An ERF transcription factor StPTI5, a novel regulator of endophyte community maintenance in potato

Potato is exceptionally sensitive to a wide range of stresses. Its successful interaction with beneficial symbionts would allow for environmentally friendly plant protection. We investigated the processes involved in colonisation of potato with beneficial Bacillus subtilis. RNAseq showed that at the time of biofilm establishment, immune responses in interacting roots were attenuated, and complex transcriptional network was triggered, including ERFs, MYBs, NACs and WRKYs. Interestingly, the response is intensified if plants are inoculated by two antagonistic B. subtilis strains. We further focused on the role of strongly induced ERF transcription factor PTI5. While PTI5 is not involved in the establishment of biofilm on roots, we show that bacterial abundance increases in PTI5-silenced plants. Remarkably, root colonization by the arbuscular mycorrhizal fungus Rhizophagus irregularis was also higher in the PTI5-silenced plants, making PTI5 an interesting breeding target. Such mechanistic understanding of plant-microbe interaction paves the way for sustainable crop management.