外源亚精胺对水稻吸收积累镉砷的影响

The effects of exogenous spermidine on the cadmium and arsenic uptake and accumulation in rice

通过水培试验和大田试验,研究外源亚精胺(Spd)对水稻吸收积累Cd、As的影响。结果表明:水培试验中,在10μmol·L-1的Cd胁迫下,外源添加250μmol·L-1的Spd能显著降低水稻茎叶Cd含量58.0%,在50μmol·L^-1的As胁迫下,添加同样浓度的Spd可以显著降低水稻茎叶As含量20.1%,阻止了水稻根系中Cd、As向茎叶的转运累积;在大田试验中,外源添加1000μmol·L^-1的Spd显著降低了水稻根系、叶片和籽粒中Cd的积累,分别降低了25.8%、51.9%和37.4%,同时降低了水稻茎和根系中As的含量,分别降低了23.9%和31.2%。研究表明,外源施用Spd可以降低苗期水稻对Cd、As的吸收积累,同时可显著降低水稻籽粒中Cd的含量。因此,可合理使用亚精胺缓解Cd、As对水稻的胁迫,为提高粮食安全提供有力保障。

Hydroponic and field experiments were performed to investigate the effects of exogenous spermidine(Spd)on the absorption and accumulation of cadmium(Cd)and arsenic(As)in rice.In the hydroponic experiment,under 10μmol·L-1 Cd stress and the exogenous addition of 250μmol·L-1 Spd,the rice stem and leaf Cd contents were significantly reduced(58.0%).Under 50μmol·L-1 Cd stress and an equivalent Spd concentration,the stem and leaf As contents were significantly reduced(20.1%),and the transport of Cd and As from the root to the stems and leaves(and subsequent accumulation)was prevented.In the field experiment,1000μmol·L-1 Spd significantly reduced the root,leaf,and grain Cd accumulation by 25.8%,51.9%,and 37.4%,respectively,and the stem and root As contents were reduced by 23.9%and 31.2%,respectively.These results support prior studies showing that the exogenous application of spermidine reduced the absorption and accumulation of Cd and As in rice at the seedling stage,and significantly reduced the Cd content in rice grains.Therefore,spermidine can be used to alleviate rice Cd and As stress and improve food security.