Pharmaceutical pollution in marine waters and benthic flora of the southern Australian coastline
- Long, Benjamin, Harriage, Samantha, Schultz, Nick, Sherman, Craig, Thomas, Michael
- Authors: Long, Benjamin , Harriage, Samantha , Schultz, Nick , Sherman, Craig , Thomas, Michael
- Date: 2023
- Type: Text , Journal article
- Relation: Environmental chemistry Vol. 19, no. 6 (2023), p. 375-384
- Full Text:
- Reviewed:
- Description: Environmental context Most human pharmaceutical waste is discharged to the environment. While the presence of pharmaceuticals in freshwater systems is well documented globally, little is known of the impact on marine ecosystems. We measured pharmaceuticals in a marine environment in south-eastern Australia and found pharmaceutical concentrations around 24 000 times higher in benthic flora than in the marine surface waters. We discuss the potential use of seaweeds as biological indicators of pharmaceutical pollution. Rationale Pharmaceuticals are emerging pollutants of concern with a range of adverse consequences for organisms and ecosystems. Their presence in freshwater and estuarine systems has been well documented, but less is known about their prevalence in open ocean, or their uptake by benthic flora. This preliminary survey of the southern Australian coastline sought to measure the concentrations of key pharmaceuticals in both surface waters and benthic flora. Methodology This study used LC-MS/MS to measure the concentration carbamazepine, tramadol and venlafaxine in (1) samples from wastewater treatment plants, (2) ocean surface waters and (3) several species of benthic flora. Surface waters and benthic flora were sampled at two sites near waste water treatment plant (WWTP) discharges, and one site away from any discharge. Results All three pharmaceuticals were detected in surface water samples with their risk assessed (via risk quotient) as medium risk (carbamazepine) or low risk (venlafaxine, tramadol). All three pharmaceuticals were also detected in benthic flora, particularly in brown macroalgae Tramadol was measured at a maximum of 34.7 ng g
- Authors: Long, Benjamin , Harriage, Samantha , Schultz, Nick , Sherman, Craig , Thomas, Michael
- Date: 2023
- Type: Text , Journal article
- Relation: Environmental chemistry Vol. 19, no. 6 (2023), p. 375-384
- Full Text:
- Reviewed:
- Description: Environmental context Most human pharmaceutical waste is discharged to the environment. While the presence of pharmaceuticals in freshwater systems is well documented globally, little is known of the impact on marine ecosystems. We measured pharmaceuticals in a marine environment in south-eastern Australia and found pharmaceutical concentrations around 24 000 times higher in benthic flora than in the marine surface waters. We discuss the potential use of seaweeds as biological indicators of pharmaceutical pollution. Rationale Pharmaceuticals are emerging pollutants of concern with a range of adverse consequences for organisms and ecosystems. Their presence in freshwater and estuarine systems has been well documented, but less is known about their prevalence in open ocean, or their uptake by benthic flora. This preliminary survey of the southern Australian coastline sought to measure the concentrations of key pharmaceuticals in both surface waters and benthic flora. Methodology This study used LC-MS/MS to measure the concentration carbamazepine, tramadol and venlafaxine in (1) samples from wastewater treatment plants, (2) ocean surface waters and (3) several species of benthic flora. Surface waters and benthic flora were sampled at two sites near waste water treatment plant (WWTP) discharges, and one site away from any discharge. Results All three pharmaceuticals were detected in surface water samples with their risk assessed (via risk quotient) as medium risk (carbamazepine) or low risk (venlafaxine, tramadol). All three pharmaceuticals were also detected in benthic flora, particularly in brown macroalgae Tramadol was measured at a maximum of 34.7 ng g
Hybrid self‐assembling peptide/gelatin methacrylate (gelma) bioink blend for improved bioprintability and primary myoblast response
- Boyd-Moss, Mitchell, Firipis, Kate, Quigley, Anita, Rifai, Aaqil, Cichocki, Artur, Whitty, Sarah, Ngan, Catherine, Dekiwadia, Chaitali, Long, Benjamin, Nisbet, David, Kapsa, Robert, Williams, Richard
