Project description:Seed abortion is one of the important reasons for the formation of seedless characters in citrus. However, the molecular mechanism of seed abortion in citrus is still unclear. We identified several genes that may play an important role in seed abortion of 'Huagan 4', such as CrWRKY74. The downstream regulatory network of CrWRKY74 was identified based on DAP seq analysis to gain insight into the molecular mechanism related to seed abortion.
Project description:Seed developmental arrest is one of the early phenotypes of seed abortion. However, the molecular mechanism underlying seed developmental arrest of citrus is still unclear. In this study, laser capture microdissection (LCM) was used to accurately divide the seeds of seedless Ponkan ‘Huagan No.4’ (Citrus reticulata) (HG) and seeded Ponkan ‘Egan No.1’ (Citrus reticulata) (EG) into nucellus and integument/seed coat tissues. The captured tissues were used for subsequent RNA-seq. Moreover, single-molecule real-time (SMRT) sequencing was used to generate full-length transcripts of EG, which were used as reference transcripts for RNA-seq. These data can be utilized to analyse the causes of citrus seedlessness formation and the molecular regulatory network in the process of seed abortion.
Project description:Interspecific hybrids in Arabidopsis result in seed abortion that causes reproductive barrier. To investigate the allelic expression pattern at transcriptome level during early seed abortion stage, we performed RNA-seq analysis in F1 interspecific hybrids with three different ecotypes in A. thaliana as maternal and A. arenosa as paternal and identified MEGs and PEGs. Interestingly, PEGs showed distinct expression pattern in several aspects, compared to MEGs: PEGs showed ecotype-specific expression pattern, suggesting a role for PEGs in ecotype-dependent seed lethality. 35% of previously known MEGs in non-lethal hybrids were found as PEGs in our lethal interspecific hybrids, implying the presence of abnormal paternal allelic upregulation. The correlation test between the upregulation of PEGs and previously reported paternal-excess interploidy cross (2X6) which exhibited seed abortion showed that dosage disruption by abnormal paternal upregulation is correlated with seed abortion. Moreover, epigenetic disruption appears to cause some of abnormal upregulation of paternal alleles in PEGs via mis-regulation of MEA-mediated PcG2 and MET1-mediated DNA methylation. The results provide clue on the critical role of PEGs in seed abortion via disruption of dosage balance and epigenetic regulation.
Project description:Seed development is sensitive to parental dosage, with excess maternal or paternal genomes creating reciprocal phenotypes. Paternal genomic excess results in extensive endosperm proliferation without cellularization and eventual seed abortion. We previously showed that loss of the RNA POL IV gene nrpd1 in tetraploid fathers represses seed abortion in paternal excess crosses. Here we show genetically that RNA-directed DNA methylation (RdDM) pathway activity in the paternal parent is sufficient to determine the viability of paternal excess seeds. The status of the RdDM pathway in paternal excess endosperm does not impact seed viability. Comparison of endosperm transcriptomes, DNA methylation, and small RNAs from balanced and paternal excess endosperm demonstrates that paternal excess seed abortion is unlikely to be dependent on either transposable element or imprinted gene mis-regulation. We suggest instead that loss of paternal RdDM modulates expression at a small subset of genes and desensitizes endosperm to paternal excess. Finally, using allele-specific transcription data, we present evidence of a transcriptional buffering system that up37 regulates maternal alleles and represses paternal alleles in response to excess paternal genomic dosage. These findings prompt reconsideration of models for dosage sensitivity in endosperm.
Project description:Seed development is sensitive to parental dosage, with excess maternal or paternal genomes creating reciprocal phenotypes. Paternal genomic excess results in extensive endosperm proliferation without cellularization and eventual seed abortion. We previously showed that loss of the RNA POL IV gene nrpd1 in tetraploid fathers represses seed abortion in paternal excess crosses. Here we show genetically that RNA-directed DNA methylation (RdDM) pathway activity in the paternal parent is sufficient to determine the viability of paternal excess seeds. The status of the RdDM pathway in paternal excess endosperm does not impact seed viability. Comparison of endosperm transcriptomes, DNA methylation, and small RNAs from balanced and paternal excess endosperm demonstrates that paternal excess seed abortion is unlikely to be dependent on either transposable element or imprinted gene mis-regulation. We suggest instead that loss of paternal RdDM modulates expression at a small subset of genes and desensitizes endosperm to paternal excess. Finally, using allele-specific transcription data, we present evidence of a transcriptional buffering system that up37 regulates maternal alleles and represses paternal alleles in response to excess paternal genomic dosage. These findings prompt reconsideration of models for dosage sensitivity in endosperm.
Project description:Seed development is sensitive to parental dosage, with excess maternal or paternal genomes creating reciprocal phenotypes. Paternal genomic excess results in extensive endosperm proliferation without cellularization and eventual seed abortion. We previously showed that loss of the RNA POL IV gene nrpd1 in tetraploid fathers represses seed abortion in paternal excess crosses. Here we show genetically that RNA-directed DNA methylation (RdDM) pathway activity in the paternal parent is sufficient to determine the viability of paternal excess seeds. The status of the RdDM pathway in paternal excess endosperm does not impact seed viability. Comparison of endosperm transcriptomes, DNA methylation, and small RNAs from balanced and paternal excess endosperm demonstrates that paternal excess seed abortion is unlikely to be dependent on either transposable element or imprinted gene mis-regulation. We suggest instead that loss of paternal RdDM modulates expression at a small subset of genes and desensitizes endosperm to paternal excess. Finally, using allele-specific transcription data, we present evidence of a transcriptional buffering system that up37 regulates maternal alleles and represses paternal alleles in response to excess paternal genomic dosage. These findings prompt reconsideration of models for dosage sensitivity in endosperm.
2019-05-01 | GSE126929 | GEO
Project description:RNA-Seq and BSA-Seq of Watermelon seed