Influence of temperature on selenium and sulphur accumulation in Brassica oleracea L.

Summary

Selenium (Se) and sulphur (S) accumulation are affected by many factors in plants. To understand how growing temperature affected Se and S uptake and accumulation in Brassica oleracea, plants were grown at three different temperatures: 10°, 20° and 30°C. Plant growth, as reflected in fresh weight (FW) and dry weight (DW), increased with increasing temperature. Se and S accumulation were temperature-dependent and tissue-specific. Se levels increased linearly with increasing temperature in the leaves, and varied from 1.73 – 2.54 mg Se g^–1 DW. Conversely, Se accumulation decreased linearly with increasing temperature in the roots, and varied from 2.17 – 2.87 mg Se g^–1 DW. Growing temperature significantly affected S accumulation in leaves, but not in shoots or in roots. Sulphur levels ranged from 20.83 – 30.98 mg g^–1 DW in leaves, and increased with higher temperatures. Sulphate accumulation was similar to S, except that accumulation decreased at the highest growing temperature. Vegetables that accumulate S can be an efficient means and an effective alternative to deliver Se in human diets. To ensure that optimal levels of Se are attained in plants, without negative effects on plant productivity, factors that affect uptake and accumulation, such as growing temperature, need to be better understood.