ORCID Profile
0000-0003-1135-6515
Current Organisation
University of Adelaide
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Publisher: MDPI AG
Date: 24-05-2021
DOI: 10.3390/IJMS22115532
Abstract: Heat stress is a major limiting factor of grain yield and quality in crops. Abiotic stresses have a transgenerational impact and the mechanistic basis is associated with epigenetic regulation. The current study presents the first systematic analysis of the transgenerational effects of post-anthesis heat stress in tetraploid wheat. Leaf physiological traits, harvest components and grain quality traits were characterized under the impact of parental and progeny heat stress. The parental heat stress treatment had a positive influence on the offspring for traits including chlorophyll content, grain weight, grain number and grain total starch content. Integrated sequencing analysis of the small RNAome, mRNA transcriptome and degradome provided the first description of the molecular networks mediating heat stress adaptation under transgenerational influence. The expression profile of 1771 microRNAs (733 being novel) and 66,559 genes was provided, with differentially expressed microRNAs and genes characterized subject to the progeny treatment, parental treatment and tissue-type factors. Gene Ontology and KEGG pathway analysis of stress responsive microRNAs-mRNA modules provided further information on their functional roles in biological processes such as hormone homeostasis, signal transduction and protein stabilization. Our results provide new insights on the molecular basis of transgenerational heat stress adaptation, which can be used for improving thermo-tolerance in breeding.
Publisher: Wiley
Date: 19-01-2016
Abstract: This study aimed to enhance total antioxidant and vitamin E content of pita bread, by replacing 50% of the standard baker's flour with flours milled from covered (WI2585 and Harrington) or hulless (Finniss) barley genotypes, previously shown to have high antioxidant and vitamin E levels at harvest. Pita breads were made from either 100% baker's flour (control) or 50% malt flour, whole-grain flour, or flour from barley grains pearled at 10%, 15%, and 20% grain weight. Antioxidant capacity and vitamin E content of flours and pitas were determined by their ability to scavenge 2,2-diphenyl-1-picrylhydrazyl radicals and high performance liquid chromatography, respectively. The physical and sensory properties of the pitas were also assessed. All pitas made from either whole grain or pearled barley flour had a higher antioxidant capacity and most also had higher vitamin E content than standard pita. The antioxidant and vitamin E levels were reduced in pearled compared to whole grains, however the extent of that reduction varied among genotypes. The greatest antioxidant and vitamin E levels were found in pita made from malt flour or Finniss whole grain flour. Furthermore, sensory analysis suggested these pitas were acceptable to consumers and retained similar physical and sensory properties to those in the control pita.
Publisher: Oxford University Press (OUP)
Date: 10-2000
DOI: 10.1104/PP.124.2.899
Abstract: Rates of H2O2 production by tobacco suspension cells inoculated with zoospores from compatible or incompatible races of the pathogen Phytophthora nicotianae were followed by direct measurement of oxygen evolution from culture supernatants following catalase addition. Rates of HO2 ./O2 −production were compared by following the formation of the formazan of sodium, 3′-[1-[phenylamino-carbonyl]-3,4-tetrazolium]-bis(4-methoxy-6-nitro) benzene-sulfonic acid hydrate. In the incompatible interaction only, both reactive oxygen species (ROS) were produced by the cultured host cells in a minor burst between 0 and 2 h and then in a major burst between 8 and 12 h after inoculation. Absolute levels of H2O2 could not be accurately measured due to its metabolism by host cells, but results are consistent with the majority of H2O2 being formed via dismutation of HO2 ./O2 −. The effects of inhibitors of endogenous Cu/Zn superoxide dismutase (diethyldithiocarbamate) and catalase (3-amino-1,2,4-triazole and salicylic acid) were also examined. Yields of ROS in the presence of the inhibitors diphenylene iodonium, allopurinol, and salicylhydroxamic acid suggest that ROS were generated in incompatible host responses by more than one mechanism.
