ORCID Profile
0000-0002-7077-4103
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In Research Link Australia (RLA), "Research Topics" refer to ANZSRC FOR and SEO codes. These topics are either sourced from ANZSRC FOR and SEO codes listed in researchers' related grants or generated by a large language model (LLM) based on their publications.
Crop and Pasture Improvement (Selection and Breeding) | Quantitative Genetics (incl. Disease and Trait Mapping Genetics) | Crop and Pasture Production | Crop and Pasture Biochemistry and Physiology
Environmentally Sustainable Plant Production not elsewhere classified | Expanding Knowledge in the Agricultural and Veterinary Sciences | Wheat |
Publisher: Oxford University Press (OUP)
Date: 25-05-2017
DOI: 10.1104/PP.17.00372
Publisher: Cold Spring Harbor Laboratory
Date: 09-05-2020
DOI: 10.1101/2020.05.08.085118
Abstract: Wheat ( Triticum aestivum L.) production is increasingly challenged by simultaneous drought and heatwaves. We assessed the effect of both stresses combined on whole plant water use and carbohydrate partitioning in eight bread wheat genotypes that showed contrasting tolerance. Plant water use was monitored throughout growth, and water-soluble carbohydrates (WSC) and starch were measured following a three-day heat treatment during drought. WSC were predominantly allocated to the spike in modern Australian varieties, whereas the stem contained most WSC in older genotypes. Combined drought and heat stress increased WSC partitioning to the spike in older genotypes but not in the modern varieties. Glucose and fructose concentrations in grains measured 12 days after anthesis were associated with final grain weight in the main spike. At the whole plant level, combined drought and heat stress differentially altered daily water use and transpiration response to vapour pressure deficit during grain filling, compared to drought only. Final grain yield was increasingly associated with aboveground biomass and total water use with increasing stress intensity. Ability to maintain transpiration, especially following combined drought and heat stress, appears essential for maintaining wheat productivity. Higher yield following drought and heat stress in wheats that maintain transpiration and have higher water-soluble carbohydrates content in grains.
Publisher: Oxford University Press (OUP)
Date: 17-03-2018
DOI: 10.1093/JXB/ERY081
Abstract: Drought and heat stress cause losses in wheat productivity in major growing regions worldwide, and both the occurrence and the severity of these events are likely to increase with global climate change. Water deficits and high temperatures frequently occur simultaneously at sensitive growth stages, reducing wheat yields by reducing grain number or weight. Although genetic variation and underlying quantitative trait loci for either in idual stress are known, the combination of the two stresses has rarely been studied. Complex and often antagonistic physiology means that genetic loci underlying tolerance to the combined stress are likely to differ from those for drought or heat stress tolerance alone. Here, we review what is known of the physiological traits and genetic control of drought and heat tolerance in wheat and discuss potential physiological traits to study for combined tolerance. We further place this knowledge in the context of breeding for new, more tolerant varieties and discuss opportunities and constraints. We conclude that a fine control of water relations across the growing cycle will be beneficial for combined tolerance and might be achieved through fine management of spatial and temporal gas exchange.
Publisher: Springer Science and Business Media LLC
Date: 26-02-2015
DOI: 10.1007/S00122-015-2482-4
Abstract: The research identified rye chromosome 4R arms associated with good pollinator traits, and demonstrated possible use of rye genetic resources to develop elite pollinators for hybrid wheat breeding. Bread wheat (Triticum aestivum) is a predominantly self-pollinating plant which has relatively small-sized anthers and produces a low number of pollen grains. These features limit the suitability of most wheat lines as pollinators for hybrid seed production. One strategy for improving the pollination ability of wheat is to introgress cross-pollination traits from related species. One such species is rye (Secale cereale L.), which has suitable traits such as high anther extrusion, long anthers containing large amounts of pollen and long pollen viability. Therefore, introducing these traits into wheat is of great interest in hybrid wheat breeding. Here, we investigated wheat-rye chromosome addition lines for the effects of rye chromosomes on anther and pollen development in wheat. Using a single nucleotide polymorphism genotyping array, we detected 984 polymorphic markers that showed expected syntenic relationships between wheat and rye. Our results revealed that the addition of rye chromosomes 1R or 2R reduced pollen fertility, while addition of rye chromosome 4R increased anther size by 16% and pollen grain number by 33%. The effect on anther length was associated with increases in both cell size and the number of endothecium cells and was attributed to the long arm of chromosome 4R. In contrast, the effect on pollen grain number was attributed to the short arm of chromosome 4R. These results indicate that rye chromosome 4R contains at least two genetic factors associated with increased anther size and pollen grain number that can favourably affect pollination traits in wheat.
