Decoding the gene regulatory network of endosperm differentiation in maize [DAP-seq]
Ontology highlight
ABSTRACT: The persistent cereal endosperm constitutes the majority of the grain volume. Dissecting the gene regulatory network underlying cereal endosperm development will facilitate yield and quality improvement of cereal crops. Here, we use single-cell transcriptomics to analyze the developing maize (Zea mays) endosperm during cell differentiation. After obtaining transcriptomic data from 17,022 single cells, we identify 12 cell clusters corresponding to five endosperm cell types and revealing complex transcriptional heterogeneity. We delineate the temporal gene expression pattern from 6 to 7 days after pollination. We profile the genomic DNA binding sites of 161 transcription factors differentially expressed between cell clusters and constructed a gene regulatory network by combining the single-cell transcriptomic data with the direct DNA-binding profiles, identifying 181 regulons containing genes encoding transcription factors along with their high-confidence targets, Furthermore, we map the regulons to endosperm cell clusters, identify cell-cluster-specific essential regulators, and experimentally validated three predicted key regulators. This study provides a framework for understanding cereal endosperm development and function at single-cell resolution.
Project description:The persistent cereal endosperm constitutes the majority of the grain volume. Dissecting the gene regulatory network underlying cereal endosperm development will facilitate yield and quality improvement of cereal crops. Here, we use single-cell transcriptomics to analyze the developing maize (Zea mays) endosperm during cell differentiation. After obtaining transcriptomic data from 17,022 single cells, we identify 12 cell clusters corresponding to five endosperm cell types and revealing complex transcriptional heterogeneity. We delineate the temporal gene expression pattern from 6 to 7 days after pollination. We profile the genomic DNA binding sites of 161 transcription factors differentially expressed between cell clusters and constructed a gene regulatory network by combining the single-cell transcriptomic data with the direct DNA-binding profiles, identifying 181 regulons containing genes encoding transcription factors along with their high-confidence targets, Furthermore, we map the regulons to endosperm cell clusters, identify cell-cluster-specific essential regulators, and experimentally validated three predicted key regulators. This study provides a framework for understanding cereal endosperm development and function at single-cell resolution.
Project description:The persistent cereal endosperm constitutes the majority of the grain volume. Dissecting the gene regulatory network underlying cereal endosperm development will facilitate yield and quality improvement of cereal crops. Here, we use single-cell transcriptomics to analyze the developing maize (Zea mays) endosperm during cell differentiation. After obtaining transcriptomic data from 17,022 single cells, we identify 12 cell clusters corresponding to five endosperm cell types and revealing complex transcriptional heterogeneity. We delineate the temporal gene expression pattern from 6 to 7 days after pollination. We profile the genomic DNA binding sites of 161 transcription factors differentially expressed between cell clusters and constructed a gene regulatory network by combining the single-cell transcriptomic data with the direct DNA-binding profiles, identifying 181 regulons containing genes encoding transcription factors along with their high-confidence targets, Furthermore, we map the regulons to endosperm cell clusters, identify cell-cluster-specific essential regulators, and experimentally validated three predicted key regulators. This study provides a framework for understanding cereal endosperm development and function at single-cell resolution.
Project description:The persistent cereal endosperm constitutes the majority of the grain volume. Dissecting the gene regulatory network underlying cereal endosperm development will facilitate yield and quality improvement of cereal crops. Here, we use single-cell transcriptomics to analyze the developing maize (Zea mays) endosperm during cell differentiation. After obtaining transcriptomic data from 17,022 single cells, we identify 12 cell clusters corresponding to five endosperm cell types and revealing complex transcriptional heterogeneity. We delineate the temporal gene expression pattern from 6 to 7 days after pollination. We profile the genomic DNA binding sites of 161 transcription factors differentially expressed between cell clusters and constructed a gene regulatory network by combining the single-cell transcriptomic data with the direct DNA-binding profiles, identifying 181 regulons containing genes encoding transcription factors along with their high-confidence targets, Furthermore, we map the regulons to endosperm cell clusters, identify cell-cluster-specific essential regulators, and experimentally validated three predicted key regulators. This study provides a framework for understanding cereal endosperm development and function at single-cell resolution.
Project description:The persistent cereal endosperm constitutes the majority of the grain volume. Dissecting the gene regulatory network underlying cereal endosperm development will facilitate yield and quality improvement of cereal crops. Here, we use single-cell transcriptomics to analyze the developing maize (Zea mays) endosperm during cell differentiation. After obtaining transcriptomic data from 17,022 single cells, we identify 12 cell clusters corresponding to five endosperm cell types and revealing complex transcriptional heterogeneity. We delineate the temporal gene expression pattern from 6 to 7 days after pollination. We profile the genomic DNA binding sites of 161 transcription factors differentially expressed between cell clusters and constructed a gene regulatory network by combining the single-cell transcriptomic data with the direct DNA-binding profiles, identifying 181 regulons containing genes encoding transcription factors along with their high-confidence targets, Furthermore, we map the regulons to endosperm cell clusters, identify cell-cluster-specific essential regulators, and experimentally validated three predicted key regulators. This study provides a framework for understanding cereal endosperm development and function at single-cell resolution.
