ORCID Profile
0000-0003-0411-9431
Current Organisation
University of Adelaide
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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 Biochemistry and Physiology | Agricultural biotechnology | Plant Cell and Molecular Biology | Genetically modified field crops and pasture | Crop and Pasture Improvement (Selection and Breeding) | Non-genetically modified uses of biotechnology | Crop and Pasture Production | Plant developmental and reproductive biology | Plant cell and molecular biology | Plant Biology | Plant biology | Sociology and Social Studies of Science and Technology | Plant physiology | Quantitative Genetics (incl. Disease and Trait Mapping Genetics) |
Environmentally Sustainable Plant Production not elsewhere classified | Winter Grains and Oilseeds not elsewhere classified | Resourcing of Education and Training Systems | Wheat | Expanding Knowledge in the Agricultural and Veterinary Sciences | Expanding Knowledge in Technology
Publisher: Elsevier BV
Date: 04-2014
DOI: 10.1016/J.COPBIO.2013.12.004
Abstract: Soil salinity is a major constraint to agriculture. To improve salinity tolerance of crops, various traits can be incorporated, including ion exclusion, osmotic tolerance and tissue tolerance. We review the roles of a range of genes involved in salt tolerance traits. Different tissues and cells are adapted for specific and often erse function, so it is important to express the genes in specific cell-types and to pyramid a range of traits. Modern biotechnology (marker-assisted selection or genetic engineering) needs to be increasingly used to introduce the correct combination of genes into elite crop cultivars. Importantly, the effects of introduced genes need to be evaluated in the field to determine their effect on salinity tolerance and yield improvement.
Publisher: Wiley
Date: 20-02-2019
DOI: 10.1002/9781119312994.APR0681
Abstract: Salinity is a major constraint limiting crop yields around the world. While considerable research to understand and enhance the salinity tolerance of plants has occurred, few commercially available salt‐tolerant bread wheat ( Triticum aestivum ), durum wheat ( Triticum durum ), or barley ( Hordeum vulgare ) varieties have been developed for farmers. This lack of salt‐tolerant varieties is despite all publications highlighting issues around global food security, the need to increase crop production to feed an increasing human population, the effects of more variable climate and farmland being degraded by abiotic stresses. We explore the progress to date in using forward and reverse genetic approaches to identify loci and candidate genes linked to plant salinity‐tolerance sub‐traits, and why, despite substantial research in understanding salt tolerance mechanisms, very few genes or loci have been introduced into commercially available varieties. We propose the need for a greater focus on validating glasshouse‐based findings of salt tolerance in saline fields, the fine mapping of quantitative trait loci linked to salt‐tolerance sub‐traits to underlying genes, and the use of marker‐assisted selection and speed breeding to pyramid beneficial salinity‐tolerance sub‐traits to develop high‐yielding bread wheat, durum wheat, and barley varieties.
Publisher: Elsevier BV
Date: 10-2019
Publisher: CSIRO Publishing
Date: 2017
DOI: 10.1071/FP17133
Abstract: Salinity is a global problem affecting agriculture that results in an estimated US$27 billion loss in revenue per year. Overexpression of vacuolar ATPase subunits has been shown to be beneficial in improving plant performance under saline conditions. Most studies, however, have not shown whether overexpression of genes encoding ATPase subunits results in improvements in grain yield, and have not investigated the physiological mechanisms behind the improvement in plant growth. In this study, we constitutively expressed Arabidopsis Vacuolar ATPase subunit C (AtVHA-C) in barley. Transgenic plants were assessed for agronomical and physiological characteristics, such as fresh and dry biomass, leaf pigment content, stomatal conductance, grain yield, and leaf Na+ and K+ concentration, when grown in either 0 or 300 mM NaCl. When compared with non-transformed barley, AtVHA-C expressing barley lines had a smaller reduction in both biomass and grain yield under salinity stress. The transgenic lines accumulated Na+ and K+ in leaves for osmotic adjustment. This in turn saves energy consumed in the synthesis of organic osmolytes that otherwise would be needed for osmotic adjustment.
Publisher: Oxford University Press (OUP)
Date: 07-2009
Abstract: Soil salinity affects large areas of cultivated land, causing significant reductions in crop yield globally. The Na+ toxicity of many crop plants is correlated with overaccumulation of Na+ in the shoot. We have previously suggested that the engineering of Na+ exclusion from the shoot could be achieved through an alteration of plasma membrane Na+ transport processes in the root, if these alterations were cell type specific. Here, it is shown that expression of the Na+ transporter HKT1 in the mature root stele of Arabidopsis thaliana decreases Na+ accumulation in the shoot by 37 to 64%. The expression of HKT1 specifically in the mature root stele is achieved using an enhancer trap expression system for specific and strong overexpression. The effect in the shoot is caused by the increased influx, mediated by HKT1 , of Na+ into stelar root cells, which is demonstrated in planta and leads to a reduction of root-to-shoot transfer of Na+. Plants with reduced shoot Na+ also have increased salinity tolerance. By contrast, plants constitutively expressing HKT1 driven by the cauliflower mosaic virus 35S promoter accumulated high shoot Na+ and grew poorly. Our results demonstrate that the modification of a specific Na+ transport process in specific cell types can reduce shoot Na+ accumulation, an important component of salinity tolerance of many higher plants.
