The Experts below are selected from a list of 11205 Experts worldwide ranked by ideXlab platform
Randy D Allen - One of the best experts on this subject based on the ideXlab platform.
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hsi2 val1 silences agl15 to regulate the developmental transition from Seed Maturation to vegetative growth in arabidopsis
The Plant Cell, 2018Co-Authors: Naichong Chen, Vijaykumar Veerappan, Haggag Abdelmageed, Miyoung Kang, Randy D AllenAbstract:Gene expression during Seed development in Arabidopsis thaliana is controlled by transcription factors including LEAFY COTYLEDON1 (LEC1) and LEC2, ABA INSENSITIVE3 (ABI3), FUSCA3 (FUS3), known as LAFL proteins, and AGAMOUS-LIKE15 (AGL15). The transition from Seed Maturation to germination and Seedling growth requires the transcriptional silencing of these Seed Maturation-specific factors leading to downregulation of structural genes including those that encode Seed storage proteins, oleosins, and dehydrins. During Seed germination and vegetative growth, B3-domain protein HSI2/VAL1 is required for the transcriptional silencing of LAFL genes. Here, we report chromatin immunoprecipitation analysis indicating that HSI2/VAL1 binds to the upstream sequences of the AGL15 gene but not at LEC1, ABI3, FUS3, or LEC2 loci. Functional analysis indicates that the HSI2/VAL1 B3 domain interacts with two RY elements upstream of the AGL15 coding region and at least one of them is required for HSI2/VAL1-dependent AGL15 repression. Expression analysis of the major Seed Maturation regulatory genes LEC1, ABI3, FUS3, and LEC2 in different genetic backgrounds demonstrates that HSI2/VAL1 is epistatic to AGL15 and represses the Seed Maturation regulatory program through downregulation of AGL15 by deposition of H3K27me3 at this locus. This hypothesis is further supported by results that show that HSI2/VAL1 physically interacts with the Polycomb Repressive Complex 2 component protein MSI1, which is also enriched at the AGL15 locus.
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HSI2/VAL1 Silences AGL15 to Regulate the Developmental Transition from Seed Maturation to Vegetative Growth in Arabidopsis.
The Plant cell, 2018Co-Authors: Naichong Chen, Vijaykumar Veerappan, Haggag Abdelmageed, Miyoung Kang, Randy D AllenAbstract:Gene expression during Seed development in Arabidopsis thaliana is controlled by transcription factors including LEAFY COTYLEDON1 (LEC1) and LEC2, ABA INSENSITIVE3 (ABI3), FUSCA3 (FUS3), known as LAFL proteins, and AGAMOUS-LIKE15 (AGL15). The transition from Seed Maturation to germination and Seedling growth requires the transcriptional silencing of these Seed Maturation-specific factors leading to downregulation of structural genes including those that encode Seed storage proteins, oleosins, and dehydrins. During Seed germination and vegetative growth, B3-domain protein HSI2/VAL1 is required for the transcriptional silencing of LAFL genes. Here, we report chromatin immunoprecipitation analysis indicating that HSI2/VAL1 binds to the upstream sequences of the AGL15 gene but not at LEC1, ABI3, FUS3, or LEC2 loci. Functional analysis indicates that the HSI2/VAL1 B3 domain interacts with two RY elements upstream of the AGL15 coding region and at least one of them is required for HSI2/VAL1-dependent AGL15 repression. Expression analysis of the major Seed Maturation regulatory genes LEC1, ABI3, FUS3, and LEC2 in different genetic backgrounds demonstrates that HSI2/VAL1 is epistatic to AGL15 and represses the Seed Maturation regulatory program through downregulation of AGL15 by deposition of H3K27me3 at this locus. This hypothesis is further supported by results that show that HSI2/VAL1 physically interacts with the Polycomb Repressive Complex 2 component protein MSI1, which is also enriched at the AGL15 locus.
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HSI2/VAL1 PHD-like domain promotes H3K27 trimethylation to repress the expression of Seed Maturation genes and complex transgenes in Arabidopsis Seedlings
BMC plant biology, 2014Co-Authors: Vijaykumar Veerappan, Naichong Chen, Angelika I Reichert, Randy D AllenAbstract:The novel mutant allele hsi2-4 was isolated in a genetic screen to identify Arabidopsis mutants with constitutively elevated expression of a glutathione S-transferase F8::luciferase (GSTF8::LUC) reporter gene in Arabidopsis. The hsi2-4 mutant harbors a point mutation that affects the plant homeodomain (PHD)-like domain in HIGH-LEVEL EXPRESSION OF SUGAR-INDUCIBLE GENE2 (HSI2)/VIVIPAROUS1/ABI3-LIKE1 (VAL1). In hsi2-4 Seedlings, expression of this LUC transgene and certain endogenous Seed-Maturation genes is constitutively enhanced. The parental reporter line (WT LUC ) that was used for mutagenesis harbors two independent transgene loci, Kan R and Kan S . Both loci express luciferase whereas only the Kan R locus confers resistance to kanamycin. Here we show that both transgene loci harbor multiple tandem insertions at single sites. Luciferase expression from these sites is regulated by the HSI2 PHD-like domain, which is required for the deposition of repressive histone methylation marks (H3K27me3) at both Kan R and Kan S loci. Expression of LUC and Neomycin Phosphotransferase II transgenes is associated with dynamic changes in H3K27me3 levels, and the activation marks H3K4me3 and H3K36me3 but does not appear to involve repressive H3K9me2 marks, DNA methylation or histone deacetylation. However, hsi2-2 and hsi2-4 mutants are partially resistant to growth inhibition associated with exposure to the DNA methylation inhibitor 5-aza-2′-deoxycytidine. HSI2 is also required for the repression of a subset of regulatory and structural Seed Maturation genes in vegetative tissues and H3K27me3 marks associated with most of these genes are also HSI2-dependent. These data implicate HSI2 PHD-like domain in the regulation of gene expression involving histone modifications and DNA methylation-mediated epigenetic mechanisms.
