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Lau WCD, Donnellan L, Briggs M, Rupasinghe T, Harris JC, Hayes JE, Hoffmann P. Sodium doping and trapped ion mobility spectrometry improve lipid detection for novel MALDI-MSI analysis of oats. Food Chem 2024; 433:137275. [PMID: 37660601 DOI: 10.1016/j.foodchem.2023.137275] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2023] [Revised: 08/08/2023] [Accepted: 08/22/2023] [Indexed: 09/05/2023]
Abstract
Oat (Avena sativa L.) is an important cereal grain with a unique nutritional profile including a high proportion of lipids. Understanding lipid composition and distribution in oats is valuable for plant, food and nutritional research, and can be achieved using MALDI mass spectrometry imaging (MALDI-MSI). However, this approach presents several challenges for sample preparation (hardness of grains) and analysis (isobaric and isomeric properties of lipids). Here, oat sections were successfully mounted onto gelatin-coated indium tin oxide slides with minimal tearing. Poor detection of triacylglycerols was resolved by applying sodium chloride during mounting, increasing signal intensity. In combination with trapped ion mobility spectrometry (TIMS), lipid identification significantly improved, and we report the separation of several isobaric and isomeric lipids with visualisation of their "true" spatial distributions. This study describes a novel MALDI-TIMS-MSI analytical technique for oat lipids, which may be used to improve the discovery of biomarkers for grain quality.
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Affiliation(s)
- Wai C D Lau
- UniSA Clinical and Health Sciences, Health and Biomedical Innovation, University of South Australia, Adelaide, South Australia 5000, Australia
| | - Leigh Donnellan
- UniSA Clinical and Health Sciences, Health and Biomedical Innovation, University of South Australia, Adelaide, South Australia 5000, Australia
| | - Matthew Briggs
- UniSA Clinical and Health Sciences, Health and Biomedical Innovation, University of South Australia, Adelaide, South Australia 5000, Australia
| | | | - John C Harris
- South Australian Research and Development Institute, Department of Primary Industries and Regions, Adelaide, South Australia 5000, Australia; School of Agriculture, Food and Wine, University of Adelaide, Waite Campus, Urrbrae, South Australia 5064, Australia
| | - Julie E Hayes
- School of Agriculture, Food and Wine, University of Adelaide, Waite Campus, Urrbrae, South Australia 5064, Australia
| | - Peter Hoffmann
- UniSA Clinical and Health Sciences, Health and Biomedical Innovation, University of South Australia, Adelaide, South Australia 5000, Australia.
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2
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Abstract
Lipids are a group of compounds with diverse structures that perform several important functions in plants. To unravel and better understand their in vivo functions, plant biologists have been using various lipidomic technologies including liquid-chromatography (LC)-mass spectrometry (MS). However, there are still significant challenges in LC-MS based plant lipidomics, which need to be addressed. In this review, we provide an overview of the key developments in LC-MS based lipidomic approaches to detect and identify plant lipids with emphasis on areas that can be further improved. Given that the cellular lipidome is estimated to contain hundreds of thousands of lipids,1,2 many of the lipid structures remain to be discovered. Furthermore, the plant lipidome is considered to be significantly more complex compared to that of mammals. Recent technical developments in mass spectrometry have made the detection of novel lipids possible; hence, approaches that can be used for plant lipid discovery are also discussed.
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Affiliation(s)
- Cheka Kehelpannala
- School of BioSciences, The University of Melbourne, Melbourne, VIC 3010, Australia.
| | | | - Thomas Hennessy
- Agilent Technologies Australia Pty Ltd, 679 Springvale Road, Mulgrave, VIC 3170, Australia
| | - David Bradley
- Agilent Technologies Australia Pty Ltd, 679 Springvale Road, Mulgrave, VIC 3170, Australia
| | - Berit Ebert
- School of BioSciences, The University of Melbourne, Melbourne, VIC 3010, Australia.
| | - Ute Roessner
- School of BioSciences, The University of Melbourne, Melbourne, VIC 3010, Australia.
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3
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Otterbach SL, Khoury H, Rupasinghe T, Mendis H, Kwan KH, Lui V, Natera SHA, Klaiber I, Allen NM, Jarvis DE, Tester M, Roessner U, Schmöckel SM. Characterization of epidermal bladder cells in Chenopodium quinoa. Plant Cell Environ 2021; 44:3606-3622. [PMID: 34510479 DOI: 10.1111/pce.14181] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Revised: 08/01/2021] [Accepted: 08/23/2021] [Indexed: 06/13/2023]
Abstract
Chenopodium quinoa (quinoa) is considered a superfood with its favourable nutrient composition and being gluten free. Quinoa has high tolerance to abiotic stresses, such as salinity, water deficit (drought) and cold. The tolerance mechanisms are yet to be elucidated. Quinoa has epidermal bladder cells (EBCs) that densely cover the shoot surface, particularly the younger parts of the plant. Here, we report on the EBC's primary and secondary metabolomes, as well as the lipidome in control conditions and in response to abiotic stresses. EBCs were isolated from plants after cold, heat, high-light, water deficit and salt treatments. We used untargeted gas chromatography-mass spectrometry (GC-MS) to analyse metabolites and untargeted and targeted liquid chromatography-MS (LC-MS) for lipids and secondary metabolite analyses. We identified 64 primary metabolites, including sugars, organic acids and amino acids, 19 secondary metabolites, including phenolic compounds, betanin and saponins and 240 lipids categorized in five groups including glycerolipids and phospholipids. We found only few changes in the metabolic composition of EBCs in response to abiotic stresses; these were metabolites related with heat, cold and high-light treatments but not salt stress. Na+ concentrations were low in EBCs with all treatments and approximately two orders of magnitude lower than K+ concentrations.
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Affiliation(s)
- Sophie L Otterbach
- Department Physiology of Yield Stability, Institute Crop Science, Faculty of Agriculture, University of Hohenheim, Stuttgart, Germany
| | - Holly Khoury
- School of BioSciences, The University of Melbourne, Parkville, Victoria, Australia
| | - Thusitha Rupasinghe
- School of BioSciences, The University of Melbourne, Parkville, Victoria, Australia
| | - Himasha Mendis
- School of BioSciences, The University of Melbourne, Parkville, Victoria, Australia
| | - Kim H Kwan
- Metabolomics Australia, The University of Melbourne, Parkville, Victoria, Australia
| | - Veronica Lui
- Metabolomics Australia, The University of Melbourne, Parkville, Victoria, Australia
| | - Siria H A Natera
- Metabolomics Australia, The University of Melbourne, Parkville, Victoria, Australia
| | - Iris Klaiber
- Core Facility Hohenheim (640). Mass Spectrometry Unit, University of Hohenheim, Stuttgart, Germany
| | - Nathaniel M Allen
- Department Physiology of Yield Stability, Institute Crop Science, Faculty of Agriculture, University of Hohenheim, Stuttgart, Germany
| | - David E Jarvis
- Department of Plant and Wildlife Sciences, College of Life Sciences, Brigham Young University, Provo, Utah, USA
| | - Mark Tester
- Center for Desert Agriculture, Biological and Environmental Sciences and Engineering Division, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
| | - Ute Roessner
- School of BioSciences, The University of Melbourne, Parkville, Victoria, Australia
| | - Sandra M Schmöckel
- Department Physiology of Yield Stability, Institute Crop Science, Faculty of Agriculture, University of Hohenheim, Stuttgart, Germany
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4
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Rupasinghe T, Silva DC, Balawardena J, Perera K, Gunasekera D, Weerasinghe S, Jeyakumaran N, Abeysinghe P, Skandarajah T, Choudhury A, Joseph N. Curative-Intent Radiotherapy for Squamous Cell Carcinoma of the Head and Neck in Sri Lanka: The Impact of Radiotherapy Technique on Survival. Clin Oncol (R Coll Radiol) 2021; 33:765-772. [PMID: 34642066 DOI: 10.1016/j.clon.2021.09.017] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2021] [Revised: 09/13/2021] [Accepted: 09/28/2021] [Indexed: 12/24/2022]
Abstract
AIMS We conducted a retrospective analysis of patients with squamous cell carcinoma of the head and neck (SCCHN) treated with curative-intent radiotherapy at the National Cancer Institute of Sri Lanka to determine the impact of the treatment technique on disease-free survival (DFS). MATERIALS AND METHODS SCCHN patients treated with radical radiotherapy or adjuvant postoperative radiotherapy from 2016 to 2017 were included in the study. Data on the following variables were collected by reviewing clinical and radiotherapy treatment records: age, gender, tumour site, stage, time to delivery of radiotherapy, use of neoadjuvant chemotherapy, use of concurrent radiosensitising chemotherapy and treatment technique. DFS, defined as the time to death, tumour recurrence or loss to follow-up, was the primary end point and outcomes were compared between patients treated with intensity-modulated radiotherapy (IMRT) in linear accelerators and those treated with conventional radiotherapy in cobalt teletherapy units. Univariate and multivariate analyses were carried out on known prognostic variables. RESULTS In total, 408 patients were included in the study, with 138 (34%) being treated with IMRT in the linear accelerator. More than 75% of patients were of stage III or IV at diagnosis. The 2-year DFS of the whole cohort was 25% (95% confidence interval 21-30%). Patients treated with IMRT in the linear accelerator had a superior DFS in comparison with those treated with conventional radiotherapy in the cobalt teletherapy units (P < 0.001, hazard ratio 0.64, 95% confidence interval 0.5-0.82). Higher stage, cobalt treatment and use of neoadjuvant chemotherapy were adversely associated with DFS on multivariate analysis. CONCLUSION A large proportion of patients with SCCHN treated with curative-intent radiotherapy in Sri Lanka had locally advanced disease and DFS was superior in patients treated with IMRT in the linear accelerator.