Publisher: Springer Science and Business Media LLC
Date: 09-04-2015
Publisher: CSIRO Publishing
Date: 2021
DOI: 10.1071/FP20167
Abstract: Bread wheat (Triticum aestivum L.) is one of the most important food crops, however it is only moderately tolerant to salinity stress. To improve wheat yield under saline conditions, breeding for improved salinity tolerance of wheat is needed. We have identified nine quantitative trail loci (QTL) for different salt tolerance sub-traits in a recombinant inbred line (RIL) population, derived from the bi-parental cross of Excalibur × Kukri. This population was screened for salinity tolerance subtraits using a combination of both destructive and non-destructive phenotyping. Genotyping by sequencing (GBS) was used to construct a high-density genetic linkage map, consisting of 3236 markers, and utilised for mapping QTL. Of the nine mapped QTL, six were detected under salt stress, including QTL for maintenance of shoot growth under salinity (QG(1-5).asl-5A, QG(1-5).asl-7B) sodium accumulation (QNa.asl-2A), chloride accumulation (QCl.asl-2A, QCl.asl-3A) and potassium:sodium ratio (QK:Na.asl-2DS2). Potential candidate genes within these QTL intervals were shortlisted using bioinformatics tools. These findings are expected to facilitate the breeding of new salt tolerant wheat cultivars.
Publisher: Wiley
Date: 22-07-2020
DOI: 10.1111/PCE.13841
Publisher: Wiley
Date: 22-02-2019
DOI: 10.1111/TPJ.14225
Publisher: Humana Press
Date: 2012
DOI: 10.1007/978-1-61779-986-0_22
Abstract: Interrogating the cell-specific transcriptome forms an important component of understanding the role that specific cells play in assisting a plant to overcome abiotic stress. Among the challenges arising when extracting RNA from in idual plant cells are: the isolation of pure cell populations the small yield of material when isolating specific cell types, and ensuring an accurate representation of the transcriptome from each cell type after lification of RNA. Here we describe two approaches for isolating RNA from specific cell types-single cell s ling and analysis (SiCSA) and laser capture microdissection. Isolated RNA can then be directly s led qualitatively using reverse transcription PCR (RT-PCR) or lified for profiling -multiple specific genes using quantitative RT-PCR and genome-wide transcript analyses.
Publisher: Springer Science and Business Media LLC
Date: 07-10-2022
DOI: 10.1007/S00122-022-04230-9
Abstract: Utilising a nested association mapping (NAM) population-based GWAS, 98 stable marker-trait associations with 127 alleles unique to the exotic parents were detected for grain yield and related traits in wheat. Grain yield, thousand-grain weight, screenings and hectolitre weight are important wheat yield traits. An understanding of their genetic basis is crucial for improving grain yield in breeding programmes. Nested association mapping (NAM) populations are useful resources for the dissection of the genetic basis of complex traits such as grain yield and related traits in wheat. Coupled with phenotypic data collected from multiple environments, NAM populations have the power to detect quantitative trait loci and their multiple alleles, providing germplasm that can be incorporated into breeding programmes. In this study, we evaluated a large-scale wheat NAM population with two recurrent parents in unbalanced trials in nine erse Australian field environments over three years. By applying a single-stage factor analytical linear mixed model (FALMM) to the NAM multi-environment trials (MET) data and conducting a genome-wide association study (GWAS), we detected 98 stable marker-trait associations (MTAs) with their multiple alleles. 74 MTAs had 127 alleles that were derived from the exotic parents and were absent in either of the two recurrent parents. The exotic alleles had favourable effects on 46 MTAs of the 74 MTAs, for grain yield, thousand-grain weight, screenings and hectolitre weight. Two NAM RILs with consistently high yield in multiple environments were also identified, highlighting the potential of the NAM population in supporting plant breeding through provision of germplasm that can be readily incorporated into breeding programmes. The identified beneficial exotic alleles introgressed into the NAM population provide potential target alleles for the genetic improvement of wheat and further studies aimed at pinpointing the underlying genes.
Publisher: Wiley
Date: 08-02-2017
DOI: 10.1111/TPJ.13456
Abstract: Plant breeding and improvements in agronomic practice are making a consistent contribution to increasing global crop production year upon year. However, the rate of yield improvement currently lags behind the targets set to produce enough food to meet the demands of the predicted global population in 2050. Furthermore, crops that are exposed to harmful abiotic environmental factors (abiotic stresses, e.g. water limitation, salinity, extreme temperature) are prone to reduced yields. Here, we briefly describe the processes undertaken in conventional breeding programmes, which are usually designed to improve yields in near-optimal conditions rather than specifically breeding for improved crop yield stability under stressed conditions. While there is extensive fundamental research activity that examines mechanisms of plant stress tolerance, there are few ex les that apply this research to improving commercial crop yields. There are notable exceptions, and we highlight some of these to demonstrate the magnitude of yield gains that could be made by translating agronomic, phenological and genetic solutions focused on improving or mitigating the effect of abiotic stress in the field in particular, we focus on improvements in crop water-use efficiency and salinity tolerance. We speculate upon the reasons for the disconnect between research and research translation. We conclude that to realise untapped rapid gains towards food security targets new funding structures need to be embraced. Such funding needs to serve both the core and collaborative activities of the fundamental, pre-breeding and breeding research communities in order to expedite the translation of innovative research into the fields of primary producers.