- Authors: Boyd-Moss, Mitchell , Firipis, Kate , Quigley, Anita , Rifai, Aaqil , Cichocki, Artur , Whitty, Sarah , Ngan, Catherine , Dekiwadia, Chaitali , Long, Benjamin , Nisbet, David , Kapsa, Robert , Williams, Richard
- Date: 2022
- Type: Text , Journal article
- Relation: Advanced NanoBiomed Research Vol. 2, no. 2 (2022), p. n/a
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- Description: Organ fabrication as the solution to renewable donor demands requires the ability to spatially deposit viable cells into biologically relevant constructs necessitating reliable and effective cell deposition through bioprinting and the subsequent ability to mature. However, effective bioink development demands advances in both printability and control of cellular response. Effective bioinks are designed to retain shape fidelity, influence cellular behavior, having bioactive morphologies stiffness and highly hydrated environment. Hybrid hydrogels are promising candidates as they reduce the need to re‐engineer materials for tissue‐specific properties, with each component offering beneficial properties. Herein, a multicomponent bioink is developed whereby gelatin methacrylate (GelMA) and fluorenylmethoxycarbonyprotected self‐assembling peptides (Fmoc‐SAPs) undergo coassembly to yield a tuneable bioink. This study shows that the reported fibronectin‐inspired fmoc‐SAPs present cell attachment epitopes RGD and PHSRN in the form of bioactive nanofibers and that the GelMA enables superior printability, stability in media, and controlled mechanical properties. Importantly, when in the hybrid format, no disruption to either the methacrylate crosslinking of GelMA, or self‐assembled peptide fibril formation is observed. Finally, studies with primary myoblasts show over 98% viability at 72 h and differentiation into fused myotubes at one and two weeks demonstrate the utility of the material as a functional bioink for muscle engineering. In this work, muscle tissue is 3D‐bioprinted with a novel bioink formulation. The bioink presents fibrous bioactive properties of the body's native scaffold, while also improving biofabrication outcomes. Self‐assembling peptides are combined with GelMA creating a hybrid bioink. This work sets the stage for future hybrid bioinks for muscle biofabrication.
- Authors: Boyd-Moss, Mitchell , Firipis, Kate , Quigley, Anita , Rifai, Aaqil , Cichocki, Artur , Whitty, Sarah , Ngan, Catherine , Dekiwadia, Chaitali , Long, Benjamin , Nisbet, David , Kapsa, Robert , Williams, Richard
- Date: 2022
- Type: Text , Journal article
- Relation: Advanced NanoBiomed Research Vol. 2, no. 2 (2022), p. n/a
- Full Text:
- Reviewed:
- Description: Organ fabrication as the solution to renewable donor demands requires the ability to spatially deposit viable cells into biologically relevant constructs necessitating reliable and effective cell deposition through bioprinting and the subsequent ability to mature. However, effective bioink development demands advances in both printability and control of cellular response. Effective bioinks are designed to retain shape fidelity, influence cellular behavior, having bioactive morphologies stiffness and highly hydrated environment. Hybrid hydrogels are promising candidates as they reduce the need to re‐engineer materials for tissue‐specific properties, with each component offering beneficial properties. Herein, a multicomponent bioink is developed whereby gelatin methacrylate (GelMA) and fluorenylmethoxycarbonyprotected self‐assembling peptides (Fmoc‐SAPs) undergo coassembly to yield a tuneable bioink. This study shows that the reported fibronectin‐inspired fmoc‐SAPs present cell attachment epitopes RGD and PHSRN in the form of bioactive nanofibers and that the GelMA enables superior printability, stability in media, and controlled mechanical properties. Importantly, when in the hybrid format, no disruption to either the methacrylate crosslinking of GelMA, or self‐assembled peptide fibril formation is observed. Finally, studies with primary myoblasts show over 98% viability at 72 h and differentiation into fused myotubes at one and two weeks demonstrate the utility of the material as a functional bioink for muscle engineering. In this work, muscle tissue is 3D‐bioprinted with a novel bioink formulation. The bioink presents fibrous bioactive properties of the body's native scaffold, while also improving biofabrication outcomes. Self‐assembling peptides are combined with GelMA creating a hybrid bioink. This work sets the stage for future hybrid bioinks for muscle biofabrication.