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Affiliation(s)
- T Rupasinghe
- National Cancer Institute, Maharagama, Sri Lanka; Sri Lanka Cancer Research Group, Sri Lanka College of Oncologists, Mahargama, Sri Lanka
| | - D C Silva
- Sri Lanka Cancer Research Group, Sri Lanka College of Oncologists, Mahargama, Sri Lanka
| | - J Balawardena
- Sri Lanka Cancer Research Group, Sri Lanka College of Oncologists, Mahargama, Sri Lanka; General Sir John Kotalawela Defence University, Kandawala, Sri Lanka
| | - K Perera
- National Cancer Institute, Maharagama, Sri Lanka; Sri Lanka Cancer Research Group, Sri Lanka College of Oncologists, Mahargama, Sri Lanka
| | - D Gunasekera
- National Cancer Institute, Maharagama, Sri Lanka; Sri Lanka Cancer Research Group, Sri Lanka College of Oncologists, Mahargama, Sri Lanka
| | - S Weerasinghe
- National Cancer Institute, Maharagama, Sri Lanka; Sri Lanka Cancer Research Group, Sri Lanka College of Oncologists, Mahargama, Sri Lanka
| | - N Jeyakumaran
- National Cancer Institute, Maharagama, Sri Lanka; Sri Lanka Cancer Research Group, Sri Lanka College of Oncologists, Mahargama, Sri Lanka
| | - P Abeysinghe
- National Cancer Institute, Maharagama, Sri Lanka; Sri Lanka Cancer Research Group, Sri Lanka College of Oncologists, Mahargama, Sri Lanka
| | - T Skandarajah
- National Cancer Institute, Maharagama, Sri Lanka; Sri Lanka Cancer Research Group, Sri Lanka College of Oncologists, Mahargama, Sri Lanka
| | - A Choudhury
- The Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK; The Christie NHS Foundation Trust, Manchester, UK
| | - N Joseph
- Sri Lanka Cancer Research Group, Sri Lanka College of Oncologists, Mahargama, Sri Lanka; Teaching Hospital, Batticaloa, Sri Lanka.
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5
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Kehelpannala C, Rupasinghe T, Pasha A, Esteban E, Hennessy T, Bradley D, Ebert B, Provart NJ, Roessner U. An Arabidopsis lipid map reveals differences between tissues and dynamic changes throughout development. Plant J 2021; 107:287-302. [PMID: 33866624 PMCID: PMC8361726 DOI: 10.1111/tpj.15278] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2021] [Revised: 04/07/2021] [Accepted: 04/09/2021] [Indexed: 05/24/2023]
Abstract
Mass spectrometry is the predominant analytical tool used in the field of plant lipidomics. However, there are many challenges associated with the mass spectrometric detection and identification of lipids because of the highly complex nature of plant lipids. Studies into lipid biosynthetic pathways, gene functions in lipid metabolism, lipid changes during plant growth and development, and the holistic examination of the role of plant lipids in environmental stress responses are often hindered. Here, we leveraged a robust pipeline that we previously established to extract and analyze lipid profiles of different tissues and developmental stages from the model plant Arabidopsis thaliana. We analyzed seven tissues at several different developmental stages and identified more than 200 lipids from each tissue analyzed. The data were used to create a web-accessible in silico lipid map that has been integrated into an electronic Fluorescent Pictograph (eFP) browser. This in silico library of Arabidopsis lipids allows the visualization and exploration of the distribution and changes of lipid levels across selected developmental stages. Furthermore, it provides information on the characteristic fragments of lipids and adducts observed in the mass spectrometer and their retention times, which can be used for lipid identification. The Arabidopsis tissue lipid map can be accessed at http://bar.utoronto.ca/efp_arabidopsis_lipid/cgi-bin/efpWeb.cgi.
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Affiliation(s)
- Cheka Kehelpannala
- School of BioSciencesThe University of MelbourneMelbourneVIC3010Australia
| | | | - Asher Pasha
- Department of Cell and Systems Biology/Centre for the Analysis of Genome Evolution and FunctionUniversity of TorontoTorontoOntarioM5S 3B2Canada
| | - Eddi Esteban
- Department of Cell and Systems Biology/Centre for the Analysis of Genome Evolution and FunctionUniversity of TorontoTorontoOntarioM5S 3B2Canada
| | - Thomas Hennessy
- Agilent Technologies Australia Pty Ltd679 Springvale RoadMulgraveVIC3170Australia
| | - David Bradley
- Agilent Technologies Australia Pty Ltd679 Springvale RoadMulgraveVIC3170Australia
| | - Berit Ebert
- School of BioSciencesThe University of MelbourneMelbourneVIC3010Australia
| | - Nicholas J. Provart
- Department of Cell and Systems Biology/Centre for the Analysis of Genome Evolution and FunctionUniversity of TorontoTorontoOntarioM5S 3B2Canada
| | - Ute Roessner
- School of BioSciencesThe University of MelbourneMelbourneVIC3010Australia
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6
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Gao J, Wang F, Ranathunge K, Arruda AJ, Cawthray GR, Clode PL, He X, Leopold M, Roessner U, Rupasinghe T, Zhong H, Lambers H. Edaphic niche characterization of four Proteaceae reveals unique calcicole physiology linked to hyper-endemism of Grevillea thelemanniana. New Phytol 2020; 228:869-883. [PMID: 32726881 DOI: 10.1111/nph.16833] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Accepted: 07/15/2020] [Indexed: 06/11/2023]
Abstract
Endemism and rarity have long intrigued scientists. We focused on a rare endemic and critically-endangered species in a global biodiversity hotspot, Grevillea thelemanniana (Proteaceae). We carried out plant and soil analyses of four Proteaceae, including G. thelemanniana, and combined these with glasshouse studies. The analyses related to hydrology and plant water relations as well as soil nutrient concentrations and plant nutrition, with an emphasis on sodium (Na) and calcium (Ca). The local hydrology and matching plant traits related to water relations partially accounted for the distribution of the four Proteaceae. What determined the rarity of G. thelemanniana, however, was its accumulation of Ca. Despite much higher total Ca concentrations in the leaves of the rare G. thelemanniana than in the common Proteaceae, very few Ca crystals were detected in epidermal or mesophyll cells. Instead of crystals, G. thelemanniana epidermal cell vacuoles contained exceptionally high concentrations of noncrystalline Ca. Calcium ameliorated the negative effects of Na on the very salt-sensitive G. thelemanniana. Most importantly, G. thelemanniana required high concentrations of Ca to balance a massively accumulated feeding-deterrent carboxylate, trans-aconitate. This is the first example of a calcicole species accumulating and using Ca to balance accumulation of an antimetabolite.