Publisher: Wiley
Date: 22-11-2014
DOI: 10.1111/PBI.12145
Abstract: Cereal varieties with improved salinity tolerance are needed to achieve profitable grain yields in saline soils. The expression of AVP1, an Arabidopsis gene encoding a vacuolar proton pumping pyrophosphatase (H⁺-PPase), has been shown to improve the salinity tolerance of transgenic plants in greenhouse conditions. However, the potential for this gene to improve the grain yield of cereal crops in a saline field has yet to be evaluated. Recent advances in high-throughput nondestructive phenotyping technologies also offer an opportunity to quantitatively evaluate the growth of transgenic plants under abiotic stress through time. In this study, the growth of transgenic barley expressing AVP1 was evaluated under saline conditions in a pot experiment using nondestructive plant imaging and in a saline field trial. Greenhouse-grown transgenic barley expressing AVP1 produced a larger shoot biomass compared to null segregants, as determined by an increase in projected shoot area, when grown in soil with 150 mM NaCl. This increase in shoot biomass of transgenic AVP1 barley occurred from an early growth stage and also in nonsaline conditions. In a saline field, the transgenic barley expressing AVP1 also showed an increase in shoot biomass and, importantly, produced a greater grain yield per plant compared to wild-type plants. Interestingly, the expression of AVP1 did not alter barley leaf sodium concentrations in either greenhouse- or field-grown plants. This study validates our greenhouse-based experiments and indicates that transgenic barley expressing AVP1 is a promising option for increasing cereal crop productivity in saline fields.
Publisher: Wiley
Date: 10-2021
DOI: 10.1002/PLD3.354
Abstract: Proton‐pumping pyrophosphatases (H + ‐PPases) have been shown to enhance biomass and yield. However, to date, there has been little work towards identify genes encoding H + ‐PPases in bread wheat ( Triticum aestivum ) ( TaVP s) and limited knowledge on how the expression of these genes varies across different growth stages and tissue types. In this study, the IWGSC database was used to identify two novel TaVP genes, TaVP4 and TaVP5 , and elucidate the complete homeolog sequences of the three known TaVP genes, bringing the total number of bread wheat TaVP s from 9 to 15. Gene expression levels of each TaVP homeolog were assessed using quantitative real‐time PCR (qRT‐PCR) in four erse wheat varieties in terms of phenotypic traits related to high vacuolar pyrophosphatase expression. Homeolog expression was analyzed across multiple tissue types and developmental stages. Expression levels of the TaVP homeologs were found to vary significantly between varieties, tissues and plant developmental stages. During early development (Z10 and Z13), expressions of TaVP1 and TaVP2 homeologs were higher in shoot tissue than root tissue, with both shoot and root expression increasing in later developmental stages (Z22). TaVP2‐D was expressed in all varieties and tissue types and was the most highly expressed homeolog at all developmental stages. Expression of the TaVP3 homeologs was restricted to developing grain (Z75), while TaVP4 homeolog expression was higher at Z22 than earlier developmental stages. Variation in TaVP4B was detected among varieties at Z22 and Z75, with Buck Atlantico (high biomass) and Scout (elite Australian cultivar) having the highest levels of expression. These findings offer a comprehensive overview of the bread wheat H + ‐PPase family and identify variation in TaVP homeolog expression that will be of use to improve the growth, yield, and abiotic stress tolerance of bread wheat.
Publisher: Elsevier BV
Date: 06-2011
DOI: 10.1016/J.PBI.2011.03.002
Abstract: Abiotic stress tolerance is complex, but as phenotyping technologies improve, components that contribute to abiotic stress tolerance can be quantified with increasing ease. In parallel with these phenomics advances, genetic approaches with more complex genomes are becoming increasingly tractable as genomic information in non-model crops increases and even whole crop genomes can be re-sequenced. Thus, genetic approaches to elucidating the molecular basis to abiotic stress tolerance in crops are becoming more easily achievable.
Publisher: CSIRO Publishing
Date: 04-10-2021
DOI: 10.1071/FP21140
Abstract: Salinity tolerance in bread wheat is frequently reported to be associated with low leaf sodium (Na+) concentrations. However, the Portuguese landrace, Mocho de Espiga Branca, accumulates significantly higher leaf Na+ but has comparable salinity tolerance to commercial bread wheat cultivars. To determine the genetic loci associated with the salinity tolerance of this landrace, an F2 mapping population was developed by crossing Mocho de Espiga Branca with the Australian cultivar Gladius. The population was phenotyped for 19 salinity tolerance subtraits using both non-destructive and destructive techniques. Genotyping was performed using genotyping-by-sequencing (GBS). Genomic regions associated with salinity tolerance were detected on chromosomes 1A, 1D, 4B and 5A for the subtraits of relative and absolute growth rate (RGR, AGR respectively), and on chromosome 2A, 2B, 4D and 5D for Na+, potassium (K+) and chloride (Cl−) accumulation. Candidate genes that encode proteins associated with salinity tolerance were identified within the loci including Na+/H+ antiporters, K+ channels, H+-ATPase, calcineurin B-like proteins (CBLs), CBL-interacting protein kinases (CIPKs), calcium dependent protein kinases (CDPKs) and calcium-transporting ATPase. This study provides a new insight into the genetic control of salinity tolerance in a Na+ accumulating bread wheat to assist with the future development of salt tolerant cultivars.
