Testimonials for Pioneer Member John Boyer

David Braun and Paula McSteen  – John is one of the kindest, most generous, creative and insightful scientists I have worked with. He gladly shares his ideas and suggestions to advance science. His contributions to plant water relations form the foundation for much of what we currrently know. He blazed a bold trail and helped many of his mentees and colleagues join him on the scientific journey. Thank you John for your friendship and leadership.

Bill Davies – John, thank you for the inspiration and friendship you provided for me, our group and the generations of young plant scientists across the world. While training at both Wisconsin and Duke, your thoughtful approach to science was often commended to us. Subsequently, your papers have stimulated many thoughtful discussions at Lancaster.

John Mullet – Great teacher, mentor and colleague. Soft spoken, deliberate and deep thinker, whose multi-scale knowledge of water relations has significantly shaped our understanding and approach to improving crop drought tolerance.

Don Ort – When I began my career at the University of Illinois, I was trained primarily in plant biochemistry. It was my great fortune to share a common laboratory with John Boyer and his research group. John patiently taught me leaf gas exchange and the concepts of leaf energy balance. In this way, John Boyer fundamentally changed the trajectory of my science and my career.

Indupulapaiti Rao – Professor John Boyer is a multifaceted, dedicated and innovative plant biologist with a genius for synthesis. Boyer is a leading international authority on the role of water status in determining plant growth and crop productivity. My name is Idupulapati M. Rao and I am an Emeritus Scientist from the International Center for Tropical Agriculture (CIAT) located in Cali, Colombia. I worked with John as a Postdoctoral Research Associate at the University of Illinois, Urbana-Champaign, from 1982 to 1984. During those two years I had the opportunity to learn how to accurately measure leaf water potentials and determine photosynthetic gas exchange characteristics. The basic skills I acquired for conducting whole plant physiological studies helped build my career in international agricultural research for development.

John developed thermodynamic methods to measure leaf water potentials and showed that photosynthesis is more sensitive than respiration to dehydration during drought stress. The marked sensitivity of photosynthesis to drought allowed him to test whether enzymes were responding directly to water deficits. He found that enzymes were not responding directly to water deficits, which gave his team a way to test whether closing stomata (which conserves water but limits carbon dioxide entry) were the cause of limited photosynthesis. Because limited photosynthesis is also accompanied by diminishing carbon dioxide demand, it seemed that photosynthesis might acclimate to water deficits. His team also showed that cellular magnesium (Mg2+) concentrations play a central role in controlling acclimation to water deficits.

I followed up this work in collaboration with Bob Sharp; we grew sunflower plants in nutrient solutions having nutritionally adequate but low or high Mg2+ concentrations and determined whether photosynthesis was affected as leaf water potentials decreased. We found that leaf magnesium contents were three to four-fold higher in plants grown in high magnesium concentrations than in those grown in low concentrations. The low magnesium contents were sufficient to support growth, plant dry weight, and photosynthesis, and the plants appeared normal. As low water potentials developed, we found inhibition of light and carbon dioxide saturated photosynthesis, but more so in higher magnesium leaves than in lower magnesium leaves, indicating that the effect could have been specific for magnesium. Because magnesium inhibits photophosphorylation and coupling factor activities at concentrations likely to occur as leaves dehydrate, magnesium may play a role in the inhibition of chloroplast reactions at low leaf water potentials, especially in leaves such as sunflower that markedly decrease in water content as leaf water potential decreases. Based on these results, we suggested that Mg2+ plays an important role in the inhibition of chloroplast reactions at low leaf water potential by increasing in concentration in the stroma and in the cell generally as water is lost from the leaf.

Most of John’s work at the University of Illinois was on maize, soybean and sunflower as test crops. These crops represent a major cereal (maize), grain legume (soybean) and an oil seed (sunflower) and therefore his findings on plant water relations and photosynthesis have been highly relevant to improving crop productivity under stressful environments. It is widely recognized that plant–water relations and photosynthesis are inherently multigenic and complex, but John’s findings demonstrated the benefits of unraveling mechanisms from the molecular level to the whole plant level. A good example of this is his work on intravenous feeding, which allowed the myriad effects of water deficits to be narrowed to just a few biochemical steps and allowed him and his co-workers to determine the genes involved and how those genes responded to feeding. With this feeding technique, they were able to prevent abortion of young embryos, which paved the way to find a genetic means for preventing seed abortion during water deficits; this knowledge is now being applied by seed companies for the benefit of agriculture.