Self-assembled peptide habitats to model tumor metastasis
- Al Balushi, Noora, Boyd-Moss, Mitchell, Samarasinghe, Rasika, Rifai, Aaqil, Franks, Stephanie, Firipis, Kate, Long, Benjamin, Darby, Ian, Nisbet, David, Pouniotis, Dodie, Williams, Richard
- Authors: Al Balushi, Noora , Boyd-Moss, Mitchell , Samarasinghe, Rasika , Rifai, Aaqil , Franks, Stephanie , Firipis, Kate , Long, Benjamin , Darby, Ian , Nisbet, David , Pouniotis, Dodie , Williams, Richard
- Date: 2022
- Type: Text , Journal article
- Relation: Gels Vol. 8, no. 6 (2022), p.
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- Description: Metastatic tumours are complex ecosystems; a community of multiple cell types, including cancerous cells, fibroblasts, and immune cells that exist within a supportive and specific microenvironment. The interplay of these cells, together with tissue specific chemical, structural and temporal signals within a three-dimensional (3D) habitat, direct tumour cell behavior, a subtlety that can be easily lost in 2D tissue culture. Here, we investigate a significantly improved tool, consisting of a novel matrix of functionally programmed peptide sequences, self-assembled into a scaffold to enable the growth and the migration of multicellular lung tumour spheroids, as proof-of-concept. This 3D functional model aims to mimic the biological, chemical, and contextual cues of an in vivo tumor more closely than a typically used, unstructured hydrogel, allowing spatial and temporal activity modelling. This approach shows promise as a cancer model, enhancing current understandings of how tumours progress and spread over time within their microenvironment. © 2022 by the authors. Licensee MDPI, Basel, Switzerland.
- Authors: Al Balushi, Noora , Boyd-Moss, Mitchell , Samarasinghe, Rasika , Rifai, Aaqil , Franks, Stephanie , Firipis, Kate , Long, Benjamin , Darby, Ian , Nisbet, David , Pouniotis, Dodie , Williams, Richard
- Date: 2022
- Type: Text , Journal article
- Relation: Gels Vol. 8, no. 6 (2022), p.
- Full Text:
- Reviewed:
- Description: Metastatic tumours are complex ecosystems; a community of multiple cell types, including cancerous cells, fibroblasts, and immune cells that exist within a supportive and specific microenvironment. The interplay of these cells, together with tissue specific chemical, structural and temporal signals within a three-dimensional (3D) habitat, direct tumour cell behavior, a subtlety that can be easily lost in 2D tissue culture. Here, we investigate a significantly improved tool, consisting of a novel matrix of functionally programmed peptide sequences, self-assembled into a scaffold to enable the growth and the migration of multicellular lung tumour spheroids, as proof-of-concept. This 3D functional model aims to mimic the biological, chemical, and contextual cues of an in vivo tumor more closely than a typically used, unstructured hydrogel, allowing spatial and temporal activity modelling. This approach shows promise as a cancer model, enhancing current understandings of how tumours progress and spread over time within their microenvironment. © 2022 by the authors. Licensee MDPI, Basel, Switzerland.
