Use of Plant Bioassays for the Detection of Genotoxins in the Aquatic Environment

Abstract

The present article describes the use of plant bioassays for the detection of genotoxins in the aquatic environment and gives an overview of test methods, their detection spectrum for environmental mutagens and carcinogens and their limitations and pitfalls. The most widely used test systems are micronucleus assays with meiotic cells of Tradescantia and with meristematic root tip cells of Allium and Vicia. In the last years, protocols for single cell gel electrophoresis assays have been developed, which can be conducted with a variety of species. Also various gene mutation test procedures have been developed with plants but they have hardly ever been used in environmental studies. Plants detect a broad variety of environmentally relevant genotoxins, in particular directly acting compounds. Many pesticides and industrial chemicals caused positive results; plant assays are also a unique tool for the detection of DNA‐reactive carcinogenic heavy metals in the environment. In many studies with complex mixtures, positive results were obtained which indicates that plants are sufficiently sensitive to detect effects without concentration of water samples. One of the shortcomings of the use of plants as indicators is their lack of sensitivity towards certain classes of promutagens such as nitrosamines, heterocyclic amines, and polycyclic aromatic hydrocarbons (PAHs). However, the former compounds are hardly encountered in the environment and PAHs can easily be detected chemically and in other mutagenicity tests. Taken together, the currently available data show that plant bioassays are a useful component of test batteries for environmental monitoring.

Genotoxicity Screening of Industrial Effluents using Onion bulbs (<i>Allium cepa L.</i>)

“…Most of the studies indicate that there is an excellent correlation between chromosome abnormalities and mutagenic activity found in root-tip systems and those found in mammalian cell systems. Observation of the root tip system of plants therefore constitutes a rapid and sensitive method for environmental monitoring (Majer et al, 2005). Allium cepa L. has been used as a first-tier assay for the detection of environmental chemicals that may pose genetic hazards from a wide range of pollutants such as sewage effluents (Ukaegbu and Odeigah, 2009), leacheates Wale-Adeyemo, 2004, Chandra et al, 2005) and chemicals (Seetharaman et al, 2004).…”

Comparative physicochemical and genotoxicity assessments of textile mill company effluent and local tie-and-dye textile wastewater

“…Lead has been implicated in enzyme inhibition, mutation, and chromosomal irregularities (Johnson, 1998). Studies have pointed out that there is a good correlation between chromosome abnormalities and mutagenic activity found in root-tip systems and those found in mammalian cell systems (Majer et al, 2005;Olorunfemi et al, 2011). Therefore, the effluents emanating from the local Adire (Tie-and-dye) textile business and the corporate textile mill company are potentially genotoxic to plant, animals and humans.…”

Untitled

“…O primeiro mecanismo de ação dos agentes genotóxicos é promover lesões no DNA (oxidação e dimerização de bases, adutos de DNA, entre outras). Essas lesões podem ter 3 destinos: reparo, alterações irreversíveis e morte celular (Majer et al, 2005). Os danos genéticos detectados neste estudo são indicativos da presença de substâncias clastogênicas (indutoras de quebras) nas amostras testadas.…”

“…Substâncias tóxicas, muitas das quais químicas, promovem a ocorrência de mutações genéticas e aberrações cromossômicas e existe um grande número de protocolos desenvolvidos para detectar essas alterações (Majer et al, 2005).…”