Cereal grains are an important source of food and feed. To provide comprehensive spatiotemporal information about biological processes in developing seeds of cultivated barley (Hordeum vulgare L. subsp. vulgare), we performed a transcriptomic study of the embryo, endosperm, and seed maternal tissues collected from grains 4-32 days after pollination. Weighted gene co-expression network and motif enrichment analyses identified specific groups of genes and transcription factors (TFs) potentially regulating barley seed tissue development. We defined a set of tissue-specific marker genes and families of TFs for functional studies of the pathways controlling barley grain development. Assessing selected groups of chromatin regulators revealed that epigenetic processes are highly dynamic and likely play a major role during barley endosperm development. The repressive H3K27me3 modification is globally reduced in endosperm tissues and at specific genes related to development and storage compounds. Altogether, this atlas uncovers the complexity of developmentally regulated gene expression in developing barley grains.

• MeSH
• endosperm * genetika   metabolismus   růst a vývoj   MeSH
• epigeneze genetická MeSH
• genové regulační sítě MeSH
• histony metabolismus   genetika   MeSH
• ječmen (rod) * genetika   růst a vývoj   metabolismus   MeSH
• regulace genové exprese u rostlin * MeSH
• rostlinné proteiny genetika   metabolismus   MeSH
• semena rostlinná * genetika   růst a vývoj   metabolismus   MeSH
• stanovení celkové genové exprese MeSH
• transkripční faktory genetika   metabolismus   MeSH
• transkriptom * genetika   MeSH
• vývojová regulace genové exprese MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• histony MeSH
• rostlinné proteiny MeSH
• transkripční faktory MeSH

Polycomb repressive complex 2 (PRC2) represents a group of evolutionarily conserved multi-subunit complexes that repress gene transcription by introducing trimethylation of lysine 27 on histone 3 (H3K27me3). PRC2 activity is of key importance for cell identity specification and developmental phase transitions in animals and plants. The composition, biochemistry, and developmental function of PRC2 in animal and flowering plant model species are relatively well described. Recent evidence demonstrates the presence of PRC2 complexes in various eukaryotic supergroups, suggesting conservation of the complex and its function. Here, we provide an overview of the current understanding of PRC2-mediated repression in different representatives of eukaryotic supergroups with a focus on the green lineage. By comparison of PRC2 in different eukaryotes, we highlight the possible common and diverged features suggesting evolutionary implications and outline emerging questions and directions for future research of polycomb repression and its evolution.

• Klíčová slova
• H3K27me3, PRC2, SAR, algae, animal, evolution, fungi, green lineage, plant, polycomb,
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH

Vernalization is a period of low non-freezing temperatures, which provides the competence to flower. This mechanism ensures that plants sown before winter develop reproductive organs in more favourable conditions during spring. Such an evolutionary mechanism has evolved in both monocot and eudicot plants. Studies in monocots, represented by temperate cereals like wheat and barley, have identified and proposed the VERNALIZATION1 (VRN1) gene as a key player in the vernalization response. VRN1 belongs to MADS-box transcription factors and is expressed in the leaves and the apical meristem, where it subsequently promotes flowering. Despite substantial research advancement in the last two decades, there are still gaps in our understanding of the vernalization mechanism. Here we summarise the present knowledge of wheat vernalization. We discuss VRN1 allelic variation, review vernalization models, talk VRN1 copy number variation and devernalization phenomenon. Finally, we suggest possible future directions of the vernalization research in wheat.

• Klíčová slova
• VRN, chromatin methylation, copy number variation, devernalization, vernalization, wheat,
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH

The VERNALIZATION1 (VRN1) gene encodes a MADS-box transcription factor and plays an important role in the cold-induced transition from the vegetative to reproductive stage. Allelic variability of VRN1 homoeologs has been associated with large differences in flowering time. The aim of this study was to investigate the genetic variability of VRN1 homoeologs (VRN-A1, VRN-B1 and VRN-D1). We performed an in-depth sequence analysis of VRN1 homoeologs in a panel of 105 winter and spring varieties of hexaploid wheat. We describe the novel allele Vrn-B1f with an 836 bp insertion within intron 1 and show its specific expression pattern associated with reduced heading time. We further provide the complete sequence of the Vrn-A1b allele, revealing a 177 bp insertion in intron 1, which is transcribed into an alternative splice variant. Copy number variation (CNV) analysis of VRN1 homoeologs showed that VRN-B1 and VRN-D1 are present in only one copy. The copy number of recessive vrn-A1 ranged from one to four, while that of dominant Vrn-A1 was one or two. Different numbers of Vrn-A1a copies in the spring cultivars Branisovicka IX/49 and Bastion did not significantly affect heading time. We also report on the deletion of secondary structures (G-quadruplex) in promoter sequences of cultivars with more vrn-A1 copies.

• Klíčová slova
• CNV, VRN1, allelic variation, alternative splice variants, next generation sequencing, wheat,
• MeSH
• alely * MeSH
• alternativní sestřih MeSH
• chléb MeSH
• genetická variace * MeSH
• genová dávka * MeSH
• inzerční mutageneze MeSH
• polyploidie * MeSH
• pšenice genetika   MeSH
• represorové proteiny genetika   MeSH
• sekvenční analýza DNA MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• represorové proteiny MeSH