Growth effects and distribution of selenite in Medicago sativa

• DOI: 10.1007/s11104-018-3589-6
• Publication Date: 2018-02-24T00:44:04Z
• Authors: Binqiang Bai; Wei Chen; Jinglong Zhang; Yixin Shen
• Keywords: 0106 biological sciences; 01 natural sciences

The detailed Se distribution in plants has been poorly described. This study was performed to determine the optimal dose of selenite for enhanced Medicago sativa growth and comprehensively explore the distribution characteristics of Se in this plant. Alfalfa pot experiments were conducted in a growth chamber. The plants were grown in sterilized quartz sand and treated with different selenite levels for 21 days to determine the effect of Se on growth. Plants exposed to 1 and 10 μM selenite were used to clarify the Se distribution in alfalfa. Alfalfa growth was significantly stimulated (P leaf>stem in the organs; rhizodermis and cortex>stele in the tissues; and younger leaf >mature leaf>older leaf and marginal leaf>midrib>internal leaf in the leaves. In addition, Se concentration in the cytoplasm fraction was significantly higher than that in cell wall fraction at 1 μM selenite, and the opposite result was found at 10 μM selenite. Appropriate selenite addition (1 μM) benefited alfalfa. Se binding in the rhizodermis and cortex of the root caused relatively low transport efficiency of Se from the root to the shoot. Se redistributions may be a possible important factor affecting the transportation of Se in shoot and Se was transported along with the transpiration stream within a single leaf. Cell wall immobilization might be a major strategy to protect plant organs from potential Se toxicity.