Nutrient‐induced spore germination of a B acillus amyloliquefaciens biocontrol agent on wheat spikes

Aims In this study, we investigated the feasibility of applying nutrient germinants to plant surfaces to stimulate the spore germination of the plant disease biocontrol agent B acillus amyloliquefaciens strain T rigo C or. Methods and Results Using the terbium chloride assay and phase‐contrast microscopy, we screened potential germinants of T rigo C or spores and found that a combination of d ‐glucose, d ‐fructose and potassium chloride ( GFK ), in addition to either l ‐asparagine ( A sn‐ GFK ) or l ‐alanine ( A la‐ GFK ), induced maximal levels of T rigo C or spore germination in vitro . The germinant mixture A sn‐ GFK was also able to significantly stimulate B acillus spore germination on wheat surfaces. Conclusions The successful in vivo stimulation of B acillus spore germination suggests that nutrient‐induced spore germination on plant surfaces is a feasible strategy for improving B acillus biocontrol. Significance and Impact of the Study One of the challenges of applying B acillus biological control agents to aboveground plant parts is that B acillus cells transition to a metabolically dormant spore state on plant surfaces, making them unable to prevent subsequent pathogen attacks. This study demonstrates that using nutrients to stimulate B acillus spore germination in vivo is a promising option for improving disease control and should be pursued further.