The effect of drought stress on polyphenolic compounds and expression of flavonoid biosynthesis related genes in Achillea pachycephala Rech.f

Shima Gharibi; Badraldin Ebrahim Sayed Tabatabaei; Ghodratolah Saeidi; Majid Talebi; Adam Matkowski

doi:10.1016/j.phytochem.2019.03.004

The effect of drought stress on polyphenolic compounds and expression of flavonoid biosynthesis related genes in Achillea pachycephala Rech.f

Phytochemistry. 2019 Jun:162:90-98. doi: 10.1016/j.phytochem.2019.03.004. Epub 2019 Mar 12.

Authors

Shima Gharibi¹, Badraldin Ebrahim Sayed Tabatabaei², Ghodratolah Saeidi³, Majid Talebi², Adam Matkowski⁴

Affiliations

¹ Department of Agronomy and Plant Breeding, College of Agriculture, Isfahan University of Technology, 8415683111, Isfahan, Iran. Electronic address: s.gharibi@ag.iut.ac.ir.
² Department of Biotechnology, College of Agriculture, Isfahan University of Technology, Isfahan, 8415683111, Iran.
³ Department of Agronomy and Plant Breeding, College of Agriculture, Isfahan University of Technology, 8415683111, Isfahan, Iran.
⁴ Department of Pharmaceutical Biology and Botanical Garden of Medicinal Plants, Wroclaw Medical University, Wrocław, Poland.

PMID: 30875522
DOI: 10.1016/j.phytochem.2019.03.004

Abstract

This study investigated the effect of drought stress on the amount of phenolic and flavonoid compounds as well as H₂O₂ and malondialdehyde (MDA) in Achillea pachycephala. The expression patterns of the key genes and their molecular mechanisms in the phenylpropanoid pathway (PAL, CHS, CHI, F3H, F3'H, F3'5'H, FLS) were also assessed during drought stress using quantitative real-time polymerase chain reaction (qRT-PCR). The samples were harvested at 0, 7, 14, 21 and 28 days after exposure to drought stress. High-performance liquid chromatography (HPLC) analysis was performed to determine the changes of phenolic and flavonoid compounds - chlorogenic acid, caffeic acid, rutin, luteolin-7-O-glycoside, 1,3-dicaffeoylquinic acid, apigenin-7-O-glycoside, luteolin, apigenin and kaempferol - during stress conditions. Concentrations of most of the compounds increased with increasing drought stress duration. Most of the phenolic acids continued to accumulate with increasing duration of stress, while flavonoids dramatically decreased at day 28 of stress. Chlorogenic acid was the most abundant phenolic acid (4.97 mg/100 g dry weight [DW]) at the beginning of the experiment, while it decreased at day 7 and increased again at day 21. However, different trends were observed for some flavonoids, such as luteolin and apigenin. At the beginning of stress treatment, high accumulation of free radicals (H₂O₂) and lipid peroxidation (MDA) led to elevated expression of most of the flavonoid genes. MDA increased from 22.66 to 43.28 μmol g^-1 DW at day 28. CHS gene expression was elevated at day 7, while chi gene expression remained unchanged. At the end of the stress period, most of the flavonoid concentrations and expression of the relevant genes also increased. The results can facilitate selection of appropriate drought conditions to obtain the highest levels of flavonoids such as luteolin and apigenin and phenolic compounds such as chlorogenic acid for improved health benefits.

Keywords: Achillea pachycephala; Asteraceae; Drought stress; Gene expression; HPLC.

MeSH terms

Achillea / genetics*
Achillea / metabolism*
Achillea / physiology
Droughts*
Flavonoids / biosynthesis*
Gene Expression Regulation, Plant*
Hydrogen Peroxide / metabolism
Lipid Peroxidation
Polyphenols / metabolism*
Stress, Physiological*

Substances

Flavonoids
Polyphenols
Hydrogen Peroxide