Strategies for Reducing Arsenic Content in Rice: A review

Abstract

Arsenic (As) is one of the most toxic metalloid that can enter the food chain through ingestion of As contaminated water or food, posing a serious threat to human health. Among cereals, rice could contain the highest amount of As because of the special growing conditions. Therefore, the importance of the reduction of As concentration in rice is essential. Many studies have been conducted to understand the mechanism of arsenic uptake, accumulation and translocation. The interactions between As and plants are influenced by soil type and other factors such as pH, mineral contents and redox status of the soil, As speciation, and microbial activity. Different nutrients including phosphates, iron, silicon and sulfur effectively regulate the uptake and accumulation of As in different parts of plants. Genetic variation has also effect on As accumulation of rice grain. Water management practices can help to decrease As content of rice plants due to changing the redox status of the soil. Phosphate and silicon transporters can be used by As to enter the rice root cells, therefore detoxification mechanisms of As in rice greatly depend on the activity of these transporters. In this review, we covered the main factors that affect the uptake, accumulation, and translocation of As in different plant organs in rice. We investigated the different soil factors and plant cell transporters needed to understand the mechanisms. This study may be useful for further research to develop strategies that inhibit As entry and transport in plant cells and contribute to safe food production.