Publisher: Oxford University Press (OUP)
Date: 05-02-2021
DOI: 10.1093/JXB/ERAB044
Abstract: Wheat (Triticum aestivum L.) productivity is severely reduced by high temperatures. Breeding of heat-tolerant cultivars can be achieved by identifying genes controlling physiological and agronomical traits when high temperatures occur and using these to select superior genotypes, but no gene underlying genetic variation for heat tolerance has previously been described. We advanced the positional cloning of qYDH.3BL, a quantitative trait locus (QTL) on bread wheat chromosome 3B associated with increased yield in hot and dry climates. The delimited genomic region contained 12 putative genes and a sequence variant in the promoter region of one gene, Seven in absentia, TaSINA. This was associated with the QTL’s effects on early vigour, root growth, plant biomass, and yield components in two distinct wheat populations grown under various growth conditions. Near isogenic lines carrying the positive allele at qYDH.3BL underexpressed TaSINA and had increased vigour and water use efficiency early in development, as well as increased biomass, grain number, and grain weight following heat stress. A survey of worldwide distribution indicated that the positive allele became widespread from the 1950s through the CIMMYT wheat breeding programme but, to date, has been selected only in breeding programmes in Mexico and Australia.
Publisher: Wiley
Date: 24-01-2013
DOI: 10.1111/PBI.12044
Abstract: Despite the international significance of wheat, its large and complex genome hinders genome sequencing efforts. To assess the impact of selection on this genome, we have assembled genomic regions representing genes for chromosomes 7A, 7B and 7D. We demonstrate that the dispersion of wheat to new environments has shaped the modern wheat genome. Most genes are conserved between the three homoeologous chromosomes. We found differential gene loss that supports current theories on the evolution of wheat, with greater loss observed in the A and B genomes compared with the D. Analysis of intervarietal polymorphisms identified fewer polymorphisms in the D genome, supporting the hypothesis of early gene flow between the tetraploid and hexaploid. The enrichment for genes on the D genome that confer environmental adaptation may be associated with dispersion following wheat domestication. Our results demonstrate the value of applying next-generation sequencing technologies to assemble gene-rich regions of complex genomes and investigate polyploid genome evolution. We anticipate the genome-wide application of this reduced-complexity syntenic assembly approach will accelerate crop improvement efforts not only in wheat, but also in other polyploid crops of significance.
Publisher: Springer Science and Business Media LLC
Date: 23-02-2016
DOI: 10.1007/S00122-016-2689-Z
Abstract: Study of three interconnected populations identified 13 maturity QTL of which eight collocate with phenology genes, and 18 QTL for traits associated with adaptation to drought-prone environments. QTL for maturity and other adaptive traits affecting barley adaptation were mapped in a drought-prone environment. Three interconnected doubled haploid (DH) populations were developed from inter-crossing three Australian elite genotypes (Commander, Fleet and WI4304). High-density genetic maps were constructed using genotyping by sequencing and single nucleotide polymorphisms (SNP) for major phenology genes controlling photoperiod response and vernalization requirement. Field trials were conducted on the three DH populations in six environments at three sites in southern Australia and over two cropping seasons. Phenotypic evaluations were done for maturity, early vigour, normalized difference vegetation index (NDVI) and leaf chlorophyll content (SPAD), leaf waxiness and leaf rolling. Thirteen maturity QTL were identified, all with significant QTL × environment interaction with one exception. Eighteen QTL were detected for other adaptive traits across the three populations, including three QTL for leaf rolling, six for leaf waxiness, three for early vigour, four for NDVI, and two QTL for SPAD. The three interlinked populations with high-density linkage maps described in this study are a significant resource for examining the genetic basis for barley adaptation in low-to-medium rainfall Mediterranean type environments.
