Genome-wide analysis of gene expression in the soybean shoot apical meristem
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ABSTRACT:
ORGANISM(S): Glycine max
PROVIDER: GSE10607 | GEO | 2009/02/20
SECONDARY ACCESSION(S): PRJNA107777
REPOSITORIES: GEO
Similar Datasets
Project description:The transition to flowering is characterized by a shift of the shoot apical meristem (SAM) from leaf production to the initiation of a floral meristem. In this study, we addressed the nature of SAM gene networks involved in the early floral initiation process in the crop legume soybean. Unique aspects (such as pod development and nitrogen fixation) of legume development make them appealing for plant development studies. Soybean, a major oilseed crop, possesses varied maturity groups; hence, understanding and unravelling initial transition control has implications in manipulating crop yield. To this end, we performed global gene expression analysis using Affymetrix® soybean GeneChip® with RNA isolated from micro-dissected soybean SAMs at various time points after plants were shifted from long-day to short-day growth conditions. Analysis of the resulting microarray data revealed a total of 331 transcripts that have differential expression profiles. Intriguingly, about 20% of the transcripts affected by the switch in the development program have orthologs reported to be responsive to abscisic acid (ABA), suggesting an increase in ABA levels in the SAM during this developmental change. A subsequent immunoassay verified this, thereby implicating its possible function as an endogenous signal during the floral evocation process. The striking occurrence of abiotic stress-related transcripts, including trehalose metabolism genes, in SAMs during the early transition to floral meristems points to an overlap of abiotic stress and floral signalling pathways in soybean. In addition, other hormones - auxin, jasmonic acid and brassinosteroids - and a number of candidate protein kinases may also act in the signalling process prior to or concurrently with the induction of the putative floral homeiotic transcripts. This indicates that molecular events mediated by multiple hormonal pathways are part of the mechanism employed by soybean to regulate the floral transition process. Keywords: transcript profiling floral transition soybean shoot apical meristem
2009-01-17 | GSE10251 | GEO
Project description:Plant growth is the result of cell proliferation in the meristems, which requires a dynamic balance between the formation of new tissue and the maintenance of a set of undifferentiated stem cells. There is much that remains unknown about this vital developmental process. In this study, we have reported the generation of 2735 ESTs from three cDNA libraries derived from dissected garden pea (Pisum sativum cv Torsdag) shoot apical meristems. Clustering analysis of the resulting sequences gave rise to 1686 non-redundant ESTs. The unique sequences generated together with 500 other pea transcripts randomly selected from the GenBank pea protein database have been utilized to construct a 2K oligonucleotide array. Using this pea array, we have obtained the transcript profiles of pea shoot apical meristems in comparison to non-apical-meristem tissues. A total of 181 or 174 transcripts were identified to be significantly up- or down-regulated in the pea shoot apical meristem, respectively. As expected, close to 61% of the transcripts down-regulated in the shoot apical mersitem are those retrieved from the public database, whereas sequences from the same source only made up 12% of the genes that were expressed at higher levels in SAMs. This revelation highlights the under-representation of transcripts from the meristmatic tissues in the current public protein database. Manual inspection of the list of up-regulated transcripts reveals the presence of sequences predicted to encode products associated with cell division and proliferation, epigenetic regulation, auxin-mediated responses and miRNA regulation. Similar genes have been implicated in the regulation of plant stem cell activity. Taken together, our EST collection as well as the microarray data provides useful starting points for more in depth analysis of the meristem function and maintenance. Keywords: shoot apical meristem transcript profiling Total RNA was extracted from dissected SAM (approximately 80 SAMs per extraction) or other plant parts (primary stem, primary roots and mature leaves) using Qiagen RNeasy Mini Kit. Four independent tissue collections and RNA extractions (designated A, B, C and D) were performed for each of the microarray hybridization experiment.The Cy5- or Cy3-labelled cDNA was then hybridized to different sector of the chip according to a balanced block design dual label experiment scheme (Cochran & Cox, 1992): Sector 1: Cy3-SAM A vs Cy5-NM A Sector 2: Cy5-SAM B vs Cy3-NM B Sector 3: Cy3-SAM C vs Cy5-NM C Sector 4: Cy5-SAM D vs Cy3-NM D
2010-05-19 | E-GEOD-9278 | biostudies-arrayexpress