Publisher: Springer Science and Business Media LLC
Date: 21-11-2017
Publisher: Oxford University Press (OUP)
Date: 23-06-2016
DOI: 10.1093/JXB/ERW237
Abstract: Salinity tolerance is correlated with shoot chloride (Cl–) exclusion in multiple crops, but the molecular mechanisms of long-distance Cl– transport are poorly defined. Here, we characterize the in planta role of AtSLAH1 (a homologue of the slow type anion channel-associated 1 (SLAC1)). This protein, localized to the plasma membrane of root stelar cells, has its expression reduced by salt or ABA, which are key predictions for a protein involved with loading Cl– into the root xylem. Artificial microRNA knockdown mutants of AtSLAH1 had significantly reduced shoot Cl− accumulation when grown under low Cl–, whereas shoot Cl– increased and the shoot nitrate/chloride ratio decreased following AtSLAH1 constitutive or stelar-specific overexpression when grown in high Cl–. In both sets of overexpression lines a significant reduction in shoot biomass over the null segregants was observed under high Cl– supply, but not low Cl– supply. Further in planta data showed AtSLAH3 overexpression increased the shoot nitrate/chloride ratio, consistent with AtSLAH3 favouring nitrate transport. Heterologous expression of AtSLAH1 in Xenopus laevis oocytes led to no detectible transport, suggesting the need for post-translational modifications for AtSLAH1 to be active. Our in planta data are consistent with AtSLAH1 having a role in controlling root-to-shoot Cl– transport.
Publisher: Public Library of Science (PLoS)
Date: 27-02-2015
Publisher: Wiley
Date: 27-01-2009
DOI: 10.1111/J.1365-3040.2008.01916.X
Abstract: Salinity stress is a major factor inhibiting cereal yield throughout the world. Tolerance to salinity stress can be considered to contain three main components: Na(+) exclusion, tolerance to Na(+) in the tissues and osmotic tolerance. To date, most experimental work on salinity tolerance in cereals has focused on Na(+) exclusion due in part to its ease of measurement. It has become apparent, however, that Na(+) exclusion is not the sole mechanism for salinity tolerance in cereals, and research needs to expand to study osmotic tolerance and tissue tolerance. Here, we develop assays for high throughput quantification of Na(+) exclusion, Na(+) tissue tolerance and osmotic tolerance in 12 Triticum monococcum accessions, mainly using commercially available image capture and analysis equipment. We show that different lines use different combinations of the three tolerance mechanisms to increase their total salinity tolerance, with a positive correlation observed between a plant's total salinity tolerance and the sum of its proficiency in Na(+) exclusion, osmotic tolerance and tissue tolerance. The assays developed in this study can be easily adapted for other cereals and used in high throughput, forward genetic experiments to elucidate the molecular basis of these components of salinity tolerance.
Publisher: Oxford University Press (OUP)
Date: 11-12-2015
DOI: 10.1104/PP.15.01163
Publisher: Springer Science and Business Media LLC
Date: 22-05-2020
DOI: 10.1038/S42003-020-0990-5
Abstract: During plant growth, sodium (Na + ) in the soil is transported via the xylem from the root to the shoot. While excess Na + is toxic to most plants, non-toxic concentrations have been shown to improve crop yields under certain conditions, such as when soil K + is low. We quantified grain Na + across a barley genome-wide association study panel grown under non-saline conditions and identified variants of a Class 1 HIGH-AFFINITY-POTASSIUM-TRANSPORTER ( HvHKT1 )-encoding gene responsible for Na + content variation under these conditions. A leucine to proline substitution at position 189 (L189P) in HvHKT1 disturbs its characteristic plasma membrane localisation and disrupts Na + transport. Under low and moderate soil Na + , genotypes containing HvHKT1:5 P189 accumulate high concentrations of Na + but exhibit no evidence of toxicity. As the frequency of HvHKT1:5 P189 increases significantly in cultivated European germplasm, we cautiously speculate that this non-functional variant may enhance yield potential in non-saline environments, possibly by offsetting limitations of low available K + .
Publisher: MDPI AG
Date: 27-09-2022
Abstract: Salinity tolerance-associated phenotypes of 35 EMS mutagenized wheat lines originating from BARI Gom-25 were compared. Vegetative growth was measured using non-destructive image-based phenotyping. Five different NaCl concentrations (0 to 160 mM) were applied to plants 19 days after planting (DAP 19), and plants were imaged daily until DAP 38. Plant growth, water use, leaf Na+, K+ and Cl− content, and thousand kernel weight (TKW) were measured, and six lines were selected for further analysis. In saline conditions, leaf Na+, K+, and Cl− content variation on a dry weight basis within these six lines were ~9.3, 1.4, and 2.4-fold, respectively. Relative to BARI Gom-25, two (OA6, OA62) lines had greater K+ accumulation, three (OA6, OA10, OA62) had 50–75% lower Na+:K+ ratios, and OA62 had ~30% greater water-use index (WUI). OA23 had ~2.2-fold greater leaf Na+ and maintained TKW relative to BARI Gom-25. Two lines (OA25, OA52) had greater TKW than BARI Gom-25 when grown in 120 mM NaCl but similar Na+:K+, WUI, and biomass accumulation. OA6 had relatively high TKW, high leaf K+, and WUI, and low leaf Na+ and Cl−. Phenotypic variation revealed differing associations between the parameters measured in the lines. Future identification of the genetic basis of these differences, and crossing of lines with phenotypes of interest, is expected to enable the assessment of which combinations of parameters deliver the greatest improvement in salinity tolerance.
