Coordinated regulation of Arabidopsis microRNA biogenesis and red light signaling through Dicer-like 1 and phytochrome-interacting factor 4

摘要

Light and microRNAs (miRNAs) are key external and internal signals for plant development, respectively. However, the relationship between the light signaling and miRNA biogenesis pathways remains unknown. Here we found that miRNA processer proteins DCL1 and HYL1 interact with a basic helix-loop-helix (bHLH) transcription factor, phytochrome-interacting factor 4 (PIF4), which mediates the destabilization of DCL1 during dark-to-red-light transition. PIF4 acts as a transcription factor for some miRNA genes and is necessary for the proper accumulation of miRNAs. DCL1, HYL1, and mature miRNAs play roles in the regulation of plant hypocotyl growth. These results uncovered a previously unknown crosstalk between miRNA biogenesis and red light signaling through the PIF4-dependent regulation of miRNA transcription and processing to affect red-light-directed plant photomorphogenesis. Author summary External light and internal miRNAs are important for plant development. This study revealed that the miRNA-processing enzyme DCL1 interacts with the red-light-regulated transcription factor PIF4, which modulates the stability of DCL1 during dark-to-red-light or red-light-to-dark transitions and acts as a transcription factor for some miRNA genes. This study revealed that DCL1 and mature miRNAs play roles in the red light signaling pathway to regulate plant photomorphogenesis. These results shed light on the crosstalk between miRNA and red light signaling pathways.