A REVIEW ON THE TOXIC EFFECT OF NICKEL INDUCED STRESS ON GROWTH AND DEVELOPMENT IN RICE SEEDLING (Oryza sativa L.)

Rice (Oryza sativa L.) is the main food of different countries in the world. Currently, the demand for food is increasing along with the increase in population in the world therefore, the demand for rice is constantly increasing due to rice being the staple food of various countries. As the population and human need increase, the environment is continuously polluted. In order to grow good crops, we mix various chemicals in the soil, besides, many harmful heavy metals mixed in the soil from various factories and household waste. One of the most harmful heavy metals is nickel. Nickel comes into contact with rice plants and plant seeds. A certain amount of nickel is good for plant growth but above this level it causes physiological and chemical process changes as well as morphology of the plant, like germination rate plant root and shoot height, weight all decrease, the activity of various enzymes required for growth cycle of rice plant is inhibited. For this increasing nickel concentration level nitrogen metabolism may not function properly because the changes of amount of nitrate, nitrite, and ammonium. Elevated levels of Nickel cause damage the biological and chemical pathway of rice plants which are very harmful for them lifecycle. This review aims to summarize the different responses of rice like physiological, morphological, molecular and biochemical changes when nickel concentration increased rapidly.