Alanine-Dependent TCA Cycle Promotion Restores the Zhongshengmycin-Susceptibility in Xanthomonas oryzae

Xanthomonas oryzae pv. oryzicola (Xoo) is a plant pathogenic bacterium that can cause rice bacterial blight disease, which results in a severe reduction in rice production. Antimicrobial-dependent microbial controlling is a useful way to control the spread and outbreak of plant pathogenic bacteria. However, the abuse and long-term use of antimicrobials also cause microbial antimicrobial resistance. As far as known, the mechanism of antimicrobial resistance in agricultural plant pathogenic bacteria still lacks prospecting. In this study, we explore the mechanism of Zhongshengmycin (ZSM)-resistance in Xoo by GC-MS-based metabolomic analysis. The results showed that the down-regulation of the TCA cycle was characteristic of antimicrobial resistance in Xoo, which was further demonstrated by the reduction of activity and gene expression levels of key enzymes in the TCA cycle. Furthermore, alanine was proven to reverse the ZSM resistance in Xoo by accelerating the TCA cycle in vivo. Our results are essential for understanding the mechanisms of ZSM resistance in Xoo and may provide new strategies for controlling this agricultural plant pathogen at the metabolic level.