Protective Role of a methanolic Extract of Spinach (Spinacia oleracea L.) Against Adverse Effects of UV-C Irradiation on Fenugreek (Trigonella foenum-graecum L.) Seedlings

Photosynthesis is an important process for plants in which plants utilize the energy from sunlight to manufacture and produce all their own food. Although UV-C damage is not physiologically relevant for plants growing in the sun, short-wavelength (UV-C) radiation from germicidal lamps has been used to study cell damage in animals as well as in plants. This study provides a review of the effects of a methanolic extract of spinach (SE) as a natural powerful antioxidants used at two concentrations (25 and 50 ppm) on fenugreek seedlings grown under UV-C stress conditions. The results revealed that exposure of fenugreek seedlings to low UV-C period (30 min) increased growth criteria of the produced seedlings. In addition, the contents of chlorophyll, total pigments, total protein, free amino acids, non-enzymatic (carotenoids, total phenol, flavonoids, α‑tocopherol & ascorbic acid contents) and enzymatic antioxidants were increased at this period. By increasing exposure periods of UV-C radiation, the growth criteria and chemical constitutes of the seedlings were decreased. Application of lower concentration of SE (25 ppm) improve the growth of the seedlings at 30-min UV-C and was able to protect seedlings from high periods of UV-C irradiation by increasing all measured parameters except CAT. These increases might be an adaptive mechanism to minimize the adverse effects of longer exposure of UV-C radiation. Moreover, treating the irradiated seedlings with spinach extract led to an obvious alteration in gene expression including synthesis of some proteins bands and disappearance of other protein sets of the protein profile.