小麦和水稻对纳米硒的吸收和转运

Absorption and Transportation of Selenium Nanoparticles in Wheat and Rice

通过水培试验,研究了不同粒径纳米硒(Se NPs)和不同p H条件对小麦(Triticum aestivum L.)及水稻(Oryza sativa L.)吸收、转运硒的影响.结果表明,小麦和水稻对不同粒径(50、100和150 nm) Se NPs的吸收规律不同. 24 h和72 h处理下,小麦根系对3种粒径Se NPs的吸收无显著差异,但其地上部中的硒含量(以干重计,下同)在50 nm Se NPs处理下达到最高,分别为(1. 89±0. 47)μg·g-1和(5. 18±1. 51)μg·g-1.硒在小麦体内的转运系数也在50 nm Se NPs处理24 h时显著高于其他粒径Se NPs处理2. 38倍(P <0. 05).对于水稻而言,50 nm Se NPs处理24 h时根系中的硒含量分别比100 nm和150 nm Se NPs处理增加了11. 18%和41. 81%,但在72 h时3种粒径Se NPs处理间根系对硒的吸收无显著差异.同时,硒在水稻中的地上部含量和转运系数也在50 nm Se NPs处理达到了最大值.另外,p H条件也会影响植物对硒的吸收和转运. Se NPs处理24h时,小麦根系在p H为6时对硒的吸收量最大,并高于亚硒酸盐处理89. 47%,但在p H为4时小麦对硒的转运能力最强.水稻在p H较低时(p H为3. 5和5. 5),对Se NPs的吸收量显著低于亚硒酸盐,且Se NPs在p H为3. 5时更易转运.以上结果表明水稻和小麦均可以吸收Se NPs,并且在p H较低的环境下Se NPs粒径越小越容易在植物体内转运.

Hydroponics experiments were carried out to study the effects of different sizes of selenium nanoparticles(Se NPs)and different p H on the absorption and transportation of Se by wheat(Triticum aestivum L.)and rice(Oryza sativa L.).The results showed that Se NPs with different sizes(50,100,and 150 nm)had various characteristics with respect to absorption and translocation in wheat and rice.There was no significant difference in the uptake of Se NPs with different sizes by wheat roots after 24 h and 72 h;however,the highest Se content in wheat shoots was(1.89±0.47)μg·g-1 dry weight(DW)and(5.18±1.51)μg·g-1 DW under the 50 nm Se NPs treatment after 24 h and 72 h,respectively.Moreover,the transfer factor for Se in wheat under the 50 nm Se NPs treatment was 2.38 times higher than that of the 100 nm and 150 nm treatments.The Se content of rice roots treated for 24 h with the50 nm Se NPs increased by 11.18%and 41.81%compared to those treated with the 100 nm and 150 nm Se NPs,respectively.There were,however,no significant differences in Se content between all of the Se NPs treatments after 72 h.The Se content of rice shoots and the Se transfer factor both reached the maximum when 50 nm Se NPs were applied.In addition,Se absorption by plants was also affected by p H.Specifically,the amount of Se absorbed by wheat roots treated with Se NPs was the greatest at a p H of 6 after 24 h,which was 89.47%higher than wheat treated with selenite.Furthermore,the highest Se transfer factor occurred at a p H of 4 in wheat.The uptake of Se NPs in rice was markedly lower than that of selenite at low p H values(p H=3.5 and 5.5)and Se NPs was more readily transported at a p H of 3.5.These results demonstrate that Se NPs could be taken up by wheat and rice and that it could be transferred more easily as small particle size(50 nm)than the larger ones(100 nm and 150 nm)at low p H values(p H 3.5).