Publisher: Scientific Societies
Date: 08-2007
Abstract: Pyrenophora teres, the causal agent of net blotch of barley (Hordeum vulgare L.), induces a combination of necrosis and extensive chlorosis in susceptible barley cultivars. Cell-free filtrates from both net and spot forms of P. teres P. teres f. sp. teres, and P. teres f. sp. maculata were found to contain phytotoxic low molecular weight compounds (LMWCs) and proteinaceous metabolites which appear to be responsible for different components of the symptoms induced by the two forms of the pathogen in a susceptible cultivar of barley (cv. Sloop). Proteins induced only brown necrotic spots or lesions similar to those induced by the pathogens 72 h after inoculation. In contrast, LMWCs induced general chlorosis seen 240 h after inoculation but not the localized necrosis. Neither hydrolyzed or heat- or protease-treated proteinaceous metabolites induced the symptoms. This is the first report of the involvement of proteins produced by P. teres in symptom development during net blotch disease of barley.
Publisher: CSIRO Publishing
Date: 2012
DOI: 10.1071/FP11253
Abstract: Various genetic-based approaches including mutant population screens, microarray analyses, cloning and transgenesis have broadened our knowledge of gene function during meiosis in plants. Nonetheless, these genetic tools are not without inherent limitations. One alternative approach to studying plant meiosis, especially in polyploids such as Triticum aestivum L. (bread wheat), is proteomics. However, protein-based approaches using proteomics have seldom been described, with only two attempts at studying early plant meiosis reported. Here, we report the investigation of early bread wheat meiosis using proteomics. Five differentially expressed protein spots were identified using 2D gel electrophoresis (2DGE) on protein extracts from four pooled stages of meiosis and three genotypes (Chinese Spring wild-type, ph1b and ph2a wheat mutant lines). Tandem mass spectrometry (MS/MS) identification of peptides from these protein spots led to the isolation and characterisation of the full-length clones of a wheat Speckle-type POZ protein, an SF21-like protein and HSP70, and a partial coding sequence of a hexose transporter. Significantly, the putative functions of the Speckle-type POZ protein and HSP70 were confirmed using in vitro DNA binding assays. Through the use of a 2DGE proteomics approach, we show that proteomics is a viable alternative to genetic-based approaches when studying meiosis in wheat. More significantly, we report a potential role for a Speckle-type POZ protein and a HSP70 in chromosome pairing during the early stages of meiosis in bread wheat.
Publisher: Springer Science and Business Media LLC
Date: 2010
DOI: 10.1071/AP10121
Publisher: CSIRO Publishing
Date: 2008
DOI: 10.1071/FP08089
Abstract: The dark discoloration of the embryo end of barley grain (known as black point) is a physiological disorder and the discovery of a quantitative trait locus (QTL) on 2H confirms this trait is controlled genetically. The mechanisms underlying black point tolerance can now be dissected through identification of candidate genes. Comparisons between the QTL identified on chromosomes 2H of barley and 2B of wheat suggest that they are in similar positions near the centromere. In silico analysis, using rice, identified genes residing on two comparative chromosomes (4 and 7) of the rice genome. Analysis of the 12.6 Mb region revealed 1928 unique annotations classified into 11 functional categories. Expressed sequence tags (ESTs) with high sequence similarity to enzymes proposed to be involved in black point formation were used to develop restriction fragment length polymorphisms (RFLPs). To ensure an even coverage of markers across the QTL, RFLP markers were also developed from other ESTs. Mapping of these markers has reduced the QTL region from 28 to 18 cM. This study has identified candidate genes for the control of black point formation and paves the way for future research to develop black point resistant barley cultivars.
Publisher: Wiley
Date: 07-09-2016
Abstract: Pyrenophora teres f. teres (Ptt) causes net form net blotch disease of barley, partially by producing necrosis-inducing proteins. The protein profiles of the culture filtrates of 28 virulent isolates were compared by a combination of 2DE and 1D-PAGE with 105 spots and 51 bands chosen for analysis by liquid chromatography electrospray ionization tandem mass spectrometry. A total of 259 in idual proteins were identified with 63 of these proteins being common to the selected virulent isolates. Ptt secretes a broad spectrum of proteins including cell wall degrading enzymes virulence factors and effectors proteins associated with fungal pathogenesis and development and proteins related to oxidation-reduction processes. Potential virulence factors and effectors identified included proteins with glucosidase activity, ricin B and concanavalin A-like lectins, glucanases, spherulin, cutinase, pectin lyase, leucine-rich repeat protein, and ceratoplatanin. Small proteins with unknown function but cysteine-rich, common to effectors, were also identified. Differences in the secretion profile of the Ptt isolates have also provided important insight into the different mechanisms contributing to virulence and the development of net form net blotch symptoms.
