Birgitte Skadhauge

Water uptake in barley grain: Physiology; genetics and industrial applications

Publisher: Elsevier BV

Date: 2016

DOI: 10.1016/J.PLANTSCI.2015.08.009

Abstract: Water uptake by mature barley grains initiates germination and is the first stage in the malting process. Here we have investigated the effects of starchy endosperm cell wall thickness on water uptake, together with the effects of varying amounts of the wall polysaccharide, (1,3 ,4)-β-glucan. In the latter case, we examined mutant barley lines from a mutant library and transgenic barley lines in which the (1,3 ,4)-β-glucan synthase gene, HvCslF6, was down-regulated by RNA interference. Neither cell wall thickness nor the levels of grain (1,3 ,4)-β-glucan were significantly correlated with water uptake but are likely to influence modification during malting. However, when a barley mapping population was phenotyped for rate of water uptake into grain, quantitative trait locus (QTL) analysis identified specific regions of chromosomes 4H, 5H and 7H that accounted for approximately 17%, 18% and 11%, respectively, of the phenotypic variation. These data indicate that variation in water uptake rates by elite malting cultivars of barley is genetically controlled and a number of candidate genes that might control the trait were identified under the QTL. The genomics data raise the possibility that the genetic variation in water uptake rates might be exploited by breeders for the benefit of the malting and brewing industries.

Identification and spatio-temporal expression analysis of barley genes that encode putative modular xylanolytic enzymes

Publisher: Elsevier BV

Date: 07-2021

DOI: 10.1016/J.PLANTSCI.2020.110792

A 2-million-year-old ecosystem in Greenland uncovered by environmental DNA

Publisher: Springer Science and Business Media LLC

Date: 07-12-2022

DOI: 10.1038/S41586-022-05453-Y

Abstract: Late Pliocene and Early Pleistocene epochs 3.6 to 0.8 million years ago 1 had climates resembling those forecasted under future warming 2 . Palaeoclimatic records show strong polar lification with mean annual temperatures of 11–19 °C above contemporary values 3,4 . The biological communities inhabiting the Arctic during this time remain poorly known because fossils are rare 5 . Here we report an ancient environmental DNA 6 (eDNA) record describing the rich plant and animal assemblages of the Kap København Formation in North Greenland, dated to around two million years ago. The record shows an open boreal forest ecosystem with mixed vegetation of poplar, birch and thuja trees, as well as a variety of Arctic and boreal shrubs and herbs, many of which had not previously been detected at the site from macrofossil and pollen records. The DNA record confirms the presence of hare and mitochondrial DNA from animals including mastodons, reindeer, rodents and geese, all ancestral to their present-day and late Pleistocene relatives. The presence of marine species including horseshoe crab and green algae support a warmer climate than today. The reconstructed ecosystem has no modern analogue. The survival of such ancient eDNA probably relates to its binding to mineral surfaces. Our findings open new areas of genetic research, demonstrating that it is possible to track the ecology and evolution of biological communities from two million years ago using ancient eDNA.

Isolation of tissues and preservation of RNA from intact, germinated barley grain

Publisher: Wiley

Date: 15-06-2017

DOI: 10.1111/TPJ.13600

Abstract: Isolated barley (Hordeum vulgare L.) aleurone layers have been widely used as a model system for studying gene expression and hormonal regulation in germinating cereal grains. A serious technological limitation of this approach has been the inability to confidently extrapolate conclusions obtained from isolated tissues back to the whole grain, where the co-location of several living and non-living tissues results in complex tissue-tissue interactions and regulatory pathways coordinated across the multiple tissues. Here we have developed methods for isolating fragments of aleurone, starchy endosperm, embryo, scutellum, pericarp-testa, husk and crushed cell layers from germinated grain. An important step in the procedure involves the rapid fixation of the intact grain to freeze the transcriptional activity of in idual tissues while dissection is effected for subsequent transcriptomic analyses. The developmental profiles of 19 611 gene transcripts were precisely defined in the purified tissues and in whole grain during the first 24 h of germination by RNA sequencing. Spatial and temporal patterns of transcription were validated against well-defined data on enzyme activities in both whole grain and isolated tissues. Transcript profiles of genes involved in mitochondrial assembly and function were used to validate the very early stages of germination, while the profiles of genes involved in starch and cell wall mobilisation matched existing data on activities of corresponding enzymes. The data will be broadly applicable for the interrogation of co-expression and differential expression patterns and for the identification of transcription factors that are important in the early stages of grain and seed germination.

Genetic analysis of grain and malt quality in an elite barley population

Publisher: Springer Science and Business Media LLC

Date: 09-2016

DOI: 10.1007/S11032-016-0554-Z

Mutations in the gene of the Gα subunit of the heterotrimeric G protein are the cause for the brachytic1 semi-dwarf phenotype in barley and applicable for practical breeding

Publisher: Springer Science and Business Media LLC

Date: 05-09-2017

DOI: 10.1186/S41065-017-0045-1

Low-cost cross-taxon enrichment of mitochondrial DNA using in-house synthesised RNA probes

Publisher: Public Library of Science (PLoS)

Date: 04-02-2019

DOI: 10.1371/JOURNAL.PONE.0209499

Genes That Mediate Starch Metabolism in Developing and Germinated Barley Grain

Publisher: Frontiers Media SA

Date: 03-2021

DOI: 10.3389/FPLS.2021.641325

Abstract: Starch is synthesized in the endosperm of developing barley grain, where it functions as the primary source of stored carbohydrate. In germinated grain these starch reserves are hydrolyzed to small oligosaccharides and glucose, which are transported to the embryo to support the growth of the developing seedling. Some of the mobilized glucose is transiently stored as starch in the scutellum of germinated grain. These processes are crucial for early seedling vigor, which is a key determinant of crop productivity and global food security. Several starch synthases (SS), starch-branching enzymes (SBEs), and starch debranching enzymes (isoamylases, ISA), together with a limit dextrinase (LD), have been implicated in starch synthesis from nucleotide-sugar precursors. Starch synthesis occurs both in the developing endosperm and in the scutellum of germinated grain. For the complete depolymerization of starch to glucose, α-amylase (Amy), β-amylase (Bmy), isoamylase (ISA), limit dextrinase (LD), and α-glucosidase (AGL) are required. Most of these enzymes are encoded by gene families of up to 10 or more members. Here RNA-seq transcription data from isolated tissues of intact developing and germinated barley grain have allowed us to identify the most important, specific gene family members for each of these processes in vivo and, at the same time, we have defined in detail the spatio-temporal coordination of gene expression in different tissues of the grain. A transcript dataset for 81,280 genes is publicly available as a resource for investigations into other cellular and biochemical processes that occur in the developing grain from 6 days after pollination.

Carlsberg Group (Denmark)

Location: Denmark

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Linkage Projects - Grant ID: LP130100600

Start Date: 11-2013

End Date: 11-2016

Amount: $675,000.00

Funder: Australian Research Council

Linkage Projects - Grant ID: LP160100700

Start Date: 12-2016

End Date: 12-2019

Amount: $520,000.00

Funder: Australian Research Council

Industrial Transformation Research Hubs - Grant ID: IH230100006

Start Date: 2023

End Date: 12-2027

Amount: $4,933,330.00

Funder: Australian Research Council