Cytogenetic and molecular identification of novel wheat- addition lines with resistance to leaf rust and the presence of leaf pubescence trait.

Introduction: Emerging new races of leaf rust ( Eriks) are threatening global wheat ( L.) production. Identifying additional resistance genes from all available gene pools is crucial to expanding wheat resistance to these virulent leaf rust races.

Does time matter? Intraspecific diversity of ribosomal RNA genes in lineages of the allopolyploid model grass Brachypodium hybridum with different evolutionary ages.

Background: Polyploidisation often results in genome rearrangements that may involve changes in both the single-copy sequences and the repetitive genome fraction. In this study, we performed a comprehensive comparative analysis of repetitive DNA, with a particular focus on ribosomal DNA (rDNA), in Brachypodium hybridum (2n = 4x = 30, subgenome composition DDSS), an allotetraploid resulting from a natural cross between two diploid species that resemble the modern B. distachyon (2n = 10; DD) and B.

Characterization of centromeric DNA of Gossypium anomalum reveals sequence-independent enrichment dynamics of centromeric repeats.

Centromeres in eukaryotes are composed of highly repetitive DNAs, which evolve rapidly and are thought to achieve a favorable structure in mature centromeres. However, how the centromeric repeat evolves into an adaptive structure is largely unknown. We characterized the centromeric sequences of Gossypium anomalum through chromatin immunoprecipitation against CENH3 antibodies.

Switch them off or not: selective rRNA gene repression in grasses.

Nucleolar dominance (ND) is selective epigenetic silencing of 35-48S rDNA loci. In allopolyploids, it is frequently manifested at the cytogenetic level by the inactivation of nucleolar organiser region(s) (NORs) inherited from one or several evolutionary ancestors. Grasses are ecologically and economically one of the most important land plant groups, which have frequently evolved through hybridisation and polyploidisation events.

Cytomolecular Organisation of the Nuclear Genome.

Modern molecular cytogenetics allows many aspects of the nuclear genome structure, function, and evolution to be analysed within the topographic context of mitotic and meiotic chromosomes and interphase nuclei [...

The Chromosome Number and rDNA Loci Evolution in (Fabaceae).

The evolution of chromosome number and ribosomal DNA (rDNA) loci number and localisation were studied in Mill. Diploid and tetraploid species, as well as two basic chromosome numbers, = 7 and = 8, were observed among analysed taxa. The chromosomal distribution of rDNA loci was presented here for the first time using fluorescence in situ hybridisation (FISH) with 5S and 35S rDNA probes.

Multiple origins, one evolutionary trajectory: gradual evolution characterizes distinct lineages of allotetraploid Brachypodium.

The "genomic shock" hypothesis posits that unusual challenges to genome integrity such as whole genome duplication may induce chaotic genome restructuring. Decades of research on polyploid genomes have revealed that this is often, but not always the case. While some polyploids show major chromosomal rearrangements and derepression of transposable elements in the immediate aftermath of whole genome duplication, others do not.

Brachypodium: 20 years as a grass biology model system; the way forward?

It has been 20 years since Brachypodium distachyon was suggested as a model grass species, but ongoing research now encompasses the entire genus. Extensive Brachypodium genome sequencing programmes have provided resources to explore the determinants and drivers of population diversity. This has been accompanied by cytomolecular studies to make Brachypodium a platform to investigate speciation, polyploidisation, perenniality, and various aspects of chromosome and interphase nucleus organisation.

Corrigendum: To Be or Not to Be Expressed: The First Evidence of a Nucleolar Dominance Tissue-Specificity in .

[This corrects the article DOI: 10.3389/fpls.2021.

Plant Cell and Organism Development 2.0.

In the editorial summarising the first edition of the Special Issue on "Plant Cell and Organism Development", we listed the key features that make plants a unique and fascinating group of living organisms [...

To Be or Not to Be Expressed: The First Evidence of a Nucleolar Dominance Tissue-Specificity in .

Nucleolar dominance (ND) is an epigenetic, developmentally regulated phenomenon that describes the selective inactivation of 35S rDNA loci derived from one progenitor of a hybrid or allopolyploid. The presence of ND was documented in an allotetraploid grass, (genome composition DDSS), which is a polyphyletic species that arose from crosses between two putative ancestors that resembled the modern (DD) and (SS). In this work, we investigated the developmental stability of ND in genotype 3-7-2 and compared it with the reference genotype ABR113.

Migration without interbreeding: Evolutionary history of a highly selfing Mediterranean grass inferred from whole genomes.