Publisher: Springer Science and Business Media LLC
Date: 22-03-2013
Publisher: Springer Science and Business Media LLC
Date: 25-08-2016
DOI: 10.1007/S10142-016-0515-Y
Abstract: MicroRNAs (miRNAs) guide regulation at the post-transcriptional level by inducing messenger RNA (mRNA) degradation or translational inhibition of their target protein-coding genes. Durum wheat miRNAs may contribute to the genotypic water-deficit stress response in different durum varieties. Further investigation of the interactive miRNA-target regulatory modules and experimental validation of their response to water stress will contribute to our understanding of the small RNA-mediated molecular networks underlying stress adaptation in durum wheat. In this study, a comprehensive genome-wide in silico analysis using the updated Triticum transcriptome assembly identified 2055 putative targets for 113 conserved durum miRNAs and 131 targets for four novel durum miRNAs that putatively contribute to genotypic stress tolerance. Predicted mRNA targets encode various transcription factors, binding proteins and functional enzymes, which play vital roles in multiple biological pathways such as hormone signalling and metabolic processes. Quantitative PCR profiling further characterised 43 targets and 5 miRNAs with stress-responsive and/or genotype-dependent differential expression in two stress-tolerant and two stress-sensitive durum genotypes subjected to pre-anthesis water-deficit stress. Furthermore, a 5' RLM-RACE approach validated nine mRNA targets cleaved by water-deficit stress-responsive miRNAs, which, to our knowledge, has not been previously reported in durum wheat. The present study provided experimental evidence of durum miRNAs and target genes in response to water-deficit stress in contrasting durum varieties, providing new insights into the regulatory roles of the miRNA-guided RNAi mechanism underlying stress adaptation in durum wheat.
Publisher: Wiley
Date: 13-09-2007
Abstract: Black point of barley grain is a disorder characterised by a brown-black discolouration at the embryo end of the grain. Black point is undesirable to the malting industry and results in significant economic loss annually. To identify proteins associated with barley black point we utilised a proteomic approach with 2-DE to compare proteins from whole grain s les of black pointed and healthy grain. From this comparison two condition-specific proteins were identified: a novel 75 kDa late embryogenesis abundant (LEA) protein and a barley grain peroxidase 1 (BP1) that were specifically more abundant in healthy grain and black pointed grain, respectively. Although LEA protein was less abundant in black pointed grain, LEA gene expression was greater suggesting protein degradation had possibly occurred in black pointed grain. Similarly, the increase in BP1 in black pointed grain could not be explained by gene expression. Western blot analysis also revealed that the identified LEA protein is biotinylated in vivo. The role that each of these proteins might have in black point development is discussed.
Publisher: Elsevier BV
Date: 11-2015
DOI: 10.1016/J.FOODCHEM.2015.04.028
Abstract: Antioxidants, including vitamin E, may have a positive effect on human health and prolong storage of food items. Vitamin E content and antioxidant capacity were measured in 25 barley genotypes before and after 4 months storage at 10 °C using high performance liquid chromatography (HPLC) and ability to scavenge DPPH radicals, respectively. As expected, α-tocotrienol (α-T3) and α-tocopherol (α-T) were the predominant tocol isomers. Vitamin E content and antioxidant capacity varied significantly among genotypes. Vitamin E ranged from 8.5 to 31.5 μg/g dry weight (DW) while ascorbic acid equivalent antioxidant capacity (AEAC) varied from 57.2 to 158.1 mg AEAC/100 g fresh weight (FW). Generally, lower vitamin E content or antioxidant capacity was observed in hulless or coloured genotypes. These results suggest that some genotypes are potential candidates for breeding of barley cultivars with high vitamin E content or antioxidant capacity at harvest, even after storage.
