Effect of arsenic and oxidative stress in plants

SILVANA MARIEL MARSA; FRANCO RUBÉN ROSSI; FANNY ZIRULNIK

Metals in Biology Systems

Research Signpost

Año: 2010; p. 71 - 85

Contamination of soil, surface water and ground waterwith organic and inorganic compounds poses an increasingenvironmental problem worldwide. Toxic mineral elements enterecosystems through both natural and anthropogenic processes.Most metals and metalloids are present naturally in the Earth crustat various levels. However, arsenic (As) poses a significant hazardto humans, animals and ecosystems. An excess of thiscontaminant in the soil results in soil quality degradation, impacts oncrop yield production and causes a poor quality of agriculturalproducts. Anthropogenic sources of contamination with As are themetal melting industry, mining, and the burning of fossil fuels andwaste, as well as the use of certain pesticides and fertilizers inagriculture. An important natural origin of As contamination isvolcanism, as observed in the south of the province of San Luis,Argentina. The toxicity of As depends on its speciation; inorganicarsenicals, for example, are thought to be more toxic than organicforms. In order to understand and manage the risks derived from soilarsenic, it is essential to know how, among other things, As is taken upby the roots and metabolized in plants. There is significant evidencethat exposure to inorganic. As species results in the generation ofreactive oxygen species (ROS). The scavenging system controllingROS comprises non-enzymatic antioxidants (e.g. glutathioneGSH), ascorbate, carotenoide and enzymatic antioxidative systems (e.g. superoxide dismutase [SOD], catalase, peroxidase, GSH reductase, anddehydrogenase). Therefore, it is very important to study the levels of sensitivity andtolerance of plants with agro- economical relevance, such as soybean.