Time-course of Growth and Main Bioactive Compound Concentrations in Red Perilla under Low Nutrient Solution Temperature Treatment

Abstract

Red perilla (Perilla frutescens) is used as a food, crude drug, and anti-allergy supplement. The main bioactive compounds in red perilla are perillaldehyde (PA), rosmarinic acid (RA), luteolin (LU), and anthocyanin (ANT). In this study, we investigated the effects of treatment duration with low nutrient solution temperature (low NST) on plant growth and main bioactive compound concentrations in red perilla. The dry weights of the aboveground part, main harvested part of red perilla, in uncontrolled NST (Control) and low NST groups were the same 0-6 days after the beginning of treatment (DAT), and that in low NST was lower than that in Control 9-12 DAT. Root dry weight in low NST was lower than that in Control regardless of treatment duration. Concerning individual leaves, the concentrations of PA and LU decreased with days; RA concentration, 0-6 days after the beginning of foliation, decreased with days, and that 6-12 days after the beginning of foliation increased with days in Control. ANT concentration did not change during foliation in Control. On the other hand, the concentrations of PA and RA increased in low NST, and the concentrations of PA and RA in low NST were maintained higher than those in Control 3-6 and 3-9 DAT, respectively. The concentrations of LU and ANT increased in low NST 9-12 DAT. Therefore, low NST treatment at 10 °C within 6 days was revealed to increase the concentrations of PA and RA without decrease in the dry weight of the harvested parts of red perilla plants.