Research | Engineering plant metabolism for high-value molecules

🧭 Research direction

What connects the work

Plants build the molecules we use as medicines, flavours, dyes and materials. Almost all of that chemistry is decided by a small number of enzymes at the branch points of metabolic pathways. Find the enzyme at a branch point and you can change what comes out of it.

How do unusual enzymes create new plant chemistry?

For most valuable plant specialised metabolites nobody knows the biosynthetic route. Finding one means knowing where to look, and the assumptions about which enzyme families are worth searching turn out to be too narrow.

How can plant metabolism be redirected towards useful molecules?

Useful compounds sit at the end of long pathways. Supply upstream, and competition for carbon along the way, decide whether a plant accumulates milligrams or grams.

What new behaviours can synthetic biology build into plant cells?

Beyond moving a known pathway: designing a plant cell to do something it has never done, predictably and on cue.

What does it take to turn interesting biology into something useful?

A transgenic line that works in a growth chamber is not a product. Crop choice, yield, extraction, stability and the existing supply chain decide whether anything leaves the greenhouse.

🌾 Current research

Aromatic metabolism, and what limits it

My current work asks how much of the carbon a plant captures can be directed into the chemistry we want.

Aromatic compounds are one of the most valuable families a plant makes. Vanillin, morphine, indigo, salicylate and a long list of pharmaceuticals and flavourings all descend from a single upstream route: the shikimate pathway, which turns fixed carbon into the aromatic amino acids, and from there into everything downstream.

That makes supply the bottleneck. However clever the downstream enzymes are, a plant cannot accumulate what it never had the carbon to build. So the interesting question is not only how to add a pathway, but how much carbon can reach the start of it, and whether the plant can be stopped from spending that carbon on something else.

An enzyme developed at UW–Madison raises carbon dioxide fixation by up to 30%. I am developing the metabolic engineering that follows: rerouting the extra assimilated carbon into aromatic amino acid biosynthesis rather than ordinary growth, then pushing it further into benzenoids and phenylpropanoids that are worth extracting. I test in tobacco because it is fast and forgiving, then move into sorghum, because a field crop is where any of this has to work.

This work is carried out with Hiroshi Maeda and Quentin Dudley at UW–Madison. Results are in progress and unpublished.

In plainer terms: a plant captures carbon from the air, and most of it becomes leaf, stem and root. I am trying to persuade a crop to spend a slice of that carbon making molecules we currently synthesise from petroleum instead.

30%More CO₂ fixed

2Host species

1Pathway underneath it all

🧫 On the bench

Current projects

Metabolic engineering

Redirecting fixed carbon into aromatics

Sorghum & tobacco · UW–Madison

Building the rerouting strategies that connect increased carbon fixation to aromatic amino acid biosynthesis, then testing which downstream branches actually accumulate product rather than leaking it back into growth.

Goal: transgenic lines that accumulate valuable aromatic end products in a field crop.

Synthetic biology

New synthetic biology project

With collaborators in the Department of Biochemistry, UW–Madison

Developing a new synthetic biology project with collaborators in the UW–Madison Department of Biochemistry, asking what new behaviours can be designed into plant cells.

Details pending.

Synthetic biology · translation

Betalain pigments in soybean seed

Soybean · with collaborators at UW–Madison

Engineering the betalain pathway into soybean so the seed accumulates red pigment, and exploring whether that line could become a production platform for a natural colourant.

Question: can a crop already grown at scale supply a replacement for synthetic red?

The venture exploration →

🧬 Previous research

PhD research: an alkaloid pathway

University of York, 2020 to 2024.

2020–2024

PhD Biology, University of York
Flueggea suffruticosa
Supervisors: Benjamin Lichman (Biology), William Unsworth (Chemistry)

Enzyme discovery Isotope labelling NMR & LC–MS

OLADO, and the same chemistry invented more than once

Problem Alkaloids give us some of our oldest and most valuable medicines, and for most of them nobody knows how the plant makes the compound. Without the pathway you cannot move it, improve it, or produce the molecule anywhere else.
What I did Worked out the first committed steps of Securinega alkaloid biosynthesis, a Δ¹-piperideine-derived pathway, combining enzyme discovery with chemical synthesis, isotope labelling, transcriptomics and heterologous expression in E. coli and in planta.
Result The step is run by OLADO, a decarboxy-oxidase whose closest relatives are bacterial rather than plant. Parallel evolution, not shared ancestry: the same chemistry arrived at multiple times, independently.
Why it matters It moves a whole enzyme family into the search space for undiscovered alkaloid pathways. If you are hunting biosynthesis in a plant that makes something valuable, bacterial-like enzymes of this kind are now worth a look.

The paper: New Phytologist 2026 ↗ Thesis abstract ↗ Blog: publication alert ↗ Blog: the podcast picked it up ↗

📚 The record

Publications and writing

Loaded live from ORCID and grouped by type. Primary research, Research Highlights written as an editor, and science communication are listed separately.

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Work with me

I am looking for collaborators across plant specialised metabolism, metabolic engineering and synthetic biology. The questions I keep returning to are how plants arrive at new chemistry in the first place, what decides how much of a compound a plant will actually accumulate, and how a pathway that works in a model species behaves once it is moved into a crop.

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