Publisher: Oxford University Press (OUP)
Date: 15-07-2015
DOI: 10.1093/JXB/ERV320
Publisher: Oxford University Press (OUP)
Date: 23-06-2011
DOI: 10.1093/PCP/PCR083
Abstract: Leaf primordia are generated around the shoot apical meristem. Mutation of the ASYMMETRIC LEAVES2 (AS2) gene of Arabidopsis thaliana results in defects in repression of the meristematic and indeterminate state, establishment of adaxial-abaxial polarity and left-right symmetry in leaves. AS2 represses transcription of meristem-specific class 1 KNOX homeobox genes and of the abaxial-determinant genes ETTIN/ARF3, KANADI2 and YABBY5. To clarify the role of AS2 in the establishment of leaf polarity, we isolated mutations that enhanced the polarity defects associated with as2. We describe here the enhancer-of-asymmetric-leaves-two1 (east1) mutation, which caused the formation of filamentous leaves with abaxialized epidermis on the as2-1 background. Levels of transcripts of class 1 KNOX and abaxial-determinant genes were markedly higher in as2-1 east1-1 mutant plants than in the wild-type and corresponding single-mutant plants. EAST1 encodes the histone acetyltransferase ELONGATA3 (ELO3), a component of the Elongator complex. Genetic analysis, using mutations in genes involved in the biogenesis of a trans-acting small interfering RNA (ta-siRNA), revealed that ELO3 mediated establishment of leaf polarity independently of AS2 and the ta-siRNA-related pathway. Treatment with an inhibitor of histone deacetylases (HDACs) caused additive polarity defects in as2-1 east1-1 mutant plants, suggesting the operation of an ELO3 pathway, independent of the HDAC pathway, in the determination of polarity. We propose that multiple pathways play important roles in repression of the expression of class 1 KNOX and abaxial-determinant genes in the development of the adaxial domain of leaves and, thus, in the establishment of leaf polarity.
Publisher: Springer Science and Business Media LLC
Date: 2010
Publisher: Oxford University Press (OUP)
Date: 11-06-2007
DOI: 10.1093/AOB/MCM102
Publisher: Oxford University Press (OUP)
Date: 04-06-2010
DOI: 10.1093/JXB/ERQ152
Abstract: Tolerance to drought is a quantitative trait, with a complex phenotype, often confounded by plant phenology. Breeding for drought tolerance is further complicated since several types of abiotic stress, such as high temperatures, high irradiance, and nutrient toxicities or deficiencies can challenge crop plants simultaneously. Although marker-assisted selection is now widely deployed in wheat, it has not contributed significantly to cultivar improvement for adaptation to low-yielding environments and breeding has relied largely on direct phenotypic selection for improved performance in these difficult environments. The limited success of the physiological and molecular breeding approaches now suggests that a careful rethink is needed of our strategies in order to understand better and breed for drought tolerance. A research programme for increasing drought tolerance of wheat should tackle the problem in a multi-disciplinary approach, considering interaction between multiple stresses and plant phenology, and integrating the physiological dissection of drought-tolerance traits and the genetic and genomics tools, such as quantitative trait loci (QTL), microarrays, and transgenic crops. In this paper, recent advances in the genetics and genomics of drought tolerance in wheat and barley are reviewed and used as a base for revisiting approaches to analyse drought tolerance in wheat. A strategy is then described where a specific environment is targeted and appropriate germplasm adapted to the chosen environment is selected, based on extensive definition of the morpho-physiological and molecular mechanisms of tolerance of the parents. This information was used to create structured populations and develop models for QTL analysis and positional cloning.
