Dr Joseph Pegler

Dr Joseph Pegler

Research Associate

School of Environmental and Life Sciences

Career Summary

Biography

Dr Joseph Pegler is a Postdoctoral Scientist on an Australian Research Council Discovery Project working alongside Professors Christopher Grof and John Patrick (FAA) at the University of Newcastle.

Joseph’s research aims to move towards addressing the serious and growing global issue of providing food security for an ever-growing global population. This is particularly relevant in an era dominated by anthropogenic driven climate change where farming is impacted by droughts, floods, and catastrophic wildfires.

Over the course of his career, Joseph hopes to develop strong interdisciplinary and cross-sector collaborations which he strongly believes are necessary for the discovery and implementation of solutions needed to address the significant global issues faced by the current and future generations in Australia and beyond.

Research focus

In his work, Joseph aims to identify and characterise novel sugar transporters of common bean with the hopes to increase the yield of grain and legume crops. As high yielding crop varieties are reaching their yield limitation, increases in crop yield often stem from the long-standing and unsustainable practice of clearing biodiverse rich ecosystems for the cultivation of additional crops, largely contributing to the global carbon footprint. Therefore, increasing our current understanding of molecular pathways which underpin plant yield is fundamental for the development of higher yielding crops, an essential quantum leap required to achieve food security while reducing environmental damage.

Legumes are ideally positioned for a more sustainable approach to achieving human protein consumption globally. Possessing additional positive nutritional contents such as fibre, carbohydrates, low glycemic index (GI) and key vitamins, legumes are widely valued and consumed in African and Asian regions lacking readily accessible animal protein. An additional benefit of grain legumes is the ability of these plants to fix nitrogen, an ability which greatly limits the need for nitrogen fertilizers.

Joseph completed his PhD (November 2020) at the University of Newcastle under the supervision of Dr. Andrew Eamens (UON), Professor Christopher Grof (UON), Professor Robert Furbank (ANU) and Professor Christopher Lambrides (UQ). Joseph’s PhD study was focused on understanding the molecular pathways a plant can utilise to tolerate stressful growth conditions such as drought, high temperature or salinity. More specifically, this research identified and manipulated microRNA profiles in the plant species Arabidopsis thaliana (a common and longstanding model plant used within laboratory settings) to generate plants with an improved tolerance to unfavourable growth conditions.


Qualifications

  • Doctor of Philosophy in Biological Sciences, University of Newcastle
  • Bachelor of Biotechnology, University of Newcastle
  • Bachelor of Biotechnology (Honours), University of Newcastle

Keywords

  • Abiotic stress
  • Plant physiology
  • RNA silencing
  • Sugar transport
  • microRNAs

Languages

  • English (Mother)

Fields of Research

Code Description Percentage
310803 Plant cell and molecular biology 50
310806 Plant physiology 50

Professional Experience

UON Appointment

Title Organisation / Department
Research Associate University of Newcastle
School of Environmental and Life Sciences
Australia
Casual Academic University of Newcastle
School of Environmental and Life Sciences
Australia
Research Associate University of Newcastle
School of Environmental and Life Sciences
Australia

Awards

Award

Year Award
2019 Collaboration Excellence Team Award
Faculty of Science | University of Newcastle
2018 Best Higher Degree by Research Engagement Award (Community, Industry or International)
Faculty of Science | University of Newcastle

Scholarship

Year Award
2018 Global Voices’ Research Fellowship for COP24 UN Framework Convention on Climate Change (UNFCCC)
Global Voices

Teaching

Code Course Role Duration
BIOL1003 Professional Skills for Biological Sciences
Faculty of Science | University of Newcastle
Demonstrator 1/1/2019 - 1/1/2021
BIOL3330 Plant Physiology and Development
Faculty of Science | University of Newcastle
Demonstrator 1/1/2019 - 1/1/2021
BIOL2002 Laboratory Skills in Biological Systems
Faculty of Science | University of Newcastle
Demonstrator 1/1/2017 - 1/1/2021
BIOL3001 Advanced Laboratory Skills in Biological Sciences
Faculty of Science | University of Newcastle
Demonstrator 1/1/2017 - 1/1/2021
SCIE1002 Multidisciplinary Laboratories
Faculty of Science | University of Newcastle
Demonstrator 1/1/2019 - 1/1/2021
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Publications

For publications that are currently unpublished or in-press, details are shown in italics.


