Dr. Mariana Schuster
Dr. Mariana Schuster is a post-doctoral researcher in the Plant Chemetics laboratory at the University of Oxford. Her research currently focuses in unravelling the role of immune cysteine proteases of tomato against the devastating pathogen Phytophthora infestans.
Dr. Jonathan Jones
Dr. Jonathan Jones is a professor of biology at the University of East Anglia, Norwich, UK, and a group leader at The Sainsbury Laboratory (TSL) in Norwich. His group studies the defense mechanisms that plants use to resist pathogen attack and the strategies that pathogens deploy to overcome the plant immune system. Jonathan has made landmark contributions to the field of plant immunity, and his work has been recognized with honors, including an EMBO membership, a Fellowship of the Royal Society, and an International Membership in the U.S. National Academy of Sciences. Jonathan was recently awarded an Honorary Membership in the British Society of Plant Pathology. On occasion of the award, I had the pleasure of interviewing him and discussing his exceptional academic career, the challenges of living as an academic and bringing one’s science to public use, and getting a glimpse of the man behind the scientist.
Jonathan recognized that he wanted to be a scientist from early on. However, he says he is an “accidental plant pathologist.” Initially interested in physics and chemistry, but always motivated by research on the mechanisms that govern life, Jonathan started his Ph.D. program in the early years of molecular genetics and working with plant DNA. He and his team then needed to acquire protein biochemistry skills to understand the mechanisms by which the genes revealed in their cloning contributed to a phenotype (1). Looking back, he highlights the benefits of the lifestyle of a scientist: “typically, in life, the more you think about yourself, the unhappier you are. When you are doing science, you become very preoccupied with thinking about your research problem, which is much more fun than thinking about yourself.”
It is no secret that the career path to become an academic has changed since Jonathan started out. He acknowledges that “now it is much tougher than back then.” But, as in the past, the key go/no-go moment to secure an academic post is when people are applying for a faculty position. Looking back, he admits that after his Ph.D. degree he “caught the wave of plant molecular genetics, where I was one of a leading group of scientists who had the skills to chase down interesting genes to begin to figure out their function” and that it was the “skill he brought to bear on the problem.” The skill was important back then and is still relevant, but now most labs have these skills: “To get a job you have to present yourself as someone who is particularly good at something, who can bring those skills to tackle a problem—and it has to be an important and interesting problem—where no one has applied those skills and methods before.” In addition, what Jonathan now looks for in applicants for group leader positions is a unique, original, and independent-minded engagement with the biological problem; a mature knowledge of the field that allows the applicant to recognize a relevant research question; and a size and outlook of the project that lies within “that sweet spot of what is ambitious yet feasible” and is also “a project that has legs.”
In his case, Jonathan became a group leader and entered the field of plant pathology by applying his skills in plant molecular genetics to the identification of the then-enigmatic Resistance (R) genes. R genes were known to confer disease resistance against pathogens. Using transposon tagging, his group was able to identify Cf-9, a gene that confers tomato resistance against the fungal pathogen Cladosporium fulvum (2). “It was very satisfying to develop a lethal selection that enabled almost effortless recovery of dozens of mutants in Cf-9,” Jonathan commented.
Cf-9 encodes a cell-surface immune receptor containing leucine-rich repeats—the first such receptor to be discovered. Immune receptors are key proteins that detect molecules from invading pathogens and then initiate the signaling that ultimately leads to defense responses. Jonathan’s group identified many such receptors and soon started researching their function.
