Dr Joe McKenna

Supervisor Details

Contact Details

School of Life Sciences, University of Warwick

Scientific Background

Research Interests

Plants are remarkable organisms, not only because they sustain nearly all life on Earth by producing oxygen and food, but also because of the extraordinary complexity hidden within their cells. Far from being static, plant cells are dynamic systems in which organelles and other components are constantly moving and interacting. This intracellular movement is essential for cellular function, development, and adaptation, yet the precise mechanisms that coordinate it remain only partially understood.

My research explores how plants regulate these intracellular dynamics under both normal and stress conditions. By integrating advanced microscopy with state-of-the-art proteomics, I aim to uncover the molecular machinery that governs organelle movement and coordination. Understanding these processes is crucial, as they underpin plant responses to environmental challenges and pathogen attack. Ultimately, this work seeks to reveal fundamental principles of plant cell biology while providing insights that could inform strategies for improving crop resilience and productivity.

Scientific Inspiration

My former postdoctoral supervisor, Professor Chris Hawes, passed away in 2019 but left a profound and lasting impact on the field of plant cell biology. Chris had an insatiable passion for both microscopy and plants, and his group was among the pioneers in studying organelle dynamics, endoplasmic reticulum morphology, and membrane trafficking. Beyond his research contributions, he was deeply committed to science outreach and had a rare gift for inspiring others. His ability to communicate the excitement of plant science and microscopy is beautifully captured in his lecture to high school students at the Science Museum (https://www.youtube.com/watch?v=eAFZbIdHZ7c), a testament to his enduring influence as both a scientist and a mentor.

Supervision Style

In three words or phrases: Supportive, Structured, Enthusiastic

Provision of Training

Your training will be a combination of direct supervision from me and guidance from experienced members of the lab. At the start of your project, we will meet formally at least once a week to ensure steady progress and provide structured support. As your independence grows, these meetings may transition to a bi-weekly schedule, tailored to your needs. In addition, because I am frequently in the lab myself, there are abundant opportunities for informal discussions and day-to-day guidance, fostering a collaborative and supportive environment.

Progression Monitoring and Management

I hold high expectations for students in my group, but I am equally committed to fostering a structured and supportive environment to help you achieve them. While initial training in the lab is essential, I expect students to gradually develop independence and take ownership of their projects. Regular meetings will provide opportunities to reflect on progress, set goals, and refine research directions, ensuring that expectations evolve in line with your growth as a researcher.

Communication

In addition to one-on-one meetings, I am always available via email when I am not on site. Although I may send messages outside regular hours, I only expect them to be read and answered during normal working times. The group also meets once a week at a scheduled time, where each member presents their progress and we engage in open, constructive discussions about current projects and future directions.

Meetings

PhD Students can expect scheduled meetings with me at least once per week. These meetings will be face-to-face. I am usually contactable for an instant response on every working day.

Work Patterns

The timing of work in my lab is completely flexible, and (other than attending pre-arranged meetings) I expect students to manage their own time.

Notice Period for Feedback

I need at least 2 weeks' notice to provide feedback on written work of up to 5,000 words.

MIBTP Project Details

Primary supervisor for:

Making contact: Understanding organelle contact sites in plants during biotic stress

See the PhD Opportunities section to see if this project is currently open for applications via MIBTP.

Please Note: The main page lists projects via BBSRC Research Theme(s) quoted and then relevant Topic(s).

Making contact: Understanding organelle contact sites in plants during biotic stress

Secondary Supervisor(s): Professor Murray Grant, Dr Emily Breeze

University of Registration: University of Warwick

BBSRC Research Themes:

Sustainable Agriculture and Food (Plant and Crop Science)
Understanding the Rules of Life (Plant Science)

Project Outline

Plants exhibit remarkable plasticity that enables survival under biotic and abiotic stress. At the cellular level, this flexibility is underpinned by dynamic organelle behavior. During plant-pathogen interactions, organelles undergo highly specific reorganizations in morphology, positioning, and activity. Crucially, organelles do not function in isolation. Increasing evidence highlights the importance of membrane contact sites (MCS): discrete domains where two organelles are closely apposed and tethered without membrane fusion. These sites mediate the exchange of metabolites and signals, coordinating organelle function with cellular responses. In plants, most work on MCS has focused on endoplasmic reticulum (ER)-based contacts, such as ER-mitochondria, ER-plasma membrane, ER-Golgi, ER-peroxisomes, and ER-chloroplasts.

This project will investigate how organelle-organelle contact sites are remodeled during pathogen infection. The study will focus on the interaction network linking the nucleus, actin cytoskeleton, ER, and peri-nuclear chloroplasts, which is strongly implicated in immune signaling. Novel fluorescent protein reporters will be used to visualize these contacts in planta with high spatial and temporal resolution using live-cell confocal microscopy. In parallel, proximity labeling proteomics (TurboID and split-TurboID) will identify proteins recruited to MCS under homeostatic and pathogen-challenged conditions.

