The Experts below are selected from a list of 240 Experts worldwide ranked by ideXlab platform
Stefan De Folter - One of the best experts on this subject based on the ideXlab platform.
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Control of stem cell activity in the carpel margin meristem (CMM) in Arabidopsis
Plant Reproduction, 2019Co-Authors: J. Irepan Reyes-olalde, Stefan De FolterAbstract:Key message Overview of the current understanding of the molecular mechanisms that regulate meristem activity in the CMM compared to the SAM. Abstract Meristems are undifferentiated cells responsible for post-embryonic plant development. The meristems are able to form new organs continuously by carefully balancing between stem cell proliferation and cell differentiation. The plant stem cell niche in each meristem harbors the stem cells that are important to maintain each meristem. The shoot apical meristem (SAM) produces all above-parts of a plant and the molecular mechanisms active in the SAM are actively studied since many years, and models are available. During the reproductive phase of the plant, the inflorescence meristem gives rise to floral meristems, which give rise to the flowers. During floral development, the gynoecium forms that contains a new meristem inside, called the carpel margin meristem (CMM). In Arabidopsis, the gynoecium consists out of two fused Carpels, where the CMM forms along the fused carpel margins. In this review, we focus on the molecular mechanisms taking place in the CMM, and we discuss similarities and differences found in the SAM.
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Control of stem cell activity in the carpel margin meristem (CMM) in Arabidopsis
Sexual Plant Reproduction, 2019Co-Authors: J. Irepan Reyes-olalde, Stefan De FolterAbstract:Overview of the current understanding of the molecular mechanisms that regulate meristem activity in the CMM compared to the SAM. Meristems are undifferentiated cells responsible for post-embryonic plant development. The meristems are able to form new organs continuously by carefully balancing between stem cell proliferation and cell differentiation. The plant stem cell niche in each meristem harbors the stem cells that are important to maintain each meristem. The shoot apical meristem (SAM) produces all above-parts of a plant and the molecular mechanisms active in the SAM are actively studied since many years, and models are available. During the reproductive phase of the plant, the inflorescence meristem gives rise to floral meristems, which give rise to the flowers. During floral development, the gynoecium forms that contains a new meristem inside, called the carpel margin meristem (CMM). In Arabidopsis, the gynoecium consists out of two fused Carpels, where the CMM forms along the fused carpel margins. In this review, we focus on the molecular mechanisms taking place in the CMM, and we discuss similarities and differences found in the SAM.
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Inside the gynoecium: at the carpel margin
Trends in Plant Science, 2013Co-Authors: J. Irepan Reyes-olalde, Victor M. Zúñiga-mayo, Ricardo A. Chávez Montes, Nayelli Marsch-martínez, Stefan De FolterAbstract:The gynoecium, which is produced at the center of most flowers, is the female reproductive organ and consists of one or more Carpels. The Arabidopsis gynoecium consists of two fused Carpels. Its inner tissues possess meristematic characteristics and are called the carpel margin meristem (CMM), because they are located at the margins of the Carpels and generate the ‘marginal' tissues of the gynoecium (placenta, ovules, septum, transmitting tract, style, and stigma). A key question is which factors are guiding the correct development of all these tissues, many of which are essential for reproduction. Besides regulatory genes, hormones play an important part in the development of the marginal tissues, and recent reports have highlighted the role of cytokinins, as discussed in this review.
Chaohai Li - One of the best experts on this subject based on the ideXlab platform.
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development of incompletely fused Carpels in maize ovary revealed by mirna target gene and phytohormone analysis
Frontiers in Plant Science, 2017Co-Authors: Hongping Li, Yufeng Wu, Jianfeng Chang, Qun Wang, Moubiao Zhang, Ting Peng, Guiliang Tang, Chaohai LiAbstract:Although the molecular basis of carpel fusion in maize ovary development remains largely unknown, increasing evidence suggests a critical role of microRNAs (miRNAs). In this study, a combination of miRNA sequencing, degradome and physiological analyses was used to characterize carpel fusion development in maize ovaries showing incompletely (IFC) and completely fused Carpels (CFC). A total of 162 known miRNAs distributed across 33 families were identified, of which 20 were differentially expressed. In addition, 53 miRNA candidates were identified, of which 10 were differentially expressed in the IFC and CFC ovaries. In degradome analysis, a total of 113 and 11 target genes were predicted for the known and novel miRNAs, respectively. Moreover, 24 (60%) target genes of the differentially expressed known miRNAs were found to code transcription factors, including auxin response factor (ARF), TB1-CYC-PCFs (TCP), APETALA2 (AP2), growth regulating factor (GRF), MYB, NAC and NF-YA, all of which have been shown to play a role in carpel fusion development. Correlation analysis of these differentially expressed known miRNAs and their targets with phytohormone signals revealed significant correlations with at least one phytohormone signal, the main regulator of carpel fusion development. These results suggest that incomplete carpel fusion is partly the result of differential expression of certain miRNAs and their targets. Overall, these findings improve our knowledge of the effect of miRNA regulation on target expression, providing a useful resource for further analysis of the interactions between miRNAs, target genes and phytohormones during carpel fusion development in maize.
