Similar Datasets
Project description:In sexually propagating organisms, genetic and epigenetic mutations are evolutionarily relevant only if they occur in the germline and provide inherited information to the next generation. In contrast to most animals, plants are thought to lack an early segregating germline, implying that somatic cells can contribute genetic information to the progeny if they differentiate into meiocytes. Here we demonstrate that two ARGONAUTE proteins, AGO5 and AGO9, are expressed in the reproductive lineage throughout development and mark an early-segregating germline. Furthermore, both AGOs are loaded with dynamic populations of small RNAs derived from highly methylated, pericentromeric, long transposons. Sequencing single nuclei revealed that many of these transposons are highly expressed within a central stem cell domain. This indicates a host-parasite tug of war and specific silencing pathways in plant shoot apical meristems (SAMs). Our results open the path to investigate transposon biology and epigenome dynamics at cellular resolution in the SAM stem cell niche.
2023-09-30 | GSE192606 | GEO
Project description:In sexually propagating organisms, genetic and epigenetic mutations are evolutionarily relevant only if they occur in the germline and provide inherited information to the next generation. In contrast to most animals, plants are thought to lack an early segregating germline, implying that somatic cells can contribute genetic information to the progeny if they differentiate into meiocytes. Here we demonstrate that two ARGONAUTE proteins, AGO5 and AGO9, are expressed in the reproductive lineage throughout development and mark an early-segregating germline. Furthermore, both AGOs are loaded with dynamic populations of small RNAs derived from highly methylated, pericentromeric, long transposons. Sequencing single nuclei revealed that many of these transposons are highly expressed within a central stem cell domain. This indicates a host-parasite tug of war and specific silencing pathways in plant shoot apical meristems (SAMs). Our results open the path to investigate transposon biology and epigenome dynamics at cellular resolution in the SAM stem cell niche.
2023-10-31 | GSE239462 | GEO
Project description:In sexually propagating organisms, genetic and epigenetic mutations are evolutionarily relevant only if they occur in the germline and provide inherited information to the next generation. In contrast to most animals, plants are thought to lack an early segregating germline, implying that somatic cells can contribute genetic information to the progeny if they differentiate into meiocytes. Here we demonstrate that two ARGONAUTE proteins, AGO5 and AGO9, are expressed in the reproductive lineage throughout development and mark an early-segregating germline. Furthermore, both AGOs are loaded with dynamic populations of small RNAs derived from highly methylated, pericentromeric, long transposons. Sequencing single nuclei revealed that many of these transposons are highly expressed within a central stem cell domain. This indicates a host-parasite tug of war and specific silencing pathways in plant shoot apical meristems (SAMs). Our results open the path to investigate transposon biology and epigenome dynamics at cellular resolution in the SAM stem cell niche.
2023-09-30 | GSE192610 | GEO
Project description:In sexually propagating organisms, genetic and epigenetic mutations are evolutionarily relevant only if they occur in the germline and provide inherited information to the next generation. In contrast to most animals, plants are thought to lack an early segregating germline, implying that somatic cells can contribute genetic information to the progeny if they differentiate into meiocytes. Here we demonstrate that two ARGONAUTE proteins, AGO5 and AGO9, are expressed in the reproductive lineage throughout development and mark an early-segregating germline. Furthermore, both AGOs are loaded with dynamic populations of small RNAs derived from highly methylated, pericentromeric, long transposons. Sequencing single nuclei revealed that many of these transposons are highly expressed within a central stem cell domain. This indicates a host-parasite tug of war and specific silencing pathways in plant shoot apical meristems (SAMs). Our results open the path to investigate transposon biology and epigenome dynamics at cellular resolution in the SAM stem cell niche.
2023-09-30 | GSE192608 | GEO
Project description:In sexually propagating organisms, genetic and epigenetic mutations are evolutionarily relevant only if they occur in the germline and provide inherited information to the next generation. In contrast to most animals, plants are thought to lack an early segregating germline, implying that somatic cells can contribute genetic information to the progeny if they differentiate into meiocytes. Here we demonstrate that two ARGONAUTE proteins, AGO5 and AGO9, are expressed in the reproductive lineage throughout development and mark an early-segregating germline. Furthermore, both AGOs are loaded with dynamic populations of small RNAs derived from highly methylated, pericentromeric, long transposons. Sequencing single nuclei revealed that many of these transposons are highly expressed within a central stem cell domain. This indicates a host-parasite tug of war and specific silencing pathways in plant shoot apical meristems (SAMs). Our results open the path to investigate transposon biology and epigenome dynamics at cellular resolution in the SAM stem cell niche.
2023-09-30 | GSE192607 | GEO
Project description:In sexually propagating organisms, genetic and epigenetic mutations are evolutionarily relevant only if they occur in the germline and provide inherited information to the next generation. In contrast to most animals, plants are thought to lack an early segregating germline, implying that somatic cells can contribute genetic information to the progeny if they differentiate into meiocytes. Here we demonstrate that two ARGONAUTE proteins, AGO5 and AGO9, are expressed in the reproductive lineage throughout development and mark an early-segregating germline. Furthermore, both AGOs are loaded with dynamic populations of small RNAs derived from highly methylated, pericentromeric, long transposons. Sequencing single nuclei revealed that many of these transposons are highly expressed within a central stem cell domain. This indicates a host-parasite tug of war and specific silencing pathways in plant shoot apical meristems (SAMs). Our results open the path to investigate transposon biology and epigenome dynamics at cellular resolution in the SAM stem cell niche.