By integrating advanced imaging and proteomics, this project will reveal how pathogen challenge reshapes inter-organelle connectivity. The expected outcomes are a deeper understanding of the molecular composition and dynamic organization of MCS during immune responses. These insights will advance knowledge of plant cell architecture and identify potential strategies to manipulate inter-organelle communication as a route to enhance resistance against pathogens.

Re-engineering a cellular dustbin into a protein storage organelle

See the PhD Opportunities section to see if this project is currently open for applications via MIBTP.

Please Note: The main page lists projects via BBSRC Research Theme(s) quoted and then relevant Topic(s).

Re-engineering a cellular dustbin into a protein storage organelle

Secondary Supervisor(s): Professor Lorenzo Frigerio

University of Registration: University of Warwick

BBSRC Research Themes:

Sustainable Agriculture and Food (Plant and Crop Science)
Understanding the Rules of Life (Plant Science)

Project Outline

Plants display extraordinary diversity in form and structure, from ornamental species to towering redwoods. Central to this diversity is the vacuole, an organelle that regulates turgor pressure to drive cell growth and morphogenesis. During seed maturation, vacuoles undergo a striking transformation: instead of maintaining a single large vacuole, cells generate multiple protein storage vacuoles (PSVs). These PSVs accumulate seed storage proteins (SSPs), which serve as nutrient reserves for germination and are a key component of the nutritional value of seeds in the human diet.

Our laboratory has uncovered a novel mechanism underlying PSV formation. We have shown that SSPs actively drive this process: upon trafficking to the vacuole, they undergo liquid-liquid phase separation to form protein-rich droplets. These condensates interact with the vacuolar membrane, deforming it and triggering budding events that give rise to discrete, SSP-enriched PSVs. This mechanism provides new insight into how protein phase separation can remodel organelles and alter their functional identity.

This PhD project will build on these unpublished findings to engineer PSV production outside its normal developmental context. By exploiting the intrinsic ability of SSPs to remodel vacuoles, we aim to design synthetic strategies for targeted PSV biogenesis and protein enrichment in non-seed tissues. This work has two main objectives:

1. To provide fundamental insight into the role of phase separation in shaping organelle architecture.

2. To create applied tools for enhancing protein accumulation and purification in crop species, with implications for nutrition, biotechnology, and sustainable agriculture.

Through an integrated approach combining molecular genetics, live-cell imaging, and synthetic biology, this project will uncover new principles of plant cell organization while developing translational applications for crop improvement.

The ties that bind: Understanding actin and endoplasmic reticulum interactions during stress in plants

See the PhD Opportunities section to see if this project is currently open for applications via MIBTP.

Please Note: The main page lists projects via BBSRC Research Theme(s) quoted and then relevant Topic(s).

The ties that bind: Understanding actin and endoplasmic reticulum interactions during stress in plants

Secondary Supervisor(s): Professor Lorenzo Frigerio

University of Registration: University of Warwick

BBSRC Research Themes:

Sustainable Agriculture and Food (Plant and Crop Science)
Understanding the Rules of Life (Plant Science)

Project Outline

Plants underpin the global food supply, yet their survival depends on remarkable cellular flexibility. To thrive, plants must maintain dynamic cellular organization while enduring daily temperature fluctuations. At the heart of this adaptability lies the endoplasmic reticulum (ER), one of the most vital organelles on the planet. The ER not only produces the majority of proteins consumed on Earth but is also highly dynamic - its remodeling is essential for function and is driven by the actin cytoskeleton. When actin dynamics are perturbed, ER remodeling ceases. Despite its importance, the precise mechanisms through which the plant actin cytoskeleton and ER interact remain unknown - an outstanding question that defines our research.

A key obstacle has been the density of these overlapping networks, which has hindered visualization with conventional light microscopy. Our lab has overcome this by developing a novel reporter system in plants that specifically labels actin only at sites of direct ER contact. For the first time, we can pinpoint these contact sites and track how they reorganize in response to environmental stress.

This project will exploit this new tool to visualize actin-ER contact sites during biotic/abiotic stress using advanced light microscopy. Complementing this, you will apply proximity labeling proteomics to identify proteins enriched at these sites under stress conditions. Together, these approaches will reveal both the structural and molecular basis of actin-ER interactions during environmental challenges.

Finally, you will assess how manipulating these proteins affects plant resilience and biomass production. Previous work has shown that altering cellular dynamics can enhance - or impair - plant growth, underscoring the direct relevance of this research. By uncovering how actin-ER interactions shape stress responses, this project addresses a critical frontier in plant cell biology with profound implications for agriculture and global food security

Co-supervisor on a project with Professor Murray Grant.