Publisher: CSIRO Publishing
Date: 2003
DOI: 10.1071/FP02123
Abstract: We examined production of reactive oxygen species (ROS) and induction of cell death in tissue-cultured tobacco cells undergoing different disease resistance responses. A superoxide-dependent hypersensitive response occurs during both the race-specific resistance response of tobacco cells challenged with incompatible zoospores of Phytophthora nicotianae and during non-specific elicitation of tobacco cells challenged with Phytophthora glucan elicitors extracted from the fungal cell wall. Inhibition studies are consistent with dependence upon endogenous Ca2+ levels, and with involvement of NAD(P)H oxidase and peroxidases in production of ROS during both specific and non-specific elicitation. The patterns of resistance expression during non-host resistance or field resistance responses appear to be similar to race-specific resistance expression with regard to the timing and order of events. However, the intensity of the response is very much reduced. In contrast, during non-specific elicitation, these temporal patterns are significantly altered. The differences in timing, intensity and extent of responses during different modes of disease resistance expression indicate that stimulation of cultured plant cells with non-specific soluble fractions in order to model in planta events during plant / Oomycete and, by implication, plant / fungal interactions, has significant limitations.
Publisher: Springer Science and Business Media LLC
Date: 05-2003
DOI: 10.1007/S00709-002-0064-1
Abstract: The interactions between Hordeum vulgare(barley) and two fungal necrotrophs, Rhynchosporium secalis and Pyrenophora teres (causal agents of barley leaf scald and net blotch), were investigated in a detached-leaf system. An early oxidative burst specific to epidermal cells was observed in both the susceptible and resistant responses to R. secalis, and later on, a second susceptible-specific burst was observed. Time points of the first and the second burst correlated closely with pathogen contact to the plasma membrane and subsequent cell death, respectively. HO(2)(*)/O(2)(-) levels in resistant and susceptible responses to P. teres were limited in comparison. During later stages, HO(2)(*)/O(2)(-) was only detected in 2 to 3 epidermal cells immediately adjacent to phenolic browning and cell death observed during the susceptible response. However, H(2)O(2) was detected in the majority of mesophyll cells adjacent to the observed lesion caused by P. teres. In contrast to observations during challenge with R. secalis, no direct contact between P. teres and the plasma membrane at sites of reactive oxygen species production was evident. Preinfiltration of leaves with antioxidants prior to challenge with either pathogen had no effect on resistance responses but did limit the growth of the pathogens and inhibit the extent of cell death during susceptible responses. These results suggest a possible role for reactive oxygen species in the induction of cell death during the challenge of a susceptible plant cell with a necrotrophic fungal leaf pathogen.
Publisher: The Institute of Brewing & Distilling
Date: 17-09-2015
DOI: 10.1002/JIB.271
Publisher: Wiley
Date: 17-07-2016
DOI: 10.1111/MPP.12399
Publisher: CSIRO Publishing
Date: 2008
DOI: 10.1071/AR08074
Abstract: Black point and kernel discoloration of barley both appear to occur under conditions of high humidity at grain fill. Both of these traits are likely to result from the enzymatic oxidation of phenolic compounds to quinones and the transformation of those oxidation products to brown or black pigments during high humidity. However, even though black point symptoms are quite distinct from other types of kernel discoloration, black point of barley has not previously been the sole focus of environmental studies or quantitative trait locus (QTL) analysis. We have evaluated black point tolerance in doubled haploid progeny of Alexis/Sloop and mapped QTLs on chromosomes 2H and 3H. We have also established that the occurrence of low vapour pressure deficit, high humidity, and low temperatures is associated with the formation of black point in susceptible varieties. These environmental conditions probably create a moist environment during grain development so that the developing grain cannot dry out. Stress or wounding to the embryo caused by this environment might then lead to black point formation. The results of this study will enable the use of comprehensive genetic and biochemical approaches to develop a more detailed understanding of this disorder.
Publisher: Public Library of Science (PLoS)
Date: 12-11-2015
Publisher: Springer Science and Business Media LLC
Date: 28-11-2013
Publisher: Elsevier BV
Date: 07-2022
DOI: 10.1016/J.TPLANTS.2021.11.015
Abstract: The agricultural sector must produce resilient and climate-smart crops to meet the increasing needs of global food production. Recent advancements in elucidating the mechanistic basis of plant stress memory have provided new opportunities for crop improvement. Stress memory-coordinated changes at the organismal, cellular, and various omics levels prepare plants to be more responsive to reoccurring stress within or across generation(s). The exposure to a primary stress, or stress priming, can also elicit a beneficial impact when encountering a secondary abiotic or biotic stress through the convergence of synergistic signalling pathways, referred to as cross-stress tolerance. 'Rewired plants' with stress memory provide a new means to stimulate adaptable stress responses, safeguard crop reproduction, and engineer climate-smart crops for the future.
