Project description:This study identified LEAFY (LFY) as a pioneer transcription factor. We made use of 35S:LFY-GR, an inducible version of the LFY protein fused to the rat glucocorticoid hormone binding domain. In root explants, steroid activated LFY-GR triggers synchronous and abundant flower induction (PMID: 15225291). We combined LFY ChIP-seq, MNase-seq before and after LFY binding and time-course RNA-seq in 35S:LFY-GR root explants to characterize the role of LFY as a pioneer transcription factor.
Project description:This study identified LEAFY (LFY) as a pioneer transcription factor. We made use of 35S:LFY-GR, an inducible version of the LFY protein fused to the rat glucocorticoid hormone binding domain. In root explants, steroid activated LFY-GR triggers synchronous and abundant flower induction (PMID: 15225291). We combined LFY ChIP-seq, MNase-seq before and after LFY binding and time-course RNA-seq in 35S:LFY-GR root explants to characterize the role of LFY as a pioneer transcription factor.
Project description:Wounding is a primary trigger of organ regeneration but how wound stress reactivates cell proliferation and promotes cellular reprogramming remains elusive. In this study we combined the transcriptome analysis with quantitative hormonal analysis to investigate how wounding induces callus formation in Arabidopsis thaliana. Our time-course RNA-seq analysis revealed that wounding induces dynamic transcriptional changes that can be categorized into five clusters with distinct temporal patterns. Gene ontology analyses uncovered that wounding modifies the expression of hormone biosynthesis and response genes, and quantitative analysis of endogenous plant hormones revealed accumulation of cytokinin prior to callus formation. Mutants defective in cytokinin synthesis and signalling display reduced efficiency in callus formation, indicating that de novo synthesis of cytokinin has major contribution in wound-induced callus formation. We further demonstrate that type-A ARABIDOPSIS RESPONSE REGULATOR (ARR)-mediated cytokinin signalling regulates the expression of CYCLIN D3;1 (CYCD3;1) and mutations in CYCD3;1 and its homologs CYCD3;2-3 cause defects in callus formation. Our transcriptome data, in addition, showed that wounding activates multiple developmental regulators, and we found novel roles of ETHYLENE RESPONSE FACTOR 115 (ERF115) and PLETHORA3 (PLT3), PLT5, PLT7 in wound-induced callus formation. Together, this study provides novel mechanistic insights into how wounding reactivates cell proliferation during callus formation.
Project description:This study identified LEAFY (LFY) as a pioneer transcription factor. We made use of 35S:LFY-GR, an inducible version of the LFY protein fused to the rat glucocorticoid hormone binding domain. In root explants, steroid activated LFY-GR triggers synchronous and abundant flower induction (PMID: 15225291). We combined LFY ChIP-seq, MNase-seq before and after LFY binding and time-course RNA-seq in 35S:LFY-GR root explants to characterize the role of LFY as a pioneer transcription factor.