John has an extraordinary academic record of world stature. He used water potential measurements to pioneer the study of water movement through plants and the molecular control of cell enlargement. John is a superb experimentalist, always paying attention to details to ensure the accuracy of his observations. He was a mentor to many young researchers, helping them in their early career to design experiments, analyze data, and prepare high quality manuscripts published in high impact journals. His pioneering contributions to plant biology are recognized and valued worldwide, particularly in the area of enhancing crop productivity under drought stress.

John’s work was unique in many ways, because of the rational to use plant-water relations to test hypotheses and develop new concepts for improving crop tolerance to water deficits. His original ideas, keen scientific mind and superb experimental skills, combined with curiosity, motivation and diligence, led to seminal discoveries, and to national and international recognition. John is recognized internationally for his insights into the fundamental principles of crop adaptation to drought, and for applications of these insights to developing drought resistant crops. His publications have been beacons of light to guide the field of drought resistance toward hypothesis testing, more logical directions for plant water relations research and practical applications of plant biological research for agricultural development.

Robert and Diane Sharp – John and Jean, thank you for your support, collegiality and friendship over many years. We came to the US in 1981, when I joined John’s lab at the University of Illinois as a Postdoctoral Research Associate for three years. I could not have wished for a better experience. John’s creative, insightful and precise approach to research was stimulating and rewarding, and has provided inspiration throughout my career. My lab still uses an isopiestic thermocouple psychrometry system that John designed for our routine measurements of plant and soil water potentials! More recently, the University of Missouri was extremely fortunate to entice John out of retirement as a part-time Distinguished Research Professor. It has been a great pleasure to have John and Jean visit Columbia for a few months each year (over the winter so that they can manage their farm in the summer!), and to have John share his wisdom and insight in plant water relations and growth physiology with the graduate students and postdocs in my and other labs.

Wendy Kuhn Silk – The research of John Boyer inspired me throughout my career. I particularly admire his ingenuity and skill in devising, building and using sensing devices to monitor aspects of plant water relations, growth, and productivity. I admired (sometimes with envy) from afar, and then our collaboration late in my career was a joy as we pursued questions of mutual interest. His exemplary service record includes decades of active administrative work in ASPB and public outreach in support of research on plant resilience in the face of environmental stress.

Elizabeth Van Volkenburgh – John Boyer provided the best postdoctoral experience anyone could possibly wish for — the other postdocs were a challenging bunch and the students were stimulating to work with. At that time, an argument about factors limiting the rate of plant cell growth was brewing. I gained a lot of perspective and understanding of how science works as a culture while watching those discussions and participating in a few. From my time prior to graduate school, working with Paul J. Kramer, and my postdoc with John Boyer, I learned plant water relations well and found this knowledge indispensable when considering how plants work and what they do.

Michelle Watt – During one of a number of research visits to CSIRO in Canberra, Australia, professor John Boyer quantified how much water could come from the phloem to support root growth in very dry soil or air. It was amazing to see a person think so clearly about an unexplained biological phenomenon; and go on to theorise and test an idea experimentally with such precision and focus (https://doi.org/10.1071/FP10108).

Chris Zinselmeier – John Boyer had a substantial impact on my development as a scientist and my professional career. My first exposure to John was while I was a graduate student working in Dr. Jerry Nelson’s lab and John was at the University of Illinois. John would often come and present seminars on campus; these visits often included time with the graduate students and I vividly recall his patience with us and the genuine curiosity he showed for the research project of each and every student. I later joined John’s lab as a post-doc for several years. During that time he exposed me to unique ways of approaching scientific challenges and the value of iterative thinking. I learned many new concepts and approaches from John, most notably his ability to discover simple and elegant solutions to complex problems; not to mention how to sail on the Delaware Bay.