Publisher: Hindawi Limited
Date: 06-02-2012
DOI: 10.1155/2012/514398
Abstract: Chromosome pairing, synapsis, and DNA recombination are three key processes that occur during early meiosis. A previous study of Poor Homologous Synapsis 1 ( PHS1 ) in maize suggested that PHS1 has a role in coordinating these three processes. Here we report the isolation of wheat ( Triticum aestivum ) PHS1 ( TaPHS1 ), and its expression profile during and after meiosis. While the Ta PHS1 protein has sequence similarity to other plant PHS1/PHS1-like proteins, it also possesses a unique region of oligopeptide repeat units. We show that Ta PHS1 interacts with both single- and double-stranded DNA in vitro and provide evidence of the protein region that imparts the DNA-binding ability. Immunolocalisation data from assays conducted using antisera raised against Ta PHS1 show that Ta PHS1 associates with chromatin during early meiosis, with the signal persisting beyond chromosome synapsis. Furthermore, Ta PHS1 does not appear to colocalise with the asynapsis protein ( Ta ASY1) suggesting that these proteins are probably independently coordinated. Significantly, the data from the DNA-binding assays and 3-dimensional immunolocalisation of Ta PHS1 during early meiosis indicates that Ta PHS1 interacts with DNA, a function not previously observed in either the Arabidopsis or maize PHS1 homologues. As such, these results provide new insight into the function of PHS1 during early meiosis in bread wheat.
Publisher: Elsevier BV
Date: 04-2017
Publisher: Springer Science and Business Media LLC
Date: 03-01-2012
DOI: 10.1007/S00425-011-1583-9
Abstract: Iron (Fe)-deficiency is a common abiotic stress in Pisum sativum L. grown in many parts of the world. The aim of the study was to investigate variation in tolerance to Fe deficiency in two pea genotypes, Santi (Fe-efficient) and Parafield (Fe-inefficient). Fe deficiency caused greater declines in chlorophyll score, leaf Fe concentration and root-shoot development in Parafield compared to Santi, suggesting greater Fe-efficiency in Santi. Fe chelate reductase activity and ethylene production were increased in the roots of Santi and to a lesser extent in Parafield under Fe deficiency, while proton extrusion was only occurred in Santi. Moreover, expression of the Fe chelate reductase gene, FRO1, and Fe transporter, RIT1 were upregulated in Fe-deficient roots of Santi. Expression of HA1 (proton extrusion) was also significantly higher in Santi when compared to Parafield grown in Fe-deficient conditions. Furthermore, the application of the ethylene biosynthesis inhibitor, 1-aminoisobutyric acid reduced the Fe chelate reductase activity, supporting a direct role for ethylene in its induction. A significant increase in root citrate was only observed in Santi under Fe deficiency indicating a role for citrate in the Fe-efficiency mechanism. Taken together, our physiological and molecular data indicate that genotypic variation in tolerance to Fe deficiency in Santi and Parafield plants is a result of variation in a number of Strategy I mechanisms and also suggest a direct role for ethylene in Fe reductase activity. The pea cultivar, Santi provides a new source of Fe-efficiency that can be exploited to breed more Fe-efficient peas.
Publisher: Elsevier BV
Date: 02-2014
Publisher: Springer Science and Business Media LLC
Date: 18-02-2012
Abstract: The synaptonemal complex (SC) is a proteinaceous tripartite structure used to hold homologous chromosomes together during the early stages of meiosis. The yeast ZIP1 and its homologues in other species have previously been characterised as the transverse filament protein of the synaptonemal complex. Proper installation of ZYP1 along chromosomes has been shown to be dependent on the axial element-associated protein, ASY1 in Arabidopsis. Here we report the isolation of the wheat ( Triticum aestivum ) ZYP1 ( TaZYP1 ) and its expression profile (during and post-meiosis) in wild-type, the ph1b deletion mutant as well as in Taasy1 RNAi knock-down mutants. Ta ZYP1 has a putative DNA-binding S/TPXX motif in its C-terminal region and we provide evidence that Ta ZYP1 interacts non-preferentially with both single- and double-stranded DNA in vitro . 3-dimensional dual immunofluorescence localisation assays conducted with an antibody raised against Ta ZYP1 show that Ta ZYP1 interacts with chromatin during meiosis but does not co-localise to regions of chromatin where Ta ASY1 is present. The Ta ZYP1 signal lengthens into regions of chromatin where Ta ASY1 has been removed in wild-type but this appears delayed in the ph1b mutant. The localisation profile of Ta ZYP1 in four Taasy1 knock-down mutants is similar to wild-type but Ta ZYP1 signal intensity appears weaker and more diffused. In contrast to previous studies performed on plant species where ZYP1 signal is sandwiched by ASY1 signal located on both axial elements of the SC, data from the 3-dimensional dual immunofluorescence localisation assays conducted in this study show that Ta ZYP1 signal only lengthens into regions of chromatin after Ta ASY1 signal is being unloaded. However, the observation that Ta ZYP1 loading appears delayed in both the ph1b and Taasy1 mutants suggests that Ta ASY1 may still be essential for Ta ZYP1 to play a role in SC formation during meiosis. These data further suggest that the temporal installation of ZYP1 onto pairing homologous chromosomes in wheat is different to that of other plant species and highlights the need to study this synaptonemal complex protein on a species to species basis.
