Application of biochar reduces Ralstonia solanacearum infection via effects on pathogen chemotaxis, swarming motility, and root exudate adsorption

Yian Gu, Yugang Hou, Dapeng Huang, Zhexia Hao, Xiaofang Wang, Zhong Wei*, Alexandre Jousset, Shiyong Tan, Dabing Xu, Qirong Shen, Yangchun Xu, Ville Petri Friman

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review


Aims: We evaluated the efficacy of biochar application for suppressing bacterial wilt of tomato and identified the potential underlying mechanisms involved in the disease control. Methods: We measured the impact of two different sized biochar (53–120 μm and 380–830 μm) on bacterial wilt incidence in a greenhouse experiment. The efficiency of different sized biochar for the adsorption of tomato root exudates and the pathogen was further examined in vitro. We also quantified the effects of biochar and tomato root exudates on two pathogen virulence factors, chemotaxis, swarming motility and examined the effect of biochar on pathogen root colonization. Results: Fine biochar application (3%; w:w) significantly decreased the bacterial wilt incidence by 19.9%. Biochar with different particle size had similar adsorption capacity for root exudates, while fine biochar was efficient (91%) in pathogen adsorption. Root exudates and fine biochar increased the chemotaxis ability of pathogen, while fine biochar reduced pathogen swarming motility and rhizosphere colonization. Conclusions: Application of fine biochar can significantly decreased bacterial wilt incidence. This was mechanistically explained by biochar ability to 1) adsorb pathogen directly and indirectly via adsorption of root exudates (based on pathogen chemotaxis) and to 2) directly suppress pathogen swarming motility and subsequent root colonization.

Original languageEnglish
Pages (from-to)1-13
Number of pages13
JournalPlant and Soil
Early online date29 Dec 2016
Publication statusE-pub ahead of print - 29 Dec 2016

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© Springer International Publishing Switzerland 2016.This is an author-produced version of the published paper. Uploaded in accordance with the publisher’s self-archiving policy. Further copying may not be permitted; contact the publisher for details.


  • Adsorption
  • Bacterial wilt
  • Biochar
  • Disease control
  • Root exudate

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