Growth-Promoting and Biocontrol Features of Pantoea Ananatis Brt175 in Tomato

Abstract

Beneficial bacteria belonging to Pantoea spp. and their interactions with plants have recently attracted growing interest for their beneficial effects, especially in promoting plant growth and health. In this study, we evaluated the growth-promoting and induced resistance activities of Pantoea ananatis strain BRT175 in tomato. In vitro assays revealed that this strain exhibits different beneficial traits, including phosphate solubilization, siderophore production, and IAA synthesis. These traits were further supported in silico by the presence of corresponding genes annotated in P. ananatis BRT175 genome. The capacity of this strain to significantly promote tomato growth was demonstrated under both growth chamber and greenhouse conditions. This bacterium also showed significant biocontrol activity through its antifungal effect against Botrytis cinerea. Interestingly, P. ananatis BRT175-derived ananatosides, a group of amphiphilic glycolipids, also showed an antifungal effect against B. cinerea. These glycolipids could therefore act as bacterial determinants contributing to protection against the pathogen. In addition, both root and leaf treatments with the bacterium resulted in a significant reduction of necrotic symptoms, suggesting that P. ananatis BRT175 potentially triggers systemic resistance of tomato. At the leaf level, P. ananatis BRT175 may displays a multifaceted protective effect by combining antifungal properties, competition for nutrients, and stimulation of tomato systemic resistance.

Keywords: Pantoea ananatis, Tomato, PGPR, ISR, Biocontrol, Botrytis cinerea, Ananatosides