Publisher: CSIRO Publishing
Date: 2013
DOI: 10.1071/FP12330
Abstract: Capsicum (Capsicum annuum L.) is categorised as a non-climacteric fruit that exhibits limited ethylene production during ripening and the molecular mechanisms associated with this process are poorly understood. A proteomic approach was used to identify the differentially expressed proteins during various ripening stages (Green (G), Breaker Red 1 (BR1) and Light Red (LR)) and the genes associated with their synthesis. From 2D gel electrophoresis (2DGE), seven protein spots were identified as selectively present either in G or BR1 and are involved in carbon metabolism, colour and fruit development, protein synthesis and chaperones or biosynthesis of amino acids and polyamines. One candidate of interest, 1-aminocyclopropane-1-carboxylic acid (ACC) oxidase (ACO) is known to be involved in ethylene biosynthesis and was only present in BR1 and is related to the tomato ACO isoform 4 (LeACO4) and hence named CaACO4. CaACO4 RNA expression as well as total ACO protein expression in multiple stages of ripening (G, Breaker (B), BR1, Breaker Red 2 (BR2), LR and Deep Red (DR)) corresponded to the 2DGE protein spot abundance in breaker stages. Our findings highlight the involvement of the ethylene pathway in non-climacteric fruit ripening.
Publisher: Queensland University of Technology
Date: 09-09-2014
DOI: 10.5204/JLD.V7I2.200
Publisher: Inderscience Publishers
Date: 2009
Publisher: No publisher found
Date: 2002
Publisher: Elsevier BV
Date: 03-2005
Publisher: MDPI AG
Date: 21-04-2021
Abstract: Stress events have transgenerational effects on plant growth and development. In Mediterranean regions, water-deficit and heat (WH) stress is a frequent issue that negatively affects crop yield and quality. Nitrogen (N) is an essential plant macronutrient and often a yield-limiting factor for crops. Here, the response of durum wheat seedlings to N starvation under the transgenerational effects of WH stress was investigated in two genotypes. Both genotypes showed a significant reduction in seedling height, leaf number, shoot and root weight (fresh and dry), primary root length, and chlorophyll content under N starvation stress. However, in the WH stress-tolerant genotype, the percentage reduction of most traits was lower in progeny from the stressed parents than progeny from the control parents. Small RNA sequencing identified 1534 microRNAs in different treatment groups. Differentially expressed microRNAs (DEMs) were characterized subject to N starvation, parental stress and genotype factors, with their target genes identified in silico. GO and KEGG enrichment analyses revealed the biological functions, associated with DEM-target modules in stress adaptation processes, that could contribute to the phenotypic differences observed between the two genotypes. The study provides the first evidence of the transgenerational effects of WH stress on the N starvation response in durum wheat.
