The major role of Spo0A in genetic competence is to downregulate abrB, an essential competence gone

We show that the major role for Spo0A in the development of genetic competence is to downregulate expression of abrB. AbrB is both a negative regulator and a positive regulator of competence. The negative effects are exerted at multiple points in competence regulation. A regulatory mechanism that is independent of mecA and abrB operates on comK expression.