Current Projects

1. Elucidating the Mechanisms of Cell Wall Priming for Enhanced Drought Tolerance

We investigate the dynamic remodelling of the plant cell wall in response to stresses such as drought. Crucially we look to distinguish between immediate short-term changes and longer-term adaptive changes. Cell walls are not merely passive barriers; their mechanical and chemical integrity are crucial for preventing catastrophic cellular rupture under drying conditions. We have compelling data showing that even mild drought stress induces persistent cell wall modifications that remain long after re-watering - a phenomenon termed cell wall priming. 

Preliminary data suggests that this primed state confers enhanced tolerance to subsequent stress episodes. This project is a comprehensive effort to chemically and biophysically characterise these long-lasting wall changes, identify the genetic and molecular pathways controlling their induction, and determine how these modifications integrate with overall plant physiological performance and survival. The ultimate objective is to pinpoint targets for engineering crops with hardwired, persistent drought resistance.

 2. Defining the Regulatory Role of Callose in Stomatal Cell Wall Dynamics

Stomata, microscopic pores formed from a pair of guard cells are essential for regulating gas exchange and transpirational water loss. They are extraordinary examples of cellular mechanics, undergoing massive and rapid pressure and shape changes multiple times daily without mechanical failure. Prior research, including our own, highlights that the cell walls of guard cells are highly specialised in the polysaccharide composition of their cell walls. 

Recently we have identified β-(1,3)-glucan (known as callose) as a critical, but mechanistically unresolved, component regulating guard cell function. Disrupting the synthesis of guard cell localised callose leads strongly disrupts stomatal function. By employing a combination of advanced imaging, genetics, and biophysics we aim to precisely map the spatial and temporal localisation of callose within stomatal cell walls and determine the molecular mechanisms by which its synthesis and degradation govern the remarkable flexibility and rapid response of stomata.

3. Engineering Next-Generation Probes for High-Resolution Cell Wall Interrogation

The precise spatial analysis of polysaccharide composition within the plant and fungal cell walls relies heavily on a limited library of existing glycan-specific antibodies. These antibodies have remarkable specificity and affinity for their polysaccharide targets, and have been heavily utilised for decades. 

This project leverages recent advances in structural biology, computational design, and synthetic biology to revolutionise this crucial analytical toolkit. Alongside generating new antibodies we are also actively engineering novel probes based on the existing antibody library, focusing on developing smaller, more mobile scaffolds (e.g. antibody fragments) optimised for high-resolution live-cell imaging of wall dynamics. Furthermore, we are employing rational and combinatorial engineering of binding sites to modify the specificity of existing probes, creating a new generation of high-affinity ligands for previously inaccessible or poorly resolved glycan epitopes.

4. Nanoscale Analysis of Cell Wall Ultrastructure in the Fungal Pathogen Zymoseptoria tritici

Fungi are highly successful organisms, partly due to the structural resilience of their polysaccharide-rich cell walls. However, the ultrastructure and genetic determinants of these fungal CWs, particularly in key pathogens, remain poorly understood. We utilise Zymoseptoria tritici, a devastating pathogen of wheat, as a model system to dissect the architecture of the fungal cell wall at the nanoscale.

 This interdisciplinary project combines advanced genetic manipulation with state-of-the-art biophysical techniques (e.g., Atomic Force Microscopy, nano-IR) to elucidate the hierarchical organisation of key wall components (chitin, β-(1,3)-glucan) at unprecedented resolution. The goal is to define how these components contribute to the pathogen's overall virulence, offering potential novel targets for antifungal therapies in agriculture.

5. Cell Wall Responses to Pathogens: Hardcoding Stress Memory in Polysaccharide Networks

Plants, as sessile organisms, rely on a sophisticated, inducible defence repertoire to survive pathogen attack. The plant cell wall is the first line of physical and chemical defence, serving as a shield and a source of signalling molecules. In addition to primary defences, plants exhibit "immune priming," a mechanism that confers long-lasting immune memory, enabling a faster and stronger response upon subsequent attack.

 This project focuses on how CW-derived damage-associated molecular patterns (DAMPs), molecules released during wall degradation, act as signals to switch on these durable immune responses. We are specifically investigating how changes in CW composition, particularly the balance and modification state of pectin polysaccharides, enhance the plant's capacity to mount a stronger primed immune response. This research directly informs agricultural applications, aiming to identify novel breeding targets or chemical priming agents that boost intrinsic crop immunity.