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hsi2 val1 phd like domain promotes h3k27 trimethylation to repress the expression of Seed Maturation genes and complex transgenes in arabidopsis Seedlings
BMC Plant Biology, 2014Co-Authors: Naichong Chen, Vijaykumar Veerappan, Angelika I Reichert, Randy D AllenAbstract:The novel mutant allele hsi2-4 was isolated in a genetic screen to identify Arabidopsis mutants with constitutively elevated expression of a glutathione S-transferase F8::luciferase (GSTF8::LUC) reporter gene in Arabidopsis. The hsi2-4 mutant harbors a point mutation that affects the plant homeodomain (PHD)-like domain in HIGH-LEVEL EXPRESSION OF SUGAR-INDUCIBLE GENE2 (HSI2)/VIVIPAROUS1/ABI3-LIKE1 (VAL1). In hsi2-4 Seedlings, expression of this LUC transgene and certain endogenous Seed-Maturation genes is constitutively enhanced. The parental reporter line (WT LUC ) that was used for mutagenesis harbors two independent transgene loci, Kan R and Kan S . Both loci express luciferase whereas only the Kan R locus confers resistance to kanamycin. Here we show that both transgene loci harbor multiple tandem insertions at single sites. Luciferase expression from these sites is regulated by the HSI2 PHD-like domain, which is required for the deposition of repressive histone methylation marks (H3K27me3) at both Kan R and Kan S loci. Expression of LUC and Neomycin Phosphotransferase II transgenes is associated with dynamic changes in H3K27me3 levels, and the activation marks H3K4me3 and H3K36me3 but does not appear to involve repressive H3K9me2 marks, DNA methylation or histone deacetylation. However, hsi2-2 and hsi2-4 mutants are partially resistant to growth inhibition associated with exposure to the DNA methylation inhibitor 5-aza-2′-deoxycytidine. HSI2 is also required for the repression of a subset of regulatory and structural Seed Maturation genes in vegetative tissues and H3K27me3 marks associated with most of these genes are also HSI2-dependent. These data implicate HSI2 PHD-like domain in the regulation of gene expression involving histone modifications and DNA methylation-mediated epigenetic mechanisms.
Belay T. Ayele - One of the best experts on this subject based on the ideXlab platform.
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Transcriptomics of cytokinin and auxin metabolism and signaling genes during Seed Maturation in dormant and non-dormant wheat genotypes.
Scientific reports, 2019Co-Authors: Pham Anh Tuan, Yuji Yamasaki, Yuri Kanno, Mitsunori Seo, Belay T. AyeleAbstract:To gain insights into the roles of cytokinin (CK) and auxin in regulating dormancy during Seed Maturation in wheat, we examined changes in the levels of CK and indole-3-acetic acid (IAA) and expression patterns of their metabolism and signaling genes in embryonic and endospermic tissues of dormant and non-dormant genotypes. Seed Maturation was associated with a decrease in the levels of isopentenyladenine in both tissues mainly via repression of the CK biosynthetic TaLOG genes. Differential embryonic trans-zeatin content and expression patterns of the CK related genes including TacZOG, TaGLU and TaARR12 between maturing Seeds of the two genotypes implicate CK in the control of Seed dormancy induction and maintenance. Seed Maturation induced a decrease of IAA level in both tissues irrespective of genotype, and this appeared to be mediated by repression of specific IAA biosynthesis, transport and IAA-conjugate hydrolysis genes. The differential embryonic IAA content and expression pattern of the IAA biosynthetic gene TaAO during the early stage of Seed Maturation between the two genotypes imply the role of IAA in dormancy induction. It appears from our data that the expression of specific auxin signaling genes including TaRUB, TaAXR and TaARF mediate the role of auxin signaling in dormancy induction and maintenance during Seed Maturation in wheat.
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Seed Maturation associated transcriptional programs and regulatory networks underlying genotypic difference in Seed dormancy and size/weight in wheat (Triticum aestivum L.)