Chapter (1 outputs)

Year Citation Altmetrics Link
2019 Pegler JL, Grof CPL, Eamens AL, 'The plant microRNA pathway: The production and action stages', Plant MicroRNAs: Methods and Protocols, Springer, New York, NY 15-39 (2019) [B1]
DOI 10.1007/978-1-4939-9042-9_2
Citations Scopus - 3
Co-authors Andy Eamens, Chris Grof

Journal article (9 outputs)

Year Citation Altmetrics Link
2021 Pegler JL, Oultram JMJ, Nguyen DQ, Grof CPL, Eamens AL, 'MicroRNA-Mediated Responses to Cadmium Stress in Arabidopsis thaliana.', Plants (Basel), 10 (2021)
DOI 10.3390/plants10010130
Co-authors Andy Eamens, Chris Grof
2021 Pegler JL, Oultram JMJ, Grof CPL, Eamens AL, 'Molecular manipulation of the miR399/PHO2 expression module alters the salt stress response of arabidopsis thaliana', Plants, 10 1-22 (2021)

© 2020 by the authors. Licensee MDPI, Basel, Switzerland. In Arabidopsis thaliana (Arabidopsis), the microRNA399 (miR399)/PHOSPHATE2 (PHO2) expression module is central to the res... [more]

© 2020 by the authors. Licensee MDPI, Basel, Switzerland. In Arabidopsis thaliana (Arabidopsis), the microRNA399 (miR399)/PHOSPHATE2 (PHO2) expression module is central to the response of Arabidopsis to phosphate (PO4) stress. In addition, miR399 has been demonstrated to also alter in abundance in response to salt stress. We therefore used a molecular modification approach to alter miR399 abundance to investigate the requirement of altered miR399 abundance in Arabidopsis in response to salt stress. The generated transformant lines, MIM399 and MIR399 plants, with reduced and elevated miR399 abundance respectively, displayed differences in their phenotypic and physiological response to those of wild-type Arabidopsis (Col-0) plants following exposure to a 7-day period of salt stress. However, at the molecular level, elevated miR399 abundance, and therefore, altered PHO2 target gene expression in salt-stressed Col-0, MIM399 and MIR399 plants, resulted in significant changes to the expression level of the two PO4 transporter genes, PHOSPHATE TRANSPORTER1;4 (PHT1;4) and PHT1;9. Elevated PHT1;4 and PHT1;9 PO4 transporter levels in salt stressed Arabidopsis would enhance PO4 translocation from the root to the shoot tissue which would supply additional levels of this precious cellular resource that could be utilized by the aerial tissues of salt stressed Arabidopsis to either maintain essential biological processes or to mount an adaptive response to salt stress.

DOI 10.3390/plants10010073
Co-authors Chris Grof, Andy Eamens
2020 Pegler JL, Nguyen DQ, Grof CPL, Eamens AL, 'Profiling of the salt stress responsive MicroRNA landscape of C4 genetic model species setaria viridis (l.) beauv', Agronomy, 10 (2020) [C1]
DOI 10.3390/agronomy10060837
Citations Scopus - 2Web of Science - 3
Co-authors Andy Eamens, Chris Grof
2020 Nguyen DQ, Brown CW, Pegler JL, Eamens AL, Grof CPL, 'Molecular manipulation of microRNA397 abundance influences the development and salt stress response of arabidopsis thaliana', International Journal of Molecular Sciences, 21 1-24 (2020) [C1]

© 2020 by the authors. Licensee MDPI, Basel, Switzerland. Arabidopsis thaliana (Arabidopsis) has been used extensively as a heterologous system for molecular manipulation to genet... [more]

© 2020 by the authors. Licensee MDPI, Basel, Switzerland. Arabidopsis thaliana (Arabidopsis) has been used extensively as a heterologous system for molecular manipulation to genetically characterize both dicotyledonous and monocotyledonous plant species. Here, we report on Arabidopsis transformant lines molecularly manipulated to overaccumulate the small regulatory RNA microRNA397 (miR397) from the emerging C4 monocotyledonous grass model species Setaria viridis (S. viridis). The generated transformant lines, termed SvMIR397 plants, displayed a range of developmental phenotypes that ranged from a mild, wild-type-like phenotype, to a severe, full dwarfism phenotype. Reverse transcriptase quantitative polymerase chain reaction (RT-qPCR)-based profiling of the SvMIR397 transformant population revealed a strong correlation between the degree of miR397 over-accumulation, repressed LACCASE (LAC) target gene expression, reduced lignin content, and the severity of the developmental phenotype displayed by SvMIR397 transformants. Further, exposure of SvMIR397 transformants to a 7-day regime of salt stress revealed the SvMIR397 transformant lines to be more sensitive to the imposed stress than were wild-type Arabidopsis plants. Taken together, the findings reported here via the use of Arabidopsis as a heterologous system show that the S. viridis miR397 small regulatory RNA is able to repress the expression of three Arabidopsis LAC genes which led to reduced lignin content and increased salt stress sensitivity.

