One layer of the innate immune system allows plants to recognize pathogen-associated molecular patterns (PAMPS)， activating a defense response known as PAMP-triggered immunity (PTI). Maintaining an active immune response， however， comes at the cost of plant growth and development; accordingly， optimization of the balance between defense and development is critical to plant fitness. The TEOSINTE BRANCHED1/CYCLOIDEA/PROLIFERATING CELL FACTOR (TCP) transcription factor family consists of well-characterized transcriptional regulators of plant development and morphogenesis. The three closely related class I TCP transcription factors TCP8， TCP14， and TCP15 have also been implicated in the regulation of ef... More
One layer of the innate immune system allows plants to recognize pathogen-associated molecular patterns (PAMPS)， activating a defense response known as PAMP-triggered immunity (PTI). Maintaining an active immune response， however， comes at the cost of plant growth and development; accordingly， optimization of the balance between defense and development is critical to plant fitness. The TEOSINTE BRANCHED1/CYCLOIDEA/PROLIFERATING CELL FACTOR (TCP) transcription factor family consists of well-characterized transcriptional regulators of plant development and morphogenesis. The three closely related class I TCP transcription factors TCP8， TCP14， and TCP15 have also been implicated in the regulation of effector-triggered immunity， but there has been no previous characterization of PTI-related phenotypes. To identify TCP targets involved in PTI， we screened a PAMP-induced gene promoter library in a yeast one-hybrid assay and identified interactions of these three TCPs with the () promoter. The direct interactions between TCP8 and were confirmed to require an intact TCP binding site in planta. A triple mutant was impaired in -dependent PTI and exhibited reduced levels of PATHOGENESIS-RELATED PROTEIN 2 and induction of expression after elicitation with elf18 but also increased production of reactive oxygen species relative to Col-0. Our data support an increasingly complex role for TCPs at the nexus of plant development and defense.