BMC Plant Biology, 2017Co-Authors: Yuji Yamasaki, Mark C. Jordan, Feng Gao, Belay T. AyeleAbstract:BackgroundMaturation forms one of the critical Seed developmental phases and it is characterized mainly by programmed cell death, dormancy and desiccation, however, the transcriptional programs and regulatory networks underlying acquisition of dormancy and deposition of storage reserves during the Maturation phase of Seed development are poorly understood in wheat. The present study performed comparative spatiotemporal transcriptomic analysis of Seed Maturation in two wheat genotypes with contrasting Seed weight/size and dormancy phenotype.ResultsThe embryo and endosperm tissues of maturing Seeds appeared to exhibit genotype-specific temporal shifts in gene expression profile that might contribute to the Seed phenotypic variations. Functional annotations of gene clusters suggest that the two tissues exhibit distinct but genotypically overlapping molecular functions. Motif enrichment predicts genotypically distinct abscisic acid (ABA) and gibberellin (GA) regulated transcriptional networks contribute to the contrasting Seed weight/size and dormancy phenotypes between the two genotypes. While other ABA responsive element (ABRE) motifs are enriched in both genotypes, the prevalence of G-box-like motif specifically in tissues of the dormant genotype suggests distinct ABA mediated transcriptional mechanisms control the establishment of dormancy during Seed Maturation. In agreement with this, the bZIP transcription factors that co-express with ABRE enriched embryonic genes differ with genotype. The enrichment of SITEIIATCYTC motif specifically in embryo clusters of maturing Seeds irrespective of genotype predicts a tissue specific role for the respective TCP transcription factors with no or minimal contribution to the variations in Seed dormancy.ConclusionThe results of this study advance our understanding of the Seed Maturation associated molecular mechanisms underlying variation in dormancy and weight/size in wheat Seeds, which is a critical step towards the designing of molecular strategies for enhancing Seed yield and quality.
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Seed Maturation associated transcriptional programs and regulatory networks underlying genotypic difference in Seed dormancy and size/weight in wheat (Triticum aestivum L.).
BMC plant biology, 2017Co-Authors: Yuji Yamasaki, Mark C. Jordan, Feng Gao, Belay T. AyeleAbstract:Maturation forms one of the critical Seed developmental phases and it is characterized mainly by programmed cell death, dormancy and desiccation, however, the transcriptional programs and regulatory networks underlying acquisition of dormancy and deposition of storage reserves during the Maturation phase of Seed development are poorly understood in wheat. The present study performed comparative spatiotemporal transcriptomic analysis of Seed Maturation in two wheat genotypes with contrasting Seed weight/size and dormancy phenotype. The embryo and endosperm tissues of maturing Seeds appeared to exhibit genotype-specific temporal shifts in gene expression profile that might contribute to the Seed phenotypic variations. Functional annotations of gene clusters suggest that the two tissues exhibit distinct but genotypically overlapping molecular functions. Motif enrichment predicts genotypically distinct abscisic acid (ABA) and gibberellin (GA) regulated transcriptional networks contribute to the contrasting Seed weight/size and dormancy phenotypes between the two genotypes. While other ABA responsive element (ABRE) motifs are enriched in both genotypes, the prevalence of G-box-like motif specifically in tissues of the dormant genotype suggests distinct ABA mediated transcriptional mechanisms control the establishment of dormancy during Seed Maturation. In agreement with this, the bZIP transcription factors that co-express with ABRE enriched embryonic genes differ with genotype. The enrichment of SITEIIATCYTC motif specifically in embryo clusters of maturing Seeds irrespective of genotype predicts a tissue specific role for the respective TCP transcription factors with no or minimal contribution to the variations in Seed dormancy. The results of this study advance our understanding of the Seed Maturation associated molecular mechanisms underlying variation in dormancy and weight/size in wheat Seeds, which is a critical step towards the designing of molecular strategies for enhancing Seed yield and quality.
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Seed Maturation associated transcriptional programs and regulatory networks underlying genotypic difference in Seed dormancy and size weight in wheat triticum aestivum l
BMC Plant Biology, 2017Co-Authors: Yuji Yamasaki, Mark C. Jordan, Feng Gao, Belay T. AyeleAbstract:Maturation forms one of the critical Seed developmental phases and it is characterized mainly by programmed cell death, dormancy and desiccation, however, the transcriptional programs and regulatory networks underlying acquisition of dormancy and deposition of storage reserves during the Maturation phase of Seed development are poorly understood in wheat. The present study performed comparative spatiotemporal transcriptomic analysis of Seed Maturation in two wheat genotypes with contrasting Seed weight/size and dormancy phenotype. The embryo and endosperm tissues of maturing Seeds appeared to exhibit genotype-specific temporal shifts in gene expression profile that might contribute to the Seed phenotypic variations. Functional annotations of gene clusters suggest that the two tissues exhibit distinct but genotypically overlapping molecular functions. Motif enrichment predicts genotypically distinct abscisic acid (ABA) and gibberellin (GA) regulated transcriptional networks contribute to the contrasting Seed weight/size and dormancy phenotypes between the two genotypes. While other ABA responsive element (ABRE) motifs are enriched in both genotypes, the prevalence of G-box-like motif specifically in tissues of the dormant genotype suggests distinct ABA mediated transcriptional mechanisms control the establishment of dormancy during Seed Maturation. In agreement with this, the bZIP transcription factors that co-express with ABRE enriched embryonic genes differ with genotype. The enrichment of SITEIIATCYTC motif specifically in embryo clusters of maturing Seeds irrespective of genotype predicts a tissue specific role for the respective TCP transcription factors with no or minimal contribution to the variations in Seed dormancy. The results of this study advance our understanding of the Seed Maturation associated molecular mechanisms underlying variation in dormancy and weight/size in wheat Seeds, which is a critical step towards the designing of molecular strategies for enhancing Seed yield and quality.
