Antibacterial mechanism of Biochanin A and its efficacy for the control of Xanthomonas axonopodis pv. glycines in soybean

BACKGROUND Xanthomonas axonopodis pv. glycines (Xag) is a hazardous pathogen able to cause bacterial pustule disease in soybean, reducing crop yield and quality. Although flavonoids rutin and genistein are known to play an important role in soybean defence, soybean is only able to produce Biochanin A in low concentration. RESULTS In this work, Biochanin A was found to produce higher antibacterial activity against Xag in comparison with genistein (minimum inhibitory concentration < 100 mu g/mL). Biochanin A was able to inhibit DNA synthesis and flagella formation in Xag, and altered the composition of the bacterial membrane. These effects reduced swimming motility, extracellular protease activity and biofilm formation. Further, Biochanin A was tested for the control of Xag in soybean leaves, showing similar, or even higher, inhibitory ability in comparison with some products commonly used for the control of this pathogen. CONCLUSIONS The antibacterial properties of Biochanin A against Xag have been studied for the first time, revealing new insights on the potential applications of this isoflavonoid for the management of bacterial pustule disease.

Automated summary

Biochanin A exhibits higher antibacterial activity against Xanthomonas axonopodis pv. glycines (Xag) compared to genistein, inhibiting DNA synthesis and flagella formation. It also reduces swimming motility, extracellular protease activity, and biofilm formation in Xag, suggesting potential applications for managing bacterial pustule disease.