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Affiliation(s)
- Jingwen Gao
- School of Biological Sciences, University of Western Australia, Crawley, Perth, WA, 6009, Australia
- Environmental Resources and Soil Fertilizer Institute, Zhejiang Academy of Agricultural Sciences, Hangzhou, 310021, China
| | - Feng Wang
- School of Biological Sciences, University of Western Australia, Crawley, Perth, WA, 6009, Australia
- Environmental Resources and Soil Fertilizer Institute, Zhejiang Academy of Agricultural Sciences, Hangzhou, 310021, China
| | - Kosala Ranathunge
- School of Biological Sciences, University of Western Australia, Crawley, Perth, WA, 6009, Australia
| | - André J Arruda
- School of Biological Sciences, University of Western Australia, Crawley, Perth, WA, 6009, Australia
| | - Gregory R Cawthray
- School of Biological Sciences, University of Western Australia, Crawley, Perth, WA, 6009, Australia
| | - Peta L Clode
- School of Biological Sciences, University of Western Australia, Crawley, Perth, WA, 6009, Australia
- Centre for Microscopy, Characterisation and Analysis, University of Western Australia, Crawley, Perth, WA, 6009, Australia
| | - Xinhua He
- Center of Excellence for Soil Biology, College of Resources and Environment, Southwest University, Beibei, Chongqing, 400715, China
| | - Matthias Leopold
- UWA School of Agriculture and Environment, University of Western Australia, Crawley, Perth, WA, 6009, Australia
| | - Ute Roessner
- School of BioSciences, The University of Melbourne, Parkville, Melbourne, Vic, 3010, Australia
| | - Thusitha Rupasinghe
- School of BioSciences, The University of Melbourne, Parkville, Melbourne, Vic, 3010, Australia
| | - Hongtao Zhong
- School of Biological Sciences, University of Western Australia, Crawley, Perth, WA, 6009, Australia
| | - Hans Lambers
- School of Biological Sciences, University of Western Australia, Crawley, Perth, WA, 6009, Australia
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7
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Martelli F, Zhongyuan Z, Wang J, Wong CO, Karagas NE, Roessner U, Rupasinghe T, Venkatachalam K, Perry T, Bellen HJ, Batterham P. Low doses of the neonicotinoid insecticide imidacloprid induce ROS triggering neurological and metabolic impairments in Drosophila. Proc Natl Acad Sci U S A 2020; 117:25840-25850. [PMID: 32989137 PMCID: PMC7568275 DOI: 10.1073/pnas.2011828117] [Citation(s) in RCA: 62] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Declining insect population sizes are provoking grave concern around the world as insects play essential roles in food production and ecosystems. Environmental contamination by intense insecticide usage is consistently proposed as a significant contributor, among other threats. Many studies have demonstrated impacts of low doses of insecticides on insect behavior, but have not elucidated links to insecticidal activity at the molecular and cellular levels. Here, the histological, physiological, and behavioral impacts of imidacloprid are investigated in Drosophila melanogaster, an experimental organism exposed to insecticides in the field. We show that oxidative stress is a key factor in the mode of action of this insecticide at low doses. Imidacloprid produces an enduring flux of Ca2+ into neurons and a rapid increase in levels of reactive oxygen species (ROS) in the larval brain. It affects mitochondrial function, energy levels, the lipid environment, and transcriptomic profiles. Use of RNAi to induce ROS production in the brain recapitulates insecticide-induced phenotypes in the metabolic tissues, indicating that a signal from neurons is responsible. Chronic low level exposures in adults lead to mitochondrial dysfunction, severe damage to glial cells, and impaired vision. The potent antioxidant, N-acetylcysteine amide (NACA), reduces the severity of a number of the imidacloprid-induced phenotypes, indicating a causal role for oxidative stress. Given that other insecticides are known to generate oxidative stress, this research has wider implications. The systemic impairment of several key biological functions, including vision, reported here would reduce the resilience of insects facing other environmental challenges.
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Affiliation(s)
- Felipe Martelli
- School of BioSciences, The University of Melbourne, Parkville, VIC, 3052, Australia
| | - Zuo Zhongyuan
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030
| | - Julia Wang
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030
| | - Ching-On Wong
- Department of Biological Sciences, Rutgers University, Newark, NJ 07102
| | - Nicholas E Karagas
- Department of Integrative Biology and Pharmacology, McGovern Medical School at the University of Texas Health Sciences Center, Houston, TX 77030
| | - Ute Roessner
- School of BioSciences, The University of Melbourne, Parkville, VIC, 3052, Australia
| | - Thusitha Rupasinghe
- School of BioSciences, The University of Melbourne, Parkville, VIC, 3052, Australia
| | - Kartik Venkatachalam
- Department of Integrative Biology and Pharmacology, McGovern Medical School at the University of Texas Health Sciences Center, Houston, TX 77030
| | - Trent Perry
- School of BioSciences, The University of Melbourne, Parkville, VIC, 3052, Australia
| | - Hugo J Bellen
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030
- Neurological Research Institute, Texas Children's Hospital, Houston, TX 77030
- Howard Hughes Medical Institute, Baylor College of Medicine, Houston, TX 77030
| | - Philip Batterham
- School of BioSciences, The University of Melbourne, Parkville, VIC, 3052, Australia;
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8
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Ho WWH, Hill CB, Doblin MS, Shelden MC, van de Meene A, Rupasinghe T, Bacic A, Roessner U. Integrative Multi-omics Analyses of Barley Rootzones under Salinity Stress Reveal Two Distinctive Salt Tolerance Mechanisms. Plant Commun 2020; 1:100031. [PMID: 33367236 PMCID: PMC7748018 DOI: 10.1016/j.xplc.2020.100031] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2019] [Revised: 01/02/2020] [Accepted: 02/06/2020] [Indexed: 05/02/2023]
Abstract
The mechanisms underlying rootzone-localized responses to salinity during early stages of barley development remain elusive. In this study, we performed the analyses of multi-root-omes (transcriptomes, metabolomes, and lipidomes) of a domesticated barley cultivar (Clipper) and a landrace (Sahara) that maintain and restrict seedling root growth under salt stress, respectively. Novel generalized linear models were designed to determine differentially expressed genes (DEGs) and abundant metabolites (DAMs) specific to salt treatments, genotypes, or rootzones (meristematic Z1, elongation Z2, and maturation Z3). Based on pathway over-representation of the DEGs and DAMs, phenylpropanoid biosynthesis is the most statistically enriched biological pathway among all salinity responses observed. Together with histological evidence, an intense salt-induced lignin impregnation was found only at stelic cell wall of Clipper Z2, compared with a unique elevation of suberin deposition across Sahara Z2. This suggests two differential salt-induced modulations of apoplastic flow between the genotypes. Based on the global correlation network of the DEGs and DAMs, callose deposition that potentially adjusted symplastic flow in roots was almost independent of salinity in rootzones of Clipper, and was markedly decreased in Sahara. Taken together, we propose two distinctive salt tolerance mechanisms in Clipper (growth-sustaining) and Sahara (salt-shielding), providing important clues for improving crop plasticity to cope with deteriorating global soil salinization.
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Affiliation(s)
- William Wing Ho Ho
- School of BioSciences, The University of Melbourne, Parkville, VIC 3010, Australia
| | - Camilla B. Hill
- School of BioSciences, The University of Melbourne, Parkville, VIC 3010, Australia
- School of Veterinary and Life Sciences, Murdoch University, Murdoch, WA 6150, Australia
| | - Monika S. Doblin
- La Trobe Institute for Agriculture & Food, Department of Animal, Plant and Soil Science, La Trobe University, Bundoora, VIC 3086, Australia
| | - Megan C. Shelden
- ARC Centre of Excellence in Plant Energy Biology, School of Agriculture, Food and Wine, University of Adelaide, Glen Osmond, SA 5064, Australia
| | - Allison van de Meene
- School of BioSciences, The University of Melbourne, Parkville, VIC 3010, Australia
| | - Thusitha Rupasinghe
- School of BioSciences, The University of Melbourne, Parkville, VIC 3010, Australia
| | - Antony Bacic
- La Trobe Institute for Agriculture & Food, Department of Animal, Plant and Soil Science, La Trobe University, Bundoora, VIC 3086, Australia
| | - Ute Roessner
- School of BioSciences, The University of Melbourne, Parkville, VIC 3010, Australia
- Metabolomics Australia, The University of Melbourne, Parkville, VIC 3010, Australia
- Corresponding author
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9
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Sarabia LD, Boughton BA, Rupasinghe T, Callahan DL, Hill CB, Roessner U. Comparative spatial lipidomics analysis reveals cellular lipid remodelling in different developmental zones of barley roots in response to salinity. Plant Cell Environ 2020; 43:327-343. [PMID: 31714612 PMCID: PMC7063987 DOI: 10.1111/pce.13653] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2019] [Revised: 08/25/2019] [Accepted: 08/27/2019] [Indexed: 05/18/2023]
Abstract
Salinity-induced metabolic, ionic, and transcript modifications in plants have routinely been studied using whole plant tissues, which do not provide information on spatial tissue responses. The aim of this study was to assess the changes in the lipid profiles in a spatial manner and to quantify the changes in the elemental composition in roots of seedlings of four barley cultivars before and after a short-term salt stress. We used a combination of liquid chromatography-tandem mass spectrometry, inductively coupled plasma mass spectrometry, matrix-assisted laser desorption/ionization mass spectrometry imaging, and reverse transcription - quantitative real time polymerase chain reaction platforms to examine the molecular signatures of lipids, ions, and transcripts in three anatomically different seminal root tissues before and after salt stress. We found significant changes to the levels of major lipid classes including a decrease in the levels of lysoglycerophospholipids, ceramides, and hexosylceramides and an increase in the levels of glycerophospholipids, hydroxylated ceramides, and hexosylceramides. Our results revealed that modifications to lipid and transcript profiles in plant roots in response to a short-term salt stress may involve recycling of major lipid species, such as phosphatidylcholine, via resynthesis from glycerophosphocholine.