Vijaykumar Veerappan - One of the best experts on this subject based on the ideXlab platform.
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hsi2 val1 silences agl15 to regulate the developmental transition from Seed Maturation to vegetative growth in arabidopsis
The Plant Cell, 2018Co-Authors: Naichong Chen, Vijaykumar Veerappan, Haggag Abdelmageed, Miyoung Kang, Randy D AllenAbstract:Gene expression during Seed development in Arabidopsis thaliana is controlled by transcription factors including LEAFY COTYLEDON1 (LEC1) and LEC2, ABA INSENSITIVE3 (ABI3), FUSCA3 (FUS3), known as LAFL proteins, and AGAMOUS-LIKE15 (AGL15). The transition from Seed Maturation to germination and Seedling growth requires the transcriptional silencing of these Seed Maturation-specific factors leading to downregulation of structural genes including those that encode Seed storage proteins, oleosins, and dehydrins. During Seed germination and vegetative growth, B3-domain protein HSI2/VAL1 is required for the transcriptional silencing of LAFL genes. Here, we report chromatin immunoprecipitation analysis indicating that HSI2/VAL1 binds to the upstream sequences of the AGL15 gene but not at LEC1, ABI3, FUS3, or LEC2 loci. Functional analysis indicates that the HSI2/VAL1 B3 domain interacts with two RY elements upstream of the AGL15 coding region and at least one of them is required for HSI2/VAL1-dependent AGL15 repression. Expression analysis of the major Seed Maturation regulatory genes LEC1, ABI3, FUS3, and LEC2 in different genetic backgrounds demonstrates that HSI2/VAL1 is epistatic to AGL15 and represses the Seed Maturation regulatory program through downregulation of AGL15 by deposition of H3K27me3 at this locus. This hypothesis is further supported by results that show that HSI2/VAL1 physically interacts with the Polycomb Repressive Complex 2 component protein MSI1, which is also enriched at the AGL15 locus.
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HSI2/VAL1 Silences AGL15 to Regulate the Developmental Transition from Seed Maturation to Vegetative Growth in Arabidopsis.
The Plant cell, 2018Co-Authors: Naichong Chen, Vijaykumar Veerappan, Haggag Abdelmageed, Miyoung Kang, Randy D AllenAbstract:Gene expression during Seed development in Arabidopsis thaliana is controlled by transcription factors including LEAFY COTYLEDON1 (LEC1) and LEC2, ABA INSENSITIVE3 (ABI3), FUSCA3 (FUS3), known as LAFL proteins, and AGAMOUS-LIKE15 (AGL15). The transition from Seed Maturation to germination and Seedling growth requires the transcriptional silencing of these Seed Maturation-specific factors leading to downregulation of structural genes including those that encode Seed storage proteins, oleosins, and dehydrins. During Seed germination and vegetative growth, B3-domain protein HSI2/VAL1 is required for the transcriptional silencing of LAFL genes. Here, we report chromatin immunoprecipitation analysis indicating that HSI2/VAL1 binds to the upstream sequences of the AGL15 gene but not at LEC1, ABI3, FUS3, or LEC2 loci. Functional analysis indicates that the HSI2/VAL1 B3 domain interacts with two RY elements upstream of the AGL15 coding region and at least one of them is required for HSI2/VAL1-dependent AGL15 repression. Expression analysis of the major Seed Maturation regulatory genes LEC1, ABI3, FUS3, and LEC2 in different genetic backgrounds demonstrates that HSI2/VAL1 is epistatic to AGL15 and represses the Seed Maturation regulatory program through downregulation of AGL15 by deposition of H3K27me3 at this locus. This hypothesis is further supported by results that show that HSI2/VAL1 physically interacts with the Polycomb Repressive Complex 2 component protein MSI1, which is also enriched at the AGL15 locus.
