The biocontrol agent Bacillus sp. CHEP5 primes the defense response against Cercospora sojina.

Glycine max (soybean) production can be dramatically affected by frogeye leaf spot (FLS) caused by Cercospora sojina Hara. The inoculation of biocontrol agents may be an alternative strategy for C. sojina control. The native biocontrol bacterium Bacillus sp. CHEP5 reduced the severity of FLS in soybean by inducing systemic resistance. We suggest that the defense response was primed since the expression of the defense related gene GmAOS was enhanced in induced plants treated with both methyl jasmonate and C. sojina. Furthermore, as GmAOS is related to jasmonic acid biosynthesis, we assume that this phytohormone is involved in induced systemic resistance signaling defense pathway in soybean against C. sojina.