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Affiliation(s)
- Lenin D. Sarabia
- School of BioSciences and Metabolomics AustraliaUniversity of MelbourneParkvilleVIC3010Australia
| | | | | | - Damien L. Callahan
- School of Life and Environmental Sciences, Centre for Chemistry and Biotechnology, (Burwood Campus)Deakin University, Geelong, Australia221 Burwood HighwayBurwoodVIC3125Australia
| | - Camilla B. Hill
- School of Veterinary and Life SciencesMurdoch UniversityMurdochWA6150Australia
| | - Ute Roessner
- School of BioSciences and Metabolomics AustraliaUniversity of MelbourneParkvilleVIC3010Australia
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10
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Leo CH, Ng HH, Marshall SA, Jelinic M, Rupasinghe T, Qin C, Roessner U, Ritchie RH, Tare M, Parry LJ. Relaxin reduces endothelium-derived vasoconstriction in hypertension: Revealing new therapeutic insights. Br J Pharmacol 2019; 177:217-233. [PMID: 31479151 DOI: 10.1111/bph.14858] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2018] [Revised: 08/21/2019] [Accepted: 08/26/2019] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND AND PURPOSE Endothelium-derived vasoconstriction is a hallmark of vascular dysfunction in hypertension. In some cases, an overproduction of endothelium-derived prostacyclin (PGI2 ) can cause contraction rather than relaxation. Relaxin is well known for its vasoprotective actions, but the possibility that this peptide could also reverse endothelium-derived vasoconstriction has never been investigated. We tested the hypothesis that short-term relaxin treatment mitigates endothelium-derived vasoconstriction in spontaneously hypertensive rats (SHR). EXPERIMENTAL APPROACH Male Wistar Kyoto rats (WKY) and SHR were subcutaneously infused with either vehicle (20 mmol·L-1 sodium acetate) or relaxin (13.3 μg·kg-1 ·hr-1 ) using osmotic minipumps for 3 days. Vascular reactivity to the endothelium-dependent agonist ACh was assessed in vitro by wire myography. Quantitative PCR and LC-MS were used to identify changes in gene expression of prostanoid pathways and PG production, respectively. KEY RESULTS Relaxin treatment ameliorated hypertension-induced endothelial dysfunction by increasing NO-dependent relaxation and reducing endothelium-dependent contraction. Notably, short-term relaxin treatment up-regulated mesenteric PGI2 receptor (IP) expression, permitting PGI2 -IP-mediated vasorelaxation. In the aorta, reversal of contraction was accompanied by suppression of the hypertension-induced increase in prostanoid-producing enzymes and reduction in PGI2 -evoked contractions. CONCLUSIONS AND IMPLICATIONS Relaxin has region-dependent vasoprotective actions in hypertension. Specifically, relaxin has distinct effects on endothelium-derived contracting factors and their associated vasoconstrictor pathways in mesenteric arteries and the aorta. Taken together, these observations reveal the potential of relaxin as a new therapeutic agent for vascular disorders that are associated with endothelium-derived vasoconstriction including hypertension.
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Affiliation(s)
- Chen Huei Leo
- School of Biosciences, The University of Melbourne, Parkville, VIC, Australia
| | - Hooi Hooi Ng
- School of Biosciences, The University of Melbourne, Parkville, VIC, Australia.,Heart Failure Pharmacology, Baker Heart & Diabetes Institute, Melbourne, VIC, Australia
| | - Sarah A Marshall
- School of Biosciences, The University of Melbourne, Parkville, VIC, Australia
| | - Maria Jelinic
- School of Biosciences, The University of Melbourne, Parkville, VIC, Australia
| | - Thusitha Rupasinghe
- Metabolomics Australia, School of Biosciences, The University of Melbourne, Parkville, VIC, Australia
| | - Chengxue Qin
- Heart Failure Pharmacology, Baker Heart & Diabetes Institute, Melbourne, VIC, Australia.,Department of Pharmacology & Therapeutics, The University of Melbourne, Parkville, VIC, Australia
| | - Ute Roessner
- School of Biosciences, The University of Melbourne, Parkville, VIC, Australia.,Metabolomics Australia, School of Biosciences, The University of Melbourne, Parkville, VIC, Australia
| | - Rebecca H Ritchie
- Heart Failure Pharmacology, Baker Heart & Diabetes Institute, Melbourne, VIC, Australia.,Department of Diabetes, Monash University, Clayton, VIC, Australia
| | - Marianne Tare
- Monash Rural Health, Monash University, Churchill, VIC, Australia.,Department of Physiology, Monash University, Clayton, VIC, Australia
| | - Laura J Parry
- School of Biosciences, The University of Melbourne, Parkville, VIC, Australia
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11
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Gupta S, Rupasinghe T, Callahan DL, Natera SHA, Smith PMC, Hill CB, Roessner U, Boughton BA. Spatio-Temporal Metabolite and Elemental Profiling of Salt Stressed Barley Seeds During Initial Stages of Germination by MALDI-MSI and µ-XRF Spectrometry. Front Plant Sci 2019; 10:1139. [PMID: 31608088 PMCID: PMC6774343 DOI: 10.3389/fpls.2019.01139] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2019] [Accepted: 08/21/2019] [Indexed: 05/05/2023]
Abstract
Seed germination is the essential first step in crop establishment, and can be severely affected by salinity stress which can inhibit essential metabolic processes during the germination process. Salt stress during seed germination can trigger lipid-dependent signalling cascades that activate plant adaptation processes, lead to changes in membrane fluidity to help resist the stress, and cause secondary metabolite responses due to increased oxidative stress. In germinating barley (Hordeum vulgare), knowledge of the changes in spatial distribution of lipids and other small molecules at a cellular level in response to salt stress is limited. In this study, mass spectrometry imaging (MSI), liquid chromatography quadrupole time-of-flight mass spectrometry (LC-QToF-MS), inductively coupled plasma mass spectrometry (ICP-MS), and X-ray fluorescence (XRF) were used to determine the spatial distribution of metabolites, lipids and a range of elements, such as K+ and Na+, in seeds of two barley genotypes with contrasting germination phenology (Australian barley varieties Mundah and Keel). We detected and tentatively identified more than 200 lipid species belonging to seven major lipid classes (fatty acyls, glycerolipids, glycerophospholipids, sphingolipids, prenol lipids, sterol lipids, and polyketides) that differed in their spatial distribution based on genotype (Mundah or Keel), time post-imbibition (0 to 72 h), or treatment (control or salt). We found a tentative flavonoid was discriminant in post-imbibed Mundah embryos under saline conditions, and a delayed flavonoid response in Keel relative to Mundah. We further employed MSI-MS/MS and LC-QToF-MS/MS to explore the identity of the discriminant flavonoid and study the temporal pattern in five additional barley genotypes. ICP-MS was used to quantify the elemental composition of both Mundah and Keel seeds, showing a significant increase in Na+ in salt treated samples. Spatial mapping of elements using µ-XRF localized the elements within the seeds. This study integrates data obtained from three mass spectrometry platforms together with µ-XRF to yield information on the localization of lipids, metabolites and elements improving our understanding of the germination process under salt stress at a molecular level.
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Affiliation(s)
- Sneha Gupta
- School of BioSciences, University of Melbourne, Parkville, VIC, Australia
| | - Thusitha Rupasinghe
- Metabolomics Australia, School of BioSciences, University of Melbourne, Parkville, VIC, Australia
| | - Damien L. Callahan
- School of Life and Environmental Sciences, Deakin University, Burwood, VIC, Australia
| | - Siria H. A. Natera
- Metabolomics Australia, School of BioSciences, University of Melbourne, Parkville, VIC, Australia
| | - Penelope M. C. Smith
- AgriBio, Centre for AgriBiosciences, Department of Animal, Plant and Soil Sciences, School of Life Sciences, La Trobe University, Bundoora, VIC, Australia
| | - Camilla B. Hill
- School of Veterinary and Life Sciences, Murdoch University, Murdoch, WA, Australia
| | - Ute Roessner
- Metabolomics Australia, School of BioSciences, University of Melbourne, Parkville, VIC, Australia
| | - Berin A. Boughton
- School of BioSciences, University of Melbourne, Parkville, VIC, Australia
- Metabolomics Australia, School of BioSciences, University of Melbourne, Parkville, VIC, Australia
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12
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Asami P, Rupasinghe T, Moghaddam L, Njaci I, Roessner U, Mundree S, Williams B. Roots of the Resurrection Plant Tripogon loliiformis Survive Desiccation Without the Activation of Autophagy Pathways by Maintaining Energy Reserves. Front Plant Sci 2019; 10:459. [PMID: 31105716 PMCID: PMC6494956 DOI: 10.3389/fpls.2019.00459] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2019] [Accepted: 03/27/2019] [Indexed: 05/18/2023]
Abstract
Being sessile, plants must regulate energy balance, potentially via source-sink relations, to compromise growth with survival in stressful conditions. Crops are sensitive, possibly because they allocate their energy resources toward growth and yield rather than stress tolerance. In contrast, resurrection plants tightly regulate sugar metabolism and use a series of physiological adaptations to suppress cell death in their vegetative tissue to regain full metabolic capacity from a desiccated state within 72 h of watering. Previously, we showed that shoots of the resurrection plant Tripogon loliiformis, initiate autophagy upon dehydration as one strategy to reinstate homeostasis and suppress cell death. Here, we describe the relationship between energy status, sugar metabolism, trehalose-mediated activation of autophagy pathways and investigate whether shoots and roots utilize similar desiccation tolerance strategies. We show that despite containing high levels of trehalose, dehydrated Tripogon roots do not display elevated activation of autophagy pathways. Using targeted and non-targeted metabolomics, transmission electron microscopy (TEM) and transcriptomics we show that T. loliiformis engages a strategy similar to the long-term drought responses of sensitive plants and continues to use the roots as a sink even during sustained stress. Dehydrating T. loliiformis roots contained more sucrose and trehalose-6-phosphate compared to shoots at an equivalent water content. The increased resources in the roots provides sufficient energy to cope with stress and thus autophagy is not required. These results were confirmed by the absence of autophagosomes in roots by TEM. Upregulation of sweet genes in both shoots and roots show transcriptional regulation of sucrose translocation from leaves to roots and within roots during dehydration. Differences in the cell's metabolic status caused starkly different cell death responses between shoots and roots. These findings show how shoots and roots utilize different stress response strategies and may provide candidate targets that can be used as tools for the improvement of stress tolerance in crops.