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HSI2/VAL1 PHD-like domain promotes H3K27 trimethylation to repress the expression of Seed Maturation genes and complex transgenes in Arabidopsis Seedlings
BMC plant biology, 2014Co-Authors: Vijaykumar Veerappan, Naichong Chen, Angelika I Reichert, Randy D AllenAbstract:The novel mutant allele hsi2-4 was isolated in a genetic screen to identify Arabidopsis mutants with constitutively elevated expression of a glutathione S-transferase F8::luciferase (GSTF8::LUC) reporter gene in Arabidopsis. The hsi2-4 mutant harbors a point mutation that affects the plant homeodomain (PHD)-like domain in HIGH-LEVEL EXPRESSION OF SUGAR-INDUCIBLE GENE2 (HSI2)/VIVIPAROUS1/ABI3-LIKE1 (VAL1). In hsi2-4 Seedlings, expression of this LUC transgene and certain endogenous Seed-Maturation genes is constitutively enhanced. The parental reporter line (WT LUC ) that was used for mutagenesis harbors two independent transgene loci, Kan R and Kan S . Both loci express luciferase whereas only the Kan R locus confers resistance to kanamycin. Here we show that both transgene loci harbor multiple tandem insertions at single sites. Luciferase expression from these sites is regulated by the HSI2 PHD-like domain, which is required for the deposition of repressive histone methylation marks (H3K27me3) at both Kan R and Kan S loci. Expression of LUC and Neomycin Phosphotransferase II transgenes is associated with dynamic changes in H3K27me3 levels, and the activation marks H3K4me3 and H3K36me3 but does not appear to involve repressive H3K9me2 marks, DNA methylation or histone deacetylation. However, hsi2-2 and hsi2-4 mutants are partially resistant to growth inhibition associated with exposure to the DNA methylation inhibitor 5-aza-2′-deoxycytidine. HSI2 is also required for the repression of a subset of regulatory and structural Seed Maturation genes in vegetative tissues and H3K27me3 marks associated with most of these genes are also HSI2-dependent. These data implicate HSI2 PHD-like domain in the regulation of gene expression involving histone modifications and DNA methylation-mediated epigenetic mechanisms.
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hsi2 val1 phd like domain promotes h3k27 trimethylation to repress the expression of Seed Maturation genes and complex transgenes in arabidopsis Seedlings
BMC Plant Biology, 2014Co-Authors: Naichong Chen, Vijaykumar Veerappan, Angelika I Reichert, Randy D AllenAbstract:The novel mutant allele hsi2-4 was isolated in a genetic screen to identify Arabidopsis mutants with constitutively elevated expression of a glutathione S-transferase F8::luciferase (GSTF8::LUC) reporter gene in Arabidopsis. The hsi2-4 mutant harbors a point mutation that affects the plant homeodomain (PHD)-like domain in HIGH-LEVEL EXPRESSION OF SUGAR-INDUCIBLE GENE2 (HSI2)/VIVIPAROUS1/ABI3-LIKE1 (VAL1). In hsi2-4 Seedlings, expression of this LUC transgene and certain endogenous Seed-Maturation genes is constitutively enhanced. The parental reporter line (WT LUC ) that was used for mutagenesis harbors two independent transgene loci, Kan R and Kan S . Both loci express luciferase whereas only the Kan R locus confers resistance to kanamycin. Here we show that both transgene loci harbor multiple tandem insertions at single sites. Luciferase expression from these sites is regulated by the HSI2 PHD-like domain, which is required for the deposition of repressive histone methylation marks (H3K27me3) at both Kan R and Kan S loci. Expression of LUC and Neomycin Phosphotransferase II transgenes is associated with dynamic changes in H3K27me3 levels, and the activation marks H3K4me3 and H3K36me3 but does not appear to involve repressive H3K9me2 marks, DNA methylation or histone deacetylation. However, hsi2-2 and hsi2-4 mutants are partially resistant to growth inhibition associated with exposure to the DNA methylation inhibitor 5-aza-2′-deoxycytidine. HSI2 is also required for the repression of a subset of regulatory and structural Seed Maturation genes in vegetative tissues and H3K27me3 marks associated with most of these genes are also HSI2-dependent. These data implicate HSI2 PHD-like domain in the regulation of gene expression involving histone modifications and DNA methylation-mediated epigenetic mechanisms.
Naichong Chen - One of the best experts on this subject based on the ideXlab platform.
