**8.1 Metabolic importance of selenium for plants**

Selenium is a non-metal that is toxic at high concentration in plants but plays an important role at lower concentrations in them. Selenium increases plant growth when triggered by ultra-violet irradiation. The selenium and UV light share a synergistic relationship in the absence of selenium the UV light is capable of damaging the plant but in the presence of Se, plant growth is increased [70]. Selenium also functions as an antioxidant in plants. This antioxidant activity is also responsible for the improved growth in the plant. Selenium exerts its antioxidant activity by alleviating lipid peroxidation through GSH-Px activity. Se induced two selenoproteins, which are the thioredoxin reductase and GSH-Px these enzymes protect the plant from oxidative stress (Djanaguiraman et al., 2010). Se protects some plants from abiotic stress at low concentrations [71].
