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Strejckova, B.

Publications and source records attributed to Strejckova, B..

3 recordsLinked to original sources

Temporal genomic imprinting regulates grain filling in barley

In cereals, the persistent endosperm accumulates starch and storage proteins, making their grains a major source of food and feed. Early grain development is epigenetically controlled through the parent-of-origin-specific expression of imprinted genes in the endosperm that regulate endosperm proliferation, nutrient accumulation and embryo nourishment. Imprinted genes have been identified in several major cereals, and a few have been functionally characterized. However, it is unclear how imprinted genes regulate the accumulation of storage compounds in cereal grains. Through spatiotemporal transcriptome analysis of 255 imprinted genes in barley (Hordeum vulgare), we identify endosperm transfer cells in grains as a hotspot of expression of imprinted genes. Furthermore, we show that transcription factor LYS3 dynamically regulates grain filling in barley through early expression of the maternal allele, followed by partial activation of the paternal allele.

plant biology↗

The transcriptome landscape of developing barley seeds reveals H3K27me3 dynamics in endosperm tissues

Cereal grains are an important food and feed. To provide comprehensive spatiotemporal information about biological processes in developing seeds of cultivated barley, we performed a transcriptomic study of the embryo, endosperm, and seed maternal tissues collected from 4 to 32 days after pollination. Weighted gene co-expression network and motif enrichment analyses pointed out specific groups of genes and transcription factors with possible impacts on regulating barley seed tissue development. We defined a set of tissue-specific marker genes and families of transcription factors for functional studies of the pathways controlling barley grain development. Assessment of selected groups of chromatin regulators revealed that epigenetic processes are highly dynamic and likely to play a major role during barley endosperm development. Repressive modification H3K27me3 is globally reduced in endosperm tissues and at specific developmental and storage compound genes. Altogether, this atlas uncovers the complexity of the developmental regulation of gene expression in barley grains. TeaserSpatiotemporal profiling of developing barley seeds revealed loss of H3K27me3 and changes in gene expression in endosperm.

plant biology↗

IDENTIFICATION OF POLYCOMB REPRESSIVE COMPLEX 1 AND 2 CORE COMPONENTS IN HEXAPLOID BREAD WHEAT

Polycomb repressive complex 1 and 2 play important roles in epigenetic gene regulation by posttranslationally modifying specific histone residues. Polycomb repressive complex 2 is responsible for the trimethylation of lysine 27 on histone H3, while Polycomb repressive complex 1 catalyzes the monoubiquitination of histone H2A at lysine 119. Although these biochemical functions are evolutionarily conserved, studies in animals and plants, mainly Arabidopsis thaliana, showed that specific subunits have evolved into small gene families, with individual members acting at different developmental stages or responding to specific environmental stimuli. However, the evolution of polycomb group gene families in monocots, particularly those with complex allopolyploid origins, is unknown. Here, we present the in silico identification of the Polycomb repressive complex 1 and 2 subunits in allohexaploid bread wheat, the reconstruction of their evolutionary history and a transcriptional analysis over a series of 33 developmental stages. The identification and chromosomal location of the Polycomb repressive complex 1 and 2 core components in bread wheat may enable a deeper understanding of developmental processes, including vernalization in commonly grown winter wheat.

plant biology↗