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hsi2 val1 silences agl15 to regulate the developmental transition from Seed Maturation to vegetative growth in arabidopsis
The Plant Cell, 2018Co-Authors: Naichong Chen, Vijaykumar Veerappan, Haggag Abdelmageed, Miyoung Kang, Randy D AllenAbstract:Gene expression during Seed development in Arabidopsis thaliana is controlled by transcription factors including LEAFY COTYLEDON1 (LEC1) and LEC2, ABA INSENSITIVE3 (ABI3), FUSCA3 (FUS3), known as LAFL proteins, and AGAMOUS-LIKE15 (AGL15). The transition from Seed Maturation to germination and Seedling growth requires the transcriptional silencing of these Seed Maturation-specific factors leading to downregulation of structural genes including those that encode Seed storage proteins, oleosins, and dehydrins. During Seed germination and vegetative growth, B3-domain protein HSI2/VAL1 is required for the transcriptional silencing of LAFL genes. Here, we report chromatin immunoprecipitation analysis indicating that HSI2/VAL1 binds to the upstream sequences of the AGL15 gene but not at LEC1, ABI3, FUS3, or LEC2 loci. Functional analysis indicates that the HSI2/VAL1 B3 domain interacts with two RY elements upstream of the AGL15 coding region and at least one of them is required for HSI2/VAL1-dependent AGL15 repression. Expression analysis of the major Seed Maturation regulatory genes LEC1, ABI3, FUS3, and LEC2 in different genetic backgrounds demonstrates that HSI2/VAL1 is epistatic to AGL15 and represses the Seed Maturation regulatory program through downregulation of AGL15 by deposition of H3K27me3 at this locus. This hypothesis is further supported by results that show that HSI2/VAL1 physically interacts with the Polycomb Repressive Complex 2 component protein MSI1, which is also enriched at the AGL15 locus.
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HSI2/VAL1 Silences AGL15 to Regulate the Developmental Transition from Seed Maturation to Vegetative Growth in Arabidopsis.
The Plant cell, 2018Co-Authors: Naichong Chen, Vijaykumar Veerappan, Haggag Abdelmageed, Miyoung Kang, Randy D AllenAbstract:Gene expression during Seed development in Arabidopsis thaliana is controlled by transcription factors including LEAFY COTYLEDON1 (LEC1) and LEC2, ABA INSENSITIVE3 (ABI3), FUSCA3 (FUS3), known as LAFL proteins, and AGAMOUS-LIKE15 (AGL15). The transition from Seed Maturation to germination and Seedling growth requires the transcriptional silencing of these Seed Maturation-specific factors leading to downregulation of structural genes including those that encode Seed storage proteins, oleosins, and dehydrins. During Seed germination and vegetative growth, B3-domain protein HSI2/VAL1 is required for the transcriptional silencing of LAFL genes. Here, we report chromatin immunoprecipitation analysis indicating that HSI2/VAL1 binds to the upstream sequences of the AGL15 gene but not at LEC1, ABI3, FUS3, or LEC2 loci. Functional analysis indicates that the HSI2/VAL1 B3 domain interacts with two RY elements upstream of the AGL15 coding region and at least one of them is required for HSI2/VAL1-dependent AGL15 repression. Expression analysis of the major Seed Maturation regulatory genes LEC1, ABI3, FUS3, and LEC2 in different genetic backgrounds demonstrates that HSI2/VAL1 is epistatic to AGL15 and represses the Seed Maturation regulatory program through downregulation of AGL15 by deposition of H3K27me3 at this locus. This hypothesis is further supported by results that show that HSI2/VAL1 physically interacts with the Polycomb Repressive Complex 2 component protein MSI1, which is also enriched at the AGL15 locus.
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HSI2/VAL1 PHD-like domain promotes H3K27 trimethylation to repress the expression of Seed Maturation genes and complex transgenes in Arabidopsis Seedlings
BMC plant biology, 2014Co-Authors: Vijaykumar Veerappan, Naichong Chen, Angelika I Reichert, Randy D AllenAbstract:The novel mutant allele hsi2-4 was isolated in a genetic screen to identify Arabidopsis mutants with constitutively elevated expression of a glutathione S-transferase F8::luciferase (GSTF8::LUC) reporter gene in Arabidopsis. The hsi2-4 mutant harbors a point mutation that affects the plant homeodomain (PHD)-like domain in HIGH-LEVEL EXPRESSION OF SUGAR-INDUCIBLE GENE2 (HSI2)/VIVIPAROUS1/ABI3-LIKE1 (VAL1). In hsi2-4 Seedlings, expression of this LUC transgene and certain endogenous Seed-Maturation genes is constitutively enhanced. The parental reporter line (WT LUC ) that was used for mutagenesis harbors two independent transgene loci, Kan R and Kan S . Both loci express luciferase whereas only the Kan R locus confers resistance to kanamycin. Here we show that both transgene loci harbor multiple tandem insertions at single sites. Luciferase expression from these sites is regulated by the HSI2 PHD-like domain, which is required for the deposition of repressive histone methylation marks (H3K27me3) at both Kan R and Kan S loci. Expression of LUC and Neomycin Phosphotransferase II transgenes is associated with dynamic changes in H3K27me3 levels, and the activation marks H3K4me3 and H3K36me3 but does not appear to involve repressive H3K9me2 marks, DNA methylation or histone deacetylation. However, hsi2-2 and hsi2-4 mutants are partially resistant to growth inhibition associated with exposure to the DNA methylation inhibitor 5-aza-2′-deoxycytidine. HSI2 is also required for the repression of a subset of regulatory and structural Seed Maturation genes in vegetative tissues and H3K27me3 marks associated with most of these genes are also HSI2-dependent. These data implicate HSI2 PHD-like domain in the regulation of gene expression involving histone modifications and DNA methylation-mediated epigenetic mechanisms.
