Table of Contents
Journal of Botany
Volume 2012, Article ID 375843, 8 pages
http://dx.doi.org/10.1155/2012/375843
Review Article

Chromium as an Environmental Pollutant: Insights on Induced Plant Toxicity

Department of Biology, CESAM, University of Aveiro, 3810-193 Aveiro, Portugal

Received 23 November 2011; Revised 15 March 2012; Accepted 16 March 2012

Academic Editor: Joanna Deckert

Copyright © 2012 Helena Oliveira. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

In the past decades the increased use of chromium (Cr) in several anthropogenic activities and consequent contamination of soil and water have become an increasing concern. Cr exists in several oxidation states but the most stable and common forms are Cr(0), Cr(III) and Cr(VI) species. Cr toxicity in plants depends on its valence state. Cr(VI) as being highly mobile is toxic, while Cr(III) as less mobile is less toxic. Cr is taken up by plants through carriers of essential ions such as sulphate. Cr uptake, translocation, and accumulation depend on its speciation, which also conditions its toxicity to plants. Symptoms of Cr toxicity in plants are diverse and include decrease of seed germination, reduction of growth, decrease of yield, inhibition of enzymatic activities, impairment of photosynthesis, nutrient and oxidative imbalances, and mutagenesis.