Pathogenicity of EPS-deficient mutants (gumB - , gumD -and gum E - ) of Xanthomonas campestris pv. campestris
摘要
Three extracellular polysaccharide (EPS) -deficient mutants of the pathogen Xantkomonas campestris pv. campestris , gumB- , gumD- and gumE- were constructed by Tn5gus45 mutagenesis in this study. The results of pathogenicity bioassay showed that three mutants had the obviously decreased pathogenicity on radish ( Raphanus sativus L.) leaves. Because dead body of the bacteria still caused symptoms, it seemed that some unknown factors on the bacterial cell surface might play certain roles in the pathogenicity of the pathogen. The extracted raw EPS could lead to the chlorotic symptom on radish leaves, and its virulence was increased with the increase of EPS dosage, which suggested that EPS was a main component that caused the damage on radish leaves.