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hsi2 val1 phd like domain promotes h3k27 trimethylation to repress the expression of Seed Maturation genes and complex transgenes in arabidopsis Seedlings
BMC Plant Biology, 2014Co-Authors: Naichong Chen, Vijaykumar Veerappan, Angelika I Reichert, Randy D AllenAbstract:The novel mutant allele hsi2-4 was isolated in a genetic screen to identify Arabidopsis mutants with constitutively elevated expression of a glutathione S-transferase F8::luciferase (GSTF8::LUC) reporter gene in Arabidopsis. The hsi2-4 mutant harbors a point mutation that affects the plant homeodomain (PHD)-like domain in HIGH-LEVEL EXPRESSION OF SUGAR-INDUCIBLE GENE2 (HSI2)/VIVIPAROUS1/ABI3-LIKE1 (VAL1). In hsi2-4 Seedlings, expression of this LUC transgene and certain endogenous Seed-Maturation genes is constitutively enhanced. The parental reporter line (WT LUC ) that was used for mutagenesis harbors two independent transgene loci, Kan R and Kan S . Both loci express luciferase whereas only the Kan R locus confers resistance to kanamycin. Here we show that both transgene loci harbor multiple tandem insertions at single sites. Luciferase expression from these sites is regulated by the HSI2 PHD-like domain, which is required for the deposition of repressive histone methylation marks (H3K27me3) at both Kan R and Kan S loci. Expression of LUC and Neomycin Phosphotransferase II transgenes is associated with dynamic changes in H3K27me3 levels, and the activation marks H3K4me3 and H3K36me3 but does not appear to involve repressive H3K9me2 marks, DNA methylation or histone deacetylation. However, hsi2-2 and hsi2-4 mutants are partially resistant to growth inhibition associated with exposure to the DNA methylation inhibitor 5-aza-2′-deoxycytidine. HSI2 is also required for the repression of a subset of regulatory and structural Seed Maturation genes in vegetative tissues and H3K27me3 marks associated with most of these genes are also HSI2-dependent. These data implicate HSI2 PHD-like domain in the regulation of gene expression involving histone modifications and DNA methylation-mediated epigenetic mechanisms.
Yuji Yamasaki - One of the best experts on this subject based on the ideXlab platform.
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Transcriptomics of cytokinin and auxin metabolism and signaling genes during Seed Maturation in dormant and non-dormant wheat genotypes.
Scientific reports, 2019Co-Authors: Pham Anh Tuan, Yuji Yamasaki, Yuri Kanno, Mitsunori Seo, Belay T. AyeleAbstract:To gain insights into the roles of cytokinin (CK) and auxin in regulating dormancy during Seed Maturation in wheat, we examined changes in the levels of CK and indole-3-acetic acid (IAA) and expression patterns of their metabolism and signaling genes in embryonic and endospermic tissues of dormant and non-dormant genotypes. Seed Maturation was associated with a decrease in the levels of isopentenyladenine in both tissues mainly via repression of the CK biosynthetic TaLOG genes. Differential embryonic trans-zeatin content and expression patterns of the CK related genes including TacZOG, TaGLU and TaARR12 between maturing Seeds of the two genotypes implicate CK in the control of Seed dormancy induction and maintenance. Seed Maturation induced a decrease of IAA level in both tissues irrespective of genotype, and this appeared to be mediated by repression of specific IAA biosynthesis, transport and IAA-conjugate hydrolysis genes. The differential embryonic IAA content and expression pattern of the IAA biosynthetic gene TaAO during the early stage of Seed Maturation between the two genotypes imply the role of IAA in dormancy induction. It appears from our data that the expression of specific auxin signaling genes including TaRUB, TaAXR and TaARF mediate the role of auxin signaling in dormancy induction and maintenance during Seed Maturation in wheat.
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Seed Maturation associated transcriptional programs and regulatory networks underlying genotypic difference in Seed dormancy and size/weight in wheat (Triticum aestivum L.)
