FIG. 8.

Hypothetical scheme for polyP accumulation and function. PolyP accumulation depends on PhoB and (p)ppGpp synthesized either by the relA (stringent-response) pathway or by the phosphate starvation-inducible spoT pathway. The inhibition by (p)ppGpp of exopolyphosphatase PPX as one means of polyP accumulation and the dependence of rpoS expression on polyP are mentioned in the text. Dashed arrows indicate either a direct or an indirect effect on the synthesis or accumulation of the gene products.