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Biocontrol of tomato wilt disease by B acillus subtilis isolates from natural environments depends on conserved genes mediating biofilm formation
Author(s) -
Chen Yun,
Yan Fang,
Chai Yunrong,
Liu Hongxia,
Kolter Roberto,
Losick Richard,
Guo Jianhua
Publication year - 2013
Publication title -
environmental microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.954
H-Index - 188
eISSN - 1462-2920
pISSN - 1462-2912
DOI - 10.1111/j.1462-2920.2012.02860.x
Subject(s) - biology , biofilm , biological pest control , bacillus subtilis , bacterial wilt , microbiology and biotechnology , pathogen , bacteria , gene , ralstonia solanacearum , phyllosphere , botany , genetics
Summary B acillus subtilis and other B acilli have long been used as biological control agents against plant bacterial diseases but the mechanisms by which the bacteria confer protection are not well understood. Our goal in this study was to isolate strains of B . subtilis that exhibit high levels of biocontrol efficacy from natural environments and to investigate the mechanisms by which these strains confer plant protection. We screened a total of 60 isolates collected from various locations across C hina and obtained six strains that exhibited above 50% biocontrol efficacy on tomato plants against the plant pathogen R alstonia solanacearum under greenhouse conditions. These wild strains were able to form robust biofilms both in defined medium and on tomato plant roots and exhibited strong antagonistic activities against various plant pathogens in plate assays. We show that plant protection by those strains depended on widely conserved genes required for biofilm formation, including regulatory genes and genes for matrix production. We provide evidence suggesting that matrix production is critical for bacterial colonization on plant root surfaces. Finally, we have established a model system for studies of B . subtilis –tomato plant interactions in protection against a plant pathogen.