Publisher: Wiley
Date: 11-07-2019
DOI: 10.1111/NPH.15864
Abstract: Agriculture is expanding into regions that are affected by salinity. This review considers the energetic costs of salinity tolerance in crop plants and provides a framework for a quantitative assessment of costs. Different sources of energy, and modifications of root system architecture that would maximize water vs ion uptake are addressed. Energy requirements for transport of salt (NaCl) to leaf vacuoles for osmotic adjustment could be small if there are no substantial leaks back across plasma membrane and tonoplast in root and leaf. The coupling ratio of the H
Publisher: CSIRO Publishing
Date: 2017
DOI: 10.1071/FP17049
Abstract: Soil salinity can severely reduce crop growth and yield. Many studies have investigated salinity tolerance mechanisms in cereals using phenotypes that are relatively easy to measure. The majority of these studies measured the accumulation of shoot Na+ and the effect this has on plant growth. However, plant growth is reduced immediately after exposure to NaCl before Na+ accumulates to toxic concentrations in the shoot. In this study, nondestructive and destructive measurements are used to evaluate the responses of 24 predominately Australian barley (Hordeum vulgare L.) lines at 0, 150 and 250 mM NaCl. Considerable variation for shoot tolerance mechanisms not related to ion toxicity (shoot ion-independent tolerance) was found, with some lines being able to maintain substantial growth rates under salt stress, whereas others stopped growing. Hordeum vulgare spp. spontaneum accessions and barley landraces predominantly had the best shoot ion independent tolerance, although two commercial cultivars, Fathom and Skiff, also had high tolerance. The tolerance of cv. Fathom may be caused by a recent introgression from H. vulgare L. spp. spontaneum. This study shows that the most salt-tolerant barley lines are those that contain both shoot ion-independent tolerance and the ability to exclude Na+ from the shoot (and thus maintain high K+ : Na+ ratios).
Publisher: Public Library of Science (PLoS)
Date: 05-08-2015
Publisher: Springer Science and Business Media LLC
Date: 05-02-2015
Publisher: Elsevier BV
Date: 02-2017
DOI: 10.1016/J.TPLANTS.2016.11.012
Abstract: Constitutive expression of the Arabidopsis vacuolar proton-pumping pyrophosphatase (H
Publisher: Cold Spring Harbor Laboratory
Date: 23-01-2020
DOI: 10.1101/2020.01.23.916742
Abstract: We quantified grain sodium (Na + ) content across a barley GWAS panel grown under optimal conditions. We identified a strong association with a region containing two low and one high Na + accumulating haplotypes of a Class 1 HIGH-AFFINITY POTASSIUM TRANSPORTER (HKT1 ) known to be involved in regulating plant Na + homeostasis. The haplotypes exhibited an average 1.8-fold difference in grain Na + content. We show that an L189P substitution disrupts Na + transport in the high Na + lines, disturbs the plasma membrane localisation typical of HKT1 and induces a conformational change in the protein predicted to compromise function. Under NaCl stress, lines containing P189 accumulate high levels of Na + , but show no significant difference in biomass. P189 increases in frequency from wild-species to elite cultivars leading us to speculate that the compromised haplotype is undergoing directional selection possibly due to the value of Na + as a functional nutrient in non-saline environments.
Publisher: Cold Spring Harbor Laboratory
Date: 30-06-2022
DOI: 10.1101/2022.06.28.497692
Abstract: Stomata are tiny pores on the leaf surface that are central to gas exchange. Stomatal number, size and aperture are key determinants of plant transpiration and photosynthesis, and variation in these traits can affect plant growth and productivity. Current methods to screen for stomatal phenotypes are tedious and not high throughput. This impedes research on stomatal biology and hinders efforts to develop resilient crops with optimised stomatal patterning. We have developed a rapid non-destructive method to phenotype stomatal traits in four species: wheat, rice, tomato and Arabidopsis. The method consists of two steps. The first is the non-destructive capture of images of the leaf surface from plants in their growing environment using a handheld microscope a process which only takes a few seconds compared to minutes for other methods. The second is to analyse stomatal features using a machine learning model that automatically detects, counts and measures stomatal number, size and aperture. The accuracy of the machine learning model in detecting stomata ranged from 76% to 99%, depending on the species, with a high correlation between measures of number, size and aperture between measurements using the machine learning models and by measuring them manually. The rapid method was applied to quickly identify contrasting stomatal phenotypes. We developed a method that combines rapid non-destructive imaging of leaf surfaces with automated image analysis. The method provides accurate data on stomatal features while significantly reducing time for data acquisition and analysis. It can be readily used to phenotype stomata in large populations in the field and in controlled environments.
