植物分子遗传学在挖掘作物重金属积累相关基因中的作用

Application of plant molecular genetics in identification of genes related to heavy metals accumulation in crops

随着我国农田土壤重金属污染问题日益严重,导致农产品重金属超标时常发生。如何阻控重金属在作物可食部位的积累,保证农产品安全和重金属中、低污染农田的安全利用,已成为我国农业生产急需解决的问题。培育重金属低积累作物品种,实现作物可食部位重金属含量达标,是解决重金属中低污染农田安全利用的经济而有效的手段之一。培育作物重金属低积累品种需要克隆控制重金属积累的相关基因,并阐明其分子遗传机理。以Os NRAMP5、Os HMA3和CAL1三个控制水稻镉吸收、转运和分配的基因为实例,介绍植物分子遗传学在挖掘作物重金属积累相关基因中的作用,包括基于正向遗传学和反向遗传学的方法,克隆控制镉在作物中积累的基因,并阐述这些功能基因控制重金属积累的分子遗传机理,同时展望这些基因在培育重金属低积累品种中的应用前景。

With increasing contamination of heavy metals in paddy soils in China,exceedance of the national safe standard in food crops is widespread in some areas,especially Southern China.Minimizing the transfer of heavy metals from soil to eatable parts of food crops and thus ensure the safety of agricultural products is a top priority of agricultural production in China.Molecular breeding of crop varieties that accumulate less heavy metals in eatable parts to meet the national safe standard is one of effective and low-cost strategies that product safe product in contaminated soils.The breeding of crop varieties that accumulate less heavy metals in eatable parts is based on the identifica?tion and characterization of genes that involved the uptake,transport and allocation of heavy metals in crops.In this review,we take OsNRAMP5,OsHMA3 and CAL1 as examples,to describe the application of plant molecular genetics including the forward and reverse genetics in identification genes which are responsible for the accumulation of cadmium(Cd)in rice.The molecular mechanism of these genes underlying the Cd accumulation in rice and the potential application of these genes in molecular breeding of rice varieties with low Cd accumulation in grains are also discussed.