Similar Datasets
Project description:To maintain the balance between long-term stem cell self-renewal and differentiation, dynamic signals need to be translated into spatially precise and temporally stable gene expression states. In the apical plant stem cell system, local accumulation of the small, highly mobile phytohormone auxin triggers differentiation while at the same time, pluripotent stem cells are maintained throughout the entire life-cycle. We find that stem cells are resistant to auxin mediated differentiation, but require low levels of signaling for their maintenance. We demonstrate that the WUSCHEL transcription factor confers this behavior by rheostatically controlling the auxin signaling and response pathway. Finally, we show that WUSCHEL acts via regulation of histone acetylation at target loci, including those with functions in the auxin pathway. Our results reveal an important mechanism that allows cells to differentially translate a potent and highly dynamic developmental signal into stable cell behavior with high spatial precision and temporal robustness.
| S-EPMC6841675 | biostudies-literature
Project description:During development and growth, dynamic signals need to be translated into spatially precise and temporally stable gene expression states, which define cell fate. In the context of the apical plant stem cell system, local accumulation of the small, highly mobile phytohormone auxin triggers organ initiation. Here we show that the WUSCHEL transcription factor locally protects stem cells from differentiation by controlling the auxin signaling and response pathways via regulation of Histone acetylation. Conversely, low levels of signaling are required for stem cell maintenance, demonstrating that WUSCHEL acts as a rheostat on the auxin pathway. Our results reveal an important mechanism that allows cells to differentially translate a potent and highly mobile developmental signal into appropriate cell behavior with high spatial precision and temporal robustness.
2019-11-11 | GSE122610 | GEO
Project description:During development and growth, dynamic signals need to be translated into spatially precise and temporally stable gene expression states, which define cell fate. In the context of the apical plant stem cell system, local accumulation of the small, highly mobile phytohormone auxin triggers organ initiation. Here we show that the WUSCHEL transcription factor locally protects stem cells from differentiation by controlling the auxin signaling and response pathways via regulation of Histone acetylation. Conversely, low levels of signaling are required for stem cell maintenance, demonstrating that WUSCHEL acts as a rheostat on the auxin pathway. Our results reveal an important mechanism that allows cells to differentially translate a potent and highly mobile developmental signal into appropriate cell behavior with high spatial precision and temporal robustness.
2019-11-11 | GSE122579 | GEO
Project description:WUSCHEL acts as a rheostat on the auxin pathway to maintain apical stem cells in Arabidopsis
| PRJNA505703 | ENA
Project description:WUSCHEL acts as a rheostat on the auxin pathway to maintain apical stem cells in Arabidopsis [ChIP-seq]
| PRJNA505666 | ENA
Project description:WUSCHEL acts as a rheostat on the auxin pathway to maintain apical stem cells in Arabidopsis [RNA-seq]
| PRJNA505705 | ENA
Project description:The homeostatic maintenance of stem cells that carry out continuous organogenesis at the shoot meristem is crucial for plant development. Key known factors act to signal between the stem cells and an underlying group of cells thought to act as the stem cell niche. In Arabidopsis thaliana the homeodomain transcription factor WUSCHEL (WUS) is essential for stem cell initiation and maintenance at shoot and flower meristems. Recent data suggest that the WUS protein may move from the niche cells directly into the stem cells to maintain stem cell identity. Here we provide evidence for a second, previously unknown, pathway for stem cell specification at shoot and flower meristems that bypasses the requirement for WUS. We demonstrate that this novel stem cell specification pathway is normally repressed by the activity of the HD-zip III transcription factors PHABULOSA (PHB), PHAVOLUTA (PHV) and CORONA (CNA). When de-repressed, this second stem cell pathway leads to an accumulation of stem cells and an enlargement of the stem cell niche. When de-repressed in a wus mutant background, this second stem cell pathway leads to functional meristems with largely normal cell layering and meristem morphology, activation of WUS cis regulatory elements, and extensive, but not indeterminate, organogenesis. Thus, WUS is largely dispensable for stem cell specification and meristem function, suggesting a set of key stem cell specification factors, competitively regulated by WUS and PHB/PHV/CNA, remain unidentified.