Project description:Plant growth is the result of cell proliferation in the meristems, which requires a dynamic balance between the formation of new tissue and the maintenance of a set of undifferentiated stem cells. There is much that remains unknown about this vital developmental process. In this study, we have reported the generation of 2735 ESTs from three cDNA libraries derived from dissected garden pea (Pisum sativum cv Torsdag) shoot apical meristems. Clustering analysis of the resulting sequences gave rise to 1686 non-redundant ESTs. The unique sequences generated together with 500 other pea transcripts randomly selected from the GenBank pea protein database have been utilized to construct a 2K oligonucleotide array. Using this pea array, we have obtained the transcript profiles of pea shoot apical meristems in comparison to non-apical-meristem tissues. A total of 181 or 174 transcripts were identified to be significantly up- or down-regulated in the pea shoot apical meristem, respectively. As expected, close to 61% of the transcripts down-regulated in the shoot apical mersitem are those retrieved from the public database, whereas sequences from the same source only made up 12% of the genes that were expressed at higher levels in SAMs. This revelation highlights the under-representation of transcripts from the meristmatic tissues in the current public protein database. Manual inspection of the list of up-regulated transcripts reveals the presence of sequences predicted to encode products associated with cell division and proliferation, epigenetic regulation, auxin-mediated responses and miRNA regulation. Similar genes have been implicated in the regulation of plant stem cell activity. Taken together, our EST collection as well as the microarray data provides useful starting points for more in depth analysis of the meristem function and maintenance. Keywords: shoot apical meristem transcript profiling
2008-10-01 | GSE9278 | GEO
Project description:All above ground organs of higher plants are ultimately derived from specialized organogenic structures called shoot apical meristems (SAMs). It is comprised of pluripotent stem cells, which divide to regenerate themselves as well as to provide cells to form other organs such as leaves and stems. To study global gene expression in maize SAM and very young primordia (P0 and P1), RNA was extracted from both SAMs (SAMs per se plus P0 and P1) and above-ground portions of seedlings collected from 14-day old B73 seedlings. These RNA samples were labeled and hybridized with cDNA microarrays that have 14,400 informative spots from maize. Statistical analyses showed that approximately 6.3% and 6.5% of the tested genes were significantly (p <0.0001) up- and down-regulated, respectively. Several control genes, whose expressions were confirmed in the maize SAM in the previous studies, were also up-regulated (p <0.01). The significantly up-regulated genes involved many novel transcription factor genes and regulatory genes as well as some kinds of enzymes, suggesting these genes play important roles in meristem maintenance and the early stage of leaf development in maize. Interestingly, several retrotransposon-related genes were greatly up-regulated in the SAM. This finding raised the possibility that retrotransposons are involved in regulatory mechanisms of maize SAM. An experimental aim is to identify genes preferentially expressed in maize SAM by comparing the transcript abundant between SAMs and seedlings using cDNA microarrays that have 14,400 informative spots from maize.
2010-06-25 | E-GEOD-4722 | biostudies-arrayexpress
Project description:At the transition from vegetative to reproductive growth in rice, a developmental program change occurs, resulting in panicle (rice inflorescence) formation. The initial event of the transition is the change of the shoot apical meristem (SAM) to an inflorescence meristem (IM), accompanied by a rapid increase in the meristem size. Suppression of leaf growth also occurs, resulting in the formation of bracts. The IM generates branch meristems (BMs), indeterminate meristems that reiteratively generate next-order meristems. All meristems eventually acquire a determinate spikelet meristem identity and terminate after producing a floret. ABERRANT PANICLE ORGANIZATION2 (APO2) is the rice ortholog of Arabidopsis (Arabidopsis thaliana) LEAFY (LFY), a plant-specific transcription factor. APO2 is a positive regulator of panicle branch formation. Here, we show that APO2 is also required to increase the meristem size of the IM and suppress bract outgrowth. We identified genes directly and indirectly regulated by APO2 and identified APO2-binding sites by ChIP-seq analysis. These analyses showed that APO2 directly controls known regulators of panicle development, including SQUAMOSA PROMOTER BINDING PROTEIN LIKE14 and NECK LEAF1. Furthermore, we revealed that a set of genes act as downstream regulators of APO2 in controlling meristem cell proliferation at the reproductive transition, bract suppression, and panicle branch formation. Our findings indicate that APO2 acts as a master regulator of rice panicle development by regulating multiple steps in the reproductive transition through directly controlling a set of genes.
