Metal ion toxicity and tolerance mechanisms in plants growing in acidic soil

Abstract

The abiotic factors have a wide effect on the growth of plants along with the cultivation of staple crops. The concentration of both essential and non-essential elements is impacted by the number of biogeochemical factors. The low pH (≤5.0) of the soil is one such factor that poses variation in the levels of metal ions and mostly it leads to metal toxicity. The excess concentrations of the elements in the soil affect the growth, yield and metabolic activities of the plants making them susceptible. However, some of the genotypes adapt themselves to metal toxicity conditions by regulating their homeostatic genes leading to develop different strategies to undergo detoxification methods. In the present review we discuss the toxicity of Al, Fe, and As which is a non-essential metal, an essential metal and an unwanted heavy metal. In a broad picture, to escape the toxic effects, plants have the strategy to exclude the excess metal outside the plant or include it in its storage cells. The insight of the present review aims at understanding these strategies in detail which can be put into agricultural applications for developing better crops.