The Korean Soclety of Plant Pathology : B ; Biological Control : B-14 ; The cyclic dipeptides from Bacillus vallismortis BS07M elicit induced systemic resistance against Pectobacterium carotovora SCC1 on tobacco plant

A promising biological control agent, Bacillus vallismortis strain BS07M (BS07M), which was originally isolated from the rhizosphere of chili pep-per, enhanced plant growth promotion in diverse crop plants including chilli pepper, cucumber, and tomato. In this study, we investigated wheth-er BS07M may involved in attenuating disease symptom and certain compounds derived from BS07M play a pivotal role in induced systemic resistance to pathogens. As expected, the disease severity of BS07M treat-ed plants was significantly reduced when compared to control plants. A total of 14 different derivatives of dipeptides from bacterial culture filtrates were characterized by high performance liquid chromatography (HPLC) and their chemical structures were determined by nuclear mag-netic resonance (NMR). Among dipeptides, induced systemic resistance to Pectobacterium carotovora SCC1 was drastically elicited by proline based dipeptides. In addition, improved abiotic stress tolerance and promoting plant growth were observed in tobacco plants treated with proline based dipeptides. Our study strongly suggests that new beneficial metabolites from BS07M are importance component in disease management as ISR elicitors.