Impact of copper treatment on phenylpropanoid biosynthesis in adventitious root culture of Althaea officinalis L.

Abstract

Althaea officinalis has been widely used in various pharmaceutical applications. The biological effects and significance of phenylpropanoids in numerous industries are well studied. However, fulfilling consumer demand for these commercially important compounds is difficult. The effect of heavy-metal toxic influence on plants is primarily due to a strong and rapid suppression of growth processes, as well as the decline in activity of the photosynthetic apparatus, also associated with progressing senescence processes. Some of the secondary metabolite production was triggered by the application of heavy metals, but there was not a stress response. In the adventitious root culture of A. officinalis, copper-mediated phenylpropanoid biosynthesis has been investigated in both concentration-and duration-dependent manners. High-performance liquid chromatography (HPLC) analysis revealed a total of nine different phenolic compounds in response to different concentrations of copper chloride. In this study, high productivity of phenolic compounds was observed in the copper chloride treated-adventitious root culture of A. officianalis. In particular, a low concentration of copper chloride led to a significant accumulation of phenolic compounds under optimal conditions. Moreover, all genes responsible for phenylpropanoid biosynthesis may be sensitive to phenolic compound production following copper treatment. Especially, the highest change in transcript level was observed from AoANS at 6 h. According to our findings, treatment with copper chloride (0.5 mM) for 48 or 96 h can be an appropriate method to maximize phenylpropanoid levels in A. officinalis adventitious root culture.

Keywords:

• Adventitious root culture
• Althaea officinalis
• copper
• heavy metal
• phenylpropanoid

Abbreviations

4CL: 4-coumarate-CoA ligase; ANR: anthocyanidin reductase; ANS: anthocyanidin synthase; C3H: 4-coumarate 3-hydroxylase; C4H: cinnamate 4-hydroxylase; CAD: cinnamyl alcohol dehydrogenase; CCR: cinnamyl-CoA reductase; CHI: chalcone isomerase; CHS: chalcone synthase; COMT: caffeic acid O-methyltransferase; DFR: dihydroflavonol 4-reductase; F3’5’H: flavonoid 3’5′ hydroxylase; F3′H: flavonoid 3′-hydroxylase; F3H: flavanone 3-hydroxylase; F5H: ferulate 5-hydroxylase; FLS: flavonol synthase; HPLC: High-performance liquid chromatography; LAR: leucoanthocyanidin reductase; PAL: phenylalanine ammonia-lyase; ROS: reactive oxygen species; RT: anthocyanidin-3-glucoside rhamnosyl transferase; UFGT: UDPG-flavonoid-3-O-glucosyltransferase.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This research was supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education [grant number 2019R1A6A1A11052070].