Publisher: Frontiers Media SA
Date: 17-03-2020
Publisher: Wiley
Date: 05-03-2008
DOI: 10.1111/J.1365-3040.2008.01801.X
Abstract: There is increasing evidence of the important roles of glutamate receptors (GLRs) in plant development and in adaptation to stresses. However, the studies of these putative ion channels, both in planta and in Xenopus oocytes, may have been limited by our lack of knowledge of possible GLR heteromer formation in plants. We have developed a modification of the single-cell s ling technique to investigate GLR co-expression, and thus potential heteromer formation, in single cells of Arabidopsis thaliana leaves. Micro-EXpression lification (MEX) has allowed us to lify gene transcripts from a single cell, enabling expression of up to 100 gene transcripts to be assayed. We measured, on average, the transcripts of five to six different AtGLRs in a single cell. However, no consistent patterns of co-expression or cell-type-specific expression were detected, except that cells s led from the same plant showed similar expression profiles. The only discernible feature was the detection of AtGLR3.7 in every cell examined, an observation supported by GUS staining patterns in plants stably expressing promoter::uidA fusions. In addition, we found AtGLR3.7 expression in oocytes induces a Ba2+-, Ca2+- and Na+-permeable plasma membrane conductance.
Publisher: Wiley
Date: 04-04-2023
DOI: 10.1111/PCE.14588
Abstract: PHOSPHORUS‐STARVATION TOLERANCE 1 ( OsPSTOL1 ) is a variably present gene that benefits crown root growth and phosphorus (P) sufficiency in rice ( Oryza sativa ). To explore the ecophysiological importance of this gene, we performed a biogeographic survey of landraces and cultivars, confirming that functional OsPSTOL1 alleles prevail in low nutrient and drought‐prone rainfed ecosystems, whereas loss‐of‐function and absence haplotypes predominate in control‐irrigated paddy varieties of east Asia. An evolutionary history analysis of OsPSTOL1 and related genes in cereal, determined it and other genes are kinase‐only domain derivatives of membrane‐associated receptor like kinases. Finally, to evaluate the potential value of this kinase of unknown function in another Gramineae, wheat ( Triticum aestivum ) lines overexpressing OsPSTOL1 were evaluated under field and controlled low P conditions. OsPSTOL1 enhances growth, crown root number, and overall root plasticity under low P in wheat. Survey of root and shoot crown transcriptomes at two developmental stages identifies transcription factors that are differentially regulated in OsPSTOL1 wheat that are similarly controlled by the gene in rice. In wheat, OsPSTOL1 alters the timing and litude of regulators of root development in dry soils and hastens induction of the core P‐starvation response. OsPSTOL1 and related genes may aid more sustainable cultivation of cereal crops.
Publisher: Springer Science and Business Media LLC
Date: 14-08-2014
DOI: 10.1186/S12284-014-0016-3
Abstract: Soil salinity is an abiotic stress wide spread in rice producing areas, limiting both plant growth and yield. The development of salt-tolerant rice requires efficient and high-throughput screening techniques to identify promising lines for salt affected areas. Advances made in image-based phenotyping techniques provide an opportunity to use non-destructive imaging to screen for salinity tolerance traits in a wide range of germplasm in a reliable, quantitative and efficient way. However, the application of image-based phenotyping in the development of salt-tolerant rice remains limited. A non-destructive image-based phenotyping protocol to assess salinity tolerance traits of two rice cultivars (IR64 and Fatmawati) has been established in this study. The response of rice to different levels of salt stress was quantified over time based on total shoot area and senescent shoot area, calculated from visible red-green-blue (RGB) and fluorescence images. The response of rice to salt stress (50, 75 and 100 mM NaCl) could be clearly distinguished from the control as indicated by the reduced increase of shoot area. The salt concentrations used had only a small effect on the growth of rice during the initial phase of stress, the shoot Na + accumulation independent phase termed the ‘osmotic stress’ phase. However, after 20 d of treatment, the shoot area of salt stressed plants was reduced compared with non-stressed plants. This was accompanied by a significant increase in the concentration of Na + in the shoot. Variation in the senescent area of the cultivars IR64 and Fatmawati in response to a high concentration of Na + in the shoot indicates variation in tissue tolerance mechanisms between the cultivars. Image analysis has the potential to be used for high-throughput screening procedures in the development of salt-tolerant rice. The ability of image analysis to discriminate between the different aspects of salt stress (shoot ion-independent stress and shoot ion dependent stress) makes it a useful tool for genetic and physiological studies to elucidate processes that contribute to salinity tolerance in rice. The technique has the potential for identifying the genetic basis of these mechanisms and assisting in pyramiding different tolerance mechanisms into breeding lines.
Publisher: Cold Spring Harbor Laboratory
Date: 18-02-2020
DOI: 10.1101/2020.02.17.953216
Abstract: Soil salinity causes large productivity losses for agriculture worldwide. “Next-generation crops” that can tolerate salt stress are required for the sustainability of global food production. Previous research in Arabidopsis thaliana aimed at uncovering novel factors underpinning improved plant salinity tolerance identified the protein kinase AtCIPK16. Overexpression of AtCIPK16 enhanced shoot Na + exclusion and increased biomass in both Arabidopsis and barley. Here, a comparative transcriptomic study on Arabidopsis lines expressing AtCIPK16 was conducted in the presence and absence of salt stress, using an RNA-Seq approach, complemented by AtCIPK16 interaction and localisation studies. We are now able to provide evidence for AtCIPK16 activity in the nucleus. Moreover, the results manifest the involvement of a transcription factor, AtTZF1, phytohormones and the ability to quickly reach homeostasis as components important for improving salinity tolerance in transgenics overexpressing AtCIPK16 . Furthermore, we suggest the possibility of both biotic and abiotic tolerance through AtCIPK16, and propose a model for the salt tolerance pathway elicited through AtCIPK16.
