Changes in content of total polyphenol and activities of antioxidizing enzymes in Perilla frutescens var. acuta Kudo and Salvia plebeia R. Br. as affected by light intensity

The effect of light intensity on content of total polyphenol and activities of antioxidizing enzymes of P. frutescens var. acuta Kudo (Perilla) and S. plebeia R. Br. (Salvia) under a controlled environment was investigated. The three treatments used were T1, 300 μmol·m-2·s-1 PPFD for 38 days; T2, 300 μmol·m-2·s-1 PPFD for 31 days and 500 μmol·m-2·s-1 PPFD for additional 7 days; and T3, 500 μmol·m-2·s-1 PPFD for 38 days. After 38 days of cultivation, shoot and root growth, contents of total chlorophyll, anthocyanin and total polyphenol, and activities of antioxidizing enzymes were measured. The shoot and root growth decreased in the T2 and T3 treatments. Moreover, the incidence of tip burn increased in the T3 treatment in both species. Anthocyanin content in the Perilla decreased, while total chlorophyll content of the Salvia increased, in the T2 and T3 treatments as compared to the T1 treatment. Total polyphenol content and activities of antioxidizing enzymes increased in the Perilla in the T3 and in the Salvia in the T2 treatments.