Big European Funding to Boost Research on the Plant Stress Hormone Jasmonate

ERC Funding Schemes: Changing the Paradigm in Plant Science

Every year, there is a great expectation when the European Research Council (ERC) publish the list of scientists that have been awarded prestigious grants to develop their ground-breaking ideas. Since 2007, this EU funding organisation has been supporting exceptional scientists to carry out cutting-edge projects in any field of research – from Physical Sciences & Engineering to Life Sciences and Social Sciences & Humanities – aimed at expanding the frontiers of human knowledge and tackling the biggest societal challenges of the XXI century.

This competitive funding scheme* (with an estimated success rate of 15%) has now reached a total budget of 2,172 million euros. Besides scientific excellence, talented applicants should also demonstrate that their proposals are creative but feasible. But which are the keys to success?

Botany One met Debora Gasperini, a plant scientist who recently won an ERC consolidator grant of 2 M euros for her research proposal on the defence strategies that plants use against pathogen attacks and physical damages. Specifically, her team will investigate the mechanism of action of the phytohormone jasmonate, which keeps the balance between plant growth and stress response.

Hi Debora, can you tell us more about your personal and scientific trajectory?

Hello, Michela and Botany One readers! I come from a small Croatian town on the Istrian Adriatic coast, where Slavic, Italian and Austro-Hungarian heritages coalesce and enrich one another. School teachers encouraged us to celebrate our different backgrounds, an attitude further heightened at the United Word College of the Adriatic (Duino, Italy) which promotes education, unity and respect across nations and cultures. During a school trip, the sight of an ethidium bromide-stained DNA gel under UV light revealed to my teenage self that working in a molecular biology lab was an absolute must. I therefore obtained a BSc degree in Biology and an MSc in Functional Genomics from the University of Trieste (Italy). Initially, I was captivated by immunology, but after realizing that working with animals or cell cultures was not for me, I grew a profound passion for plant biology.

A PhD in Simon Griffiths lab at the John Innes Centre (JIC, Norwich, UK) enabled me to appreciate complex genetic traits by investigating the basis of wheat height variation. I then joined Edward Farmer’s lab at the University of Lausanne (Switzerland) as a postdoc to study plant wound signalling, before founding my own research group (“Jasmonate signalling”) at the Leibniz Institute of Plant Biochemistry in Halle (Germany) in 2016. Team members are studying the mechanisms of action of the phytohormone Jasmonate, a regulator of plant defense responses that play key roles in the protection against herbivore insects, necrotrophic pathogens, and wounding.

Plants have hormones too … how did you get interested in this topic?

During my PhD, I was investigating the effects of phytohormones on plant architecture, especially Gibberellins that promote cell elongation and growth. The high-yielding wheat, rice and maize varieties that transformed the world during the Green Revolution, are all mutants in gibberellin biosynthesis or signalling genes that make plants shorter and resistant to lodging (i.e., bending of plant stem from an upright position to soil). Now, we aim to understand the role of jasmonates in environmental acclimation**.

Phytohormones are just awesome! A pinch of one or the other can entirely transform a plant’s life. They are extremely powerful and act in highly sophisticated ways. They are master regulators of almost everything, triggering massive changes at minuscule doses in highly specific cellular contexts.

“To me phytohormones are like magic, with scientists trying to unlock and harness their superpowers”.

Congratulations on your recently awarded ERC grant. In your field of research, what does “changing the paradigm” mean?

Thank you. Our work is centred on how plants perceive, transmit and integrate stress signals into basal development to overcome occurring threats such as pathogen attacks or wounding. Specifically, we study fundamental aspects of the signal transduction pathway activated by jasmonate using the model species Arabidopsis thaliana. This essential hormone accumulates in response to stress but the activation of the JA pathway often correlates with inhibition of growth. Interestingly, plants have developed complex mechanisms to finely tune the trade-off existing between growth and defence.

Bioactive jasmonates are synthesized from polyunsaturated fatty acids residing in chloroplast membranes. Although the metabolic and signalling pathways are well characterized, it is still unknown how damage signals are transmitted to plastids to initiate phytohormone production. In addition, the nature of the transmitted signal is still unresolved, despite its vital roles in sustaining plant fitness (e.g., viability and fertility).

It has been proposed that elicitors (i.e., compounds that stimulate defence responses) trigger the activation of putative plasma membrane receptors to stimulate jasmonate production, but there is currently no conclusive genetic evidence to sustain this hypothesis (i.e., ligand-based mechanism).

Intriguingly, our group recently discovered that changes in cell turgor induced by osmotic pressure can promote jasmonate biosynthesis (Mielke et al., 2021). This finding suggests that the transmission of mechanical signals through tissues and cell compartments may result in hormone biosynthesis initiation. In other words, changes in turgor pressure can lead to biophysical changes of plastidial membranes that increase substrate accessibility to pre-existing biosynthesis enzymes. My team and I are very much looking forward to testing exciting new hypotheses over the next few years. The ERC grant will now enable us to verify this paradigm shift by using a variety of interdisciplinary approaches.

Jasmonate activation triggered by osmotically driven biomechanical signals. Microscopy images of Arabidopsis roots showing activation of a Jasmonate reporter (in yellow) upon changes in cell turgor (adapted from Mielke et al., 2021).

Looking back, how did you imagine your scientific career when you were a PhD student?

I started a PhD because I enjoyed conducting experiments in the lab and was eager to learn as much as possible about plant genetics. These reasons may have been naïve as I did not have a clear idea of what to do afterwards, nor if I was good enough to dream bigger, but back then they were all that mattered. Being embedded in an ambitious yet supportive PhD environment helped me think more critically, but I still needed to become more confident. As for many PhD students, some days felt rather intense. Attending several career courses available from the graduate school was informative, but not helpful to clarify my mind.

The decision to pursue an academic career materialized during thesis writing. I discovered to enjoy the writing process deeply. This gave me the will to continue with a postdoc position in an environment that fostered creativity and independence. Looking back at those PhD years, I now consider them to be among the most decisive for character and resilience building.

Looking forward, how did you envision advances in your field of research in 10 years?

Uncovering the molecular and biophysical mechanisms governing jasmonate elicitation will not only advance our understanding on stress phytohormone biology and plant acclimation, but also expand our knowledge on plant mechano-sensing and osmo-sensing. I am also excited about decoding cell type-specific roles of the jasmonate pathway in defense and stress acclimation, as they may provide appealing opportunities for harnessing fundamental findings to economically relevant crop species.

In addition to furthering knowledge through our research, I look forward working next to young scientists and support them in reaching their full potential. Nurturing a diverse community of future leaders is key to promote creative ideas with which to tackle arising challenges.