Biological Activities of Two Essential Oils from Pogostemon cablin and Eupatorium fortunei and Their Major Components against Fungi Isolated from Panax notoginseng

Abstract

Panax notoginseng (Burkill) F.H.Chen (Araliaceae), of which the dry root and rhizome are precious traditional Chinese medicine, suffers severely from diseases during planting. Essential oils (EOs) with antimicrobial activity are a possibility for the development of green pesticides. We extracted EOs from Pogostemon cablin (Blanco) Benth. and Eupatorium fortunei Turcz., respectively and tested their inhibitory rates on fungi isolated from diseased P. notoginseng by the Oxford cup method. The compounds of the EO were identified by GC/MS and the minimum inhibitory concentrations (MICs) of the EOs and their main components were evaluated by the 96-well plate method. We also mixed P. cablin EO, E. fortunei EO and hymexazol in pairs to explore whether their combinations produce stronger antifungal effects than individual components. Finally, we evaluated the effects of the EOs against Fusarium oxysporum in vivo. P. cablin EO and E. fortunei EO exhibited different antifungal activities against fungi, with the inhibitory rates of 21.02 %-100 % and 54.84 %-100 % and MICs of 0.07-0.88 mg/mL and 0.20-1.17 mg/mL, respectively. Pogostone (24.96 %) and thymol (15.64 %) were the major compounds of P. cablin EO and E. fortunei EO, respectively, and they exhibited stronger antifungal activities than EOs, with MICs of 0.008-0.078 mg/mL and 0.12-0.31 mg/mL, respectively. Moreover, hymexazol was mixed with E. fortunei EO, and the inhibitory effect against Cylindrocarpon destructans was enhanced with a synergistic effect. The disease incidence and disease index of EO treatments decreased significantly in vivo. Based on our study, P. cablin EO and E. fortunei EO have great potential to be developed into green fungicides for use in agriculture to control diseases of P. notoginseng.

The antifungal effects of the essential oils of Artemisia argyi and Acorus tatarinowii on Panax notoginseng root rot disease

“…The antifungal effect of EOs was determined using an improved Oxford cup (QQ Li, et al 2020) . Brie y, the EOs were thoroughly blended and dissolved in a 1% DMSO-0.1% Tween-80 (T-80) aqueous solution at a concentration of 50 mg/mL.…”

“…Brie y, the EOs were thoroughly blended and dissolved in a 1% DMSO-0.1% Tween-80 (T-80) aqueous solution at a concentration of 50 mg/mL. Then, according to the method described by LQQ et al (QQ Li, et al 2020) , the same volume of solvent was added as a negative control; similarly, a positive control solution of 5 mg/ml was prepared. Each treatment was repeated four times, and cultures were grown in an incubator at 28 °C.…”

Single-cell transcriptome of Nepeta tenuifolia leaves reveal differentiation trajectories in glandular trichomes

“…Specific plant organs are used for many medicinal purposes. The leaves of Artemisia annua , Mentha haplocalyx , Perilla frutescens , Pogostemon cablin , Lavandula angustifolia , and Ocimum basilicum , are widely used in medicines, cosmetics, and other industries ( Giuliani et al., 2009 ; Ahmed and Tavaszi-Sarosi, 2019 : Li et al, 2020 ). In aromatic medicinal plants, leaves are covered with special multicellular structures, trichomes, which are divided into glandular trichomes (GTs) and non-glandular trichomes (NGTs) depending on their secondary metabolism capability ( Liu et al., 2019 ).…”

Complete genome sequence of the Pogostemon cablin bacterial wilt pathogen Ralstonia solanacearum strain SY1

“…Pogostemon cablin , commonly called patchouli, is an important aromatic herb belonging to the Lamiaceae family (Li et al 2020 ). The essential oil extracted from this plant is an important material in the cosmetics and perfume industries (Phuwajaroanpong et al 2020 ).…”