Heavy-metal phytotoxicity induces oxidative stress in a moss, Taxithellium sp.

摘要

Highly reactive free radicals are produced with the exposure of plants to a range of abiotic stresses which include water, salt, heavy-metal toxicity, etc. These reactive oxygen species have been implicated directly with molecular damage in plant cells. Heavy metals are integrated components of the ecosystem. Though some heavy metals are essential as micronutrients, uptake of higher concentrations of heavy metal is found to be toxic for plants. Certain metals are known to produce/act as catalysts for the production of free radicals in biological systems. Many heavy metals like Fe, Cu, Cd, Cr, Zn, etc. have been shown to cause oxidative damage in various higher plants. Bryophytes are important members of the lower plant community and are also found to be sensitive to various abiotic stresses. However, little is known about the mechanism of oxidative stress in bryophytes under heavy-metal exposure. The present investigation was carried out to study the induction of oxidative stress in Taxithellium sp., a bryophyte subjected to heavy-metal treatment.