Project description:Transcription factors (TFs) play an important role in maize endosperm development regulation. The temporal RNA-seq and co-expression network analysis of maize endosperm reveals a hiararchical regulatory network architechture modulating the endosperm development. In the network, NKD1 and NKD2 are central regulators, and GBF1, HSFTF10, NACTF49 and HB115 are secondary regulators downstream of NKD1 and 2. To further test the relationship between these TFs, a DNA affinity purification and sequencing (DAP-seq) assay was performed. The result shows that the assay on NKD1 and NKD2 called 1,951 and 56,855 peaks, and 93 and 1,692 peaks are located within 3 kb distance to transcription starting site (TSS), respectively. And assays on GBF1, HSFTF10, NACTF49 and HB115 called 15,543; 38,147; 7,388 and 936 peaks, respectively.
Project description:Barley (Hordeum vulgare) is one of the major food sources for humans and forage source for animal livestock. Barley endosperm is structured into three distinct cell layers: the starchy endosperm, which acts essentially as storage tissue for starch, the subaleurone, which is characterized by a high accumulation of endoplasmic reticulum (ER)-derived seed storage proteins (SSP) and finally the aleurone beside the seed coat with a prominent role during seed germination. Prolamins account for more than 50% of the total protein amount in mature seeds. Together with other seed storage proteins (SSPs) they are important for both grain quality and flour quality. Prolamins are synthesized on the rough ER, translocated into the ER lumen and accumulate in distinct, ER-derived protein bodies (PBs) that are most abundant in the SE. PB formation is regulated by the protein disulfide isomerase (PDI) that is involved in the disulfide transfer pathway. Here, we used laser microdisection (LMD) to characterize spatio-temporal molecular and morphological differences of the ER during barley endosperm development. We revealed by nanoLC-MS/MS proteomic analyses performed on whole seeds and collected tissues at different seed development stages that the protein level of the protein disulfide isomerase HvPDIL1-1 is spatio-temporally regulated in developing barley endosperm. Our microscopic studies showed that HvPDIL1-1 preferentially accumulates in SE, especially at 12 days after pollination (dap). HvPDIL1-1 re-localized from PBs to the protein matrix at the periphery of starch granules along grain filling process. Detailed analysis of SE proteome dynamics identified clusters of proteins with similar expression pattern as HvPDIL1-1, which were analysed in a protein-protein network. It revealed a strong functional interconnection between transcription and translation, protein folding and amino acid synthesis with sucrose and starch metabolism. Our data indicate a role of HvPDIL1-1 in the coordination of protein synthesis and prolamins deposition during grain filling processes in developing barley endosperm. These results are discussed in relation to the putative role of HvPDIL1-1 for cereal food end-product quality and recombinant protein production in cereal seeds.
Project description:Transcriptional profiling of developing rice endosperm at seven days after flowering comparing aleurone layers with central starchy endosperm. Cereal productivity is dependent on the accumulation of storage compounds in the endosperm, a nutritive tissue that is composed of aleurone cells in the outermost regions and starchy endosperm in the inner region. The transcriptional analyses provides clues to the molecular basis for different metabolic pathways in response to the spatial and nutritional differences between rice aleurone cells and starchy endosperm.
Project description:The cereal endosperm consists of starchy endosperm (ST) cells, which accumulate storage proteins and starch, the peripheral aleurone (AL) cells, which mobilize these storage compounds during germination, and transfer cells in contact with the maternal vascular tissues, and the embryo-surrounding region. We conducted RNA-sequencing and analyzed transcript profiles of AL and ST tissues at 18 and 22 days after pollination (DAP), when storage compounds such as proteins, starch, triacylglycerols, specialized metabolites, and minerals are actively synthesized in the maize endosperm. We combined published RNA-seq datasets from other kernel tissues at different developmental stages to analyze gene expression connected to synthesis and accumulation of storage compounds and metabolites. Using weighted correlation network analysis (WGCNA), we identified gene modules associated with metabolic pathways related to nutritional properties of the maize endosperm. We also provide information of novel marker genes specifically expressed in AL and ST, at either early or late developmental stages. This study is important for understanding maize endosperm development and for developing strategies to improve nutritional quality of maize kernels.
Project description:Cytosine methylation silences transposable elements in plants, vertebrates and fungi, but also regulates gene expression1. Plant methylation is catalyzed by three families of enzymes, each with a preferred sequence context: CG, CHG (H = A, C or T) and CHH, with CHH methylation targeted by the RNA interference (RNAi) pathway2. Arabidopsis thaliana endosperm, a placenta-like tissue that nourishes the embryo, is globally hypomethylated in the CG context while retaining high non-CG methylation3. Global methylation dynamics in seeds of cereal crops that provide the bulk of human nutrition remain unknown. Here we show that rice endosperm DNA is hypomethylated in all sequence contexts. Non-CG methylation is reduced evenly across the genome, while CG hypomethylation is localized. CHH methylation of small transposable elements is increased in embryos, suggesting that endosperm demethylation enhances transposon silencing. Genes preferentially expressed in endosperm, including those coding for major storage proteins and starch synthesizing enzymes, are frequently hypomethylated in endosperm, indicating that DNA methylation is a crucial regulator of rice endosperm biogenesis. Our data demonstrate that genome-wide reshaping of seed DNA methylation is conserved among angiosperms and has a profound effect on gene expression in cereal crops. Keywords: Epigenetics