2025/05/01 by Luis Valdez · 1 voice
Medicine · #Empathy and Medical Education
paper · pdf · doi:10.1111/tpj.70229
openalex publication_date 2025/05/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/03/10
In this interview, Dr. León shares her journey from a young girl looking at bugs under a borrowed microscope to becoming a leading scientist in plant biology. She reflects on her educational path, the pivotal moments that shaped their research interests, and the challenges and triumphs of establishing a lab in Mexico. Dr. León also delves into her current work, exploring the evolutionary significance of retrograde signaling and the innovative use of Marchantia polymorpha as a model organism. Along the way, she offers insights into the broader challenges facing their field, the importance of international collaboration, and the delicate balance between a demanding scientific career and a fulfilling personal life. Join us as we explore the story of a scientist whose work not only advances our understanding of plant biology but also inspires the next generation of researchers to push the boundaries of science. 1. Can you tell us about yourself, your childhood, and your educational background? Anything you're comfortable sharing. I was exposed to science from a very young age. My parents were chemists, and my grandfather was a physician. He would often take me to his medical practice to assist him when appropriate. In elementary school, I would borrow a microscope from my friend's parents, who were chemists too, to examine bugs up close. Growing up, I developed a strong interest in medicine and science, and my family always supported my passions. I attended the Colegio de Ciencias y Humanidades (School of Sciences and Humanities) in high school. For my undergraduate studies, I went to the Universidad Nacional Autónoma de México (National Autonomous University of Mexico), torn between medical school and biology. Ultimately, I chose biology because I knew I lacked the emotional resilience to cope with patient deaths. I was initially interested in ecology, but molecular biology quickly captivated me. At the time, this field was in its infancy—techniques like molecular cloning, vector construction, and the generation of transgenic organisms were groundbreaking. It was also an exciting period for molecular biology in Mexico. Dr. Francisco Bolívar had returned from the U.S., bringing cutting-edge molecular biology tools, particularly for cloning, which significantly advanced the field in the country. 2. How did you become interested in plant biology? Were you into plants growing up, or did that come later in life? I can't say I was passionate about plants at the start of my scientific career. What truly interested me was molecular biology. At the time, the best tools were available for studying bacteria, which allowed me to explore questions related to regulatory mechanisms and gene expression. Starting in my fifth semester, I worked with the enzyme glutathione transferase in sulfur bacteria. For my undergraduate thesis, under the guidance of Dr. Carmen Gómez-Ekman, I studied the mechanism of tetracycline resistance in E. coli, cloning resistance genes and analyzing their function using mini-cells. It wasn't until I joined Dr. Virginia Walbot's lab at Stanford University that I began working with plants, specifically maize. Later, in Dr. Jen Sheen's lab at Harvard University, I was introduced to Arabidopsis. 3. How have your research interests developed over time? How did your lab start, and what led you to your current research? I completed my master's degree in Dr. Alejandra Covarrubias's group in Mexico, where I worked on bacterial genetics and nitrogen metabolism. During this time, Dr. Covarrubias moved to the Nitrogen Fixation Research Center, shifting her focus to biotechnological engineering and nitrogen fixation. At the end of my master's, my husband secured a postdoctoral position at Stanford. Following the advice of Dr. Federico Sánchez, I was accepted in Dr. Virginia Walbot's lab. There, I pursued a second master's degree and began working with plants for the first time. My research focused on understanding the replication and maintenance of a linear maize mitochondrial plasmid, which encodes the unique tRNA for tryptophan. This work sparked my interest in plant organelle biology. I later enrolled in a PhD program in Mexico but conducted most of my experimental work at Stanford as part of a collaboration between Dr. Covarrubias and Dr. Walbot. My research involved developing strategies to establish cell cultures from the common bean and optimizing transformation protocols to study gene expression regulation in this plant system. Subsequently, I was awarded the PEW Fellowship, which allowed me to conduct postdoctoral work in Dr. Jen Sheen's lab with Arabidopsis, investigating sugar signaling. 4. What are your current research interests? How do you describe your field? During my time at Stanford, I developed an interest in organelle biology, particularly chloroplasts. Currently, one of the primary research interests in my lab is understanding chloroplast development and the mechanisms governing organelle-nucleus communication (retrograde signaling). We are also studying the regulation of the MEP pathway, a key biosynthetic pathway responsible for producing essential plant compounds and biotechnologically valuable products like carotenoids. Another area of interest is the relationship between sugar signaling and chloroplast development. For instance, when plants grow in high-sugar conditions, chloroplasts fail to develop. We aim to uncover the signaling mechanisms that allow plants to perceive sugar levels and how this signal is transduced to halt chloroplast development. From an evolutionary viewpoint, I find retrograde signaling to be a fascinating adaptation. While this regulation is typically seen as a mechanism for controlling chloroplast development and photosynthesis, I believe its role extends much further. My view is that retrograde signaling plays a crucial role in regulating plant development beyond photosynthesis and helps plants respond to environmental changes. Throughout evolution, the differentiation of plastids likely gave rise to a complex network of communication between different plastid types and tissues. Decoding this complex “language” is something I find particularly intriguing. 