Effects of nutrient solution temperature on the concentration of major bioactive compounds in red perilla

Abstract

Red perilla Perilla frutescens is used as food, stomachic and antitussive crude drugs, and anti-allergy supplements. The major bioactive compounds of red perilla are perillaldehyde PA , rosmarinic acid RA , luteolin LU , and anthocyanin ANT . In this study, we investigated the effects of 6 days low 10, 12, and 15°C and control 20°C nutrient solution temperature NST treatments on plant growth and major bioactive compound concentrations in red perilla leaves at the node position. No significant difference was detected in the dry weight of leaves of the main shoot, which is the main part harvested, among the treatments. However, leaf water content tended to decrease with a decrease in NST, especially in plants grown at 10°C NST, which exhibited values significantly lower than those of plants grown at 15°C and 20°C NSTs. PA and ANT concentrations in the 3rd to 5th nodes did not differ among treatments. Conversely, RA concentration increased with a decrease in NST, irrespective of the node position. LU concentration at 10°C NST was the highest in all treatments, irrespective of the node position. This suggested that the production of bioactive compounds under the low NSTs differed depending on leaf maturity stage and compound. Additionally, the contents of RA and LU in the whole plant increased because there was no reduction in growth of the harvested part under the low NSTs. Therefore, 6 days exposure to root-zone temperatures at 10°C appears to be an effective method to increase both RA and LU concentrations and their contents in the whole plant of red perilla for its use as a crude drug or medicinal material.

Short-Term Root-Zone Temperature Treatment Enhanced the Accumulation of Secondary Metabolites of Hydroponic Coriander (Coriandrum sativum L.) Grown in a Plant Factory

“…This finding was consistent with the results of Chadirin et al [28,29], who reported that applying 7 days of 5 • C or 3 days of 30 • C RZT reduces the shoot DW of spinach. However, applying 7 days of 10 • C RZT and 6 days of 10 • C, 12 • C, or 15 • C RZT did not affect the DWs of red leaf lettuce [15] and red perilla [30] compared with 20 • C RZT, respectively.…”

“…Regardless of stress period (3 or 6 days), the leaf FW was decreased significantly by RZT 35,30,20, and 15, compared with the control ( Figure 4A, Table S1). The stem FW responded similarly except for the treatment 30-3, which was no significant difference as the control ( Figure 4B, Table S1).…”

Effects of Concentration and Temperature of Nutrient Solution on Growth and Camptothecin Accumulation of Ophiorrhiza pumila

“…In general, low NST inhibited water absorption and often induced water stress, thus generating ROS. This ROS generation is known to be a trigger of secondary metabolite production in many vegetables [16] and medicinal plants [17,18]. Although there are few reports on alkaloid production under low NST, Malik et al [34] reported that the expression levels of alkaloid biosynthetic enzymes and target alkaloid accumulation in all organs of Catharanthus roseus and the roots of Nicotiana tabacum were higher at root-zone temperatures of 12 • C than at 25 and 30 • C. In our experiment, at T10, the plants showed a typical water stress phenomenon because of low NST; however, the CPT concentration at T10 was the same as that at T20.…”

“…Low NST also inhibits plant growth because it suppresses water absorption by roots. Moreover, NSTs of 5-15 • C were found to induce oxidative stress through the suppression of water absorption and increase the ascorbic acid concentration and sugar content in spinach [16] and the bioactive compounds in red perilla [17] and canola [18]. Previous studies reported that oxidative stress imposed by, for example, treatment with hydrogen peroxide (H 2 O 2 ), can induce the accumulation of indole alkaloids by root cultures and cell suspensions of the medicinal plant Uncaria tomentosa [19,20].…”

Flavonoid Productivity Optimized for Green and Red Forms of Perilla frutescens via Environmental Control Technologies in Plant Factory

“…On the other hand, both biotic and abiotic factors of stress induce the formation of SMs, such as phenolic compounds [6]. Meanwhile, a few attempts have been made to evaluate the quality of plants grown under different environments by detailing the stable expressions of the secondary metabolisms and concentrations of bioactive SMs that are expected to be included in plant-based foods as an additional health promoting component [7].…”