Agriculture Reference
In-Depth Information
Chapter 16
Arsenic Toxicity in Crop Plants: Approaches
for Stress Resistance
Dhammaprakash Pandahri Wankhede, Meetu Gupta
and Alok Krishna Sinha
1 Introduction
Among the heavy metals (HM), arsenic is one of the major environmental health
concerns for human (Nriagu
2002
). For plants, arsenic is a nonessential element and
is toxic to them. Regions of South and Southeast Asia along with South America
are worst affected by arsenic pollution. Anthropogenic activities like use of arsenic-
based herbicide, insecticides, mining activities and also irrigation with arsenic con-
taminated ground water has added to arsenic pollution in the soil.
Arsenic is readily taken up by crop plants, enters food chain and causes food
safety problem. Rice plants in particular are shown to be an efficient accumulator of
arsenic. Arsenic is also found in rice grain at higher concentrations that pose serious
health threats to the people dependent on rice as their staple food (Williams et al.
2007
; Zhu et al.
2008
). Inorganic arsenic mostly exists in arsenate or arsenite forms.
In some regions, arsenic is also found in methylated form. Phosphate transporter
recognizes arsenate while arsenite is taken up as a silicon (Si) transporter. Arse-
nate interferes in the processes like ATP synthesis and oxidative phosphorylation,
arsenite on the other hand binds with sulphhydryl group and interferes in general
protein synthesis.
