Open Access

ARTICLE

Antibacterial Activity and Mechanisms of Ethanol Extracts from Scutellaria baicalensis Georgi and Magnolia officinalis against Phytophthora nicotianae

Xu Gao, Ziqi Shen, Jinliang Xu, Min Fan, Qiang Li^*

College of Agronomy, Hunan Agricultural University, Changsha, 410128, China

* Corresponding Author: Qiang Li. Email:

Phyton-International Journal of Experimental Botany 2023, 92(7), 1987-1999. https://doi.org/10.32604/phyton.2023.027318

Received 24 October 2022; Accepted 26 January 2023; Issue published 29 May 2023

Abstract

Phytophthora nicotianae causes substantial economic losses in most countries where tobacco is produced. At present, the control of P. nicotianae mainly depends on chemical methods, with considerable environmental and health issues. We investigated the effects of ethanol extracts from Scutellaria baicalensis Georgi (SBG) and Magnolia officinalis (MO). On mycelial growth, sporangium formation, and zoospore release of P. nicotianae. Both extracts inhibited the growth of P. nicotianae, with mycelial growth inhibition rates of 88.92% and 93.92%, respectively, at 40 mg/mL, and EC50 values of 5.39 and 5.74 mg/mL, respectively. The underlying mechanisms were the inhibition of sporangium formation, the reduction of zoospore number, and the destruction of the mycelium structure. At an SBG extract concentration of 16.17 mg/mL, the inhibition rates for sporangia and zoospores were 98.66% and 99.39%, respectively. At an MO extract concentration of 2.87 mg/mL, the production of sporangia and zoospores was completely inhibited. The hyphae treated with the two plant extracts showed different degrees of deformation and damage. Hyphae treated with SBG extract showed adhesion and local swelling, whereas treatment with MO extract resulted in broken hyphae. Mixture of the extracts resulted in a good synergistic effect.

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Keywords

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