Non-cell autonomous and spatiotemporal signaling from a tissue organizer orchestrates root vascular development
Ontology highlight
ABSTRACT:
ORGANISM(S): Arabidopsis thaliana
PROVIDER: GSE179820 | GEO | 2021/10/10
REPOSITORIES: GEO
Similar Datasets
Project description:Optimal plant growth is hampered by limiting amounts of the essential macronutrient phosphate in most soils. As a response, plant roots produce root hairs to capture this immobile nutrient. Although vital to high-yielding crops, this response remains poorly understood. By generating and exploiting a high spatial and temporal resolution single cell atlas of the Arabidopsis root, we show a remarkable enrichment of TMO5/LHW target genes in root hair epidermal cells. Moreover, these vascular bHLH factors are sufficient to induce a root hair formation response in the epidermal cells, similar as observed during low phosphate conditions, via the downstream cytokinin signaling. We further show that root hair formation under low phosphate conditions is almost absent when TMO5 function or cytokinin signaling is perturbed. In conclusion, cytokinin signaling links the adaptation of roots under low phosphate conditions in the epidermis to perception in vascular cells.
2020-09-18 | GSE141730 | GEO
Project description:As plant cells are fixed within their tissue context, a precise control of cell division orientation is crucial to generate complex three-dimensional organs. The transcription factor complex formed by TARGET OF MONOPTEROS5 (TMO5) and LONESOME HIGHWAY (LHW) triggers a change in cell division orientation leading to radial expansion, at least in part by activating local cytokinin biosynthesis. However, it remains unclear how cytokinin controls these oriented cell divisions. Here, we analyzed the transcriptional responses upon simultaneous induction of both TMO5 and LHW in detail. Using inferred network analysis, we identify AT2G28510/DOF2.1 as a cytokinin-dependent downstream target gene of the TMO5/LHW heterodimer complex. We further show that DOF2.1 is specifically required and sufficient for vascular cell proliferation without inducing other cytokinin-dependent effects such as the inhibition of vascular differentiation. In summary, we have identified DOF2.1 as a TMO5/LHW target gene, specifically responsible for controlling vascular cell proliferation leading to radial expansion.
2019-01-24 | GSE116858 | GEO
Project description:The final size and arrangement of the plant vasculature requires precise adjustment of cell proliferation. In particular, radial growth of vascular bundles is to a large extent controlled by a bHLH transcription factor heterodimer formed by TARGET OF MONOPTEROS5 (TMO5) and LONESOME HIGHWAY (LHW). Excess activity of this TMO5/LHW dimer causes excessive proliferation of vascular cell divisions and thus suggests the existence of a molecular mechanism that restricts its activity in space and time. Here we show that this overproliferation phenotype is similar to acaulis5 (acl5) mutants, suggesting a role for ACL5 in controlling TMO5/LHW activity. We further identify the clade of SAC51-LIKE (SACL) bHLH transcription factors whose translation is regulated by ACL5, as inhibitors of TMO5/LHW activity. We show that SACL proteins interact with LHW impairing activation of downstream targets and alleviating the overproliferation caused by TMO5/LHW misexpression. Given that transcription of SACL genes is induced by TMO5/LHW and its upstream trigger auxin, we propose that SACL proteins represent a feedback mechanism that limits activity of this pathway and controls periclinal cell divisions.
2015-09-01 | GSE70157 | GEO
Project description:The final size and arrangement of the plant vasculature requires precise adjustment of cell proliferation. In particular, radial growth of vascular bundles is to a large extent controlled by a bHLH transcription factor heterodimer formed by TARGET OF MONOPTEROS5 (TMO5) and LONESOME HIGHWAY (LHW). Excess activity of this TMO5/LHW dimer causes excessive proliferation of vascular cell divisions and thus suggests the existence of a molecular mechanism that restricts its activity in space and time. Here we show that this overproliferation phenotype is similar to acaulis5 (acl5) mutants, suggesting a role for ACL5 in controlling TMO5/LHW activity. We further identify the clade of SAC51-LIKE (SACL) bHLH transcription factors whose translation is regulated by ACL5, as inhibitors of TMO5/LHW activity. We show that SACL proteins interact with LHW impairing activation of downstream targets and alleviating the overproliferation caused by TMO5/LHW misexpression. Given that transcription of SACL genes is induced by TMO5/LHW and its upstream trigger auxin, we propose that SACL proteins represent a feedback mechanism that limits activity of this pathway and controls periclinal cell divisions. Three biological replicates were generated per sample. The goal of this experiment is to compare different genotypes that suppress the acl5 mutant as Columbia-0, acl5 + pHS::SACL3 and acl5 ajax2-31, against the acl5 mutant. Every pair of samples that were compared in the same array, were also growth in the same plate. The acl5 + pHS::SACL3 seedlings (and the acl5 ones against they are went compared) were treated to 37C degrees heat shock and then collected at the different times (30 and 210 min) after heat shock. In each comparison 1 or 2 or the replcates were reversed-labeled.
2015-09-01 | E-GEOD-70157 | biostudies-arrayexpress
Project description:This model is from the article:
The influence of cytokinin-auxin cross-regulation on cell-fate determination in Arabidopsis thaliana root development
Muraro D, Byrne H, King J, Voss U, Kieber J, Bennett M.
J Theor Biol.2011 Aug 21;283(1):152-67.