Publisher: Springer Science and Business Media LLC
Date: 19-05-2011
Abstract: Although second generation sequencing (2GS) technologies allow re-sequencing of previously gold-standard-sequenced genomes, whole genome shotgun sequencing and de novo assembly of large and complex eukaryotic genomes is still difficult. Availability of a genome-wide physical map is therefore still a prerequisite for whole genome sequencing for genomes like barley. To start such an endeavor, large insert genomic libraries, i.e. Bacterial Artificial Chromosome (BAC) libraries, which are unbiased and representing deep haploid genome coverage, need to be ready in place. Five new BAC libraries were constructed for barley ( Hordeum vulgare L.) cultivar Morex. These libraries were constructed in different cloning sites ( Hind III, EcoR I, Mbo I and BstX I) of the respective vectors. In order to enhance unbiased genome representation and to minimize the number of gaps between BAC contigs, which are often due to uneven distribution of restriction sites, a mechanically sheared library was also generated. The new BAC libraries were fully characterized in depth by scrutinizing the major quality parameters such as average insert size, degree of contamination (plate wide, neighboring, and chloroplast), empty wells and off-scale clones (clones with or fragments). Additionally a set of gene-based probes were hybridized to high density BAC filters and showed that genome coverage of each library is between 2.4 and 6.6 X. BAC libraries representing haploid genomes are available as a new resource to the barley research community. Systematic utilization of these libraries in high-throughput BAC fingerprinting should allow developing a genome-wide physical map for the barley genome, which will be instrumental for map-based gene isolation and genome sequencing.
Publisher: Wiley
Date: 03-07-2012
DOI: 10.1111/J.1467-7652.2012.00718.X
Abstract: Single nucleotide polymorphisms (SNPs) are the most abundant type of molecular genetic marker and can be used for producing high-resolution genetic maps, marker-trait association studies and marker-assisted breeding. Large polyploid genomes such as wheat present a challenge for SNP discovery because of the potential presence of multiple homoeologs for each gene. AutoSNPdb has been successfully applied to identify SNPs from Sanger sequence data for several species, including barley, rice and Brassica, but the volume of data required to accurately call SNPs in the complex genome of wheat has prevented its application to this important crop. DNA sequencing technology has been revolutionized by the introduction of next-generation sequencing, and it is now possible to generate several million sequence reads in a timely and cost-effective manner. We have produced wheat transcriptome sequence data using 454 sequencing technology and applied this for SNP discovery using a modified autoSNPdb method, which integrates SNP and gene annotation information with a graphical viewer. A total of 4,694,141 sequence reads from three bread wheat varieties were assembled to identify a total of 38 928 candidate SNPs. Each SNP is within an assembly complete with annotation, enabling the selection of polymorphism within genes of interest.
Publisher: Proceedings of the National Academy of Sciences
Date: 13-05-2005
Abstract: The key enzyme for transcription of protein-encoding genes in eukaryotes is RNA polymerase II (RNAPII). The recruitment of this enzyme during transcription initiation and its passage along the template during transcription elongation is regulated through the association and dissociation of several complexes. Elongator is a histone acetyl transferase complex, consisting of six subunits (ELP1–ELP6), that copurifies with the elongating RNAPII in yeast and humans. We demonstrate that point mutations in three Arabidopsis thaliana genes, encoding homologs of the yeast Elongator subunits ELP1 , ELP3 (histone acetyl transferase), and ELP4 are responsible for the phenotypes of the elongata2 ( elo2 ), elo3 , and elo1 mutants, respectively. The elo mutants are characterized by narrow leaves and reduced root growth that results from a decreased cell ision rate. Morphological and molecular phenotypes show that the ELONGATA ( ELO ) genes function in the same biological process and the epistatic interactions between the ELO genes can be explained by the model of complex formation in yeast. Furthermore, the plant Elongator complex is genetically positioned in the process of RNAPII-mediated transcription downstream of Mediator. Our data indicate that the Elongator complex is evolutionarily conserved in structure and function but reveal that the mechanism by which it stimulates cell proliferation is different in yeast and plants.