Publisher: Elsevier BV
Date: 07-2016
DOI: 10.1016/J.YMPEV.2016.03.031
Abstract: Calcineurin B-like protein interacting protein kinases (CIPKs) are key regulators of pre-transcriptional and post-translational responses to abiotic stress. Arabidopsis thaliana CIPK16 (AtCIPK16) was identified from a forward genetic screen as a gene that mediates lower shoot salt accumulation and improved salinity tolerance in Arabidopsis and transgenic barley. Here, we aimed to gain an understanding of the evolution of AtCIPK16, and orthologues of CIPK16 in other plant species including barley, by conducting a phylogenetic analysis of terrestrial plant species. The resulting protein sequence based phylogenetic trees revealed a single clade that included AtCIPK16 along with two segmentally duplicated CIPKs, AtCIPK5 and AtCIPK25. No monocots had proteins that fell into this clade instead the most closely related monocot proteins formed a group basal to the entire CIPK16, 5 and 25 clade. We also found that AtCIPK16 contains a core Brassicales specific indel and a putative nuclear localisation signal, which are synapomorphic characters of CIPK16 genes. In addition, we present a model that proposes the evolution of CIPK16, 5 and 25 clade.
Publisher: Elsevier
Date: 2016
Publisher: Frontiers Media SA
Date: 23-06-2017
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: 15-11-2023
Abstract: Research into crop yield and resilience has underpinned global food security, evident in yields tripling in the past 5 decades. The challenges that global agriculture now faces are not just to feed 10+ billion people within a generation, but to do so under a harsher, more variable, and less predictable climate, and in many cases with less water, more expensive inputs, and declining soil quality. The challenges of climate change are not simply to breed for a “hotter drier climate,” but to enable resilience to floods and droughts and frosts and heat waves, possibly even within a single growing season. How well we prepare for the coming decades of climate variability will depend on our ability to modify current practices, innovate with novel breeding methods, and communicate and work with farming communities to ensure viability and profitability. Here we define how future climates will impact farming systems and growing seasons, thereby identifying the traits and practices needed and including exemplars being implemented and developed. Critically, this review will also consider societal perspectives and public engagement about emerging technologies for climate resilience, with participatory approaches presented as the best approach.
Publisher: Springer Science and Business Media LLC
Date: 28-04-2014
Publisher: Cold Spring Harbor Laboratory
Date: 24-01-2020
DOI: 10.1101/2020.01.21.909887
Abstract: Improving salinity tolerance in the most widely cultivated cereal, bread wheat ( Triticum aestivum L.), is essential to increase grain yields on saline agricultural lands. A Portuguese landrace, Mocho de Espiga Branca accumulates up to 6 folds greater leaf and sheath sodium (Na + ) than two Australian cultivars, Gladius and Scout, under salt stress. Despite high leaf and sheath Na + concentrations, Mocho de Espiga Branca maintained similar salinity tolerance compared to Gladius and Scout. A naturally occurring single nucleotide substitution was identified in the gene encoding a major Na + transporter TaHKT1 -D in Mocho de Espiga Branca, which resulted in a L190P amino acid residue variation. This variant prevents Mocho de Espiga Branca from retrieving Na + from the root xylem leading to a high shoot Na + concentration. The identification of the tissue tolerant Mocho de Espiga Branca will accelerate the development of more elite salt tolerant bread wheat cultivars.
Publisher: Springer Science and Business Media LLC
Date: 02-2011
Abstract: With the establishment of advanced technology facilities for high throughput plant phenotyping, the problem of estimating plant biomass of in idual plants from their two dimensional images is becoming increasingly important. The approach predominantly cited in literature is to estimate the biomass of a plant as a linear function of the projected shoot area of plants in the images. However, the estimation error from this model, which is solely a function of projected shoot area, is large, prohibiting accurate estimation of the biomass of plants, particularly for the salt-stressed plants. In this paper, we propose a method based on plant specific weight for improving the accuracy of the linear model and reducing the estimation bias (the difference between actual shoot dry weight and the value of the shoot dry weight estimated with a predictive model). For the proposed method in this study, we modeled the plant shoot dry weight as a function of plant area and plant age. The data used for developing our model and comparing the results with the linear model were collected from a completely randomized block design experiment. A total of 320 plants from two bread wheat varieties were grown in a supported hydroponics system in a greenhouse. The plants were exposed to two levels of hydroponic salt treatments (NaCl at 0 and 100 mM) for 6 weeks. Five harvests were carried out. Each time 64 randomly selected plants were imaged and then harvested to measure the shoot fresh weight and shoot dry weight. The results of statistical analysis showed that with our proposed method, most of the observed variance can be explained, and moreover only a small difference between actual and estimated shoot dry weight was obtained. The low estimation bias indicates that our proposed method can be used to estimate biomass of in idual plants regardless of what variety the plant is and what salt treatment has been applied. We validated this model on an independent set of barley data. The technique presented in this paper may extend to other plants and types of stresses.
