toxicity inhibited root length and root biomass by 43% and 76% respectively, and induced a 71% decrease in the mitotic index. Chromosomal aberrations such as anaphase bridges, stickiness and vagrant were also induced in treated roots. The damaging effect of Cu on the mitotic index was reduced to 16% and 34% by EDTA and SA, respectively. Though SA was not as effective as EDTA in protecting root length and biomass, it demonstrated some degree of ameliorative effects on the sticky chromosomes. However, the impact of EDTA seemed to be hindered by the presence of SA. In all treatments the absorbance ratio (A260/280) of DNA remained 1.8-2.0, indicating that the quality of DNA was not significantly affected by the tested Cu concentration. Chelating Cu with EDTA protected root growth and cytotoxic effects while SA corrected genotoxic effects caused by Cu toxicity.
Allium cepa , copper , EDTA , salicylic acid , aberrations , DNA
Umebese, C. E., Azeez, T. A. and K. Adekoya, 2013. Role of ethylenediamine tetraacetic acid and salicylic acid in alleviating cytogenetic toxicity of copper in roots of Allium cepa. Genetics and Plant Physiology 3: 98-108