Publisher: Springer Science and Business Media LLC
Date: 04-07-2016
Publisher: Wiley
Date: 16-03-2023
DOI: 10.1111/NPH.18771
Abstract: The ‘One Hundred Important Questions Facing Plant Science Research’ project aimed to capture a global snapshot of the current issues and future questions facing plant science. This revisiting builds on the original 2011 paper. Over 600 questions were collected from anyone interested in plants, which were reduced to a final list of 100 by four teams of global panellists. There was remarkable consensus on the most important topics between the global subpanels. We present the top 100 most important questions facing plant science in 2022, ranging from how plants can contribute to tackling climate change, to plant‐defence priming and epigenome plasticity. We also provide explanations of why each question is important. We demonstrate how focussing on climate change, community and protecting plant life has become increasingly important for plant science over the past 11 years. This revisiting illustrates the collaborative and international need for long‐term funding of plant science research, alongside the broad community‐driven efforts to actively ameliorate and halt climate change, while adapting to its consequences.
Publisher: Springer Science and Business Media LLC
Date: 17-08-2018
Publisher: Oxford University Press (OUP)
Date: 02-2007
Abstract: Chromatin modification and transcriptional activation are novel roles for E3 ubiquitin ligase proteins that have been mainly associated with ubiquitin-dependent proteolysis. We identified HISTONE MONOUBIQUITINATION1 (HUB1) (and its homolog HUB2) in Arabidopsis thaliana as RING E3 ligase proteins with a function in organ growth. We show that HUB1 is a functional homolog of the human and yeast BRE1 proteins because it monoubiquitinated histone H2B in an in vitro assay. Hub knockdown mutants had pale leaf coloration, modified leaf shape, reduced rosette biomass, and inhibited primary root growth. One of the alleles had been designated previously as ang4-1. Kinematic analysis of leaf and root growth together with flow cytometry revealed defects in cell cycle activities. The hub1-1 (ang4-1) mutation increased cell cycle duration in young leaves and caused an early entry into the endocycles. Transcript profiling of shoot apical tissues of hub1-1 (ang4-1) indicated that key regulators of the G2-to-M transition were misexpressed. Based on the mutant characterization, we postulate that HUB1 mediates gene activation and cell cycle regulation probably through chromatin modifications.
Publisher: Elsevier BV
Date: 2011
DOI: 10.1016/J.TIBTECH.2010.09.006
Abstract: Adoption of new breeding technologies is likely to underpin future gains in crop productivity. The rapid advances in 'omics' technologies provide an opportunity to generate new datasets for crop species. Integration of genome and functional omics data with genetic and phenotypic information is leading to the identification of genes and pathways responsible for important agronomic phenotypes. In addition, high-throughput genotyping technologies enable the screening of large germplasm collections to identify novel alleles from erse sources, thus offering a major expansion in the variation available for breeding. In this review, we discuss these advances, which have opened the door to new techniques for construction and screening of breeding populations, to increase ultimately the efficiency of selection and accelerate the rates of genetic gain.
Publisher: Oxford University Press (OUP)
Date: 03-2008
Abstract: Trithorax function is essential for epigenetic maintenance of gene expression in animals, but little is known about trithorax homologs in plants. ARABIDOPSIS TRITHORAX1 (ATX1) was shown to be required for the expression of homeotic genes involved in flower organogenesis. Here, we report a novel function of ATX1, namely, the epigenetic regulation of the floral repressor FLOWERING LOCUS C (FLC). Downregulation of FLC accelerates the transition from vegetative to reproductive development in Arabidopsis thaliana. In the atx1 mutant, FLC levels are reduced and the FLC chromatin is depleted of trimethylated, but not dimethylated, histone 3 lysine 4, suggesting a specific trimethylation function of ATX1. In addition, we found that ATX1 directly binds the active FLC locus before flowering and that this interaction is released upon the transition to flowering. This dynamic process stands in contrast with the stable maintenance of homeotic gene expression mediated by trithorax group proteins in animals but resembles the dynamics of plant Polycomb group function.
