Pioneer in tree molecular genetics, John Carlson, retires after four decades

UNIVERSITY PARK, Pa. — John Carlson, professor of molecular genetics in Penn State’s College of Agricultural Sciences and director of the Schatz Center for Tree Molecular Genetics, is retiring this month after a career spanning four decades of pioneering research with forest trees.

Best known for developing new approaches and resources for genetic linkage mapping and conservation genetics with trees and wildlife, Carlson in 1997 came to Penn State, where his position is co-funded by the Huck Institutes of the Life Sciences.

“John Carlson has had an amazing career working on conservation and restoration genetics,” said Bradley Cardinale, professor and head of the Department of Ecosystem Science and Management.

“One of his lasting signatures at Penn State is the Schatz Center, which he formed to work on the conservation and restoration of threatened tree species,” Cardinale said. “There are many examples of the impact John has had on his field. One of my favorites is his work to save American chestnut, which was hammered by introduction of the chestnut blight fungus. John and his colleagues published the first reference genome for chestnut, which opened the door for researchers to look for a genetic basis of adaptive traits that might allow chestnut to evolve blight resistance."

Born in DuBois, Carlson grew up in Indiana, Pennsylvania, with close family members working in forestry. He said these formative years fostered an attachment to trees and forests and an interest in a career as a scientist. It turned out — even early on — that he was on the cutting edge of his field.

“I wanted to learn about molecular biology and about genes and how they function and things at the molecular level, that’s why I chose biochemistry for an undergraduate degree,” he recalled. “If there had been an opportunity to learn about forests and molecular genetics at the same time, I might have taken a different path. But I really wanted to have that opportunity to learn about what was, at the time, a new area of science, molecular biology, and specifically molecular genetics, which was then just starting off as its own discipline.”

Carlson received his bachelor’s degree in biochemistry from the University of Pittsburgh in 1974, a master’s degree in plant physiology and agronomy from the University of Illinois in 1978, and a doctoral degree in genetics from the University of Illinois in 1983.  

He obtained postdoctoral training in 1982-83 in the Department of Plant Pathology at Kansas State University, followed by a research scientist position with the biotechnology company Allelix Inc., in Toronto, from 1983 to 1988. Carlson served as a faculty member at the University of British Columbia from 1988 to 1997, with a joint appointment in the Michael Smith Biotechnology Laboratory and the Department of Forest Sciences.

Recognized internationally for his expertise, Carlson held a visiting professorship with the Department of Bioenergy Science and Technology at Chonnam National University in South Korea from 2009 to 2014, and he served previously as a visiting professor at the Northeastern Forestry University in Harbin, the Hong Kong University of Science and Technology, and Peking University — all in China. 

Recently, he was awarded a Mercator Fellowship as visiting professor at the University of Gottingen in Germany for 2019-23. That came in recognition of his almost 40 years of experience in genomics, biotechnology, conservation genetics and gene expression research related primarily to forest trees, wildlife and biomass energy.

Over his long career, Carlson has been extremely productive. He has authored 158 peer-reviewed articles and has been granted three patents. He has contributed to 15 books and has presented 132 invited talks at national and international venues.

He has mentored 31 graduate students, 21 postdoctoral scholars and 34 undergraduates. He also was active in intercollege graduate programs at Penn State, including plant biology, genetics and, as inaugural director, of bioinformatics and genomics.

Carlson said his most gratifying experiences as a faculty member and director of the Schatz Center have been the many collaborations he enjoyed with scientists across the U.S. and around the world, and the opportunity to provide cutting-edge research experiences to more than 80 undergraduate students, nine postdoctoral fellows and 24 visiting scientists from 11 countries.

“I’m thankful for the privilege of building a career around the study of trees and to retire knowing that under my directorship, the Schatz Center has helped lay a strong foundation of training, publications and databases to enable even greater achievements in tree molecular genetics research in the future,” he said.

As Carlson contemplates retirement, he doesn’t sound like a man who is poised to slow down anytime soon, mentioning that he still has a grant from the U.S. Department of Agriculture to develop a genome sequence in northern red oak with the Department of Energy, and that he is part of a team that recently completed a high-quality genome for green ash.

“We’re almost finished writing the manuscript on that, and currently I am principal investigator on a switchgrass microbiome and breeding project that continues through 2022,” he said. “It is a transition time for me, going from being a regular faculty member to being an emeritus faculty member. I hope to be able to continue to do research with colleagues here at Penn State and elsewhere, and to contribute even beyond retirement.”

And, Carlson said, he looks forward to following the continued impacts of the Schatz Center under its new director, Jill Hamilton, who joins the Department of Ecosystem Science and Management Aug. 1.