S元素对水稻耐重金属Cu毒性的影响

Effect of Sulfate on Copper Toxicity to Rice Seedlings

将水稻幼苗置于含有不同浓度硫元素（S，1、10mmol·L^-1）和铜元素（Cu，0．16、100μmol·L^-1和1mmol·L^-1）的培养液中培养，12h后测定植物体内的Cu含量、叶绿素含量、抗坏血酸含量和抗氧化酶活性的变化。结果表明，施加较高浓度的S（10mmol·L^-1）能抑制植物根部对Cu的吸收和积累，但能促进根部Cu元素向地上部的运输。本研究还表明，Cu处理后的0-3h，S能促成抗坏血酸含量的提高；并且S可以激活抗氧化酶类活性迅速增加消除胁迫产生的膜脂过氧化胁迫，但是不同浓度的S和Cu对叶绿素含量的影响效果不明显。

Rice seedlings were cuhivated in hydroponic culture solution with supplies of copper （（ Cu ）0.16, 100 μmol· L^-1, and 1 mmol· L^-1） and sulfate （（S）1 and 10 mmol· L^-1 ）under controlled growth conditions. The copper concentrations of leaves and roots, the pigments, ascrobate acid （AsA）contents and enzymes （dehydroascorbate reduetase （DHAR）and ascorbate peroxidase （APX））activities were investigated during 12 h treatment. The result indicated, the sulfate （ 10 mmol· L^-1 ）which exerts higher concentration could suppress the plant root absorption and accumulation of Cu, but could promote the transportation and accumulation of Cu to shoots. This research still indicated, 0-3 hours when Cu is treated, the sulfate could facilitate the improvement of the content of AsA, and no significant difference was observed between two sulfate concentration treatments. Furthermore, sulfate could activate antioxidative enzymes and reduce toxic effect by Cu stress. In detail, the higher sulfate concentration could more rapidly induce to the increase of DHAR and APX activity than lower sulfate concentration. However, the sulfate or Cu of different concentrations impact on content of chlorophyll was not obvious. All experiment results suggested that sulfate could effectively reduce copper toxicity to seedlings.