PMID: 21640126,
Abstract:
Root growth and development in Arabidopsis thaliana are sustained by a specialised zone termed the meristem, which contains a population of dividing and differentiating cells that are functionally analogous to a stem cell niche in animals. The hormones auxin and cytokinin control meristem size antagonistically. Local accumulation of auxin promotes cell division and the initiation of a lateral root primordium. By contrast, high cytokinin concentrations disrupt the regular pattern of divisions that characterises lateral root development, and promote differentiation. The way in which the hormones interact is controlled by a genetic regulatory network. In this paper, we propose a deterministic mathematical model to describe this network and present model simulations that reproduce the experimentally observed effects of cytokinin on the expression of auxin regulated genes. We show how auxin response genes and auxin efflux transporters may be affected by the presence of cytokinin. We also analyse and compare the responses of the hormones auxin and cytokinin to changes in their supply with the responses obtained by genetic mutations of SHY2, which encodes a protein that plays a key role in balancing cytokinin and auxin regulation of meristem size. We show that although shy2 mutations can qualitatively reproduce the effect of varying auxin and cytokinin supply on their response genes, some elements of the network respond differently to changes in hormonal supply and to genetic mutations, implying a different, general response of the network. We conclude that an analysis based on the ratio between these two hormones may be misleading and that a mathematical model can serve as a useful tool for stimulate further experimental work by predicting the response of the network to changes in hormone levels and to other genetic mutations.
2012-04-10 | BIOMD0000000416 | BioModels
Project description:Differentiation processes in the primary root meristem are controlled by several signaling pathways that are regulated by phytohormones or by secreted peptides. Long term maintenance of an active root meristem requires that the generation of new root meristem cells and the loss of cells from the meristem due to differentiation is precisely coordinated. Via phenotypic and large scale transcriptome analyses of mutants, we show that the signalling peptide CLE40 and the receptor proteins CLV2 and CRN act in two genetically separable pathways that antagonistically regulate cell differentiation in the proximal root meristem. CLE40 inhibits cell differentiation throughout the primary root meristem by controlling genes with roles in abscisic acid, auxin and cytokinin signalling. CRN and CLV2 jointly control target genes that promote cell differentiation specifically in the transition zone of the proximal root meristem. While CRN and CLV2 are not acting in the CLE40 signaling pathway under normal growth conditions, both proteins are required when the levels of CLE40 or related CLE peptides increase. We show here that two antagonistically acting pathways controlling root meristem differentiation can be activated by the same peptide in a dosage dependent manner. 3 replicates reference(Col-0), clv2-gabi, cle40-2; 2 replicates crn-3
2014-10-02 | E-GEOD-59167 | biostudies-arrayexpress
Project description:Differentiation processes in the primary root meristem are controlled by several signaling pathways that are regulated by phytohormones or by secreted peptides. Long term maintenance of an active root meristem requires that the generation of new root meristem cells and the loss of cells from the meristem due to differentiation is precisely coordinated. Via phenotypic and large scale transcriptome analyses of mutants, we show that the signalling peptide CLE40 and the receptor proteins CLV2 and CRN act in two genetically separable pathways that antagonistically regulate cell differentiation in the proximal root meristem. CLE40 inhibits cell differentiation throughout the primary root meristem by controlling genes with roles in abscisic acid, auxin and cytokinin signalling. CRN and CLV2 jointly control target genes that promote cell differentiation specifically in the transition zone of the proximal root meristem. While CRN and CLV2 are not acting in the CLE40 signaling pathway under normal growth conditions, both proteins are required when the levels of CLE40 or related CLE peptides increase. We show here that two antagonistically acting pathways controlling root meristem differentiation can be activated by the same peptide in a dosage dependent manner.
2014-10-02 | GSE59167 | GEO
Project description:Plant vascular tissues are essential for the existence of land plants. Many studies have revealed the process underlying the development of vascular tissues. However, the initiation of vascular development is still a mystery. LONESOME HIGHWAY (LHW), which encodes a bHLH transcription factor, is expressed in the initial step of vascular development in roots. LHW and TMO5 LIKE1 (T5L1) interact each other and function as a heterodimer. Here, we identified specific genes downstream of LHW-T5L1 with transformed suspension culture cells in microarray experiments. To identify genes downstream of LHW-T5L1, we collected three samples at 0h and 12h with or without estrogen with triplicates.
2014-08-18 | E-GEOD-57860 | biostudies-arrayexpress
Project description:Plant vascular tissues are essential for the existence of land plants. Many studies have revealed the process underlying the development of vascular tissues. However, the initiation of vascular development is still a mystery. LONESOME HIGHWAY (LHW), which encodes a bHLH transcription factor, is expressed in the initial step of vascular development in roots. LHW and TMO5 LIKE1 (T5L1) interact each other and function as a heterodimer. Here, we identified specific genes downstream of LHW-T5L1 with transformed suspension culture cells in microarray experiments.
2014-08-18 | GSE57860 | GEO
Project description:We report the discovery of a root growth program in Arabidopsis that is independent of a functional quiescent center (QC). In this regulatory program, PHABULOSA (PHB), posttranscriptionally regulated by SHR and SCR, plays a central role. In phb shr and phb scr mutants, root meristem/growth activity recovers significantly. Interestingly, this recovery does not accompany the resurgence of QC cells. PHB regulates apical root growth in stele cells of the root meristem, located proximal to the QC. Our genome-wide investigation suggests that PHB exerts its influence on root growth by regulating auxin-cytokinin homeostasis. Apical root growth was restored when cytokinin levels were genetically reduced in the shr mutant. Conversely, when miRNA-resistant PHB was expressed in the root stele cells, apical root growth and meristem functions were significantly inhibited without blocking the QC identity. Taken together, our investigation reveals two mechanisms through which SHR regulates root growth and stem cell activities: one is to specify and maintain the QC and the other is to regulate the proximal meristem activity through PHB and cytokinin. In this regulation, QC seems to be more involved in maintaining the “growth signal” and thus ensure the indeterminate root growth.
2012-12-31 | GSE33015 | GEO