Phytosulfokine peptide regulates the growth-immunity trade-off through CAMTA3-mediated transcriptional signaling in Arabidopsis

However, the underlying mechanism remains poorly understood. Here we show that PSK regulates the trade-off between growth and immunity by mediating stabilization and cytosol-nucleus translocation of Calmodulin-binding Transcription Activator 3 (CAMTA3).

By genetic screening of an Arabidopsis thaliana mutant library, we identified a mutant named growth retardation and autoimmunity 1 (gra1). Map-based cloning and bulk population sequencing disclosed that GRA1 encodes TYROSYLPROTEIN SULFOTRANSFERASE (TPST) for the biosynthesis of sulfated peptides. Treatment with PSK can restore the reduced callus proliferation of gra1 mutants and overexpression of PSK can promote plant growth but reduce immune responses.