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differential morphology and transcriptome profile between the incompletely fused Carpels ovary and its wild type in maize
Scientific Reports, 2016Co-Authors: Hongping Li, Yufeng Wu, Yali Zhao, Xiuli Hu, Jianfeng Chang, Qun Wang, Pengfei Dong, Moubiao Zhang, Chaohai LiAbstract:We have isolated a new mutation in maize, incompletely fused Carpels (ifc), which results in an open stylar canal on the ovary and an incomplete pericarp at the top of the kernel. The maize ovary derives from the fusion of three Carpels; however, the molecular networks regulating maize carpel fusion remain largely unclear. In this study, RNA sequencing (RNA-seq) was performed on wild-type (WT) and ifc ovaries that were collected after carpel fusion defects could be morphologically distinguished. In total, 877 differentially expressed genes were identified. Functional analysis revealed overexpression of genes related to “DNA binding”, “transcription regulation”, “hormones”, and “stress responses”. Among the 88 differentially expressed transcription factor (TF) genes, five showed a high degree of conservation (77.7–88.0% amino acid identity) of their conserved domains with genes associated with carpel fusion deficiency in Arabidopsis thaliana, suggesting that these five genes might control carpel fusion in maize. In addition, 30 genes encoding components of hormone synthesis and signaling pathways were differentially expressed between ifc and WT ovaries, indicating complex hormonal regulation during carpel fusion. These results help elucidate the underlying mechanisms that regulate carpel fusion, supporting the functional analysis of genes involved in producing this phenotype.
John L Bowman - One of the best experts on this subject based on the ideXlab platform.
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activation of crabs claw in the nectaries and Carpels of arabidopsis
The Plant Cell, 2005Co-Authors: Stuart F Baum, John Paul Alvarez, Amita Patel, Daniel H Chitwood, John L BowmanAbstract:CRABS CLAW (CRC), a member of the YABBY gene family, is required for nectary and carpel development. To further understand CRC regulation in Arabidopsis thaliana, we performed phylogenetic footprinting analyses of 5′ upstream regions of CRC orthologs from three Brassicaceae species, including Arabidopsis. Phylogenetic footprinting efficiently identified functionally important regulatory regions (modules), indicating that CRC expression is regulated by a combination of positive and negative regulatory elements in the modules. Within the conserved modules, we identified putative binding sites of LEAFY and MADS box proteins, and functional in vivo analyses revealed their importance for CRC expression. Both expression and genetic studies demonstrate that potential binding sites for MADS box proteins within the conserved regions are functionally significant for the transcriptional regulation of CRC in nectaries. We propose that in wild-type flowers, a combination of floral homeotic gene activities, specifically the B class genes APETALA3 and PISTILLATA and the C class gene AGAMOUS act redundantly with each other and in combination with SEPALLATA genes to activate CRC in the nectaries and Carpels. In the absence of B and C class gene activities, other genes such as SHATTERPROOF1/2 can substitute if they are ectopically expressed, as in an A class mutant background (apetala2). These MADS box proteins may provide general floral factors that must work in conjunction with specific factors in the activation of CRC in the nectaries and Carpels.
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distinct mechanisms promote polarity establishment in Carpels of arabidopsis
Cell, 1999Co-Authors: Yuval Eshed, Stuart F Baum, John L BowmanAbstract:Abstract Lateral organs of plants display asymmetry with abaxial identity being specified by members of the Arabidopsis YABBY gene family. Mutations in CRABS CLAW , the founding family member, display ectopic formation of adaxial carpel tissues only when the functions of other genes, such as GYMNOS or KANADI , are also compromised. Mutations in these genes alone do not result in loss of polar differentiation, and therefore, they act redundantly with CRABS CLAW to establish polarity. As GYMNOS encodes a uniformly expressed homolog of the chromatin-remodeling protein, Mi2, we argue that the unique genetic interactions do not reflect a molecular redundancy. Rather, CRABS CLAW regulates transcription spatially, whereas GYMNOS regulates downstream targets temporally to ensure proper differentiation of the Carpels.