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Affiliation(s)
- Pauline Asami
- Centre for Tropical Crops and Biocommodities, Queensland University of Technology, Brisbane, QLD, Australia
| | - Thusitha Rupasinghe
- Metabolomics Australia, School of BioSciences, The University of Melbourne, Melbourne, VIC, Australia
| | - Lalehvash Moghaddam
- Centre for Tropical Crops and Biocommodities, Queensland University of Technology, Brisbane, QLD, Australia
| | - Isaac Njaci
- Biosciences Eastern and Central Africa-International Livestock Research Institute, Nairobi, Kenya
| | - Ute Roessner
- Metabolomics Australia, School of BioSciences, The University of Melbourne, Melbourne, VIC, Australia
| | - Sagadevan Mundree
- Centre for Tropical Crops and Biocommodities, Queensland University of Technology, Brisbane, QLD, Australia
| | - Brett Williams
- Centre for Tropical Crops and Biocommodities, Queensland University of Technology, Brisbane, QLD, Australia
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13
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Lev S, Rupasinghe T, Desmarini D, Kaufman-Francis K, Sorrell TC, Roessner U, Djordjevic JT. The PHO signaling pathway directs lipid remodeling in Cryptococcus neoformans via DGTS synthase to recycle phosphate during phosphate deficiency. PLoS One 2019; 14:e0212651. [PMID: 30789965 PMCID: PMC6383925 DOI: 10.1371/journal.pone.0212651] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2019] [Accepted: 02/06/2019] [Indexed: 12/16/2022] Open
Abstract
The phosphate sensing and acquisition (PHO) pathway of Cryptococcus neoformans is essential for growth in phosphate-limiting conditions and for dissemination of infection in a mouse model. Its key transcription factor, Pho4, regulates expression of genes controlling the acquisition of phosphate from both external and cellular sources. One such gene, BTA1, is highly up-regulated during phosphate starvation. Given that a significant proportion of cellular phosphate is incorporated into phospholipids, and that the Pho4-dependent BTA1 gene encodes an enzyme predicted to catalyse production of a phosphorus-free betaine lipid, we investigated whether phospholipids provide an accessible reservoir of phosphate during phosphate deficiency. By comparing lipid profiles of phosphate-starved WT C. neoformans, PHO4 (pho4Δ) and BTA1 (bta1Δ) deletion mutants using thin layer chromatography and liquid chromatography mass spectrometry, we showed that phosphatidylcholine (PC) is substituted by the phosphorus-free betaine lipids diacylglyceryl-N,N,N-trimethylhomoserine (DGTS) and diacylgyceryl hydroxymethyl-N,N,N-trimethyl-beta-alanine (DGTA) in a Pho4- and Bta1-dependent manner, and that BTA1 encodes a functional DGTS synthase. Synthesis of DGTA tightly correlated with that of DGTS, consistent with DGTS being the precursor of DGTA. Similar to pho4Δ, bta1Δ grew more slowly than WT in cell culture medium (RPMI) and was hypovirulent in a murine model of cryptococcosis. In contrast to pho4Δ, bta1Δ tolerated alkaline pH and disseminated to the brain. Our results demonstrate that Bta1-dependent substitution of PC by betaine lipids is tightly regulated in C. neoformans by the PHO pathway, to conserve phosphate and preserve membrane integrity and function. This phospholipid remodeling strategy may also contribute to cryptococcal virulence during host infection.
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Affiliation(s)
- Sophie Lev
- Centre for Infectious Diseases and Microbiology, Fungal Pathogenesis Group, Westmead Institute for Medical Research, Westmead, New South Wales, Australia
- Sydney Medical School-Westmead, University of Sydney at Westmead Hospital, Westmead, New South Wales, Australia
- Marie Bashir Institute for Infectious Diseases and Biosecurity, University of Sydney, Sydney, New South Wales, Australia
| | - Thusitha Rupasinghe
- Metabolomics Australia, School of Biosciences, The University of Melbourne, Melbourne, Victoria, Australia
| | - Desmarini Desmarini
- Centre for Infectious Diseases and Microbiology, Fungal Pathogenesis Group, Westmead Institute for Medical Research, Westmead, New South Wales, Australia
| | - Keren Kaufman-Francis
- Centre for Infectious Diseases and Microbiology, Fungal Pathogenesis Group, Westmead Institute for Medical Research, Westmead, New South Wales, Australia
- Sydney Medical School-Westmead, University of Sydney at Westmead Hospital, Westmead, New South Wales, Australia
- Marie Bashir Institute for Infectious Diseases and Biosecurity, University of Sydney, Sydney, New South Wales, Australia
| | - Tania Christine Sorrell
- Centre for Infectious Diseases and Microbiology, Fungal Pathogenesis Group, Westmead Institute for Medical Research, Westmead, New South Wales, Australia
- Sydney Medical School-Westmead, University of Sydney at Westmead Hospital, Westmead, New South Wales, Australia
- Marie Bashir Institute for Infectious Diseases and Biosecurity, University of Sydney, Sydney, New South Wales, Australia
| | - Ute Roessner
- Metabolomics Australia, School of Biosciences, The University of Melbourne, Melbourne, Victoria, Australia
| | - Julianne Teresa Djordjevic
- Centre for Infectious Diseases and Microbiology, Fungal Pathogenesis Group, Westmead Institute for Medical Research, Westmead, New South Wales, Australia
- Sydney Medical School-Westmead, University of Sydney at Westmead Hospital, Westmead, New South Wales, Australia
- Marie Bashir Institute for Infectious Diseases and Biosecurity, University of Sydney, Sydney, New South Wales, Australia
- * E-mail:
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14
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Melino VJ, Casartelli A, George J, Rupasinghe T, Roessner U, Okamoto M, Heuer S. RNA Catabolites Contribute to the Nitrogen Pool and Support Growth Recovery of Wheat. Front Plant Sci 2018; 9:1539. [PMID: 30455708 PMCID: PMC6230992 DOI: 10.3389/fpls.2018.01539] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Accepted: 10/01/2018] [Indexed: 05/23/2023]
Abstract
Turn-over of RNA and catabolism of nucleotides releases one to four ammonia molecules; the released nutrients being reassimilated into primary metabolism. Preliminary evidence indicates that monocots store high levels of free nucleotides and nucleosides but their potential as a source of internal organic nitrogen for use and remobilization is uncharted. Early tillering wheat plants were therefore starved of N over a 5-day time-course with examination of nucleic acid yields in whole shoots, young and old leaves and roots. Nucleic acids constituted ∼4% of the total N pool of N starved wheat plants, which was comparable with the N available from nitrate (NO3 -) and greater than that available from the sum of 20 proteinogenic amino acids. Methods were optimized to detect nucleotide (purine and pyrimidine) metabolites, and wheat orthologs of RNA degradation (TaRNS), nucleoside transport (TaENT1, TaENT3) and salvage (TaADK) were identified. It was found that N starved wheat roots actively catabolised RNA and specific purines but accumulated pyrimidines. Reduced levels of RNA corresponded with induction of TaRNS2, TaENT1, TaENT3, and TaADK in the roots. Reduced levels of GMP, guanine, xanthine, allantoin, allantoate and glyoxylate in N starved roots correlated with accumulation of allantoate and glyoxylate in the oldest leaf, suggesting translocation of allantoin. Furthermore, N starved wheat plants exogenously supplied with N in the form of purine catabolites grew and photosynthesized as well as those plants re-supplied with NO3 -. These results support the hypothesis that the nitrogen and carbon recovered from purine metabolism can support wheat growth.