- Boyd-Moss, Mitchell, Firipis, Kate, O'Connell, Cathal, Rifai, Aaqil, Long, Benjamin
- Authors: Boyd-Moss, Mitchell , Firipis, Kate , O'Connell, Cathal , Rifai, Aaqil , Long, Benjamin
- Date: 2021
- Type: Text , Journal article
- Relation: Materials Chemistry Frontiers Vol. 5, no. 22 (2021), p. 8025-8036
- Full Text: false
- Reviewed:
- Description: The challenge with engineering soft materials is to find a chemically functionalized material that can be easily fabricated into complex structures while providing a supportive cellular milieu. The current gold standard is gelatin methacryloyl (GelMA), a semi-synthetic collagen-derived biomaterial that has found widespread utility as a bioink for 3D bioprinting. Although a fundamental understanding of controlling the mechanical properties of GelMA exists, the nano- and cell-scale network topology needs to be investigated to produce controlled structures. Here, for the first time, small-angle X-ray scattering (SAXS) is used to elucidate how structural changes on the network level dictate the final properties within a GelMA hydrogel. Scaffold nanostructure was observed pre- and post-crosslinking, with emphasis on assessing structural changes in response to changes in Degree of Functionalization (DoF) and polymer concentration. Samples were modelled regarding local-polymer conformation (mass fractal dimension), distance between entanglements (correlation length), and mesh size. Importantly, DoF is observed to alter crosslinked polymer conformation and nanoscale mesh size. These results inform future design of GelMA-based bioinks, allowing researchers to further leverage the young and evolving bioprinting technology for broad-spectrum applications such as cell/stem cell printing, organoid-based tissue structure, building cell/organ-on-a-chip, through to the hierarchical engineering of multicellular living systems. © 2021 the Partner Organisations. **Please note that there are multiple authors for this article therefore only the name of the first 5 including Federation University Australia affiliate “Benjamin Long" is provided in this record**
Temperature characteristics for a deep water supply reservoir : a case study for Lake Bellfield
- Barton, Andrew, Long, Benjamin
- Authors: Barton, Andrew , Long, Benjamin
- Date: 2021
- Type: Text , Conference paper
- Relation: Hydrology and Water Resources Symposium 2021: Digital Water, 31 August to 1 September 2022, HWRS 2021: Digital Water: Hydrology and Water Resources Symposium 2021 p. 139-148
- Full Text: false
- Reviewed:
- Description: Deep reservoirs are known to undergo thermal stratification driven by seasonaltemperature changes across the year. Stratified conditions can encourage poor waterquality at depth, particularly with low dissolved oxygen and associated implications fordissolved manganese, iron and other water quality parameters. Ecological impactsdue to cold water discharge can also be exacerbated where stratified conditionsprevent the water column from mixing and thus keeping temperatures artificially lowcompared to warmer surface waters.This study presents the first ever comprehensive information for Lake Bellfield, a keywater supply reservoir located in the Grampians National Park, Victoria, Australia.Three years of temperature monitoring data has been recorded, along with three yearsof meteorological data from a nearby weather station. The thermal profile over time ispresented, along with the associated weather information.Results show that the reservoir does indeed undergo stratification, and that ‘turnover’or mixing event typically occur in late April or early May of each year. The magnitudeof stratification is also shown with temperature extremes between the hypolimnion andepilimnion shown. Further information is presented on the likely predictors of thoseturnover events using the nearby weather station information.Discussion is provided on possible strategies to mitigate water quality and ecologicalissues associated with the thermal stratification.
- Hunt, Cameron, Penna, Vanessa, Gantner, Carlos, Moriarty, Niamh, Long, Benjamin
- Authors: Hunt, Cameron , Penna, Vanessa , Gantner, Carlos , Moriarty, Niamh , Long, Benjamin
- Date: 2021
- Type: Text , Journal article
- Relation: Advanced Functional Materials Vol. 31, no. 47 (2021), p.
