Accumulation of relA gene-independent ppGpp in Bacillus subtilis vegetative cells upon temperature shift-down

Both Bacillus subtilis BR16S (rel+) and BR16R (relA-) cells accumulated ppGpp after a temperature shift-down from 37 to 0 degree C. This indicates that a ppGpp accumulation system is present in B. subtilis vegetative cells, which is induced upon cold-shock treatment and is mediated by a relA gene-independent product.