2024-04-09 | GSE263431 | GEO
Project description:The shoot apical meristem (SAM) of angiosperm plants is a highly organized minute structure that gives rise to all above-ground organs. The SAM is divided into three different functional domains. The central zone (CZ) at the SAM tip harbors the self-renewing pluripotent stem cells and the organizing center, providing daughter cells that are continuously displaced into the interior rib zone (RZ) or to the surrounding peripheral zone (PZ), from which organ primordia are initiated. Despite the constant flow of cells from the CZ into the RZ or PZ, and cell recruitment for primordium formation, a stable balance is maintained between the distinct cell populations in the SAM. Here we combined an in depth phenotypic analysis with a comparative RNA-Seq approach to characterize meristems from selected combinations of clavata3 (clv3), jabba-1D (jba1D) and erecta (er) mutants. We demonstrate that CLV3 restricts meristem expansion along the apical basal axis, while class III HD-ZIP and ER pathways restrict meristem expansion laterally, but in distinct and possibly perpendicular orientations. Our k-means analysis reveals that clv3, jba-1D/+ and er lead to meristem enlargement by affecting different aspects of meristem function, e.g., that clv3 displays increase in stem cell population, whereas jba-1D/+ er exhibits increase in mitotic activity and in meristematic cell population. We demonstrate that thecombination of genetic and mRNA-Seq comparative approach provides a precise and sensitive method to identify cell type specific transcriptomes in a small structure such as the SAM.
2016-04-02 | GSE79839 | GEO
Project description:SHOOTMERISTEMLESS (STM) is a well characterized key regulator of the shoot apical meristem (SAM) activity in diverse plant species. We used a transgenic approach to investigate how the altered expression of Brassica napus (Bn) STM affects the morphology and behavior of microspore-derived embryos (MDEs). Down-regulation of BnSTM repressed the formation of the SAM and reduced the number of MDEs able to regenerate viable plants at germination. This was in contrast to embryos over-expressing BnSTM which displayed enlarged SAMs with an improved regeneration frequency. To further investigate the regulatory mechanisms underpinning these different responses, global changes in transcript levels were analysed in laser micro dissected SAMs of the transformed MDEs. The induction of BnSTM up-regulated the expression of many transcription factors (TFs) some of which directly involved in the formation of the SAM, i.e. CUPSHAPED COTYLEDON1 and WUSCHEL, and regulatory components ofthe antioxidant response, hormone signalling, and cell wall synthesis and modification. Opposite expression patterns for some of these genes were observed in the SAMs of MDEs down-regulating BnSTM. These data were interpreted in relation to the ability of BnSTM to modulate the size and functionality of the SAM. Structural and expression studies were further conducted to confirm the role of BnSTM in mediating the regulatory network of cell wall and lignin synthesis. Besides lowering the transcript levels of early components of cell wall and lignin biosynthetic pathways in the SAM, BnSTM had a remarkable repressing effect on the expression of PHENYLALANINE AMMONIA LYASE2, CINNAMATE 4-4HYDROXYLASE, andCINNAMYL ALCOHOL DEHYDROGENASE. Since lignin formation is a feature of irreversible cell differentiation, these results suggest that one way in which BnSTM promotes indeterminate cell fate may be by preventing the expression of components of biochemical pathways involved in the accumulation of lignin in the meristematic cells. Overall these studies provide evidence for a novel function of BnSTM in enhancing the quality of in vitro produced meristems, and propose that this gene can be used as a potential target to improve regeneration of cultured embryos. 2 mutants and 1 wild type
2012-02-23 | E-GEOD-35992 | biostudies-arrayexpress