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Affiliation(s)
- Vanessa Jane Melino
- Waite Research Institute, University of Adelaide, Glen Osmond, SA, Australia
- School of Agriculture and Food, University of Melbourne, Parkville, VIC, Australia
| | - Alberto Casartelli
- Waite Research Institute, University of Adelaide, Glen Osmond, SA, Australia
| | - Jessey George
- Waite Research Institute, University of Adelaide, Glen Osmond, SA, Australia
| | - Thusitha Rupasinghe
- Metabolomics Australia, School of Biosciences, The University of Melbourne, Parkville, VIC, Australia
| | - Ute Roessner
- Metabolomics Australia, School of Biosciences, The University of Melbourne, Parkville, VIC, Australia
| | - Mamoru Okamoto
- Waite Research Institute, University of Adelaide, Glen Osmond, SA, Australia
| | - Sigrid Heuer
- Waite Research Institute, University of Adelaide, Glen Osmond, SA, Australia
- Department of Plant Biology and Crop Science, Rothamsted Research, Harpenden, United Kingdom
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15
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Ebert B, Rautengarten C, McFarlane HE, Rupasinghe T, Zeng W, Ford K, Scheller HV, Bacic A, Roessner U, Persson S, Heazlewood JL. A Golgi UDP-GlcNAc transporter delivers substrates for N-linked glycans and sphingolipids. Nat Plants 2018; 4:792-801. [PMID: 30224661 DOI: 10.1038/s41477-018-0235-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/17/2017] [Accepted: 07/26/2018] [Indexed: 05/20/2023]
Abstract
Glycosylation requires activated glycosyl donors in the form of nucleotide sugars to drive processes such as post-translational protein modifications and glycolipid and polysaccharide biosynthesis. Most of these reactions occur in the Golgi, requiring cytosolic-derived nucleotide sugars, which need to be actively transferred into the Golgi lumen by nucleotide sugar transporters. We identified a Golgi-localized nucleotide sugar transporter from Arabidopsis thaliana with affinity for UDP-N-acetyl-D-glucosamine (UDP-GlcNAc) and assigned it UDP-GlcNAc transporter 1 (UGNT1). Profiles of N-glycopeptides revealed that plants carrying the ugnt1 loss-of-function allele are virtually devoid of complex and hybrid N-glycans. Instead, the N-glycopeptide population from these alleles exhibited high-mannose structures, representing structures prior to the addition of the first GlcNAc in the Golgi. Concomitantly, sphingolipid profiling revealed that the biosynthesis of GlcNAc-containing glycosyl inositol phosphorylceramides (GIPCs) is also reliant on this transporter. By contrast, plants carrying the loss-of-function alleles affecting ROCK1, which has been reported to transport UDP-GlcNAc and UDP-N-acetylgalactosamine, exhibit no changes in N-glycan or GIPC profiles. Our findings reveal that plants contain a single UDP-GlcNAc transporter that delivers an essential substrate for the maturation of N-glycans and the GIPC class of sphingolipids.
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Affiliation(s)
- Berit Ebert
- School of Biosciences, University of Melbourne, Melbourne, Victoria, Australia
| | | | - Heather E McFarlane
- School of Biosciences, University of Melbourne, Melbourne, Victoria, Australia
| | - Thusitha Rupasinghe
- Metabolomics Australia, School of Biosciences, University of Melbourne, Melbourne, Victoria, Australia
| | - Wei Zeng
- School of Biosciences, University of Melbourne, Melbourne, Victoria, Australia
- ARC Centre of Excellence in Plant Cell Walls, School of Biosciences, University of Melbourne, Melbourne, Victoria, Australia
| | - Kristina Ford
- School of Biosciences, University of Melbourne, Melbourne, Victoria, Australia
- ARC Centre of Excellence in Plant Cell Walls, School of Biosciences, University of Melbourne, Melbourne, Victoria, Australia
| | - Henrik V Scheller
- Joint BioEnergy Institute and Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
- Department of Plant and Microbial Biology, University of California, Berkeley, CA, USA
| | - Antony Bacic
- School of Biosciences, University of Melbourne, Melbourne, Victoria, Australia
- ARC Centre of Excellence in Plant Cell Walls, School of Biosciences, University of Melbourne, Melbourne, Victoria, Australia
| | - Ute Roessner
- Metabolomics Australia, School of Biosciences, University of Melbourne, Melbourne, Victoria, Australia
| | - Staffan Persson
- School of Biosciences, University of Melbourne, Melbourne, Victoria, Australia
| | - Joshua L Heazlewood
- School of Biosciences, University of Melbourne, Melbourne, Victoria, Australia.
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16
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Sarabia LD, Boughton BA, Rupasinghe T, van de Meene AML, Callahan DL, Hill CB, Roessner U. High-mass-resolution MALDI mass spectrometry imaging reveals detailed spatial distribution of metabolites and lipids in roots of barley seedlings in response to salinity stress. Metabolomics 2018; 14:63. [PMID: 29681790 PMCID: PMC5907631 DOI: 10.1007/s11306-018-1359-3] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/18/2017] [Accepted: 04/09/2018] [Indexed: 01/12/2023]
Abstract
INTRODUCTION Mass spectrometry imaging (MSI) is a technology that enables the visualization of the spatial distribution of hundreds to thousands of metabolites in the same tissue section simultaneously. Roots are below-ground plant organs that anchor plants to the soil, take up water and nutrients, and sense and respond to external stresses. Physiological responses to salinity are multifaceted and have predominantly been studied using whole plant tissues that cannot resolve plant salinity responses spatially. OBJECTIVES This study aimed to use a comprehensive approach to study the spatial distribution and profiles of metabolites, and to quantify the changes in the elemental content in young developing barley seminal roots before and after salinity stress. METHODS Here, we used a combination of liquid chromatography-mass spectrometry (LC-MS), inductively coupled plasma mass spectrometry (ICP-MS), and matrix-assisted laser desorption/ionization (MALDI-MSI) platforms to profile and analyze the spatial distribution of ions, metabolites and lipids across three anatomically different barley root zones before and after a short-term salinity stress (150 mM NaCl). RESULTS We localized, visualized and discriminated compounds in fine detail along longitudinal root sections and compared ion, metabolite, and lipid composition before and after salt stress. Large changes in the phosphatidylcholine (PC) profiles were observed as a response to salt stress with PC 34:n showing an overall reduction in salt treated roots. ICP-MS analysis quantified changes in the elemental content of roots with increases of Na+ and decreases of K+ content. CONCLUSION Our results established the suitability of combining three mass spectrometry platforms to analyze and map ionic and metabolic responses to salinity stress in plant roots and to elucidate tolerance mechanisms in response to abiotic stress, such as salinity stress.
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Affiliation(s)
- Lenin D Sarabia
- School of BioSciences, University of Melbourne, Parkville, VIC, 3010, Australia
| | - Berin A Boughton
- Metabolomics Australia, School of BioSciences, University of Melbourne, Parkville, VIC, 3010, Australia.
| | - Thusitha Rupasinghe
- Metabolomics Australia, School of BioSciences, University of Melbourne, Parkville, VIC, 3010, Australia
| | | | - Damien L Callahan
- School of Life and Environmental Sciences, Centre for Chemistry and Biotechnology, Deakin University, 221 Burwood Highway, Burwood, VIC, 3125, Australia
| | - Camilla B Hill
- School of Veterinary and Life Sciences, Murdoch University, Murdoch, WA, 6150, Australia
| | - Ute Roessner
- School of BioSciences, University of Melbourne, Parkville, VIC, 3010, Australia
- Metabolomics Australia, School of BioSciences, University of Melbourne, Parkville, VIC, 3010, Australia
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17
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Summers MA, Rupasinghe T, Vasiljevski ER, Evesson FJ, Mikulec K, Peacock L, Quinlan KGR, Cooper ST, Roessner U, Stevenson DA, Little DG, Schindeler A. Dietary intervention rescues myopathy associated with neurofibromatosis type 1. Hum Mol Genet 2017; 27:577-588. [DOI: 10.1093/hmg/ddx423] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2017] [Accepted: 11/29/2017] [Indexed: 02/07/2023] Open
Affiliation(s)
- Matthew A Summers
- Orthopaedic Research & Biotechnology, The Children’s Hospital at Westmead, Westmead, NSW, Australia
- Discipline of Paediatrics & Child Heath, Faculty of Medicine, University of Sydney, Camperdown, NSW, Australia
| | | | - Emily R Vasiljevski
- Orthopaedic Research & Biotechnology, The Children’s Hospital at Westmead, Westmead, NSW, Australia
- Discipline of Paediatrics & Child Heath, Faculty of Medicine, University of Sydney, Camperdown, NSW, Australia
| | - Frances J Evesson
- Institute for Neuroscience and Muscle Research, The Children’s Hospital Westmead, Sydney, NSW, Australia
| | - Kathy Mikulec
- Orthopaedic Research & Biotechnology, The Children’s Hospital at Westmead, Westmead, NSW, Australia
| | - Lauren Peacock
- Orthopaedic Research & Biotechnology, The Children’s Hospital at Westmead, Westmead, NSW, Australia
| | - Kate G R Quinlan
- Discipline of Paediatrics & Child Heath, Faculty of Medicine, University of Sydney, Camperdown, NSW, Australia
- Institute for Neuroscience and Muscle Research, The Children’s Hospital Westmead, Sydney, NSW, Australia
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, NSW, Australia
| | - Sandra T Cooper
- Discipline of Paediatrics & Child Heath, Faculty of Medicine, University of Sydney, Camperdown, NSW, Australia
- Institute for Neuroscience and Muscle Research, The Children’s Hospital Westmead, Sydney, NSW, Australia
| | - Ute Roessner
- Metabolomics Australia, University of Melbourne, VIC, Australia
| | - David A Stevenson
- Division of Medical Genetics, Stanford University, Stanford, CA, USA
| | - David G Little
- Orthopaedic Research & Biotechnology, The Children’s Hospital at Westmead, Westmead, NSW, Australia
- Discipline of Paediatrics & Child Heath, Faculty of Medicine, University of Sydney, Camperdown, NSW, Australia
| | - Aaron Schindeler
- Orthopaedic Research & Biotechnology, The Children’s Hospital at Westmead, Westmead, NSW, Australia
- Discipline of Paediatrics & Child Heath, Faculty of Medicine, University of Sydney, Camperdown, NSW, Australia
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Kiani-Pouya A, Roessner U, Jayasinghe NS, Lutz A, Rupasinghe T, Bazihizina N, Bohm J, Alharbi S, Hedrich R, Shabala S. Epidermal bladder cells confer salinity stress tolerance in the halophyte quinoa and Atriplex species. Plant Cell Environ 2017; 40:1900-1915. [PMID: 28558173 DOI: 10.1111/pce.12995] [Citation(s) in RCA: 60] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2017] [Accepted: 05/21/2017] [Indexed: 05/02/2023]
Abstract
Epidermal bladder cells (EBCs) have been postulated to assist halophytes in coping with saline environments. However, little direct supporting evidence is available. Here, Chenopodium quinoa plants were grown under saline conditions for 5 weeks. One day prior to salinity treatment, EBCs from all leaves and petioles were gently removed by using a soft cosmetic brush and physiological, ionic and metabolic changes in brushed and non-brushed leaves were compared. Gentle removal of EBC neither initiated wound metabolism nor affected the physiology and biochemistry of control-grown plants but did have a pronounced effect on salt-grown plants, resulting in a salt-sensitive phenotype. Of 91 detected metabolites, more than half were significantly affected by salinity. Removal of EBC dramatically modified these metabolic changes, with the biggest differences reported for gamma-aminobutyric acid (GABA), proline, sucrose and inositol, affecting ion transport across cellular membranes (as shown in electrophysiological experiments). This work provides the first direct evidence for a role of EBC in salt tolerance in halophytes and attributes this to (1) a key role of EBC as a salt dump for external sequestration of sodium; (2) improved K+ retention in leaf mesophyll and (3) EBC as a storage space for several metabolites known to modulate plant ionic relations.