| S-EPMC4444308 | biostudies-literature
Project description:The dynamic maintenance of polar domains in the plasma membrane (PM) is critical for many fundamental processes, e.g., polar cell growth and growth guidance but remains poorly characterized. Rapid tip growth of Arabidopsis pollen tubes requires dynamic distribution of active ROP1 GTPase to the apical domain. Here, we show that clathrin-mediated endocytosis (CME) coordinates lateral REN4 with apical ROP1 signaling. REN4 interacted with but antagonized active ROP1. REN4 also interacts and co-localizes with CME components, but exhibits an opposite role to CME, which removes both REN4 and active ROP1 from the PM. Mathematical modeling shows that REN4 restrains the spatial distribution of active ROP1 and is important for the robustness of polarity control. Hence our results indicate that REN4 acts as a spatiotemporal rheostat by interacting with ROP1 to initiate their removal from the PM by CME, thereby coordinating a dynamic demarcation between apical and lateral domains during rapid tip growth.
| S-EPMC6030205 | biostudies-literature
Project description:The phytohormone auxin plays critical roles in the regulation of plant growth and development. Indole-3-acetic acid (IAA) has been recognized as the major auxin for more than 70 y. Although several pathways have been proposed, how auxin is synthesized in plants is still unclear. Previous genetic and enzymatic studies demonstrated that both TRYPTOPHAN AMINOTRANSFERASE OF ARABIDOPSIS (TAA) and YUCCA (YUC) flavin monooxygenase-like proteins are required for biosynthesis of IAA during plant development, but these enzymes were placed in two independent pathways. In this article, we demonstrate that the TAA family produces indole-3-pyruvic acid (IPA) and the YUC family functions in the conversion of IPA to IAA in Arabidopsis (Arabidopsis thaliana) by a quantification method of IPA using liquid chromatography-electrospray ionization-tandem MS. We further show that YUC protein expressed in Escherichia coli directly converts IPA to IAA. Indole-3-acetaldehyde is probably not a precursor of IAA in the IPA pathway. Our results indicate that YUC proteins catalyze a rate-limiting step of the IPA pathway, which is the main IAA biosynthesis pathway in Arabidopsis.
| S-EPMC3215075 | biostudies-literature
Project description:Plants have a profound capacity to regenerate organs from differentiated somatic tissues, based on which propagating plants in vitro was made possible. Beside its use in biotechnology, in vitro shoot regeneration is also an important system to study de novo organogenesis. Phytohormones and transcription factor WUSCHEL (WUS) play critical roles in this process but whether and how epigenetic modifications are involved is unknown. Here, we report that epigenetic marks of DNA methylation and histone modifications regulate de novo shoot regeneration of Arabidopsis through modulating WUS expression and auxin signaling. First, functional loss of key epigenetic genes-including METHYLTRANSFERASE1 (MET1) encoding for DNA methyltransferase, KRYPTONITE (KYP) for the histone 3 lysine 9 (H3K9) methyltransferase, JMJ14 for the histone 3 lysine 4 (H3K4) demethylase, and HAC1 for the histone acetyltransferase-resulted in altered WUS expression and developmental rates of regenerated shoots in vitro. Second, we showed that regulatory regions of WUS were developmentally regulated by both DNA methylation and histone modifications through bisulfite sequencing and chromatin immunoprecipitation. Third, DNA methylation in the regulatory regions of WUS was lost in the met1 mutant, thus leading to increased WUS expression and its localization. Fourth, we did a genome-wide transcriptional analysis and found out that some of differentially expressed genes between wild type and met1 were involved in signal transduction of the phytohormone auxin. We verified that the increased expression of AUXIN RESPONSE FACTOR3 (ARF3) in met1 indeed was due to DNA demethylation, suggesting DNA methylation regulates de novo shoot regeneration by modulating auxin signaling. We propose that DNA methylation and histone modifications regulate de novo shoot regeneration by modulating WUS expression and auxin signaling. The study demonstrates that, although molecular components involved in organogenesis are divergently evolved in plants and animals, epigenetic modifications play an evolutionarily convergent role in this process.
| S-EPMC3158056 | biostudies-literature