Publisher: Oxford University Press (OUP)
Date: 31-12-2009
Abstract: To identify genes involved in vascular patterning in Arabidopsis (Arabidopsis thaliana), we screened for abnormal venation patterns in a large collection of leaf shape mutants isolated in our laboratory. The rotunda1-1 (ron1-1) mutant, initially isolated because of its rounded leaves, exhibited an open venation pattern, which resulted from an increased number of free-ending veins. We positionally cloned the RON1 gene and found it to be identical to FRY1/SAL1, which encodes an enzyme with inositol polyphosphate 1-phosphatase and 3′ (2′),5′-bisphosphate nucleotidase activities and has not, to our knowledge, previously been related to venation patterning. The ron1-1 mutant and mutants affected in auxin homeostasis share perturbations in venation patterning, lateral root formation, root hair length, shoot branching, and apical dominance. These similarities prompted us to monitor the auxin response using a DR5-GUS auxin-responsive reporter transgene, the expression levels of which were increased in roots and reduced in leaves in the ron1-1 background. To gain insight into the function of RON1/FRY1/SAL1 during vascular development, we generated double mutants for genes involved in vein patterning and found that ron1 synergistically interacts with auxin resistant1 and hemivenata-1 but not with cotyledon vascular pattern1 (cvp1) and cvp2. These results suggest a role for inositol metabolism in the regulation of auxin responses. Microarray analysis of gene expression revealed that several hundred genes are misexpressed in ron1-1, which may explain the pleiotropic phenotype of this mutant. Metabolomic profiling of the ron1-1 mutant revealed changes in the levels of 38 metabolites, including myoinositol and indole-3-acetonitrile, a precursor of auxin.
Publisher: Oxford University Press (OUP)
Date: 31-10-2013
DOI: 10.1093/JXB/ERT333
Abstract: Global food security demands the development and delivery of new technologies to increase and secure cereal production on finite arable land without increasing water and fertilizer use. There are several options for boosting wheat yields, but most offer only small yield increases. Wheat is an inbred plant, and hybrids hold the potential to deliver a major lift in yield and will open a wide range of new breeding opportunities. A series of technological advances are needed as a base for hybrid wheat programmes. These start with major changes in floral development and architecture to separate the sexes and force outcrossing. Male sterility provides the best method to block self-fertilization, and modifying the flower structure will enhance pollen access. The recent explosion in genomic resources and technologies provides new opportunities to overcome these limitations. This review outlines the problems with existing hybrid wheat breeding systems and explores molecular-based technologies that could improve the hybrid production system to reduce hybrid seed production costs, a prerequisite for a commercial hybrid wheat system.
Publisher: Wiley
Date: 28-02-2011
DOI: 10.1111/J.1467-7652.2010.00587.X
Abstract: The genome of bread wheat (Triticum aestivum) is predicted to be greater than 16 Gbp in size and consist predominantly of repetitive elements, making the sequencing and assembly of this genome a major challenge. We have reduced genome sequence complexity by isolating chromosome arm 7DS and applied second-generation technology and appropriate algorithmic analysis to sequence and assemble low copy and genic regions of this chromosome arm. The assembly represents approximately 40% of the chromosome arm and all known 7DS genes. Comparison of the 7DS assembly with the sequenced genomes of rice (Oryza sativa) and Brachypodium distachyon identified large regions of conservation. The syntenic relationship between wheat, B. distachyon and O. sativa, along with available genetic mapping data, has been used to produce an annotated draft 7DS syntenic build, which is publicly available at www.wheatgenome.info. Our results suggest that the sequencing of isolated chromosome arms can provide valuable information of the gene content of wheat and is a step towards whole-genome sequencing and variation discovery in this important crop.