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Affiliation(s)
- Ali Kiani-Pouya
- School of Land and Food, University of Tasmania, 7001, Hobart, Tasmania, Australia
| | - Ute Roessner
- School of BioSciences, The University of Melbourne, 3010, Parkville, Victoria, Australia
- Metabolomics Australia, School of BioSciences, The University of Melbourne, 3010, Parkville, Victoria, Australia
| | - Nirupama S Jayasinghe
- Metabolomics Australia, School of BioSciences, The University of Melbourne, 3010, Parkville, Victoria, Australia
| | - Adrian Lutz
- Metabolomics Australia, School of BioSciences, The University of Melbourne, 3010, Parkville, Victoria, Australia
| | - Thusitha Rupasinghe
- Metabolomics Australia, School of BioSciences, The University of Melbourne, 3010, Parkville, Victoria, Australia
| | - Nadia Bazihizina
- School of Land and Food, University of Tasmania, 7001, Hobart, Tasmania, Australia
- Deptartment of Agrifood Production and Environmental Science, University of Florence, I-50019, Florence, Italy
| | - Jennifer Bohm
- School of Land and Food, University of Tasmania, 7001, Hobart, Tasmania, Australia
- Institute for Molecular Plant Physiology and Biophysics, Biocenter, Würzburg University, 97082, Wurzburg, Germany
| | - Sulaiman Alharbi
- Zoology Department, College of Science, King Saud University, P.O. Box 2455, Riyadh, 11451, Saudi Arabia
| | - Rainer Hedrich
- Institute for Molecular Plant Physiology and Biophysics, Biocenter, Würzburg University, 97082, Wurzburg, Germany
| | - Sergey Shabala
- School of Land and Food, University of Tasmania, 7001, Hobart, Tasmania, Australia
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19
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Durrant J, Michaelides EB, Rupasinghe T, Tull D, Green MP, Jones TM. Constant illumination reduces circulating melatonin and impairs immune function in the cricket Teleogryllus commodus. PeerJ 2015; 3:e1075. [PMID: 26339535 PMCID: PMC4558066 DOI: 10.7717/peerj.1075] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2015] [Accepted: 06/12/2015] [Indexed: 12/19/2022] Open
Abstract
Exposure to constant light has a range of negative effects on behaviour and physiology, including reduced immune function in both vertebrates and invertebrates. It is proposed that the associated suppression of melatonin (a ubiquitous hormone and powerful antioxidant) in response to the presence of light at night could be an underlying mechanistic link driving the changes to immune function. Here, we investigated the relationship between constant illumination, melatonin and immune function, using a model invertebrate species, the Australian black field cricket, Teleogryllus commodus. Crickets were reared under either a 12 h light: 12 h dark regimen or a constant 24 h light regimen. Circulating melatonin concentration and immune function (haemocyte concentration, lytic activity and phenoloxidase (PO) activity) were assessed in individual adult crickets through the analysis of haemolymph. Constant illumination reduced melatonin and had a negative impact on haemocyte concentrations and lytic activity, but its effect on PO activity was less apparent. Our data provide the first evidence, to our knowledge, of a link between exposure to constant illumination and variation in haemocyte concentration in an invertebrate model, while also highlighting the potential complexity of the immune response following exposure to constant illumination. This study provides insight into the possible negative effect of artificial night-time lighting on the physiology of invertebrates, but whether lower and potentially more ecologically relevant levels of light at night produce comparable results, as has been reported in several vertebrate taxa, remains to be tested.
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Affiliation(s)
- Joanna Durrant
- School of BioSciences, The University of Melbourne , Melbourne, Victoria , Australia
| | - Ellie B Michaelides
- School of BioSciences, The University of Melbourne , Melbourne, Victoria , Australia
| | - Thusitha Rupasinghe
- Metabolomics Australia, Bio21 Institute, The University of Melbourne , Melbourne, Victoria , Australia
| | - Dedreia Tull
- Metabolomics Australia, Bio21 Institute, The University of Melbourne , Melbourne, Victoria , Australia
| | - Mark P Green
- School of BioSciences, The University of Melbourne , Melbourne, Victoria , Australia
| | - Therésa M Jones
- School of BioSciences, The University of Melbourne , Melbourne, Victoria , Australia
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Ramakrishnan S, Docampo MD, MacRae JI, Ralton JE, Rupasinghe T, McConville MJ, Striepen B. The intracellular parasite Toxoplasma gondii depends on the synthesis of long-chain and very long-chain unsaturated fatty acids not supplied by the host cell. Mol Microbiol 2015; 97:64-76. [PMID: 25825226 DOI: 10.1111/mmi.13010] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/27/2015] [Indexed: 12/15/2022]
Abstract
Apicomplexa are parasitic protozoa that cause important human diseases including malaria, cryptosporidiosis and toxoplasmosis. The replication of these parasites within their target host cell is dependent on both salvage as well as de novo synthesis of fatty acids. In Toxoplasma gondii, fatty acid synthesis via the apicoplast-localized FASII is essential for pathogenesis, while the role of two other fatty acid biosynthetic complexes remains unclear. Here, we demonstrate that the ER-localized fatty acid elongation (ELO) complexes are essential for parasite growth. Conditional knockdown of the nonredundant hydroxyacyl-CoA dehydratase and enoyl-CoA reductase enzymes in the ELO pathway severely repressed intracellular parasite growth. (13) C-glucose and (13) C-acetate labeling and comprehensive lipidomic analyses of these mutants showed a selective defect in synthesis of unsaturated long and very long-chain fatty acids (LCFAs and VLCFAs) and depletion of phosphatidylinositol and phosphatidylethanolamine species containing unsaturated LCFAs and VLCFAs. This requirement for ELO pathway was bypassed by supplementing the media with specific fatty acids, indicating active but inefficient import of host fatty acids. Our experiments highlight a gap between the fatty acid needs of the parasite and availability of specific fatty acids in the host cell that the parasite has to close using a dedicated synthesis and modification pathway.
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Affiliation(s)
| | - Melissa D Docampo
- Center for Tropical & Emerging Global, University of Georgia, Athens, GA, USA
| | - James I MacRae
- Department of Biochemistry and Molecular Biology, University of Melbourne, Melbourne, Vic., Australia
| | - Julie E Ralton
- Department of Biochemistry and Molecular Biology, University of Melbourne, Melbourne, Vic., Australia
| | - Thusitha Rupasinghe
- Metabolomics Australia, Bio21 Institute of Molecular Science and Biotechnology, University of Melbourne, Melbourne, Vic., Australia
| | - Malcolm J McConville
- Department of Biochemistry and Molecular Biology, University of Melbourne, Melbourne, Vic., Australia
| | - Boris Striepen
- Department of Cellular Biology, University of Georgia, Athens, GA, USA.,Center for Tropical & Emerging Global, University of Georgia, Athens, GA, USA
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21
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Gran P, Larsen AE, Bonham M, Dordevic AL, Rupasinghe T, Silva C, Nahid A, Tull D, Sinclair AJ, Mitchell CJ, Cameron-Smith D. Muscle p70S6K phosphorylation in response to soy and dairy rich meals in middle aged men with metabolic syndrome: a randomised crossover trial. Nutr Metab (Lond) 2014; 11:46. [PMID: 25302072 PMCID: PMC4190399 DOI: 10.1186/1743-7075-11-46] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2014] [Accepted: 09/22/2014] [Indexed: 12/25/2022] Open
Abstract
Background The mammalian target of rapamycin (mTOR) pathway is the primary regulator of muscle protein synthesis. Metabolic syndrome (MetS) is characterized by central obesity and insulin resistance; little is known about how MetS affects the sensitivity of the mTOR pathway to feeding. Methods The responsiveness of mTOR pathway targets such as p706Sk to a high protein meal containing either dairy or soy foods was investigated in healthy insulin sensitive middle-aged men and those presenting with metabolic syndrome (MetS). Twenty male subjects (10 healthy controls, 10 MetS) participated in a single-blinded randomized cross-over study. In a random sequence, subjects ingested energy-matched breakfasts composed predominately of either dairy-protein or soy-protein foods. Skeletal muscle biopsies were collected in the fasted state and at 2 and 4 h post-meal ingestion for the analysis of mTOR- and insulin-signalling kinase activation. Results Phosphorylated Akt and Insulin receptor substrate 1 (IRS1) increased during the postabsorptive period with no difference between groups. mTOR (Ser448) and ribosomal protein S6 phosphorylation increased 2 h following dairy meal consumption only. p70S6K (Thr389) phosphorylation was increased after feeding only in the control subjects and not in the MetS group. Conclusions These data demonstrate that the consumption of a dairy-protein rich but not a soy-protein rich breakfast activates the phosphorylation of mTOR and ribosomal protein S6, required for protein synthesis in human skeletal muscle. Unlike healthy controls, subjects with MetS did not increase muscle p70S6K(Thr389) phosphorylation in response to a mixed meal. Trial registration This trial was registered with the Australian New Zealand Clinical Trials Registry (ANZCTR) as ACTRN12610000562077.