Publisher: MDPI AG
Date: 21-10-2020
DOI: 10.3390/IJMS21207772
Abstract: Crop reproduction is highly sensitive to water deficit and heat stress. The molecular networks of stress adaptation and grain development in tetraploid wheat (Triticum turgidum durum) are not well understood. Small RNAs (sRNAs) are important epigenetic regulators connecting the transcriptional and post-transcriptional regulatory networks. This study presents the first multi-omics analysis of the sRNAome, transcriptome, and degradome in T. turgidum developing grains, under single and combined water deficit and heat stress. We identified 690 microRNAs (miRNAs), with 84 being novel, from 118 sRNA libraries. Complete profiles of differentially expressed miRNAs (DEMs) specific to genotypes, stress types, and different reproductive time-points are provided. The first degradome sequencing report for developing durum grains discovered a significant number of new target genes regulated by miRNAs post-transcriptionally. Transcriptome sequencing profiled 53,146 T. turgidum genes, swith differentially expressed genes (DEGs) enriched in functional categories such as nutrient metabolism, cellular differentiation, transport, reproductive development, and hormone transduction pathways. miRNA–mRNA networks that affect grain characteristics such as starch synthesis and protein metabolism were constructed on the basis of integrated analysis of the three omics. This study provides a substantial amount of novel information on the post-transcriptional networks in T. turgidum grains, which will facilitate innovations for breeding programs aiming to improve crop resilience and grain quality.
Publisher: CSIRO Publishing
Date: 2014
DOI: 10.1071/CP13306
Abstract: Durum wheat (Triticum turgidum ssp. durum) is susceptible to Fusarium pseudograminearum and sensitive to zinc (Zn) deficiency in Australian soils. However, little is known about the interaction between these two potentially yield-limiting factors, especially for Australian durum varieties. The critical Zn concentration (concentration of Zn in the plant when there is a 10% reduction in yield) and degree of susceptibility to F. pseudograminearum was therefore determined for five Australian durum varieties (Yawa, Hyperno, Tjilkuri, WID802, UAD1153303). Critical Zn concentration averaged 24.6 mg kg–1 for all durum varieties but differed for the in idual varieties (mg kg–1: Yawa, 21.7 Hyperno, 22.7 Tjilkuri, 24.1 WID802, 24.8 UAD1153303, 28.7). Zinc efficiency also varied amongst genotypes (39–52%). However, Zn utilisation was similar amongst genotypes under Zn-deficient or Zn-sufficient conditions (0.51–0.59 and 0.017–0.022 g DM μg–1 Zn, respectively). All varieties were susceptible to F. pseudograminearum but the development of symptoms and detrimental effect on shoot biomass and grain yield were significantly greater in Tjilkuri. Even though crown rot symptoms may still be present, the supply of adequate Zn in the soil helped to maintain biomass and grain yield in all durum varieties. However, the extent to which durum varieties were protected from plant growth penalties due to crown rot by Zn treatment was genotype-dependent.
Publisher: Deakin University
Date: 23-05-2016
DOI: 10.21153/JTLGE2016VOL7NO1ART585
Abstract: The national Learning and Teaching Academics Standards statement for agriculture (AgLTAS) defines the nature and extent of the discipline and provides threshold learning outcomes (TLOs) that define what a graduate should know, understand and do at graduation. The AgLTAS standards are endorsed by the Australian Council of Deans of Agriculture and can be used to communicate to potential and current students the minimum standards of their degree, but can also be used to inform curriculum design. While the AgLTAS document provides explanatory notes to assist educators to further understand the intent of the TLOs there are no exemplars on how the AgLTAS standards can be implemented. This paper presents two case studies of how academics at the University of Tasmania and the University of Adelaide used the AgLTAS to map their respective agriculture curricula. Curriculum mapping was used to evaluate the links between the curriculum and the target learning outcomes, and to identify gaps and areas for improvement. Results include the curriculum maps but also a survey of academic staff and their reactions to the TLOs, plus a reflective commentary on what we believe are the next steps and implications of the AgLTAS for curriculum development, industry engagement and graduate employability in the agriculture discipline.
Publisher: Elsevier BV
Date: 2008
Publisher: Elsevier BV
Date: 11-2016
DOI: 10.1016/J.TPLANTS.2016.07.006
Abstract: In cereal breeding programs, improved yield potential and stability are ultimate goals when developing new varieties. To facilitate achieving these goals, reproductive success under stressful growing conditions is of the highest priority. In recent times, small RNA (sRNA)-mediated pathways have been associated with the regulation of genes involved in stress adaptation and reproduction in both model plants and several cereals. Reproductive and physiological traits such as flowering time, reproductive branching, and root architecture can be manipulated by sRNA regulatory modules. We review sRNA-mediated pathways that could be exploited to expand crop ersity with adaptive traits and, in particular, the development of high-yielding stress-tolerant cereals: SMARTER cereal breeding through 'Small RNA-Mediated Adaptation of Reproductive Targets in Epigenetic Regulation'.
