In conversation with Dr. Jenny Mortimer

Abstract

@Jenny_Mortimer1

http://www.mortimerlab.org/

Jenny Mortimer is an Associate Professor of Plant Synthetic Biology at the University of Adelaide's School of Agriculture, Food and Wine and serves as the Interim Deputy Director of The Waite Research Institute. With affiliations at the Lawrence Berkeley National Laboratory and leadership roles at the Joint BioEnergy Institute, her work focuses on engineering plant cell metabolism, particularly glycosylation, to develop crops that support a sustainable bioeconomy. Her research spans biofuel production, resilient crop development, and space agriculture, with collaborations across Australia and the US, including projects funded by the US Department of Energy and the Australian Research Council. In this interview, Jenny discusses her journey, the challenges and exciting possibilities of plant synthetic biology, and how her team's work could transform industries ranging from renewable energy to space exploration. She also shares insights into the future of sustainable agriculture and how synthetic biology can address pressing global challenges.

1. Would you tell us about your background? Where did you grow up and go to school, anything that you want to share?

I grew up in a fairly international family. My dad was Maltese, and my mum, though British, was born in Malaysia. My dad was in the British army, so I was born in Brunei, but we moved around a lot. This was disruptive to schooling, but it helped me adapt to, and even enjoy, the frequent relocations that often come with an academic career. I earned my bachelor's degree in biological sciences from the University of Bristol (UK), and after a brief detour into bioinformatics for my master's at the University of Exeter (UK), I realized I loved bench experiments. As a result, I pursued my PhD in plant physiology and biochemistry at the University of Cambridge (UK).

2. Was science a natural thing for you growing up or did it come later in life?

I was fascinated by how things worked from an early age. Although no one in my family or social circle had gone to university or worked in science, I was always encouraged to explore my curiosity – through books or visits to museums. Initially, I thought I would be a marine biologist, but then David Attenborough's series “The Private Life of Plants” came out when I was about 13. It used time-lapse cameras to show how plants move and respond, and from that moment, I was hooked.

3. What is your current research about?

My group is using synthetic biology to develop sustainable novel crops for food production and bioproducts as well as to understand the fundamentals of glycosylation in plants. These strands come together in our work to engineer the plant cell wall to improve its performance in the biorefinery to make biofuels and bioproducts. There is a huge amount we still do not know about how individual polysaccharides are made, let alone how they come together to form a functional wall. We are only beginning to scratch the surface of how to predictably design and engineer biomass. This is critical to a sustainable and economically viable bioeconomy, where biomass is going to be the major source of carbon for biomanufacturing.

Glycosylation also happens to be a fascinating piece of biochemistry and it regulates the function of proteins, lipids, and metabolites as well as building the cell wall. I believe a lot of this complexity is currently overlooked, as we lack good tools for large-scale analysis, despite a large fraction of the genome being predicted to be involved in glycosylation.

An example of complex glycosylation that is fascinating to us in the lab has been the polysaccharide rhamnogalacturonan-II (RG-II), the most structurally complex plant polysaccharide, which has 21 distinct sugar linkages. It is found in all plant cell walls, and this complex structure is essentially conserved across all plants. Evidence is accumulating to show that any changes to the RG-II structure are lethal to the plant, and RG-II in the wall forms dimers mediated by boron. This dimerization is a major reason why boron is an essential element. We are fascinated by this molecule, but its essential nature has made it hard to identify the genes underlying its synthesis. We have recently developed a new method that allows us to gene-edit callus, removing the need to generate whole plants. Using this, we have been able to knock out candidate RG-II synthesis genes to determine their likely function and generate new forms of RG-II glycan so that we explore its structural relationship with other cell wall components.

4. Can you talk about the Plants for Space program? And what is your experience working with them?

Plants for Space (P4S) is a new Australian Research Council (ARC) Centre of Excellence. Focused on basic research carried out at Australian universities, our partners also include industry (such as vertical farming and commercial space companies) and government (including NASA and the Australian Space Agency).

Our goal is to re-imagine plant design and bioresource production through the lens of space. We are exploring how plants can be used to support long-term off-Earth habitation while using this to inspire innovative solutions that enhance sustainability on Earth. Our research themes include the development of complete nutrition plant-based foods, zero-waste plants optimized for controlled environments, and on-demand bioresource production. Alongside this, we have a big focus on both training students and outreach and education. Our team is a diverse mix of skills from plant scientists and engineers, to psychologists and lawyers. This has challenged me to develop projects that not only consider the immediate question but also upstream and downstream impact. We only formally started in Jan 2024, but it has been very exciting and provided opportunities that I never expected. For example, I am part of a team, led by a P4S partner company, US-based Space Lab Technology, which is developing a payload for Artemis III. Artemis III will return humans to the lunar surface for the first time in more than 50 years. The LEAF payload is designed to germinate plants on the lunar surface (Arabidopsis thaliana, Wolffia australiana, and Brassica rapus). Excitingly, for the first time, the plants will be fixed, allowing them to be returned to our labs to analyze the impact of the lunar environment on their gene expression, cell wall, and growth.

