Chen Si-Yang, Jiang Rong-Feng, Li Hua-Fen
College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, China.
Huan Jing Ke Xue. 2011 Jan;32(1):284-9.
Solution culture experiments were carried out to study the uptake and translocation of selenate (Na2SeO4) or selenite (Na2SeO3) by wheat and rice seedlings. When supplied with Na2SeO4 in nutrient solution, the concentrations of selenium (Se) in normal shoots and roots of rice were 30.3 mg x kg(-1) and 39.0 mg x kg(-1) respectively, and the absorbed Se was quickly translocated to shoots accounting for 80% of the total uptake. Se concentrations in wheat shoots and roots were 1.76 mg x kg(-1) and 6.99 mg x kg(-1) respectively, accounting for 62% in shoots. However, when supplied with Na2SeO3, Se concentrations in shoots and roots of rice were 4.40 mg x kg(-1) and 230 mg x kg(-1) respectively, 1.24 mg x kg(-1) and 88.3 mg x kg(-1) in shoots and roots of wheat respectively, and only 8.2% was transferred to shoots. The influence of phosphorus (P) starvation on Se uptake was different for rice and wheat seedlings. Comparing to normal plants, the Se concentrations in the shoots and roots of rice under P starvation condition were decreased, however increased for wheat. In Na2SeO3 uptake kinetics, K(m) of wheat seedlings was 8.7 folds of that of rice, and the affinity of wheat root to selenite was much weaker than that of rice. The Se uptake rate of wheat (V(max)) was 14% lower than that of rice. The uptake and translocation mechanisms of selenate and selenite by rice and wheat seedlings were revealed. And the results demonstrate that the absorbed selenate is quickly translocated to shoot and selenite is mainly accumulated in root. These results provide basic information for biofortification of crops with Se.
进行了水培试验，以研究小麦和水稻幼苗对硒酸盐（Na2SeO4）或亚硒酸盐（Na2SeO3）的吸收和转运。在营养液中供应Na2SeO4时，水稻正常地上部和根部的硒（Se）浓度分别为30.3 mg·kg-1和39.0 mg·kg-1，吸收的Se迅速转运到地上部，占总吸收量的80%。小麦地上部和根部的Se浓度分别为1.76 mg·kg-1和6.99 mg·kg-1，地上部占62%。然而，当供应Na2SeO3时，水稻地上部和根部的Se浓度分别为4.40 mg·kg-1和230 mg·kg-1，小麦地上部和根部的Se浓度分别为1.24 mg·kg-1和88.3 mg·kg-1，只有8.2%转移到地上部。磷（P）饥饿对水稻和小麦幼苗硒吸收的影响不同。与正常植株相比，缺磷条件下水稻地上部和根部的Se浓度降低，而小麦则升高。在Na2SeO3吸收动力学中，小麦幼苗的Km是水稻的8.7倍，小麦根对亚硒酸盐的亲和力远低于水稻。小麦的硒吸收速率（Vmax）比水稻低14%。揭示了水稻和小麦幼苗对硒酸盐和亚硒酸盐的吸收和转运机制。结果表明，吸收的硒酸盐迅速转运到地上部，亚硒酸盐主要积累在根部。这些结果为作物硒生物强化提供了基础信息。
