Biological responses of maize (Zea mays) plants exposed to chlorobenzenes. Case study of monochloro-, 1,4-dichloro- and 1,2,4-trichloro-benzenes

Abstract

A 7-day-exposure time experiment was designed to investigate the phytotoxicity of chlorobenzenes (CBs) on Zea mays seedlings, focusing on the growth and generation of oxidative stress. Significant growth inhibition (based on biomass gain) was observed for exposure to monochlorobenzene (MCB), dichlorobenzene (DCB) and trichlorobenzene (TCB) concentrations higher than 10 mg l(-1). It would seem that CBs inhibit cell division, since the mitotic index decreased for roots exposed to DCB at 80 mg l(-1) dose (8%) and to all the TCB concentrations tested (20% inhibition). CBs exposure resulting in an increase in the oxidative stress response in maize seedlings [reactive oxygen species like H(2)O(2), antioxidant enzymes (POD, GR), lipid peroxidation] correlated to the compound's degree of chlorination, where damage increasing with the number of chlorine atoms (MCB < DCB < TCB). This biological response was also dependent on the dose-exposure. Z. mays exposed to CBs at concentrations <10 mg l(-1) did not induce sufficient oxidative damage to cause root cell death. Therefore, CBs at current environmental concentrations are unlikely to produce evident phytotoxic effects on Z. mays seedlings.

Biodegradation of γ-hexachlorocyclohexane by transgenic hairy root cultures of Cucurbita moschata that accumulate recombinant bacterial LinA

“…Error bars indicate the mean ± SD, n = 3 (Liu et al 2004a;Miguel et al 2012), However, the concentration (136-198 lg/L, estimated from S1 Table) of 1,2,4-TCB detected in this study was not sufficiently high to inhibit the growth of the hairy root cultures. The acute oral toxicity value of 1,2,4-TCB for rats ranges between 756 and 1107 mg/kg (European Union Risk Assessment Report 2003), which is 8.4-to 12.4-fold higher compared with that of c-HCH (88-91 mg/kg) (Gaines 1969).…”

A Comparative Analysis on the Physiological Effects of the Physical and Chemical Properties of the Trihalomethanes on Nutrient Levels, Oxidative Stress and Sterol Compositions of Leaf Oils in Solanum Lycopersicum Cultivars

“…Plants are known to increase their phenolic content as a non-enzymatic response to free radical production from oxidative stress (Nogués et al, 2014). The exposure of plants to chlorinated organic compounds has been reported to induce the production of the peroxide H 2 O 2 free radical (Menone et al, 2008;Michalowicz and Duda, 2009;San Miguel et al, 2012). The FRAP assay measures the total antioxidant power of biological fluids and as such most non-enzymatic activity (scavenging of free radicals) is mediated by redox reactions.…”

“…The initial contact physiological and morphological response mechanisms of plants to chlorinated organics have been reported (Faure et al, 2012;San Miguel et al, 2012;Ahammed et al, 2013;Guittonny-Philippe et al, 2015). Imfeld et al (2009); Doucette et al (2013); and Chen et al (2014), also noted that some plants have the ability to stimulate the removal of chlorinated organic pollutants through plant uptake, phytovolatilization and/or phytodegradation.…”

Quinclorac-habituation of bean ( Phaseolus vulgaris ) cultured cells is related to an increase in their antioxidant capacity

“…The exposure of plant cells to a variety of abiotic stresses such as heavy metals (Paradiso et al, 2008), organochlorines San Miguel et al, 2012) and herbicides (Geoffroy et al, 2004;García-Angulo et al, 2009) often unbalances ROS production and scavenging, leading to oxidative stress (Apel and Hirt, 2004;Gill and Tuteja, 2010). Excessive ROS production can damage cellular components such as proteins, lipids, DNA and polysaccharides, which interrupts normal metabolism (Dat et al, 2000).…”