PIF4 enhances DNA binding of CDF2 to co-regulate target gene expression and promote Arabidopsis hypocotyl cell elongation (Nature Plants)

Responses to environmental and internal signals require the recruitment of transcription factors (TFs). TFs recognize simple DNA sequences to activate specific genes that will accomplish the required functions. DOF (DNA-binding with one finger) is a large family of plant TFs that encloses the CYCLING DOF FACTORS (CDF) subfamily. CDF are regulated by the circadian clock and also promote hypocotyl elongation and regulate abiotic stress responses., but how CDFs are recruited to specific genes is unknown. In this work, Gao et al., describe how CDF2 interacts with PHYTOCHROME-INTERACTING 4 (PIF4), a TF that promotes growth in response to light and temperature.  CDF2-PIF4 interaction promotes the elongation of hypocotyl cells, co-regulating common targets such as YUC8 in cotyledons. The authors showed that the increased binding strength and specificity of CDF2 in the presence of PIF4 contributes to auxin biosynthesis through the action of YUCCA enzymes, promoting the hypocotyl growth. This article shows the importance of studying  specificity within gene regulatory networks. (Summary by Eva Maria Gomez Alvarez, @eva_ga96) Nature Plants. 10.1038/s41477-022-01213-y