MORF4 and infection: The pre-inoculum densities (PID) of SEN∆alr, SEN∆3897, SEN∆dadX and SEN ∆alr∆dadX prior to infection were 2.0 * 106, 1.7 * 106, 1.9 * 106 and 1.3 * 106 respectively relative to WT (1.5 * 106).