Quorum sensing system (QSS) plays a central role
in the virulence of B. glumae. Although the phytotoxin
production and motility were lost or reduced in CMMs,
AHLs were produced normally by 16 h after incubation,
and no mutations were associated with genes for QSS such
as tofI, tofR and qsmR. Thus, QSS in the CMMs seemed to
function normally, with virulence reduced by another
unknown mechanism. Furthermore, culture pH values
decreased in the wild-type strain but increased in the CMMs
at 30 C in Luria–Bertani medium.