Project description:All above ground organs of higher plants are ultimately derived from specialized organogenic structures called shoot apical meristems (SAMs). It is comprised of pluripotent stem cells, which divide to regenerate themselves as well as to provide cells to form other organs such as leaves and stems. To study global gene expression in maize SAM and very young primordia (P0 and P1), RNA was extracted from both whole SAMs (SAMs, P0 and P1) and whole seedlings (above ground part of seedlings) collected from 14-day old B73 seedlings. These RNA samples were labeled and hybridized with cDNA microarrays that have about 30,000 maize cDNA clones. Statistical analyses showed that approximately 7% and 8% of the tested genes were significantly up-regulated and down-regulated, respectively. Several control genes, whose expressions were confirmed in the maize SAM in the previous studies, were significantly up-regulated. Many histone genes and cell cycle related genes were also significantly up-regulated. Those observations validated our microarray results. The significantly up-regulated genes involved many novel transcription factor genes and regulatory genes as well as some kind of enzymes, suggesting those genes play important roles in meristem maintenance and the early stage of leaf development in maize. Surprisingly, several retrotransposon-related genes were greatly up-regulated with the statistical significance. This finding raised the possibility that retrotransposons are involved in regulatory mechanism of maize SAM. An experimental aim is to identify genes preferentially expressed in maize SAM by comparing the transcript abundant between whole SAMs and whole seedlings using cDNA microarrays that have about 30,000 maize cDNA clones.
2010-06-25 | E-GEOD-4004 | biostudies-arrayexpress
Project description:The shoot apical meristem (SAM) of angiosperm plants is a highly organized minute structure that gives rise to all above-ground organs. The SAM is divided into three different functional domains. The central zone (CZ) at the SAM tip harbors the self-renewing pluripotent stem cells and the organizing center, providing daughter cells that are continuously displaced into the interior rib zone (RZ) or to the surrounding peripheral zone (PZ), from which organ primordia are initiated. Despite the constant flow of cells from the CZ into the RZ or PZ, and cell recruitment for primordium formation, a stable balance is maintained between the distinct cell populations in the SAM. Here we combined an in depth phenotypic analysis with a comparative RNA-Seq approach to characterize meristems from selected combinations of clavata3 (clv3), jabba-1D (jba1D) and erecta (er) mutants. We demonstrate that CLV3 restricts meristem expansion along the apical basal axis, while class III HD-ZIP and ER pathways restrict meristem expansion laterally, but in distinct and possibly perpendicular orientations. Our k-means analysis reveals that clv3, jba-1D/+ and er lead to meristem enlargement by affecting different aspects of meristem function, e.g., that clv3 displays increase in stem cell population, whereas jba-1D/+ er exhibits increase in mitotic activity and in meristematic cell population. We demonstrate that thecombination of genetic and mRNA-Seq comparative approach provides a precise and sensitive method to identify cell type specific transcriptomes in a small structure such as the SAM. Ten samples enriched in shoot apical meristem tissue were analyzed, corresponding to 5 different genotypes (Col-0, clv3-2, jba-1D/+, jba-1D/+ er-20, and jba-1D/+ er-20 clv3-2) at two different developmental stages (8-day-old seedlings and 15-day-old seedlings).
2016-04-02 | E-GEOD-79839 | biostudies-arrayexpress
Project description:All above ground organs of higher plants are ultimately derived from shoot apical meristems (SAMs). The SAM exhibits distinctive structural organization, and monocot SAMs such as maize are comprised of two cell layers, a single cell layered tunica (L1) and a corpus (L2). Although recent research has revealed roles of these cell layers in the SAM, intra- and inter-cell-layer signaling networks involved in organ development remain largely unknown except for a few differentially expressed genes. Here, we used Illumnia technology to conduct RNA-seq of L1 and L2 cell layers in maize B73 maize shoot apical meristem.
2013-01-28 | GSE16868 | GEO