[en] The development of common scab (CS) disease on root and tuber crops is caused by few pathogenic Streptomyces with Streptomyces scabiei 87–22 as the model species. Thaxtomin phytotoxins are the primary virulence determinants. Induction of thaxtomin biosynthesis requires the import of cello-oligosaccharides (cellobiose and/or cellotriose) by the CebEFG sugar ABC transporter. Once inside the cytoplasm, the imported cello-oligosaccharides inhibit the DNA-binding ability of the transcriptional repressor CebR which in turn allows the expression of the thaxtomin (txt) biosynthetic gene cluster (BGC). Although the path from cello-oligosaccharide uptake to activation of thaxtomin biosynthesis is well described at the molecular level, many questions regarding elicitors of CS remain unsolved. An even more important question is the exact composition of the arsenal of specialized metabolites that together with thaxtomin constitutes the virulome of S. scabiei. In this work we used comparative transcriptomic and metabolomic analyses to determine which part of the specialized metabolism of S. scabiei is dedicated to its pathogenic lifestyle.
