Berberine induces resistance against tobacco mosaic virus in tobacco.

Abstract

Plant systemic resistance induced by botanical compounds is a promising alternative method of disease management. The natural product berberine, usually used as an antimicrobial in medicine, has been proven to have antifungal activity in agriculture. To investigate the induced resistance imparted by berberine, the effect of berberine against tobacco mosaic virus (TMV) and the mechanism governing this effect were determined. Berberine exhibited considerable in vivo anti-TMV activity of up to 68.3% but had no in vitro direct effect on TMV. Moreover, berberine could induce immune responses against TMV in tobacco, including the hypersensitive reaction (HR), accumulation of H2 O2 , increases in defense enzymes and overexpression of pathogenesis-related (PR) proteins. In addition, upregulation of salicylic acid (SA) biosynthesis genes PAL, CM1, ICS, PBS3 and the enzyme benzoic acid 2-hydroxylase (BA2H) confirmed that SA was involved in the defensive signals. Berberine can induce crop resistance against TMV, Phytophthora nicotianae, Botrytis cinerea and Blumeria graminis in the greenhouse. This paper highlights the use of berberine in manipulating tobacco to generate defense responses against TMV, which can be attributed to SA-mediated induced resistance. The paper provides a theoretical basis for the application of berberine as a resistance activator and for further research on induced resistance by botanical natural product. © 2019 Society of Chemical Industry.