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Gibberellin-insensitive reduced height genes are widely spread in modern wheat varieties, making them resistant to lodging under conditions of intensive farming. However, the limited diversity of these genes present in wheat germplasm can limit the adaptability of newly created cultivars to the changing climate. The diversity of the gibberellin signaling pathway genes involved in plant height control—Reduced height 1 (Rht-D1), Gibberellin-insensitive dwarf 1 (Gid1-D) and Gibberellin-insensitive dwarf 2 (Gid2-D)—was studied in the diploid wild goatgrass Aegilops tauschii Coss., one of the ancestral species of the bread wheat (Triticum aestivum L.) and the donor of its D subgenome, using high-throughput sequencing. The examination of 24 Ae. tauschii accessions of different geographical origins revealed a large number of new alleles (haplotypes) not found in bread wheat varieties. Some of the detected polymorphisms lead to changes in the amino acid sequence of proteins. Four isoforms (amino acid sequence variants) were found for the RHT-D1 protein, and two isoforms—for the GID1 and GID2 proteins, each. An analysis of the co-occurrence frequencies of various isoforms of the three proteins showed that their combinations were not random in Ae. tauschii, which may indicate the functional significance of their differences. New alleles of the Rht-D1, Gid1-D, and Gid2-D genes are promising for introgression into bread wheat and studying their effect on plant height and adaptability. [ABSTRACT FROM AUTHOR]

Down-regulator associated protein, DrAp1, acts as a negative cofactor (NC2α) in a transcription repressor complex together with another subunit, down-regulator Dr1 (NC2β). In binding to promotors and regulating the initiation of transcription of various genes, DrAp1 plays a key role in plant transition to flowering and ultimately in seed production. TaDrAp1 and TaDrAp2 genes were identified, and their expression and genetic polymorphism were studied using bioinformatics, qPCR analyses, a 40K Single nucleotide polymorphism (SNP) microarray, and Amplifluor-like SNP genotyping in cultivars of bread wheat (Triticum aestivum L.) and breeding lines developed from a cross between spelt (T. spelta L.) and bread wheat. TaDrAp1 was highly expressed under non-stressed conditions, and at flowering, TaDrAp1 expression was negatively correlated with yield capacity. TaDrAp2 showed a consistently low level of mRNA production. Drought caused changes in the expression of both TaDrAp1 and TaDrAp2 genes in opposite directions, effectively increasing expression in lower yielding cultivars. The microarray 40K SNP assay and Amplifluor-like SNP marker, revealed clear scores and allele discriminations for TaDrAp1 and TaDrAp2 and TaRht-B1 genes. Alleles of two particular homeologs, TaDrAp1-B4 and TaDrAp2-B1, co-segregated with grain yield in nine selected breeding lines. This indicated an important regulatory role for both TaDrAp1 and TaDrAp2 genes in plant growth, ontogenesis, and drought tolerance in bread and spelt wheat. [ABSTRACT FROM AUTHOR]

Background: Leaves of Poaceae have a unique morphological feature: they consist of a proximal sheath and a distal blade separated by a ligular region. The sheath provides structural support and protects young developing leaves, whereas the main function of the blade is photosynthesis. The auricles allow the blade to tilt back for optimal photosynthesis and determine the angle of a leaf, whereas the ligule protects the stem from the entry of water, microorganisms, and pests. Liguleless variants have an upright leaf blade that wraps around the culm. Research on liguleless mutants of maize and other cereals has led to identification of genes that are involved in leaf patterning and differentiation. Results: We characterized an induced liguleless mutant (LM) of Aegilops tauschii Coss., a donor of genome D of bread wheat Triticum aestivum L.. The liguleless phenotype of LM is under dominant monogenic control (Lgt). To determine precise position of Lgt on the Ae. tauschii genetic map, highly saturated genetic maps were constructed containing 887 single-nucleotide polymorphism (SNP) markers derived via diversity arrays technology (DArT)seq. The Lgt gene was mapped to chromosome 5DS. Taking into account coordinates of the SNP markers, flanking Lgt, on the pseudomolecule 5D, a chromosomal region that contains this gene was determined, and a list of candidate genes was identified. Morphological features of the LM phenotype suggest that Lgt participates in the control of leaf development, mainly, in leaf proximal–distal patterning, and its dominant mutation causes abnormal ligular region but does not affect reproductive development. Conclusions: Here we report characterization of a liguleless Ae. tauschii mutant, whose phenotype is under control of a dominant mutation of Lgt. The dominant mode of inheritance of the liguleless trait in a Triticeae species is reported for the first time. The position of the Lgt locus on chromosome 5DS allowed us to identify a list of candidate genes. This list does not contain Ae. tauschii orthologs of any well-characterized cereal genes whose mutations cause liguleless phenotypes. Thus, the characterized Lgt mutant represents a new model for further investigation of plant leaf patterning and differentiation. [ABSTRACT FROM AUTHOR]

Background: Leaves of Poaceae have a unique morphological feature: they consist of a proximal sheath and a distal blade separated by a ligular region. The sheath provides structural support and protects young developing leaves, whereas the main function of the blade is photosynthesis. The auricles allow the blade to tilt back for optimal photosynthesis and determine the angle of a leaf, whereas the ligule protects the stem from the entry of water, microorganisms, and pests. Liguleless variants have an upright leaf blade that wraps around the culm. Research on liguleless mutants of maize and other cereals has led to identification of genes that are involved in leaf patterning and differentiation. Results: We characterized an induced liguleless mutant (LM) of Aegilops tauschii Coss., a donor of genome D of bread wheat Triticum aestivum L.. The liguleless phenotype of LM is under dominant monogenic control (Lgt). To determine precise position of Lgt on the Ae. tauschii genetic map, highly saturated genetic maps were constructed containing 887 single-nucleotide polymorphism (SNP) markers derived via diversity arrays technology (DArT)seq. The Lgt gene was mapped to chromosome 5DS. Taking into account coordinates of the SNP markers, flanking Lgt, on the pseudomolecule 5D, a chromosomal region that contains this gene was determined, and a list of candidate genes was identified. Morphological features of the LM phenotype suggest that Lgt participates in the control of leaf development, mainly, in leaf proximal–distal patterning, and its dominant mutation causes abnormal ligular region but does not affect reproductive development. Conclusions: Here we report characterization of a liguleless Ae. tauschii mutant, whose phenotype is under control of a dominant mutation of Lgt. The dominant mode of inheritance of the liguleless trait in a Triticeae species is reported for the first time. The position of the Lgt locus on chromosome 5DS allowed us to identify a list of candidate genes. This list does not contain Ae. tauschii orthologs of any well-characterized cereal genes whose mutations cause liguleless phenotypes. Thus, the characterized Lgt mutant represents a new model for further investigation of plant leaf patterning and differentiation. [ABSTRACT FROM AUTHOR]