Wild plant populations show extensive genetic subdivision and are far from the ideal of panmixia which permeates population genetic theory. Understanding the spatial and temporal scale of population structure is therefore fundamental for empirical population genetics - and of interest in itself, as it yields insights into the history and biology of a species. In this study we extend the genomic resources for the wild Mediterranean grass Brachypodium distachyon to investigate the scale of population structure and its underlying history at whole-genome resolution.

3,4-Dehydro-L-proline Induces Programmed Cell Death in the Roots of .

As cell wall proteins, the hydroxyproline-rich glycoproteins (HRGPs) take part in plant growth and various developmental processes. To fulfil their functions, HRGPs, extensins (EXTs) in particular, undergo the hydroxylation of proline by the prolyl-4-hydroxylases. The activity of these enzymes can be inhibited with 3,4-dehydro-L-proline (3,4-DHP), which enables its application to reveal the functions of the HRGPs.

Changes in the Cell Wall Proteome of Leaves in Response to High Temperature Stress in .

High temperature stress leads to complex changes to plant functionality, which affects, i.a., the cell wall structure and the cell wall protein composition.

Allotetraploidization in May Have Led to the Dominance of One Parent's Metabolome in Germinating Seeds.

Seed germination is a complex process during which a mature seed resumes metabolic activity to prepare for seedling growth. In this study, we performed a comparative metabolomic analysis of the embryo and endosperm using the community standard lines of three annual species, i.e.

Metabolomic Variation Aligns with Two Geographically Distinct Subpopulations of before and after Drought Stress.

(Brachypodium) is a non-domesticated model grass that has been used to assess population level genomic variation. We have previously established a collection of 55 Brachypodium accessions that were sampled to reflect five different climatic regions of Turkey; designated 1a, 1c, 2, 3 and 4. Genomic and methylomic variation differentiated the collection into two subpopulations designated as coastal and central (respectively from regions 1a, 1c and the other from 2, 3 and 4) which were linked to environmental variables such as relative precipitation.

The formation and evolution of centromeric satellite repeats in Saccharum species.

Centromeres in eukaryotes are composed of tandem DNAs and retrotransposons. However, centromeric repeats exhibit considerable diversity, even among closely related species, and their origin and evolution are largely unknown. We conducted a genome-wide characterization of the centromeric sequences in sugarcane (Saccharum officinarum).

Defining the Cell Wall, Cell Cycle and Chromatin Landmarks in the Responses of to Salinity.

Excess salinity is a major stress that limits crop yields. Here, we used the model grass (Brachypodium) reference line Bd21 in order to define the key molecular events in the responses to salt during germination. Salt was applied either throughout the germination period ("salt stress") or only after root emergence ("salt shock").

Genetic and Methylome Variation in Turkish Accessions Differentiate Two Geographically Distinct Subpopulations.

(Brachypodium) is a non-domesticated model grass species that can be used to test if variation in genetic sequence or methylation are linked to environmental differences. To assess this, we collected seeds from 12 sites within five climatically distinct regions of Turkey. Seeds from each region were grown under standardized growth conditions in the UK to preserve methylated sequence variation.

Plant Cell and Organism Development.

Plants represent a unique and fascinating group of living organisms [...

Gradual polyploid genome evolution revealed by pan-genomic analysis of Brachypodium hybridum and its diploid progenitors.

Our understanding of polyploid genome evolution is constrained because we cannot know the exact founders of a particular polyploid. To differentiate between founder effects and post polyploidization evolution, we use a pan-genomic approach to study the allotetraploid Brachypodium hybridum and its diploid progenitors. Comparative analysis suggests that most B.

Comparative Genomics of and Revealed Characteristic Features of Both Species.

Although strains are efficient biocontrol agents, their field applications have raised concerns due to their possible threat to human health. The non-pathogenic species, which is closely related to has been proposed as an alternative. However, knowledge regarding the genetics of is limited.

From Single Cell to Plants: Mesophyll Protoplasts as a Versatile System for Investigating Plant Cell Reprogramming.

Plants are sessile organisms that have a remarkable developmental plasticity, which ensures their optimal adaptation to environmental stresses. Plant cell totipotency is an extreme example of such plasticity, whereby somatic cells have the potential to form plants via direct shoot organogenesis or somatic embryogenesis in response to various exogenous and/or endogenous signals. Protoplasts provide one of the most suitable systems for investigating molecular mechanisms of totipotency, because they are effectively single cell populations.