根表铁膜对水稻体内重金属迁移积累影响的研究进展

Research Progress on the Effect of Root Surface Iron Plaque on the Transfer and Accumulation of Heavy Metals in Rice

水稻作为全球重要的粮食作物之一,在保障粮食安全、促进经济社会发展等方面起着重要作用。稻田重金属(HMs)污染会影响水稻正常生长,导致产量和品质下降,甚至危害人类身体健康。根表铁膜是在水稻根表面形成的铁锰(氢)氧化物胶膜,能够通过氧化-还原、吸附-解吸、共沉淀等物理化学作用,影响重金属自水稻根部到籽粒的迁移和积累。本文阐明了植物通过根表铁膜对重金属的外源性抵抗和内源性耐受机制,综述了水分管理、施肥(有机肥、化肥、叶面肥等)、根系通气能力等对根表铁膜形成的影响,及对重金属在水稻体内积累与迁移的影响。促进高重金属积累量的红褐色铁膜形成的钝化剂或修复手段可作为未来重金属污染土壤安全利用的研究方向。

As one of the most important food crops,rice plays an important role in ensuring food security and promoting economic and social development.However,heavy metal pollution in paddy fields not only decreases the yield and quality of rice,but also poses potential risk on human health.Root surface iron plaque is an iron and manganese oxides plaque formed on the surface of paddy roots,which is capable of influencing the accumulation and transfer of heavy metals from rice root to grain through oxidation-reduction,adsorption-desorption,and co-precipitation.The article elucidated the mechanisms of exogenous resistance and endogenous tolerance of plants to heavy metals through root surface iron plaque,and reviewed the factors affecting the formation of root surface iron plaque from the perspectives of water management,application of fertilizers(e.g.organic or inorganic fertilizers,foliage fertilizer),root aeration capacity,and its impact on the accumulation and transfer of heavy metals in rice.In the future,searching soil amendments or proper remediation technology to enhance the form of reddish brown iron plaque with effective heavy metals adsorption may be a direction for safety utilization of heavy metals contaminated soils.