- Full Text: false
- Reviewed:
- Description: The survival and synaptic integration of transplanted dopaminergic (DA) progenitors are essential for ameliorating motor symptoms in Parkinson's disease (PD). Human pluripotent stem cell (hPSC)-derived DA progenitors are, however, exposed to numerous stressors prior to, and during, implantation that result in poor survival. Additionally, hPSC-derived grafts show inferior plasticity compared to fetal tissue grafts. These observations suggest that a more conducive host environment may improve graft outcomes. Here, tissue-specific support to DA progenitor grafts is provided with a fully characterized self-assembling peptide hydrogel. This biomimetic hydrogel matrix is programmed to support DA progenitors by i) including a laminin epitope within the matrix; and ii) shear encapsulating glial cell line-derived neurotrophic factor (GDNF) to ensure its sustained delivery. The biocompatible hydrogel biased a 51% increase in A9 neuron specification—a subpopulation of DA neurons critical for motor function. The sustained delivery of GDNF induced a 2.7-fold increase in DA neurons and enhanced graft plasticity, resulting in significant improvements in motor deficits at 6 months. These findings highlight the therapeutic benefit of stepwise customization of tissue-specific hydrogels to improve the physical and trophic support of human PSC-derived neural transplants, resulting in improved standardization, predictability and functional efficacy of grafts for PD. © 2021 Wiley-VCH GmbH. **Please note that there are multiple authors for this article therefore only the name of the first 5 including Federation University Australia affiliate “Benjamin Long” is provided in this record**
- Firipis, Kate, Boyd-Moss, Mitchell, Long, Benjamin, Dekiwadia, Chaitali, Hoskin, William
- Authors: Firipis, Kate , Boyd-Moss, Mitchell , Long, Benjamin , Dekiwadia, Chaitali , Hoskin, William
- Date: 2021
- Type: Text , Journal article
- Relation: ACS Biomaterials Science and Engineering Vol. 7, no. 7 (2021), p. 3340-3350
- Full Text: false
- Reviewed:
- Description: Synthetic materials designed for improved biomimicry of the extracellular matrix must contain fibrous, bioactive, and mechanical cues. Self-assembly of low molecular weight gelator (LMWG) peptides Fmoc-DIKVAV (Fmoc-aspartic acid-isoleucine-lysine-valine-alanine-valine) and Fmoc-FRGDF (Fmoc-phenylalanine-arginine-glycine-aspartic acid-phenylalanine) creates fibrous and bioactive hydrogels. Polysaccharides such as agarose are biocompatible, degradable, and non-toxic. Agarose and these Fmoc-peptides have both demonstrated efficacy in vitro and in vivo. These materials have complementary properties; agarose has known mechanics in the physiological range but is inert and would benefit from bioactive and topographical cues found in the fibrous, protein-rich extracellular matrix. Fmoc-DIKVAV and Fmoc-FRGDF are synthetic self-assembling peptides that present bioactive cues "IKVAV"and "RGD"designed from the ECM proteins laminin and fibronectin. The work presented here demonstrates that the addition of agarose to Fmoc-DIKVAV and Fmoc-FRGDF results in physical characteristics that are dependent on agarose concentration. The networks are peptide-dominated at low agarose concentrations, and agarose-dominated at high agarose concentrations, resulting in distinct changes in structural morphology. Interestingly, at mid-range agarose concentration, a hybrid network is formed with structural similarities to both peptide and agarose systems, demonstrating reinforced mechanical properties. Bioactive-LMWG polysaccharide hydrogels demonstrate controllable microenvironmental properties, providing the ability for tissue-specific biomaterial design for tissue engineering and 3D cell culture. © 2021 American Chemical Society.