Publisher: Wiley
Date: 05-2003
DOI: 10.1046/J.1365-313X.2003.01744.X
Abstract: There are a variety of methods for characterising gene expression at the level of in idual cells and for demonstrating that the cells also contain the encoded proteins. However, measuring the activity of enzymes at the resolution of single cells in complex tissues, such as leaves, is problematic. We have addressed this by using single-cell s ling to extract 10-100 pl droplets of sap from in idual plant cells and then measuring enzyme activities in these droplets with nanolitre-scale fluorescence-based assays. We have optimised these assays and used them to measure and characterise the activities of acid phosphatase, cysteine protease and nitrate reductase in sap s les from epidermal and mesophyll cells of barley (Hordeum vulgare L.) and Arabidopsis thaliana leaves exposed to different developmental and environmental conditions. During leaf senescence in barley, we found that the dynamics with which acid phosphatase and protease activities changed were different in each cell type and did not mirror the changes occurring at the whole-leaf level. Increases in nitrate reductase activities after exposure of barley plants to nitrate were large in mesophyll cells but small in epidermal cells. The technique was applied successfully to Arabidopsis and, as in barley, revealed cell-specific differences in the activities of both acid phosphatase and nitrate reductase. The assays add to the spectrum of techniques available for characterising cells within complex plant tissues, thus extending the opportunity to relate gene expression to biochemical activities at the single-cell level.
Publisher: Springer Science and Business Media LLC
Date: 2013
DOI: 10.1007/S00425-012-1827-3
Abstract: In cereals, a common salinity tolerance mechanism is to limit accumulation of Na(+) in the shoot. In a cross between the barley variety Barque-73 (Hordeum vulgare ssp. vulgare) and the accession CPI-71284 of wild barley (H. vulgare ssp. spontaneum), the HvNax3 locus on chromosome 7H was found to determine a ~10-25 % difference in leaf Na(+) accumulation in seedlings grown in saline hydroponics, with the beneficial exclusion trait originating from the wild parent. The Na(+) exclusion allele was also associated with a 13-21 % increase in shoot fresh weight. The HvNax3 locus was delimited to a 0.4 cM genetic interval, where it cosegregated with the HVP10 gene for vacuolar H(+)-pyrophosphatase (V-PPase). Sequencing revealed that the mapping parents encoded identical HVP10 proteins, but salinity-induced mRNA expression of HVP10 was higher in CPI-71284 than in Barque-73, in both roots and shoots. By contrast, the expression of several other genes predicted by comparative mapping to be located in the HvNax3 interval was similar in the two parent lines. Previous work demonstrated roles for V-PPase in ion transport and salinity tolerance. We therefore considered transcription levels of HVP10 to be a possible basis for variation in shoot Na(+) accumulation and biomass production controlled by the HvNax3 locus under saline conditions. Potential mechanisms linking HVP10 expression patterns to the observed phenotypes are discussed.
Publisher: Wiley
Date: 10-09-2012
DOI: 10.1111/J.1365-3040.2012.02595.X
Abstract: Salinity is a major abiotic stress which affects crop plants around the world, resulting in substantial loss of yield and millions of dollars of lost revenue. High levels of Na(+) in shoot tissue have many adverse effects and, crucially, yield in cereals is commonly inversely proportional to the extent of shoot Na(+) accumulation. We therefore need to identify genes, resistant plant cultivars and cellular processes that are involved in salinity tolerance, with the goal of introducing these factors into commercially available crops. Through the use of an Arabidopsis thaliana mapping population, we have identified a highly significant quantitative trait locus (QTL) linked to Na(+) exclusion. Fine mapping of this QTL identified a protein kinase (AtCIPK16), related to AtSOS2, that was significantly up-regulated under salt stress. Greater Na(+) exclusion was associated with significantly higher root expression of AtCIPK16, which is due to differences in the gene's promoter. Constitutive overexpression of the gene in Arabidopsis leads to plants with significant reduction in shoot Na(+) and greater salinity tolerance. amiRNA knock-downs of AtCIPK16 in Arabidopsis show a negative correlation between the expression levels of the gene and the amount of shoot Na(+) . Transgenic barley lines overexpressing AtCIPK16 show increased salinity tolerance.
Publisher: Wiley
Date: 29-11-2019
DOI: 10.1111/NPH.15555
Location: United Kingdom of Great Britain and Northern Ireland
Location: United Kingdom of Great Britain and Northern Ireland
Start Date: 2013
End Date: 2017
Funder: Grains Research and Development Corporation
View Funded ActivityStart Date: 2017
End Date: 2018
Funder: South Australian Grain Industry Trust Fund
View Funded ActivityStart Date: 2017
End Date: 2018
Funder: Grains Research and Development Corporation
View Funded ActivityStart Date: 2010
End Date: 2013
Funder: Grains Research and Development Corporation
View Funded ActivityStart Date: 2013
End Date: 2019
Funder: United States Agency for International Development
View Funded ActivityStart Date: 2023
End Date: 12-2025
Amount: $748,474.00
Funder: Australian Research Council
View Funded ActivityStart Date: 2023
End Date: 06-2024
Amount: $1,042,177.00
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 ActivityStart Date: 09-2022
End Date: 08-2027
Amount: $5,000,000.00
Funder: Australian Research Council
View Funded Activity