J. Irepan Reyes-olalde - One of the best experts on this subject based on the ideXlab platform.
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Control of stem cell activity in the carpel margin meristem (CMM) in Arabidopsis
Plant Reproduction, 2019Co-Authors: J. Irepan Reyes-olalde, Stefan De FolterAbstract:Key message Overview of the current understanding of the molecular mechanisms that regulate meristem activity in the CMM compared to the SAM. Abstract Meristems are undifferentiated cells responsible for post-embryonic plant development. The meristems are able to form new organs continuously by carefully balancing between stem cell proliferation and cell differentiation. The plant stem cell niche in each meristem harbors the stem cells that are important to maintain each meristem. The shoot apical meristem (SAM) produces all above-parts of a plant and the molecular mechanisms active in the SAM are actively studied since many years, and models are available. During the reproductive phase of the plant, the inflorescence meristem gives rise to floral meristems, which give rise to the flowers. During floral development, the gynoecium forms that contains a new meristem inside, called the carpel margin meristem (CMM). In Arabidopsis, the gynoecium consists out of two fused Carpels, where the CMM forms along the fused carpel margins. In this review, we focus on the molecular mechanisms taking place in the CMM, and we discuss similarities and differences found in the SAM.
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Control of stem cell activity in the carpel margin meristem (CMM) in Arabidopsis
Sexual Plant Reproduction, 2019Co-Authors: J. Irepan Reyes-olalde, Stefan De FolterAbstract:Overview of the current understanding of the molecular mechanisms that regulate meristem activity in the CMM compared to the SAM. Meristems are undifferentiated cells responsible for post-embryonic plant development. The meristems are able to form new organs continuously by carefully balancing between stem cell proliferation and cell differentiation. The plant stem cell niche in each meristem harbors the stem cells that are important to maintain each meristem. The shoot apical meristem (SAM) produces all above-parts of a plant and the molecular mechanisms active in the SAM are actively studied since many years, and models are available. During the reproductive phase of the plant, the inflorescence meristem gives rise to floral meristems, which give rise to the flowers. During floral development, the gynoecium forms that contains a new meristem inside, called the carpel margin meristem (CMM). In Arabidopsis, the gynoecium consists out of two fused Carpels, where the CMM forms along the fused carpel margins. In this review, we focus on the molecular mechanisms taking place in the CMM, and we discuss similarities and differences found in the SAM.
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Inside the gynoecium: at the carpel margin
Trends in Plant Science, 2013Co-Authors: J. Irepan Reyes-olalde, Victor M. Zúñiga-mayo, Ricardo A. Chávez Montes, Nayelli Marsch-martínez, Stefan De FolterAbstract:The gynoecium, which is produced at the center of most flowers, is the female reproductive organ and consists of one or more Carpels. The Arabidopsis gynoecium consists of two fused Carpels. Its inner tissues possess meristematic characteristics and are called the carpel margin meristem (CMM), because they are located at the margins of the Carpels and generate the ‘marginal' tissues of the gynoecium (placenta, ovules, septum, transmitting tract, style, and stigma). A key question is which factors are guiding the correct development of all these tissues, many of which are essential for reproduction. Besides regulatory genes, hormones play an important part in the development of the marginal tissues, and recent reports have highlighted the role of cytokinins, as discussed in this review.
William J Lucas - One of the best experts on this subject based on the ideXlab platform.
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establishment of a cell to cell communication pathway between separate Carpels during gynoecium development
Planta, 1995Co-Authors: Chris Van Der Schoot, Margaret A Dietrich, Marc Storms, Judith A Verbeke, William J LucasAbstract:In the evolutionarily advanced angiosperm flower, postgenital fusion is often involved in the formation of the female reproductive organ, the gynoecium. In the present study, we report on the early establishment of a cytoplasmic cell-to-cell communication pathway between the two fusing carpel primordia in Catharanthus roseus L. (periwinkle). Upon carpel contact, diffusible factors move between the two Carpels to initiate the rapid redifferentiation of epidermal cells into parenchymatous cells, resulting in carpel fusion. Microinjection of the lipid-impermeable molecule, Lucifer Yellow CH (LYCH), into cells on either side of the epidermal fusion plane revealed that cytoplasmic continuity was established very early in this redifferentiation process. Electron-microscopic analysis confirmed that this inter-carpel cytoplasmic coupling was established by the formation of plasmodesmata produced between the contacting epidermal cells. The evolution of and role for this inter-carpel communication pathway is discussed in terms of the coordinate development of the gynoecium and its overall effect on reproductive fitness.