Rapid cross-linking of epoxy thermosets induced by solvate ionic liquids
- Hameed, Nishar, Eyckens, Daniel, Long, Benjamin, Salim, Nisa, Capricho, Jaworski, Servinis, Linden, De Souza, Mandy, Perus, Magenta, Varley, Russell, Henderson, Luke
- Authors: Hameed, Nishar , Eyckens, Daniel , Long, Benjamin , Salim, Nisa , Capricho, Jaworski , Servinis, Linden , De Souza, Mandy , Perus, Magenta , Varley, Russell , Henderson, Luke
- Date: 2020
- Type: Text , Journal article
- Relation: ACS Applied Polymer Materials Vol. 2, no. 7 (2020), p. 2651-2657
- Full Text:
- Reviewed:
- Description: The high-volume manufacture of fiber-reinforced composites faces a huge challenge because long resin curing times put a low ceiling on the total output of parts produced per year. To translate the benefits from using epoxy in large-volume production platforms, cure cycle times of less than 1 min must be achieved. In this work, we report solvate ionic liquids (SILs) as simple and efficient rapid curing catalytic additives in epoxy systems. Ultrafast curing was observed at low levels of 1-5% of SIL in epoxy resin, and the cure rate is enhanced up to 26-fold without compromising the mechanical and thermal properties. Further investigations revealed that enhancement in the cure rate is dependent on the type of SILs employed, influenced by the metal center, the ligands around the metal, and the identity of the counter anion. The relative Lewis acidity of each of the active complexes was calculated, and the rapid cure effect was attributed to the activation of the epoxide moietyviathe Lewis acidic nature of the SIL. Making epoxy thermosets rapidly processable enables enormous benefits, finding applications in a whole variety of transformation methods that exist for traditional glass and metals. Copyright © 2020 American Chemical Society
- Authors: Hameed, Nishar , Eyckens, Daniel , Long, Benjamin , Salim, Nisa , Capricho, Jaworski , Servinis, Linden , De Souza, Mandy , Perus, Magenta , Varley, Russell , Henderson, Luke
- Date: 2020
- Type: Text , Journal article
- Relation: ACS Applied Polymer Materials Vol. 2, no. 7 (2020), p. 2651-2657
- Full Text:
- Reviewed:
- Description: The high-volume manufacture of fiber-reinforced composites faces a huge challenge because long resin curing times put a low ceiling on the total output of parts produced per year. To translate the benefits from using epoxy in large-volume production platforms, cure cycle times of less than 1 min must be achieved. In this work, we report solvate ionic liquids (SILs) as simple and efficient rapid curing catalytic additives in epoxy systems. Ultrafast curing was observed at low levels of 1-5% of SIL in epoxy resin, and the cure rate is enhanced up to 26-fold without compromising the mechanical and thermal properties. Further investigations revealed that enhancement in the cure rate is dependent on the type of SILs employed, influenced by the metal center, the ligands around the metal, and the identity of the counter anion. The relative Lewis acidity of each of the active complexes was calculated, and the rapid cure effect was attributed to the activation of the epoxide moietyviathe Lewis acidic nature of the SIL. Making epoxy thermosets rapidly processable enables enormous benefits, finding applications in a whole variety of transformation methods that exist for traditional glass and metals. Copyright © 2020 American Chemical Society
Development of self-assembling peptide inspired bioinks for neural tissue engineering applications
- Boyd-Moss, Mitchell, Quigley, Anita, Firipis, Kate, Long, Benjamin, Nisbet, David, Williams, Richard
- Authors: Boyd-Moss, Mitchell , Quigley, Anita , Firipis, Kate , Long, Benjamin , Nisbet, David , Williams, Richard
- Date: 2019
- Type: Text , Conference paper
- Relation: Transactions of the 42nd Annual Meeting of the Society for Biomaterials and the Annual International Biomaterials Symposium p. 961
- Full Text: false
- Reviewed:
- Description: © 2019 Omnipress - All rights reserved. Statement of Purpose: The ability to fabricate artificial tissue constructs offers significant promise to regenerative medicine and tissue engineering. Advances in additive manufacturing have enabled the bioprinting of spatially defined cell-laden constructs capable of providing spatiotemporal presentation of biological and physical cues to cells in a multicomponent structure. 1 Despite significant advance in bioprinting techniques, a key challenge remains in developing soft biomaterials that can adequately recapitulate the complexities of native extracellular matrix (ECM) whilst facilitating bioprinting. Self-Assembling Peptides (SAPs) are a unique class of hydrogels which spontaneously immobilize surrounding solvents through formation of biomimetic structures, resulting in hydrogel networks highly reminiscent of native ECM. Through strategic engineering of SAP sequences, ECM inspired bioactive motifs may be introduced. IKVAV, a laminin motif, can be used to generate Fmoc-DIKVAV (a fibril forming SAP) shown to support the survival and migration of transplanted cortical neural progenitor cells in vivo. 2 Despite Fmoc-DIKVAV’s excellent biocompatibility, the inherent lack of covalent bonds between fibrils results in poor printability and extensive swelling in vitro. For this reason, there is a key need to modify this material to enhance printability without compromising bioactivity.