DOI 10.3390/ijms21217879
Co-authors Chris Grof, Andy Eamens
2019 Pegler JL, Oultram JMJ, Curtin SJ, Grof CPL, Eamens AL, 'Further Disruption of the TAS3 Pathway via the Addition of the AGO7 Mutation to the DRB1, DRB2 or DRB4 Mutations Severely Impairs the Reproductive Competence of Arabidopsis thaliana', Agronomy, 9 (2019) [C1]
DOI 10.3390/agronomy9110680
Co-authors Chris Grof, Andy Eamens
2019 Pegler JL, Oultram JMJ, Grof CPL, Eamens AL, 'DRB1, DRB2 and DRB4 Are Required for Appropriate Regulation of the microRNA399/PHOSPHATE2 Expression Module in Arabidopsis thaliana.', Plants, 8 (2019) [C1]
DOI 10.3390/plants8050124
Citations Scopus - 6Web of Science - 6
Co-authors Chris Grof, Andy Eamens
2019 Pegler JL, Oultram JMJ, Grof CPL, Eamens AL, 'Profiling the Abiotic Stress Responsive microRNA Landscape of Arabidopsis thaliana.', Plants, 8 (2019) [C1]
DOI 10.3390/plants8030058
Citations Scopus - 15Web of Science - 14
Co-authors Andy Eamens, Chris Grof
2018 Pegler JL, Grof CPL, Eamens AL, 'Profiling of the Differential Abundance of Drought and Salt Stress-Responsive MicroRNAs Across Grass Crop and Genetic Model Plant Species', AGRONOMY-BASEL, 8 (2018) [C1]
DOI 10.3390/agronomy8070118
Citations Scopus - 7Web of Science - 7
Co-authors Chris Grof, Andy Eamens
2016 McGaughey SA, Osborn HL, Chen L, Pegler JL, Tyerman SD, Furbank RT, et al., 'Roles of aquaporins in setaria viridis stem development and sugar storage', Frontiers in Plant Science, 7 (2016) [C1]

© 2016 McGaughey, Osborn, Chen, Pegler, Tyerman, Furbank, Byrt and Grof. Setaria viridis is a C4 grass used as a model for bioenergy feedstocks. The elongating internodes in devel... [more]

© 2016 McGaughey, Osborn, Chen, Pegler, Tyerman, Furbank, Byrt and Grof. Setaria viridis is a C4 grass used as a model for bioenergy feedstocks. The elongating internodes in developing S. viridis stems grow from an intercalary meristem at the base, and progress acropetally toward fully expanded cells that store sugar. During stem development and maturation, water flow is a driver of cell expansion and sugar delivery. As aquaporin proteins are implicated in regulating water flow, we analyzed elongating and mature internode transcriptomes to identify putative aquaporin encoding genes that had particularly high transcript levels during the distinct stages of internode cell expansion and maturation. We observed that SvPIP2;1 was highly expressed in internode regions undergoing cell expansion, and SvNIP2;2 was highly expressed in mature sugar accumulating regions. Gene co-expression analysis revealed SvNIP2;2 expression was highly correlated with the expression of five putative sugar transporters expressed in the S. viridis internode. To explore the function of the proteins encoded by SvPIP2;1 and SvNIP2;2, we expressed them in Xenopus laevis oocytes and tested their permeability to water. SvPIP2;1 and SvNIP2;2 functioned as water channels in X. laevis oocytes and their permeability was gated by pH. Our results indicate that SvPIP2;1 may function as a water channel in developing stems undergoing cell expansion and SvNIP2;2 is a candidate for retrieving water and possibly a yet to be determined solute from mature internodes. Future research will investigate whether changing the function of these proteins influences stem growth and sugar yield in S. viridis.

DOI 10.3389/fpls.2016.01815
Citations Scopus - 7Web of Science - 8
Co-authors Chris Grof
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Dr Joseph Pegler

Positions

Research Associate
School of Environmental and Life Sciences
College of Engineering, Science and Environment

Casual Academic
School of Environmental and Life Sciences
College of Engineering, Science and Environment

Contact Details

Email joseph.pegler@newcastle.edu.au
Phone (02) 4921 6129

Office

Room BAG06
Building Basden Annex
Location Callaghan
University Drive
Callaghan, NSW 2308
Australia
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