I have listed only a couple examples of the fundamental discoveries that Jonathan’s group has made in our understanding of the proteins that confer resistance to pathogen attack. In fact, when asked which contribution to plant pathology he is proudest of, he answers: “I could mention a few.” Hunting for the mechanism of action of receptor-like proteins (RLPs), he devised a theoretical framework for how receptors could be activated, now known as the guard hypothesis (3). “This was my first theoretical contribution to be later validated experimentally in a nice collaboration with the group of Pierre de Wit,” he said. He referred to work on Cf-2, another immune receptor from tomato that monitors (guards) the activity status of tomato cysteine protease Rcr3, an important component of the plant’s defense repertoire. Rcr3 is targeted by the pathogen effector Avr2, a cysteine protease inhibitor. Once the pathogen tries to disarm the plant by inactivating Rcr3, it falls into the trap of the guard mechanism that ends in a strong Cf-2–dependent defense response (4). He’s also proud to have contributed to the success of TSL, alongside his superb set of colleagues who continue to do pioneering science at TSL, and of the success of the alumni who are former students or postdocs from his lab, such as Tina Romeis, Martin Parniske, Brande Wulff, and Cyril Zipfel. He’s also hugely grateful to all the students and postdocs who’ve contributed to the success of his lab over the last 32 years, and to David Sainsbury‘s Gatsby Foundation for their sustained and generous funding of TSL.
Inspired by the work of the Brian Staskawicz lab that showed that a pepper immune receptor can confer disease resistance in tomato (5), Jonathan decided to open an applied research stream in his group that aims to tackle crop losses due to diseases. The idea is elegant and powerful: generate pathogen-resistant crop varieties by introducing immune receptors into plants that lack them. When asked about how that experience compares to life as an academic, he starts by stressing that fundamental discoveries in science are the major source of solutions for “real life problems,” and that although he is satisfied with the balance between applied and basic research in his group, he is conscious that “you cannot do everything, so any time I spend in applied research, is time I do not spend making fundamental discoveries, although work with an applied intent can reveal new and interesting scientific problems.”
Some examples of resistant plant varieties developed with contributions from Jonathan’s group can be found in the June 2016 edition of Nature Biotechnology: soybean resistant to Asian soybean rust (6), potato resistant to late blight (7), and wheat resistant to stem rust (8). Two of these three papers were dependent on RenSeq (8), the sequence capture method for R gene cloning developed in his lab. Jonathan is happy to have contributed to applied plant science but acknowledges that he did not predict, and thus underestimated, the fact that people would find problems in the solutions he provided. He finds the need to work around these problems frustrating, but acknowledges that even scientists must have faith and hopes that his solutions will be implemented eventually.
Jonathan is a happy husband, father, and proud grandfather of four: “two 2‑year olds, one 5‑year old, and one 8‑year old. Seeing them develop and grow is a great source of happiness!” On work–life balance and family, he points out that “it’s hard enough to get your own life right, let alone anybody else’s.” He highlights his appreciation for his illustrious partner Professor Dame Caroline Dean. Their family features in the book Mothers in Science.
When asked about his passion aside from science and family, Jonathan told me that he likes to sail on the weekends and that he owns a sailing boat called “zigzagzig,” which is both the name of what one must do to take a sailboat upwind and of the model describing the immune system for which he is famous (8). “The Zig-zag-zig model was proposed to bring together two schools of thought: the geneticists investigating gene-for-gene interactions, and the biochemists who added elicitors to cell cultures and defined what happens.” According to this model, plants use cell-surface receptors to recognize the presence of a pathogen and mount an immune response termed pattern-triggered-immunity (PTI). Adapted pathogens use effectors to inactivate PTI and cause disease (effector-triggered-susceptibility [ETS]). In turn, resistant plants deploy specialized receptors, generally intracellular, to detect these effectors and mount a stronger defense response termed effector-triggered-immunity (ETI).
As to what is Jonathan up to today, on April 1 (not a joke) of this year, his group published a new paper in which they further explain the relation between PTI and ETI (10). This was independently verified by another lab’s report published in the same issue of Nature. Beforehand, the nature of ETI was rarely studied in the absence of PTI. “These papers show that ETI replenishes and restores PTI, not only helping us better understand the dynamics of the plant immune system but also why R gene stacking for disease resistance works so well. It’s been very satisfying to see how the basic and applied science in my lab has (dare I say?) mutually potentiated.”