Publisher: Springer Science and Business Media LLC
Date: 30-07-2018
DOI: 10.1007/S00122-018-3146-Y
Abstract: Novel QTL for salinity tolerance traits have been detected using non-destructive and destructive phenotyping in bread wheat and were shown to be linked to improvements in yield in saline fields. Soil salinity is a major limitation to cereal production. Breeding new salt-tolerant cultivars has the potential to improve cereal crop yields. In this study, a doubled haploid bread wheat mapping population, derived from the bi-parental cross of Excalibur × Kukri, was grown in a glasshouse under control and salinity treatments and evaluated using high-throughput non-destructive imaging technology. Quantitative trait locus (QTL) analysis of this population detected multiple QTL under salt and control treatments. Of these, six QTL were detected in the salt treatment including one for maintenance of shoot growth under salinity ( QG (1 – 5) .asl - 7A ), one for leaf Na + exclusion ( QNa.asl - 7A ) and four for leaf K + accumulation ( QK.asl - 2B.1 , QK.asl - 2B.2 , QK.asl - 5A and QK:Na.asl - 6A ). The beneficial allele for QG (1 – 5) .asl - 7A (the maintenance of shoot growth under salinity) was present in six out of 44 mainly Australian bread and durum wheat cultivars. The effect of each QTL allele on grain yield was tested in a range of salinity concentrations at three field sites across 2 years. In six out of nine field trials with different levels of salinity stress, lines with alleles for Na + exclusion and/or K + maintenance at three QTL ( QNa.asl - 7A , QK.asl - 2B.2 and QK:Na.asl - 6A ) excluded more Na + or accumulated more K + compared to lines without these alleles. Importantly, the QK.asl - 2B.2 allele for higher K + accumulation was found to be associated with higher grain yield at all field sites. Several alleles at other QTL were associated with higher grain yields at selected field sites.
Publisher: Oxford University Press (OUP)
Date: 20-03-2016
DOI: 10.1093/JXB/ERW125
Publisher: Proceedings of the National Academy of Sciences
Date: 08-01-2010
Abstract: In eukaryotes, transcription of protein-encoding genes is strongly regulated by posttranslational modifications of histones that affect the accessibility of the DNA by RNA polymerase II (RNAPII). The Elongator complex was originally identified in yeast as a histone acetyltransferase (HAT) complex that activates RNAPII-mediated transcription. In Arabidopsis thaliana , the Elongator mutants elo1 , elo2 , and elo3 with decreased leaf and primary root growth due to reduced cell proliferation identified homologs of components of the yeast Elongator complex, Elp4, Elp1, and Elp3, respectively. Here we show that the Elongator complex was purified from plant cell cultures as a six-component complex. The role of plant Elongator in transcription elongation was supported by colocalization of the HAT enzyme, ELO3, with euchromatin and the phosphorylated form of RNAPII, and reduced histone H3 lysine 14 acetylation at the coding region of the SHORT HYPOCOTYL 2 auxin repressor and the LAX2 auxin influx carrier gene with reduced expression levels in the elo3 mutant. Additional auxin-related genes were down-regulated in the transcriptome of elo mutants but not targeted by the Elongator HAT activity showing specificity in target gene selection. Biological relevance was apparent by auxin-related phenotypes and marker gene analysis. Ethylene and jasmonic acid signaling and abiotic stress responses were up-regulated in the elo transcriptome and might contribute to the pleiotropic elo phenotype. Thus, although the structure of Elongator and its substrate are conserved, target gene selection has erged, showing that auxin signaling and influx are under chromatin control.
Publisher: Wiley
Date: 02-12-2017
DOI: 10.1111/JAC.12193
Publisher: Oxford University Press (OUP)
Date: 09-2001
DOI: 10.1093/JEXBOT/52.362.1857
Abstract: The identification of QTL for several physiological traits in sunflower is described. Traits related to photosynthesis (leaf chlorophyll concentration, net photosynthesis and internal CO(2) concentration) and water status (stomatal conductance, transpiration, predawn leaf water potential, and relative water content) were evaluated in a population of recombinant inbred lines under greenhouse conditions. Narrow-sense heritabilities were low to average. Using an AFLP linkage map, 19 QTL were detected explaining 8.8-62.9% of the phenotypic variance for each trait. Among these, two major QTL for net photosynthesis were identified on linkage group IX. One QTL co-location was found on linkage group VIII for stomatal movements and water status. Coincident locations for QTL regulating photosynthesis, transpiration and leaf water potential were described on linkage group XIV. These results lead to the first description of the organization of genomic regions related to yield in sunflower.
Publisher: Public Library of Science (PLoS)
Date: 23-05-2017
Publisher: Springer Science and Business Media LLC
Date: 10-10-2014
Start Date: 2013
End Date: 2018
Funder: Australian Research Council
View Funded ActivityStart Date: 07-2015
End Date: 06-2020
Amount: $4,308,668.00
Funder: Australian Research Council
View Funded Activity