- Chadha, Aakansha, Florentine, Singarayer, Chauhan, Bhagirath, Long, Benjamin, Jayasundera, Mithila, Javaid, Muhammad, Turville, Christopher
- Authors: Chadha, Aakansha , Florentine, Singarayer , Chauhan, Bhagirath , Long, Benjamin , Jayasundera, Mithila , Javaid, Muhammad , Turville, Christopher
- Date: 2019
- Type: Text , Journal article
- Relation: Crop and Pasture Science Vol. 70, no. 8 (2019), p. 709-717
- Full Text: false
- Reviewed:
- Description: Wild lettuce (Lactuca serriola L.) is a significant emerging agricultural and environmental weed in many countries. This invasive species is now naturalised in Australia and is claimed to cause significant losses within the agricultural industry. Sustainable management of wild lettuce has been hampered by a lack of detailed knowledge of its seed ecology. Laboratory-based studies were performed to examine the potential influence of environmental factors including temperature and light conditions, salinity, pH, moisture availability and burial depth on the germination and emergence of two spatially distant populations of wild lettuce. Results suggested that the germination of wild lettuce seeds occurred across a broad range of temperature conditions (12-h cycle: 30°C/20°C, 25°C/15°C and 17°C/7°C) for both populations. We also found that these seeds are non-photoblastic germination was not affected by darkness, with >80% germination in darkness for both populations at all tested temperature ranges. Germination significantly declined as salinity and osmotic stress increased for both populations, with seeds from the Tempy population were more affected by NaCl >100 mM than seeds from Werribee, but in neither population was there any observed effect of pH on germination (>80% germination in both populations at all tested pH ranges). For both populations, germination significantly decreased as burial depth increased however, the two populations differed with regard to response to burial depth treatment, whereby seeds from the Tempy population had higher emergence than those from Werribee at 0.5 cm burial depth. These results suggest that light-reducing management techniques such as mulching or use of crop residues will be unsuccessful for preventing germination of wild lettuce. By contrast, burial of seeds at a depth of at least 4 cm will significantly reduce their emergence.
