Abstract
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.
Highlights
This study revealed that the miRNA-processing enzyme DCL1 interacts with the red-light-regulated transcription factor phytochrome-interacting factor 4 (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
We show that DCL1 interacts with PIF4 which integrates miRNA biogenesis and red light signaling by regulating the transcription of a group of miRNA genes and the stability of DCL1 during dark-to-red-light or red-light-to-dark transitions
Summary
Arabidopsis thaliana (ecotype Col-0), phyB (SALK_022035C), dcl1-9 [25,39], hyl (Salk_064863), pif (CS66043), miR160b (SALK_152649), miR319b (SALK_037093C), miR167b (CS872594) and miR848 (CS812734) mutants were used. All plants were grown in soil or Murashige and Skoog (MS) medium at 16 hr light/8 hr dark photoperiod unless indicated otherwise. The PIF4, DCL1 and HYL1 coding sequences were cloned into pCambia1301 with the CaMV35S promoter and a YFP tag [25] and confirmed by sequencing. Primers used to amplify these genes are listed in S3 Table. The upstream regulatory sequence of PIF4 and coding region were cloned into pCambia1301 with a YFP tag to generate pPIF4::PIF4-YFP vector and confirmed by sequencing.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
