Effects of selenate and selenite on selenium accumulation and speciation in lettuce

Lettuce is a common vegetable in hydroponic production. In this paper, a selenium (Se)-biofortification method was provided. The Se content, speciation, and the effects of different concentrations of selenate and selenite on lettuce growth and amino acids were investigated. The results showed that lettuce had strong ability to accu-mulate exogenous selenium, and inorganic Se could be effectively converted into organic Se. The proportion of organic Se in the shoots under treatment with 4 mu mol L-1 selenite was 100%. Selenomethionine was the main organic Se, accounting for 51% (selenate) and 90% (selenite) of the total Se. Adding Se improves photosynthesis of lettuce and promotes growth. The growth with 2 mu mol L-1 selenate and 4 mu mol L-1 selenite was better than CK, and the shoot fresh weight was increased by 143.22% and 166.98%, respectively. Furthermore, the optimum Se application is 2 mu mol L-1, and some areas can apply 4 mu mol L-1 selenite. But Se-excessive areas are not recommended to grow selenium-rich foods. Therefore, lettuce has strong biofortification potential.

Automated summary

This paper investigated the selenium accumulation ability of lettuce and the effects of selenate and selenite on its growth and amino acid content. The results showed that lettuce could effectively convert inorganic selenium into organic selenium, and the addition of selenium improved photosynthesis and growth. The optimal selenium application was found to be 2 mu mol L-1, with some regions able to use 4 mu mol L-1 selenite. However, excessive selenium areas are not recommended for growing selenium-rich foods. Overall, lettuce has strong biofortification potential.