Publisher: Scientific Societies
Date: 09-2007
Abstract: Germin-like proteins (GLP) have various proposed roles in plant development and defense. Seven novel GLP cDNA clones were isolated from grapevine (Vitis vinifera cv. Chardonnay). Reverse transcriptase-polymerase chain reaction expression analysis revealed that the VvGLP genes exhibit erse and highly specific patterns of expression in response to a variety of abiotic and biotic treatments, including challenge by Erysiphe necator, Plasmopara viticola, and Botrytis cinerea, suggesting a ersity of roles for each of the GLP family members. Significantly, one of the grapevine GLP genes, VvGLP3, is induced specifically by E. necator infection and expression is closely linked to the site of infection. Subcellular localization of VvGLP3 determined by transient expression of a VvGLP3:GFP fusion construct in onion cells indicated that the recombinant protein was targeted to the cell wall. Recombinant VvGLP3 was successfully expressed in Arabidopsis thaliana and the partially purified recombinant protein was demonstrated to have superoxide dismutase activity. This data has provided an insight into the erse nature of the GLP family in grapevine and suggests that VvGLP3 may be involved in the defense response against E. necator.
Publisher: Elsevier BV
Date: 12-2009
Publisher: Wiley
Date: 25-01-2010
Publisher: MDPI AG
Date: 04-02-2020
Abstract: Water deficiency and heat stress can severely limit crop production and quality. Stress imposed on the parents during reproduction could have transgenerational effects on their progeny. Seeds with different origins can vary significantly in their germination and early growth. Here, we investigated how water-deficit and heat stress on parental durum wheat plants affected seedling establishment of the subsequent generation. One stress-tolerant and one stress-sensitive Australian durum genotype were used. Seeds were collected from parents with or without exposure to stress during reproduction. Generally, stress on the previous generation negatively affected seed germination and seedling vigour, but to a lesser extent in the tolerant variety. Small RNA sequencing utilising the new durum genome assembly revealed significant differences in microRNA (miRNA) expression in the two genotypes. A bioinformatics approach was used to identify multiple miRNA targets which have critical molecular functions in stress adaptation and plant development and could therefore contribute to the phenotypic differences observed. Our data provide the first confirmation of the transgenerational effects of reproductive-stage stress on germination and seedling establishment in durum wheat. New insights gained on the epigenetic level indicate that durum miRNAs could be key factors in optimising seed vigour for breeding superior germplasm and/or varieties.
Publisher: Oxford University Press (OUP)
Date: 06-1998
DOI: 10.1104/PP.117.2.491
Abstract: The relationship between the production of reactive oxygen species and the hypersensitive response (HR) of tobacco (Nicotiana tabacum L.) toward an incompatible race of the Oomycete Phytophthora parasitica var nicotianae has been investigated. A new assay for superoxide radical (O2−) production based on reduction of the tetrazolium dye sodium,3′-(1-[phenylamino-carbonyl]-3,4-tetrazolium)-bis(4-methoxy-6-nitro) benzene-sulfonic acid hydrate (XTT) has enabled the quantitative estimation of perhydroxyl/superoxide radical acid-base pair (HO2·/O2−) production during the resistant response. Tobacco suspension cells were inoculated with zoospores from compatible or incompatible races of the pathogen. Subsequent HO2·/O2− production was monitored by following the formation of XTT formazan. In the incompatible interaction only, HO2·/O2− was produced in a minor burst between 0 and 2 h and then in a major burst between 8 and 10 h postinoculation. During this second burst, rates of XTT reduction equivalent to a radical flux of 9.9 × 10−15 mol min−1 cell−1 were observed. The HO2·/O2− scavengers O2− dismutase and Mn(III)desferal each inhibited dye reduction. An HR was observed in challenged, resistant cells immediately following the second burst of radical production. Both scavengers inhibited the HR when added prior to the occurrence of either radical burst, indicating that O2−production is a necessary precursor to the HR.
Start Date: 2003
End Date: 2005
Funder: Australian Research Council
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Funder: Grains Research and Development Corporation
View Funded ActivityStart Date: 2007
End Date: 2009
Funder: Australian Research Council
View Funded ActivityStart Date: 2003
End Date: 2005
Funder: Australian Research Council
View Funded Activity