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Affiliation(s)
- Petra Gran
- Molecular Nutrition Unit, School of Exercise and Nutrition Sciences, Deakin University, Burwood, Victoria Australia
| | - Amy E Larsen
- Molecular Nutrition Unit, School of Exercise and Nutrition Sciences, Deakin University, Burwood, Victoria Australia
| | - Maxine Bonham
- Molecular Nutrition Unit, School of Exercise and Nutrition Sciences, Deakin University, Burwood, Victoria Australia
| | - Aimee L Dordevic
- Molecular Nutrition Unit, School of Exercise and Nutrition Sciences, Deakin University, Burwood, Victoria Australia
| | - Thusitha Rupasinghe
- Metabolomics Australia, University of Melbourne, Parkville, Victoria Australia
| | - Claudio Silva
- Metabolomics Australia, University of Melbourne, Parkville, Victoria Australia
| | - Amsha Nahid
- Metabolomics Australia, University of Melbourne, Parkville, Victoria Australia
| | - Dedreia Tull
- Metabolomics Australia, University of Melbourne, Parkville, Victoria Australia
| | - Andrew J Sinclair
- School of Medicine, Deakin University, Waurn Ponds, Victoria Australia
| | - Cameron J Mitchell
- The Liggins Institute, Faculty of Medical and Science Health, University of Auckland, 85 Park Road, Grafton, Private Bag 92019, Auckland, 1023 New Zealand
| | - David Cameron-Smith
- Molecular Nutrition Unit, School of Exercise and Nutrition Sciences, Deakin University, Burwood, Victoria Australia ; The Liggins Institute, Faculty of Medical and Science Health, University of Auckland, 85 Park Road, Grafton, Private Bag 92019, Auckland, 1023 New Zealand
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22
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Macrae JI, Lopaticki S, Maier AG, Rupasinghe T, Nahid A, Cowman AF, McConville MJ. Plasmodium falciparum is dependent on de novo myo-inositol biosynthesis for assembly of GPI glycolipids and infectivity. Mol Microbiol 2014; 91:762-76. [PMID: 24350823 DOI: 10.1111/mmi.12496] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/15/2013] [Indexed: 12/27/2022]
Abstract
Intra-erythrocytic stages of the malaria parasite, Plasmodium falciparum, are thought to be dependent on de novo synthesis of phosphatidylinositol, as red blood cells (RBC) lack the capacity to synthesize this phospholipid. The myo-inositol headgroup of PI can either be synthesized de novo or scavenged from the RBC. An untargeted metabolite profiling of P. falciparum infected RBC showed that trophozoite and schizont stages accumulate high levels of myo-inositol-3-phosphate, indicating increased de novo biosynthesis of myo-inositol from glucose 6-phosphate. Metabolic labelling studies with (13) C-U-glucose in the presence and absence of exogenous inositol confirmed that de novo myo-inositol synthesis occurs in parallel with myo-inositol salvage pathways. Unexpectedly, while both endogenous and scavenged myo-inositol was used to synthesize bulk PI, only de novo-synthesized myo-inositol was incorporated into GPI glycolipids. Moreover, gene disruption studies suggested that the INO1 gene, encoding myo-inositol 3-phosphate synthase, is essential in asexual parasite stages. Together these findings suggest that P. falciparum asexual stages are critically dependent on de novo myo-inositol biosynthesis for assembly of a sub-pool of PI species and GPI biosynthesis. These findings highlight unexpected complexity in phospholipid biosynthesis in P. falciparum and a lack of redundancy in some nutrient salvage versus endogenous biosynthesis pathways.
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Affiliation(s)
- James I Macrae
- Department of Biochemistry and Molecular Biology, Bio21 Institute of Molecular Science and Biotechnology, 30 Flemington Road, Melbourne, Vic., 3010, Australia
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23
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Vodstrcil LA, Rupasinghe T, Tull D, Worthington K, Chen MY, Huston WM, Fairley CK, McConville M, Tabrizi SN, Hocking JS. P2.082 Post-Treatment Detection of Azithromycin in High-Vaginal Swabs Using Liquid Chromatography and Tandem Mass Spectrometry (LC-MS/MS). Br J Vener Dis 2013. [DOI: 10.1136/sextrans-2013-051184.0346] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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24
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De Livera AM, Dias DA, De Souza D, Rupasinghe T, Pyke J, Tull D, Roessner U, McConville M, Speed TP. Normalizing and integrating metabolomics data. Anal Chem 2012; 84:10768-76. [PMID: 23150939 DOI: 10.1021/ac302748b] [Citation(s) in RCA: 141] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Metabolomics research often requires the use of multiple analytical platforms, batches of samples, and laboratories, any of which can introduce a component of unwanted variation. In addition, every experiment is subject to within-platform and other experimental variation, which often includes unwanted biological variation. Such variation must be removed in order to focus on the biological information of interest. We present a broadly applicable method for the removal of unwanted variation arising from various sources for the identification of differentially abundant metabolites and, hence, for the systematic integration of data on the same quantities from different sources. We illustrate the versatility and the performance of the approach in four applications, and we show that it has several advantages over the existing normalization methods.
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Affiliation(s)
- Alysha M De Livera
- Metabolomics Australia at The University of Melbourne, Melbourne, Victoria, Australia.
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25
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Dagley MJ, Gentle IE, Beilharz TH, Pettolino FA, Djordjevic JT, Lo TL, Uwamahoro N, Rupasinghe T, Tull DL, McConville M, Beaurepaire C, Nantel A, Lithgow T, Mitchell AP, Traven A. Cell wall integrity is linked to mitochondria and phospholipid homeostasis in Candida albicans through the activity of the post-transcriptional regulator Ccr4-Pop2. Mol Microbiol 2010; 79:968-89. [PMID: 21299651 DOI: 10.1111/j.1365-2958.2010.07503.x] [Citation(s) in RCA: 101] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The cell wall is essential for viability of fungi and is an effective drug target in pathogens such as Candida albicans. The contribution of post-transcriptional gene regulators to cell wall integrity in C. albicans is unknown. We show that the C. albicans Ccr4-Pop2 mRNA deadenylase, a regulator of mRNA stability and translation, is required for cell wall integrity. The ccr4/pop2 mutants display reduced wall β-glucans and sensitivity to the echinocandin caspofungin. Moreover, the deadenylase mutants are compromised for filamentation and virulence. We demonstrate that defective cell walls in the ccr4/pop2 mutants are linked to dysfunctional mitochondria and phospholipid imbalance. To further understand mitochondrial function in cell wall integrity, we screened a Saccharomyces cerevisiae collection of mitochondrial mutants. We identify several mitochondrial proteins required for caspofungin tolerance and find a connection between mitochondrial phospholipid homeostasis and caspofungin sensitivity. We focus on the mitochondrial outer membrane SAM complex subunit Sam37, demonstrating that it is required for both trafficking of phospholipids between the ER and mitochondria and cell wall integrity. Moreover, in C. albicans also Sam37 is essential for caspofungin tolerance. Our study provides the basis for an integrative view of mitochondrial function in fungal cell wall biogenesis and resistance to echinocandin antifungal drugs.
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Affiliation(s)
- Michael J Dagley
- Department of Biochemistry and Molecular Biology, Monash University, Melbourne, Australia
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Rupasinghe T, Cardwell TJ, Cattrall RW, Potter ID, Kolev SD. Determination of arsenic by pervaporation-flow injection hydride generation and permanganate spectrophotometric detection. Anal Chim Acta 2004. [DOI: 10.1016/j.aca.2004.01.006] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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27
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Rupasinghe T, Cardwell TJ, Cattrall RW, de Castro MD, Kolev SD. Pervaporation-flow injection determination of arsenic based on hydride generation and the molybdenum blue reaction. Anal Chim Acta 2001. [DOI: 10.1016/s0003-2670(01)01256-9] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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