2023-09-30 | GSE192609 | GEO
Project description:The shoot apical meristem (SAM) ensures continuous plant growth and organogenesis. In LD 30 °C, plants lacking AtFTSH4, an ATP-dependent mitochondrial protease that counteracts accumulation of internal oxidative stress, exhibit a puzzling phenotype of premature SAM termination. We aimed to elucidate the underlying cellular and molecular processes that link AtFTSH4 with SAM arrest. We studied AtFTSH4 expression, internal oxidative stress accumulation, and SAM morphology. Directly in the SAM we analysed H2O2 accumulation, mitochondria behaviour, and identity of stem cells using WUS/CLV3 expression. AtFTSH4 was expressed in proliferating tissues, particularly during the reproductive phase. In the mutant, SAM, in which internal oxidative stress accumulates predominantly at 30 °C, lost its meristematic fate. This process was progressive and stage-specific. Premature meristem termination was associated with an expansion in SAM area, where mitochondria lost their functionality. All these effects destabilised the identity of the stem cells. SAM termination in ftsh4 mutants is caused both by internal oxidative stress accumulation with time/age and by the tissue-specific role of AtFTSH4 around the flowering transition. Maintaining mitochondria functionality within the SAM, dependent on AtFTSH4, is vital to preserving stem cell activity throughout development.
| S-EPMC4913265 | biostudies-literature
Project description:WUSCHEL (WUS) protein regulates stem cell function in shoot apical meristem of Arabidopsis. The expression of WUS gene is strictly regulated by developmental cues and environmental factors. As DnaJ domain-containing proteins, SDJ1 and SDJ3 have been proven to play an important role in transcriptional activation of promoter methylated genes. Here, we showed that three DnaJ domain-containing proteins including SDJ1 and SDJ3 can bind WUS protein as a complex, which further maintain the expression of WUS gene by binding to WUS promoter. We propose a model how DnaJ domain-containing proteins are involved in the self-regulation of WUS gene in stem cells maintenance of Arabidopsis.
| S-EPMC7827474 | biostudies-literature
Project description:The stereotypic pattern of cell shapes in the Arabidopsis shoot apical meristem (SAM) suggests that strict rules govern the placement of new walls during cell division. When a cell in the SAM divides, a new wall is built that connects existing walls and divides the cytoplasm of the daughter cells. Because features that are determined by the placement of new walls such as cell size, shape, and number of neighbors are highly regular, rules must exist for maintaining such order. Here we present a quantitative model of these rules that incorporates different observed features of cell division. Each feature is incorporated into a "potential function" that contributes a single term to a total analog of potential energy. New cell walls are predicted to occur at locations where the potential function is minimized. Quantitative terms that represent the well-known historical rules of plant cell division, such as those given by Hofmeister, Errera, and Sachs are developed and evaluated against observed cell divisions in the epidermal layer (L1) of Arabidopsis thaliana SAM. The method is general enough to allow additional terms for nongeometric properties such as internal concentration gradients and mechanical tensile forces.
| S-EPMC4403164 | biostudies-literature
Project description:BACKGROUND:In plants, the shoot apical meristem (SAM) has two main functions, involving the production of all aerial organs on the one hand and self-maintenance on the other, allowing the production of organs during the entire post-embryonic life of the plant. Transcription factors, microRNA, hormones, peptides and forces have been involved in meristem function. Whereas phosphatidylinositol phosphates (PIPs) have been involved in almost all biological functions, including stem cell maintenance and organogenesis in animals, the processes in meristem biology to which PIPs contribute still need to be delineated. RESULTS:Using biosensors for PI4P and PI(4,5)P2, the two most abundant PIPs at the plasma membrane, we reveal that meristem functions are associated with a stereotypical PIP tissue-scale pattern, with PI(4,5)P2 always displaying a more clear-cut pattern than PI4P. Using clavata3 and pin-formed1 mutants, we show that stem cell maintenance is associated with reduced levels of PIPs. In contrast, high PIP levels are signatures for organ-meristem boundaries. Interestingly, this pattern echoes that of cortical microtubules and stress anisotropy at the meristem. Using ablations and pharmacological approaches, we further show that PIP levels can be increased when the tensile stress pattern is altered. Conversely, we find that katanin mutant meristems, with increased isotropy of microtubule arrays and slower response to mechanical perturbations, exhibit reduced PIP gradients within the SAM. Comparable PIP pattern defects were observed in phospholipase A3β overexpressor lines, which largely phenocopy katanin mutants at the whole plant level. CONCLUSIONS:Using phospholipid biosensors, we identified a stereotypical PIP accumulation pattern in the SAM that negatively correlates with stem cell maintenance and positively correlates with organ-boundary establishment. While other cues are very likely to contribute to the final PIP pattern, we provide evidence that the patterns of PIP, cortical microtubules and mechanical stress are positively correlated, suggesting that the PIP pattern, and its reproducibility, relies at least in part on the mechanical status of the SAM.
| S-EPMC5803925 | biostudies-literature