Analysis of defense-related enzymes and metabolites induced by lansiumamide B against Ralstonia solanacearum in tobacco

Abstract

In this study we investigated the ability of lansiumamide B to protect tobacco against bacterial wilt caused by Ralstonia solanacearum. The results of pot experiments indicated that lansiumamide B profoundly reduced the disease severity of bacterial wilt, with the control efficiency on tobacco bacterial wilt at 87.28% and 77.75% at 15 and 30 days, respectively. The activities of antioxidative enzymes, such as peroxidase (POD) and superoxide dismutase (SOD) were enhanced after treatment with lansiumamide B. The activity of phenylalanine ammonium lyase (PAL) and polyphenol oxidase (PPO) were also increased, which plays an important role in protecting the plant against pathogenic bacteria attack. The isozymes analysis results showed that the expressions of POD and PPO isozymes were enhanced after treatment with lansiumamide B. Detection of metabolites showed that the relative contents of resistance-related substances, such as Myo-inositol, Nicotine, Propanedioic acid, Lactic acid, Glycerol acid, Malic acid, L-threonic acid, D-lyxose, Ribitol, Tetradecanol, L-arabinose, Ribonic acid, Shikimic acid, Tartaric acid, 1, 2, 3-Propanetricarboxylic acid, L-arabitol and Octadecanoic acid in the groups of inoculation, BTH, and lansiumamide B were higher compared to solvent control. These results suggested that lansiumamide B might attenuate the harmful effects of Ralstonia solanacearum on tobacco plants.