Improving yield and polyphenol content of Perilla frutescens (L.) by foliar methionine application

Abstract

Perilla frutescens (L.) is a popular medicinal plant cultivated primarily for its pharmacological benefits. Research has recently focused on boosting crop yield without using excessive chemical fertilizers and plant growth regulators which could harm the environment and human health. One of them, methionine, has been discovered to play a crucial role in synthesizing growth-regulating compounds and accumulating secondary compounds in some plants. This study investigated the effects of methionine concentrations (0, 50, 100 and 150 mg/L) on the growth of Perilla frutescens. Agronomic, physiological and biochemical parameters were assessed. The results of the variance analysis show that spraying methionine increases the agronomic parameters. Additionally, methionine spraying increased photosynthetic and respiration rates. Compared to the control, spraying 150 mg/L of methionine increased phenolic and flavonoid accumulation by 89% and 115% respectively. These findings might provide a rationale from a scientific standpoint for cultivating Perilla frutescens to increase polyphenol content.