BMC Plant Biology, 2017Co-Authors: Yuji Yamasaki, Mark C. Jordan, Feng Gao, Belay T. AyeleAbstract:BackgroundMaturation forms one of the critical Seed developmental phases and it is characterized mainly by programmed cell death, dormancy and desiccation, however, the transcriptional programs and regulatory networks underlying acquisition of dormancy and deposition of storage reserves during the Maturation phase of Seed development are poorly understood in wheat. The present study performed comparative spatiotemporal transcriptomic analysis of Seed Maturation in two wheat genotypes with contrasting Seed weight/size and dormancy phenotype.ResultsThe embryo and endosperm tissues of maturing Seeds appeared to exhibit genotype-specific temporal shifts in gene expression profile that might contribute to the Seed phenotypic variations. Functional annotations of gene clusters suggest that the two tissues exhibit distinct but genotypically overlapping molecular functions. Motif enrichment predicts genotypically distinct abscisic acid (ABA) and gibberellin (GA) regulated transcriptional networks contribute to the contrasting Seed weight/size and dormancy phenotypes between the two genotypes. While other ABA responsive element (ABRE) motifs are enriched in both genotypes, the prevalence of G-box-like motif specifically in tissues of the dormant genotype suggests distinct ABA mediated transcriptional mechanisms control the establishment of dormancy during Seed Maturation. In agreement with this, the bZIP transcription factors that co-express with ABRE enriched embryonic genes differ with genotype. The enrichment of SITEIIATCYTC motif specifically in embryo clusters of maturing Seeds irrespective of genotype predicts a tissue specific role for the respective TCP transcription factors with no or minimal contribution to the variations in Seed dormancy.ConclusionThe results of this study advance our understanding of the Seed Maturation associated molecular mechanisms underlying variation in dormancy and weight/size in wheat Seeds, which is a critical step towards the designing of molecular strategies for enhancing Seed yield and quality.
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Seed Maturation associated transcriptional programs and regulatory networks underlying genotypic difference in Seed dormancy and size/weight in wheat (Triticum aestivum L.).
BMC plant biology, 2017Co-Authors: Yuji Yamasaki, Mark C. Jordan, Feng Gao, Belay T. AyeleAbstract:Maturation forms one of the critical Seed developmental phases and it is characterized mainly by programmed cell death, dormancy and desiccation, however, the transcriptional programs and regulatory networks underlying acquisition of dormancy and deposition of storage reserves during the Maturation phase of Seed development are poorly understood in wheat. The present study performed comparative spatiotemporal transcriptomic analysis of Seed Maturation in two wheat genotypes with contrasting Seed weight/size and dormancy phenotype. The embryo and endosperm tissues of maturing Seeds appeared to exhibit genotype-specific temporal shifts in gene expression profile that might contribute to the Seed phenotypic variations. Functional annotations of gene clusters suggest that the two tissues exhibit distinct but genotypically overlapping molecular functions. Motif enrichment predicts genotypically distinct abscisic acid (ABA) and gibberellin (GA) regulated transcriptional networks contribute to the contrasting Seed weight/size and dormancy phenotypes between the two genotypes. While other ABA responsive element (ABRE) motifs are enriched in both genotypes, the prevalence of G-box-like motif specifically in tissues of the dormant genotype suggests distinct ABA mediated transcriptional mechanisms control the establishment of dormancy during Seed Maturation. In agreement with this, the bZIP transcription factors that co-express with ABRE enriched embryonic genes differ with genotype. The enrichment of SITEIIATCYTC motif specifically in embryo clusters of maturing Seeds irrespective of genotype predicts a tissue specific role for the respective TCP transcription factors with no or minimal contribution to the variations in Seed dormancy. The results of this study advance our understanding of the Seed Maturation associated molecular mechanisms underlying variation in dormancy and weight/size in wheat Seeds, which is a critical step towards the designing of molecular strategies for enhancing Seed yield and quality.
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Seed Maturation associated transcriptional programs and regulatory networks underlying genotypic difference in Seed dormancy and size weight in wheat triticum aestivum l
BMC Plant Biology, 2017Co-Authors: Yuji Yamasaki, Mark C. Jordan, Feng Gao, Belay T. AyeleAbstract:Maturation forms one of the critical Seed developmental phases and it is characterized mainly by programmed cell death, dormancy and desiccation, however, the transcriptional programs and regulatory networks underlying acquisition of dormancy and deposition of storage reserves during the Maturation phase of Seed development are poorly understood in wheat. The present study performed comparative spatiotemporal transcriptomic analysis of Seed Maturation in two wheat genotypes with contrasting Seed weight/size and dormancy phenotype. The embryo and endosperm tissues of maturing Seeds appeared to exhibit genotype-specific temporal shifts in gene expression profile that might contribute to the Seed phenotypic variations. Functional annotations of gene clusters suggest that the two tissues exhibit distinct but genotypically overlapping molecular functions. Motif enrichment predicts genotypically distinct abscisic acid (ABA) and gibberellin (GA) regulated transcriptional networks contribute to the contrasting Seed weight/size and dormancy phenotypes between the two genotypes. While other ABA responsive element (ABRE) motifs are enriched in both genotypes, the prevalence of G-box-like motif specifically in tissues of the dormant genotype suggests distinct ABA mediated transcriptional mechanisms control the establishment of dormancy during Seed Maturation. In agreement with this, the bZIP transcription factors that co-express with ABRE enriched embryonic genes differ with genotype. The enrichment of SITEIIATCYTC motif specifically in embryo clusters of maturing Seeds irrespective of genotype predicts a tissue specific role for the respective TCP transcription factors with no or minimal contribution to the variations in Seed dormancy. The results of this study advance our understanding of the Seed Maturation associated molecular mechanisms underlying variation in dormancy and weight/size in wheat Seeds, which is a critical step towards the designing of molecular strategies for enhancing Seed yield and quality.
