title: Correlation analysis between the rate of respiration in the root and the active components in licorice (Glycyrrhiza uralensis).
abstract: The aim of this study was to investigate the correlation between root respiration and the percentage of active components in licorice (Glycyrrhiza uralensisFisch.), in order to provide a foundation for the regulation and modulation of the quality ofG. uralensis. Respiration efflux of annual and biennialG. uralensiswas determined using a Li-7000 CO2/H2O analyzer. The root systems were scanned at a resolution of 3,000 dpi using an Epson Expression 10000XL scanner. Root growth was determined by analyzing the scanned images using WinRHIZO version Pro2007d software and the rate of respiration in the root was subsequently calculated. In addition, the percentages of the five major active components in licorice, glycyrrhizic acid, glycyrrhizin, isoliquiritin, liquiritigenin and isoliquiritigenin, were detected using high-performance liquid chromatography (HPLC). The correlation between the root respiration and the percentage of the active components was investigated. Significant seasonal changes were observed in the rates of respiration of first and zero-class roots. In annual and biennialG. uralensis, the maximum and minimum values for rate of respiration were present in July (P<0.05) and November (P<0.05), respectively. The correlation coefficients between the five major active components and the rate of respiration were -0.304 (glycyrrhizin), -0.129 (liquiritigenin), -0.441 (glycyrrhizic acid; P<0.05), -0.471 (isoliquiritin; P<0.05) and 0.148 (isoliquiritigenin). The percentages of glycyrrhizic acid and isoliquiritin were significantly negatively correlated with the rate of respiration in annual and biennialG. uralensis. Understanding the correlation between the root rate of respiration and the active components inG. uralensismay be beneficial to ensuring the quality of cultivatedG. uralensis.
authors.affiliation: School of Chinese Materia Medica, Beijing University of Chinese Medicine, Beijing 100029, P.R. China.
authors.forename: Peijun
authors.initials: P
authors.lastname: Guo
authors.affiliation: School of Chinese Materia Medica, Beijing University of Chinese Medicine, Beijing 100029, P.R. China.
authors.forename: Zhirong
authors.initials: Z
authors.lastname: Sun
authors.affiliation: School of Chinese Materia Medica, Beijing University of Chinese Medicine, Beijing 100029, P.R. China.
authors.forename: Wenlan
authors.initials: W
authors.lastname: Liu
authors.affiliation: School of Chinese Materia Medica, Beijing University of Chinese Medicine, Beijing 100029, P.R. China.
authors.forename: Long
authors.initials: L
authors.lastname: Chen
authors.affiliation: School of Chinese Materia Medica, Beijing University of Chinese Medicine, Beijing 100029, P.R. China.
authors.forename: Yuan
authors.initials: Y
authors.lastname: DU
authors.affiliation: School of Chinese Materia Medica, Beijing University of Chinese Medicine, Beijing 100029, P.R. China.
authors.forename: Xinxin
authors.initials: X
authors.lastname: Wei
keywords: Glycyrrhiza uralensis; active component; correlation analysis; root respiration