Liquiritin elicitation can increase the content of medicinally important glucosinolates and phenolic compounds in Chinese kale plants.

Brassica oleracea var. alboglabra (Chinese kale) is an important vegetable grown in southern China. This study was aimed at searching for environmental-friendly and affordable approaches to increase the production of medicinally relevant glucosinolates and phenolic compounds in Chinese kale plants. For this purpose, the foliar application of liquiritin at 0 (control), 250, 500, and 750 ppm was tested starting from the four-leaf stage and repeated every two weeks until plants were two-month-old.Foliar application of liquiritin in Chinese kale plants significantly increased glucosinolates and total phenolic content, in a dose-dependent manner. Compared with control plants, 2.3- and 1.9-fold increases in yields of glucosinolates and total phenolic content, respectively, were corroborated in Chinese kale plants treated with 750 ppm of liquiritin. Along with rises in the content of eight different glucosinolates, liquiritin elicitation effectively increased the concentration of glycosilated and acylated flavonoids and hydroxycinnamic acids. The expression of genes involved in glucosinolates and phenolics biosynthesis was significantly higher in liquiritin-treated plants as compared to controls.Liquiritin elicitation is a feasible and environmental-friendly practice to increase the production of medicinally important glucosinolates and phenolic compounds in Chinese kale plants, which may improve this plant's value as a nutraceutical food. This study also contributes to understanding the molecular mechanisms underlying liquiritin elicitation. This is the first report documenting the use of liquiritin for an elicitation purpose in plants. This article is protected by copyright. All rights reserved.