水稻积累及耐受镉和砷的分子机制与育种实践

Molecular Mechanisms and Breeding Practices of Accumulation and Tolerance to Cadmium and Arsenic in Rice

近些年来,我国农田镉、砷污染日益严重,导致稻米镉、砷超标事件时有发生。稻米是全球约一半人口的主粮,也是人体从食物中摄入镉和砷的主要来源,土壤中的镉和砷被水稻吸收后,通过食物链的富集作用在人体内积累,进而危害人体健康。因此,减少镉、砷在稻米中的积累成为保障我国粮食质量安全和促进水稻产业发展亟待解决的重要问题。研究水稻对镉和砷的累积机制,在此基础上培育镉、砷低积累水稻品种,是解决稻米镉和砷超标最经济的方法,对实现污染农田的稻米安全生产具有重要意义。本研究主要综述了农田镉和砷的存在形态及生物有效性,阐述了水稻吸收、转运镉和砷的分子机制,以及镉、砷耐受机制,概述了镉、砷低积累水稻育种进展,并对未来的发展方向进行了展望,旨在为减少水稻籽粒镉、砷含量的研究提供一些参考。

In recent years, cadmium and arsenic contamination in China’s farmland has became increasingly serious, resulting in the occurrence of excessive cadmium and arsenic in grains. Rice is the main food for about half of the world’s population. Cadmium and arsenic in the soil will accumulate in the human body through the enrichment of the food chain after being absorbed by rice, thereby harming human health. Therefore, reducing the accumulation of cadmium and arsenic in rice has became an urgent and important issue to ensure grain quality security and promote the development of rice industry. To study the accumulation mechanism of cadmium and arsenic in rice and to cultivate rice varieties with low accumulation of cadmium and arsenic is the most economical way to solve the excessive cadmium and arsenic in grains, which is of great significance to realize the safe production of rice in contaminated farmland. In this review, we summarize the morphology and bioavailability of cadmium and arsenic in farmland, the molecular mechanism of cadmium and arsenic uptake and transport in rice, and the main mechanism of rice tolerance to cadmium and arsenic. We also review the progress in breeding of rice cultivars with low cadmium and arsenic level in grains, and prospected the future development direction. The purpose of this paper is providing some references for reducing cadmium and arsenic content in rice grains.