African Journal of
Microbiology Research

  • Abbreviation: Afr. J. Microbiol. Res.
  • Language: English
  • ISSN: 1996-0808
  • DOI: 10.5897/AJMR
  • Start Year: 2007
  • Published Articles: 5210

Full Length Research Paper

Hemin transported protein of Xanthomonas axonopodis pv. glycines functions on leaf colonization and virulence on soybean

Sutruedee Prathuangwong1*, Dusit Athinuwat2, Wilawan Chuaboon1, Lawan Kladsuwan1, Malida Choorin1 and Tiyakhon Chatnaparat1
1Department of Plant Pathology, Faculty of Agriculture, Kasetsart University, Bangkok 10900, Thailand. 2Major of Organic Farming Management, Faculty of Science and Technology, Thammasat University, Pathumthani 12121, Thailand.
Email: [email protected]

  •  Accepted: 20 September 2013
  •  Published: 25 October 2013


Xanthomonas axonopodis pv. glycines (Xag) causes bacterial pustule disease on soybean. This bacterium is present worldwide around hot and humid growing regions such as Southeast Asia. To understand if the gene coding for hemin transport protein (hem) is involved in virulence of the pathogen in soybean, we generated a hem mutant in Xag by overlapping PCR mutagenesis. Disruption of hem significantly reduced the population size and the disease incidence when sprayed on soybean but not when injected directly to soybean. The hem mutant caused the hypersensitive response induction on tobacco as an Xag wildtype. Interestingly, the hem expression was also reduced when the Xag wildtype grow in planta. The hemin transporter protein involved in the production of extracellular polysaccharide, biofilm formation, motility and attachment but not for extracellular enzymes. This confirmed that epiphytic fitness of Xag strongly required hem functions. These results suggest that hem gene is essential for virulence of Xag on soybean during the infection process.


Key words: Bacterial pustule disease, virulence factors, iron uptake system, hem gene, epiphytic fitness.