Effects Of Di-(2-ethylhexyl) Phthalate (dehp) On Seed And Growth Of Seedling Of Vicia Faba

Phthalate esters (PAEs) are synthetic compounds which have been used as pesticide carriers or insect repellents, as well as in cosmetics, fragrances, lubricants and defoaming agents. However, by far, they are mostly utilized as additives in plastic products. Several PAEs are carcinogenic in animal models. Recent investigations have shown that several PAEs are environmental hormones. The most commonly used PAEs have been included in the list of priority pollutants in several countries.The content of PAEs in soils has been investigated in some countries. Soil samples were investigated in Danish that total contents of the six PAE compounds ranged from 0.02706 to 0.04628 mg-kg-1. Relevant research found that DBP and DEHP were 0.006 and 0.0318 mg-kg-1 in soil from Denmark, respectively. Vegetable field soil samples were investigated in areas of Guangzhou and Shenzhen of China, the result showed that the total concentration of the six PAE compounds in all soils varied from 3.00 to 45.67 mg-kg-1, where lots of agricultural plastic films were widely used.There has been a growing concern regarding the environmental behavior and potential toxicity to plants associated with DBP and DEHP. Most of the publications report fate, mobility, conversion and degradation of DBP and DEHP in soil, or in the plant-soil system, or in sludge-amended soil. Only a minority of the reports deal with plant uptake, and the toxic effects of DEHP on crop and vegetable growth, and no data is available concerning the effects of DEHP on the qualities of crop and vegetable products. In this study, the root-tip of Vicia faba was exposed to different concentrations of DEHP to investigate the toxic effects of DEHP. The results are as followed: 1. DEHP coursed chromosomal aberration Vicia faba has been used for evaluating chromosomal aberrations since the early 1920s. In addition, the detection of micronuclei in Vicia root tips has been more recently developed to evaluate the genotoxicity in some different matrices, including water, soils, waste water and industrial effluent.Results from the cytogenetic study are reported that there were significant differences (p<0.05) in the micronucleus of Vicia faba root tips between the exposed groups and the control group. The types of chromosomal aberrations found were chromatid gaps, chromatid breaks, acentric fragments and dicentrics.2. Oxidative damage induced by DEHP POD, SOD, and MDA are common and important indices for evaluating the status of plant redox, whose higher activities of the former two and whose lower of MDA display higher anti-oxidative ability, reflecting higher resistance environment.Results showed the SOD and POD activity and content of MDA of stem and leaf of the seedling of Vicia faba increased with the increase of concentrations of DEHP (0-20mg·kg-1); the SOD and POD activity decreased slightly when the concentrations of DEHP were over 20mg·kg-1 These results suggested that DEHP could induce the acute oxidative damage effects on the seedling of Vicia faba.3. DNA damage induced by DEHPRandom amplified polymorphic DNA (RAPD)'fingerprinting'technique is based on the amplification of genomic DNA with 10 bp primers of arbitrary nucleotide sequence which anneals to multiple regions of the genomic DNA. The PCR reactions thus generate many amplicons of variable lengths which can be separated by gel electrophoresis to obtain DNA fingerprint. RAPD assays were successfully used to detect genetic instability in DNA alterations in animals, bacteria and plants induced by low doses of pollutants, mainly in the aquatic systems; while a few of the research on DNA alterations in plants induced by soil contamination stress have been reported. The objectives of this study were to detect DNA damage induced by DEHP soil using the RAPD technique, to compare changes in RAPD profiles with root growth and total soluble protein level in the root tips of barley seedlings measured under laboratory conditions, and to evaluate the usefulness of the RAPD assay in risk assessment of contaminated soil.The random amplified polymorphic DNA profiles showed obvious differences between normal and exposed plantlets, indicating a does-effect relationship. These results suggested that DEHP could induce the genotoxic effects in growth of seedling of Vicia faba.