Project description:Genome-wide identification of PIF3-binding sites and direct-target genes of PIF3 transcriptional regulation in skotomorphogenesis [RNA-Seq]
Project description:Genome-wide identification of PIF3-binding sites and direct-target genes of PIF3 transcriptional regulation in skotomorphogenesis [ChIP-Seq]
Project description:Dark-grown seedlings exhibit skotomorphogenic development. Genetic and molecular evidence indicates that a quartet of Arabidopsis Phytochrome (phy)-Interacting bHLH Factors (PIF4, 3, 4 and 5) are critically necessary to maintaining this developmental state, and that light activation of phy induces a switch to photomorphogenic development by inducing rapid degradation of the PIFs. Here, using combined ChIP-seq and RNA-seq analyses, we have identified genes that are direct targets of PIF4 transcriptional regulation, and we provide evidence that the quartet collectively regulate these genes by shared, direct binding to the target promoters in promoting skotomorphogenesis. Three biological replicates data of PIF4-binding sites were collected by comparing the parallel ChIP samples from Myc-epitope-tagged-PIF4 (P1M) overexpressing transgenic seedlings and the wild-type (WT) control.
Project description:Dark-grown seedlings exhibit skotomorphogenic development. Genetic and molecular evidence indicates that a quartet of Arabidopsis Phytochrome (phy)-Interacting bHLH Factors (PIF4, 3, 4 and 5) are critically necessary to maintaining this developmental state, and that light activation of phy induces a switch to photomorphogenic development by inducing rapid degradation of the PIFs. Here, using combined ChIP-seq and RNA-seq analyses, we have identified genes that are direct targets of PIF4 transcriptional regulation, and we provide evidence that the quartet collectively regulate these genes by shared, direct binding to the target promoters in promoting skotomorphogenesis.
Project description:Plant growth is coordinately regulated by environmental and hormonal signals. Brassinosteroid (BR) plays essential roles in growth regulation by light and temperature, but the interactions between BR and these environmental signals remain poorly understood at the molecular level. Here, we show that direct interaction between the dark- and heat-activated transcription factor phytochrome-interacting factor4 (PIF4) and the BR-activated transcription factor BZR1 integrates the hormonal and environmental signals. BZR1 and PIF4 interact with each other in vitro and in vivo, bind to nearly two thousand common target genes, and synergistically regulate many of these target genes, including the PRE family HLH factors required for promoting cell elongation. Genetic analysis indicates that BZR1 and PIFs are interdependent in promoting cell elongation in response to BR, darkness, or heat. These results show that the BZR1-PIF4 interaction controls a core transcription network, allowing plant growth co-regulation by the steroid and environmental signals. Genome-wide identification of PIF4 binding sites in etiolated Arabidopsis seedlings.
Project description:Auxin is a major plant hormone for both development and environmental adaptation. Auxin responses are context dependent and highly modulated by light, temperature, the circadian clock, brassinosteroid, and gibberellin, but the underlying mechanisms remain unclear. Here, we show that auxin signaling integrates with other signals through direct interactions of AUXIN RESPONSE FACTOR6 (ARF6) with PHYTOCHROME INTERACTING FACTOR4 (PIF4), the brassinosteroid-signaling transcription factor BZR1, and the gibberellin-signaling repressor RGA. ChIP-Seq and RNA-Seq experiments show that ARF6, PIF4, and BZR1 bind to largely overlapping targets in the genome and synergistically activate gene expression. In vitro and in vivo assays show that ARF6-promoter binding is enhanced by PIF4 and BZR1 but blocked by RGA. Furthermore, a tripartite HLH/bHLH module feedback regulates PIF activity and thus modulates auxin sensitivity according to additional developmental and environmental cues. Our results demonstrate a central growth-regulation transcriptional network that coordinates hormonal, environmental, and developmental control of cell elongation and plant growth. Genome-wide identification of ARF6 DNA-binding sites in etiolated Arabidopsis seedlings.