5. Recently, your lab started using Marchantia polymorpha as a model. What are the advantages and disadvantages of this model compared to Arabidopsis? What was the most difficult part of adopting this new model? Pragmatically, I chose Marchantia as a model organism because of its shorter life cycle, which allows for faster experimentation. However, its evolutionary position also appealed to me. Marchantia is related to the plants that first colonized land, but unlike similar organisms like Physcomitrium, which only has chloroplasts, Marchantia already possesses different types of plastids. This makes it an excellent model to study plastid-to-nucleus signaling during organelle differentiation and its connection to organismal development. Recently, we discovered that most of the retrograde signaling genes known in Arabidopsis are conserved in Marchantia. However, unlike Arabidopsis, many of these genes exist as single copies. This has advantages and drawbacks: studying gene function is easier, but if a mutation is lethal, it becomes a major challenge. Plants like Arabidopsis are complex systems, and experiments can take a long time. Using Marchantia for foundational research and transitioning to other models provides an evolutionary perspective often overlooked in the field. The biggest challenge in adopting Marchantia as a model was learning how to cultivate and handle it, as it's very different from flowering plants. Implementing the necessary techniques was initially difficult, but fortunately, progress moved relatively quickly. I was lucky to find a highly talented student who drove the project forward. Another challenge is that working with both Arabidopsis and Marchantia requires expertise in comparative genomics and bioinformatics tools, areas in which I had no prior experience. Thankfully, I've had excellent collaborators—without them, we would be lost. International collaborations are crucial to avoid isolation in Mexico and to ensure our research remains at the forefront of the field. 6. What are the major challenges and trends in your field? The main challenge in retrograde signaling research is that, even after 30 years of intense exploration, most of the signals and their corresponding pathways remain unknown. Of the few identified so far, many are metabolites. This makes intuitive sense, as metabolites provide a direct way to monitor cellular processes. However, experimentally altering metabolite levels often leads to pleiotropic effects, complicating their analysis. A long-standing limitation in this field has been the pleiotropic nature of the classic experimental tools used. Many molecules identified as potential retrograde signals are supported by evidence from mutants with defective chloroplast development. However, disrupting chloroplast development impacts numerous other processes, as plant development is deeply interconnected with plastid function. The key challenge, then, is how to disentangle these effects—how to analyze the specific role of retrograde signals without inadvertently disrupting broader developmental processes. Finding ways to address this remains one of the biggest challenges in the field. 7. How do you envision your field evolving over the next 10 years? I think the field will evolve toward a deeper understanding of retrograde signaling, particularly its role in plant development and environmental responses. The increased use of genomic and bioinformatics tools will be fundamental to studying these processes in greater detail. A major priority is developing experimental approaches that minimize the pleiotropic effects of using mutants. Tools enabling cell-specific or tissue-specific expression studies will be crucial for dissecting the impact of retrograde signaling pathways at the cellular level. Additionally, identifying how signals are generated in different plastid types, their signaling pathways, and determining their specific targets will be key to advancing the field. 8. Since you started your lab in Mexico, how has science changed in the country? Is it better supported now, or is funding harder to get? The funding situation in Mexico is challenging. Research grants are scarce, and when available, they are often limited—for instance, a typical grant provides around 30 000 spread over three years. On top of that, funding can be cut if publications are not produced within the expected time frame. This reality forces researchers to think strategically about survival, and for me, working with Marchantia is one such strategy. When I started my lab, funding was already difficult, but I remained hopeful that the situation would improve. Unfortunately, I now see setbacks rather than progress, which is disheartening. Still, if we cannot convince the younger generations of the importance of science and inspire them to pursue it, the country will never move forward. Investing in and motivating young researchers is essential for building a future where scientific progress drives societal development. An important strategy for overcoming these challenges is through international collaborations. Encouraging global scientific interactions is essential, especially for young researchers, as they now have unprecedented opportunities to engage in research beyond national borders. 9. How about work-life balance? How do you manage all the work necessary to be a successful scientist and a functional person? I think maintaining a balance is important, though you never fully achieve it. You're always anxious about whether you're working too much and not spending enough time with your family, or vice versa. Personally, I don't think I'm very good at balancing these two things, but I do my best. For me, spending time with my family is very important. I also try to exercise daily, though I don't always manage to do it. Science is my passion, but I'm also passionate about music, traveling, and being with my family. I don’t think I would be happy if I were dedicated only to my career, nor would I be happy if I were fully dedicated to my family—I would probably get bored. When my daughters were little, my husband and I took turns caring for them. We both considered our careers equally important, and that helped us maintain a balance. 10. If you were a plant, what would you be? It's a very hard question. On one hand, I could be one of those tiny orchids, but they are very dependent on others. I could also be a long-lived tree, like a nitrogen-fixing legume—they're very smart!