# Metabolomics Reveals Lysinibacillus capsici TT41-Induced Metabolic Shifts Enhancing Drought Stress Tolerance in Kimchi Cabbage (Brassica rapa L. subsp. pekinensis)

## TL;DR

This study shows that a specific bacteria, Lysinibacillus capsici TT41, helps kimchi cabbage survive drought by altering its metabolism, including increasing lactic acid.

## Contribution

The novel finding is that TT41 induces a metabolomic shift in kimchi cabbage, enhancing drought tolerance through lactic acid production.

## Key findings

- TT41-treated kimchi cabbage showed significant plant parameter improvements under drought stress.
- Metabolomic analysis revealed TT41-treated plants clustered with well-watered plants, indicating similar metabolic profiles.
- Lactic acid was identified as a key metabolite enhancing drought tolerance, with direct application showing similar effects to TT41 treatment.

## Abstract

Climate change has increased variable weather patterns that affect plants. To address these issues, we developed a microbial biocontrol agent against drought stress in kimchi cabbage (Brassica rapa L. subsp. pekinensis). We selected three bacterial strains (Leifsonia sp. CS9, Bacillus toyonensis TSJ7, and Lysinibacillus capsici TT41) because they showed a survival rate of up to 50% and good growth rate when treated with 30% PEG 6000. The three strains were treated with kimchi cabbage to confirm their enhanced drought stress resistance under non-watering conditions. Among the three strains, the TT41 treated group showed a significant increase in various plant parameters compared with the negative control on the 7th day. We performed extensive profiling of primary and secondary metabolites from kimchi cabbage and the TT41 strain. Multivariate and pathway analyses revealed that only the TT41 group clustered with the well-watered group and showed almost the same metabolome on the 7th day. When treated with TT41, lactic acid was identified as an indicator metabolite that significantly improved drought stress tolerance. Furthermore, lactic acid treatment effectively induced drought stress tolerance in kimchi cabbage, similar to that achieved with the TT41 strain.