Influence of soil moisture regimes on growth, photosynthetic capacity, leaf biochemistry and reproductive capabilities of the invasive agronomic weed; Lactuca serriola
- Chadha, Aakansha, Florentine, Singarayer, Chauhan, Bhagirath, Long, Benjamin, Jayasundera, Mithila
- Authors: Chadha, Aakansha , Florentine, Singarayer , Chauhan, Bhagirath , Long, Benjamin , Jayasundera, Mithila
- Date: 2019
- Type: Text , Journal article
- Relation: PLoS ONE Vol. 14, no. 6 (2019), p. 1-17
- Full Text:
- Reviewed:
- Description: Global temperatures are predicted to increase by 1.5–5.9C during this century, and this change is likely to impact average rainfall, with predictions that water deficit will perhaps be the most severe threat to sustainable agriculture. In this respect, invasive weeds, which have traits better adapted to drought stress than crops, add to concerns regarding crop sustainability. Lactuca serriola, an aggressive agronomic weed is thought to be a successful weed because of its ability to maintain high water use efficiency under drought conditions. In this study, experiments were conducted to examine the influence of different soil moisture regimes (100%, 75%, 50% and 25% water holding capacity (WHC)) on growth, photosynthetic capacity, leaf biochemistry and reproduction of this species. Soil moisture significantly affected plant’s height, stem diameter, number of leaves and biomass. The highest plant height (115.14 cm ± 11.64), shoot diameter (9.4 mm ± 0.18), leaf area (1206.5 mm2 ± 73.29), plant fresh weight (83.1 ± 3.98) and dry weight (22.38 ± 1.24) were recorded at 75% soil moisture content. A fundamental adaptation to drought was observed as plants in the 25% WHC treatment had the highest root: shoot ratio. Soluble sugars and total phenolic content were highest in the 25% WHC treatment and significantly different to 100% WHC which was a response to soil moisture stress to ameliorate the damaging effects of reactive oxygen species produced under stress conditions. Results also indicate that L. serriola can survive and produce seeds under water stress as more than 6000 seeds were produced per plant in all WHC treatments. In this study, there was no significant difference in the seed weight, number of seeds produced and their germination ability. This can have a huge impact on agricultural systems as the species can survive both under low and high soil moisture conditions. We therefore suggest that the demonstrated ability of L. serriola to complete its life cycle and produce biomass and seeds under water stressed conditions leads to the introduction of strategies that minimize weed survival while maximizing irrigation efficiency for the crop. A clear understanding of the ecological and biological characteristics of this weed will help land managers take appropriate control measures to mitigate the effect of this species on economic crop productivity.
- Authors: Chadha, Aakansha , Florentine, Singarayer , Chauhan, Bhagirath , Long, Benjamin , Jayasundera, Mithila
- Date: 2019
- Type: Text , Journal article
- Relation: PLoS ONE Vol. 14, no. 6 (2019), p. 1-17
- Full Text:
- Reviewed:
- Description: Global temperatures are predicted to increase by 1.5–5.9C during this century, and this change is likely to impact average rainfall, with predictions that water deficit will perhaps be the most severe threat to sustainable agriculture. In this respect, invasive weeds, which have traits better adapted to drought stress than crops, add to concerns regarding crop sustainability. Lactuca serriola, an aggressive agronomic weed is thought to be a successful weed because of its ability to maintain high water use efficiency under drought conditions. In this study, experiments were conducted to examine the influence of different soil moisture regimes (100%, 75%, 50% and 25% water holding capacity (WHC)) on growth, photosynthetic capacity, leaf biochemistry and reproduction of this species. Soil moisture significantly affected plant’s height, stem diameter, number of leaves and biomass. The highest plant height (115.14 cm ± 11.64), shoot diameter (9.4 mm ± 0.18), leaf area (1206.5 mm2 ± 73.29), plant fresh weight (83.1 ± 3.98) and dry weight (22.38 ± 1.24) were recorded at 75% soil moisture content. A fundamental adaptation to drought was observed as plants in the 25% WHC treatment had the highest root: shoot ratio. Soluble sugars and total phenolic content were highest in the 25% WHC treatment and significantly different to 100% WHC which was a response to soil moisture stress to ameliorate the damaging effects of reactive oxygen species produced under stress conditions. Results also indicate that L. serriola can survive and produce seeds under water stress as more than 6000 seeds were produced per plant in all WHC treatments. In this study, there was no significant difference in the seed weight, number of seeds produced and their germination ability. This can have a huge impact on agricultural systems as the species can survive both under low and high soil moisture conditions. We therefore suggest that the demonstrated ability of L. serriola to complete its life cycle and produce biomass and seeds under water stressed conditions leads to the introduction of strategies that minimize weed survival while maximizing irrigation efficiency for the crop. A clear understanding of the ecological and biological characteristics of this weed will help land managers take appropriate control measures to mitigate the effect of this species on economic crop productivity.
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