Gatifloxacin hydrochloride confers broad-spectrum antibacterial activity against phytopathogenic bacteria.

Bacterial diseases pose significant threats to agriculture and natural ecosystems, causing substantial crop losses and impacting food security. Until now, there has been a less efficient control strategy against some bacterial diseases such as bacterial wilt, caused by . In this study, we screened a library of 58 microorganism-derived natural products for their antibacterial activity against . Gatifloxacin hydrochloride exhibited the best inhibitory effect with an inhibition rate of 95% at 0.0625 mg/L. Further experiments demonstrate that gatifloxacin hydrochloride inhibits growth in a concentration-dependent manner, with the minimum inhibitory concentration of 0.125 mg/L. Treatment with 0.5 mg/L of gatifloxacin hydrochloride killed more than 95% of bacteria. Gatifloxacin hydrochloride significantly inhibited biofilm formation by . Gatifloxacin hydrochloride also shows good antibacterial activity against pv. DC3000 and pv. . Exogenous application of gatifloxacin hydrochloride suppressed disease development caused by and . In summary, our results demonstrate the great potential of microorganism-derived compounds as broad-spectrum antibacterial compounds, providing alternative ways for the efficient control of bacterial plant diseases.