5. What do you think of adopting orphan crops, and what will be their role in future global food security?

Agriculture is under immense pressure globally. We are not only using it for the production of food but increasingly for the production of feedstocks and commodities as we look to reduce our reliance on fossil fuels. This is at a time of additional challenges, such as increasing population, reductions in soil fertility, and the impact of climate change. I think it is really a case of exploring all options. There is not going to be one solution – instead, it will be making use of an array of solutions that work best in particular locations and for particular markets. As part of this, I think it is important to explore additional crops. Technologies such as gene editing offer the possibility of accelerating domestication to increase productivity and desired agronomic traits.

I am particularly interested in how this applies to closed environment agriculture (CEA) and in particular vertical farms. There is an opportunity to develop new crops that are suited to these environments, for example, for the production of protein or other macronutrients. We (and others) have been exploring duckweeds such as Wolffia spp., which due to their rapid growth and high protein content, make an excellent starting point for further improvement.

6. In your opinion, what are the biggest challenges in your field?

Efficient tissue-culture-free transformation that is species and cultivar-agnostic. The promise of synthetic biology and its application in agriculture really requires us to be able to test things in high throughput. This is because of our inability to often predict the response of metabolism to our engineering efforts! Plants are immensely complex multicellular organisms with a phenotypic output that is determined by the interplay of genetics and environment. Our ability to be more predictive will require us first to be able to do a significant number of design-build-test-learn (DBTL) cycles.

Oh, and in glycobiology – better analytical tools! Glycan modifications of proteins and metabolites, as well as polysaccharide structures, are still poorly understood.

7. How does your research approach solutions for those challenges?

Like many others around the world, we have been developing improved transformation methods. We have a focus on sorghum, as a promising bioenergy crop, and duckweed as both a promising food crop (see below) and synbio chassis. We have been working collaboratively to share approaches (including what has not worked – and to report that) and to develop robust protocols. We are hoping that working with plants such as duckweed, which have a much faster lifecycle than most model plants and can be grown in six-well plates, will allow us to speed round that DBTL cycle a bit faster too!

As for glycobiology, we have been employing a range of methods. These include a fairly low-tech one called PACE, that was developed in the lab of my postdoc advisor, Prof. Paul Dupree. You can think of it as a restriction digest for polysaccharides, which makes use of large format gels (the ones used to sequence DNA). We are currently expanding the types of polysaccharides that can be analyzed, including RG-II. We also make use of highly complex tools, such as multi-dimensional solid-state NMR (ssNMR), another method that we started to develop when I was a postdoc with Paul. This allows us to look at intact cell walls and understand how the different polymers interact to form a functional material. We have used it to look at our engineered walls so that we can link changes to activity of single glycosyltransferases and the resulting plant phenotype (including saccharification) to modified cell wall structure. We are then using this information to improve future engineering strategies.

8. What are the biggest challenges you have faced as a woman in science?

This is a hard question because sometimes it is a challenge to unravel what is due specifically to being a woman versus challenges that everyone faces (although I have to say, sometimes it has been made crystal clear to me!). I have also noticed that the challenges change due to career stage but also due to the culture of the country that you are working in, as well as how attitudes to women in science have changed more broadly during the last 20 years. I think one challenge that I am more aware of recently has been the huge decline in the number of female colleagues as you become more senior. This can both be isolating, but also can massively increase the service workload, as guidelines often suggest that every committee and event needs female representation. While I do see that this comes from a place of positive intent, it can lead to serious impacts on productivity. However, I am also conscious that this is not limited to women – those who are members of other minority groups, and particularly those who sit at the intersection of minority groups, such as women of color, bear this burden in an outsized way.

I will say, that I find the plant science community on the whole very inclusive and welcoming, and making strides to be positive. I was a member of the ASPB Women in Plant Science Committee until recently, and I felt that we had the opportunity and, importantly the support of ASPB leadership, to implement a policy that could have a positive impact both for our members, but also to lead change more widely by engaging with other professional societies. I also have been supported and encouraged throughout my career by a whole cast of wonderful plant scientists (mostly male) and I definitely would not be where I am today without them.

9. If you were a plant, what would you be and why?

Tough question, and I am sure that this answer might change depending on what day you ask me! However, on a sunny Spring day in Australia like today, I think I might be an Eremophila (emu bush). These small resilient plants are endemic to my adopted home, Australia. They survive in all sorts of environments and are bird-pollinated, so really enrich a garden. I have lots in mine. I am short, fairly resilient, and I aspire to improve the research environment for others now, and for those who come after me!