UNIVERSITY PARK, Pa. — Jonathan Lynch, distinguished professor of plant nutrition, retired this fall after an innovative and impactful 33-year career in Penn State’s College of Agricultural Sciences, focused on conducting research to alleviate world hunger and enhance crop production by subsistence farmers in developing countries.
A faculty member in the Department of Plant Science who also served as the founding director of the Center for Root and Rhizosphere Biology in the Huck Institutes of the Life Sciences, Lynch was among the top 1% of cited plant scientists in 2022, with more than 250 publications. He also secured more than $24 million in external grant funding at Penn State since 2007.
His website, which was available in three languages, boasted more than 50,000 visitors annually, and he trained or advised more than 100 graduate students and postdoctoral scholars. Lynch was a committed teacher, leading a flagship undergraduate course in plant nutrition, encouraging undergraduate students to conduct research in his laboratory.
“I realized early on that agricultural innovation is the key to the grand challenge we confront — how to sustain 10 billion people in a degraded environment,” he said. “That motivated my work over the decades.”
Lynch’s lab conducted seminal research on plant nutrition and the acquisition of phosphorus and nitrogen, which established a clear connection between root architecture and acquiring nutrients. He also studied drought tolerance in crops and plant response to salinity and heavy metal toxicity. Through the invention of laser ablation tomography, he found new ways to map root anatomy in 3D.
His efforts to pioneer phenotyping platforms for use on plants grown in the field and develop computer simulations to facilitate the testing of conceptual models have advanced scientists’ understanding of how plants respond to stress and nutrient availability. He and his collaborators identified novel root traits that are now commonplace in breeding programs for crops such as beans, maize and soybean, according to Erin Connolly, professor and head of the Department of Plant Science.
“Jonathan had a long and incredibly productive and successful career in both research and teaching,” she said. “His work has been simply pathbreaking and has transformed our understanding of how plants modify below-ground, root-based processes to adapt to a changing environment. He is an exceptional, award-winning scientist and is internationally recognized not just for his contributions to the field, but also for the immense impact this work has had on the improvement of crop production in North America, Latin America and Africa.
“Lynch has been one of our most respected teachers and mentors,” Connolly added. “Without a doubt, his efforts in research, mentoring and teaching leave a remarkable legacy that will continue to be felt for years to come.”
Lynch excelled in research commercialization — including multiple invention disclosures, patents and grant awards — to advance crop productivity and plant adaptation to stress, with an eye toward improving yield and food security. He was a prolific inventor who was named on 10 Penn State invention disclosures and is a two-time co-inventor with collaborators from Wisconsin. Three of his patents were licensed and commercialized successfully by startup companies.
“Jonathan’s work and influence are so powerful that not only has he made the world a better place, but he has led, inspired and empowered those around him to make a positive difference in their own ways,” said Blair Siegfried, associate dean for research and graduate education. “His positive impact on this world has been profound.”
Lynch remembers becoming aware of food insecurity in Africa caused by infertile tropical soils at age 9 and resolving to address the challenge, he said. As a result, he focused on plant nutrition as an undergraduate at the University of California, Berkeley, and in his graduate work at the University of California, Davis, where he conducted field research in Brazil. After earning his doctorate, he led a plant nutrition research program at the headquarters of the International Center of Tropical Agriculture in Colombia, returning to the U.S. to take a faculty position at Penn State in 1991.
Looking back on his career, Lynch said the focus of his research has been understanding how plants adapt to drought and low soil fertility, to guide the development of more resilient, productive crops.
“In developing nations, such crops would yield more, improving food security and economic development, while in rich nations such crops would reduce input costs and environmental degradation,” he said. “Improving drought tolerance is a global concern since drought is currently the greatest threat to crop production and is worsening as a result of global climate change.”
It quickly became apparent to Lynch that the path to better crop growth in dry and infertile soils is better roots, and much of his research focused on understanding how root traits can be harnessed in crop breeding. This included discovery of specific root traits that improve stress tolerance, how they can be quickly measured in the field, their genetic control, and the ecological impacts of crops with improved roots on agricultural ecosystems.
The studies led to the creation of new research tools, concepts and paradigms, multiple patents, two startup companies led by Penn State undergraduate students, and new crops with better stress tolerance and higher yields that are being grown in Africa, Asia and Latin America.
“This work was highly collaborative, involving many Penn State undergraduate and graduate researchers, as well as postdoctoral scholars and many collaborators throughout the world,” he said. “As I retire, I’m pleased to know that many of these colleagues are continuing this work to develop the more efficient, resilient crops urgently needed in global agriculture.”
Lynch noted that his wife, Kathleen Brown, Penn State professor emerita, was an essential partner in his research and supported him throughout his career.