Manganese and nickel induced metabolic and proteomic studies in rice

Abstract

Plants are immobileand often exposed to various abiotic and biotic stresses which cause loss in agricultural yield in different parts of the world. Among abiotic stresses excessive level of metals in the soil environment has been a cause of greater concern that limits productivity. Due to anthropogenic and various other activities, agricultural soils in many parts of the world are slightly, moderately or even highly contaminated with different essential metals such as Mn,Cu, Zn, Ni, Co as well as metal/metalloid pollutants like Cd, Pb, Cr, Hg, As, Al, etc. Long-term use of phosphatic fertilizers, sewage sludge application, dust from smelters, industrial wastes, exhaust of chimneys, and improper watering practices has aggravated metal toxicity problems for the crops. When these metals are taken up by the plants roots in excess, toxicity effects of the metals are evident. These metals are taken by the roots of plants and are transported to different parts of plants and in turn contaminate food chain leading to health hazards. Rice is a staple food crop for the majority of world population and is seldom exposed to variety of abiotic stresses that limit rice yield. In acid soils rice productivity is greatly lowered due to high availability of Al and Mn. Exposure to elevated concentrations of metals in the soil to rice plants results in growth inhibition and decreased productivity.After prolonged metal exposure, sensitive plants develop visible symptoms of toxicity such as chlorosis and necrotic lesions. During the past few decades, symptoms of metal toxicity and deficiency in plants have been studied extensively. However, our knowledge related to the details of biochemical basis of metals induced various physiological and biochemical alterations in plants, the components associated with metal tolerance and possible methods for alleviation of metal toxicity in plants is insufficient.