Philip Benfey, Paul Kramer Distinguished Professor of Biology, shown in 2002. Photo by Jim Wallace

Duke Flags Lowered: Philip Benfey, Plant Biologist Who Studied Roots as a Window to Development, Dies

After one year of college, he dropped out and spent the next six years traveling the world in search of inspiration for a novel. He worked as a mechanic in American Samoa, laid bricks and worked on a railroad crew in Australia and dabbled in the film industry in the Philippines. He spent time as a gardener in Japan, and a carpenter in France.

Along the way, he wrote some short stories and sent them off to U.S. magazines, but they kept getting rejected.

It wasn’t until his French girlfriend, Elisabeth -- who would become his wife of 44 years -- suggested he find a day job other than struggling writer that he decided to try his hand at biology.

He went back to school, earning an undergraduate degree in biochemistry from the University of Paris in 1981 before getting into graduate school at Harvard, “for which I was totally unprepared,” he said.

Benfey’s early work focused on cloning and sequencing genes involved in the allergic response in humans, but after finishing his Ph.D. in 1986 he moved to The Rockefeller University for a postdoc and turned his attention to plants, particularly the parts most of us think little about: roots.

“For most people, roots are out of sight, out of mind,” Benfey said.

But to Benfey, roots offered a window into how cell fates are determined.

Close-up images of Arabidopsis thaliana seedlings growing in Philip Benfey's lab. Their translucent tissues make it possible to peer through a microscope and watch development unfold. Photo by Jim Wallace.

Roots grow longer thanks to a small region of stem cells in the root’s tip that divide to produce a constant supply of new cells, propelling the root tip further downward through the soil. The daughter cells that are left behind stay put, and eventually stop dividing and take on different roles, from transporting water and nutrients to sensing gravity.

What that means, Benfey said, is that, peering at a root under the microscope is like looking at a developmental timeline.

Slicing a root lengthwise reveals stacks of cells at different stages of development, with the earliest, least specialized cells near the root’s growing tip, and the older, fully formed cells higher up.

What’s more, the different tissues of the root are cylinders nested one inside the other, such that if you slice a root horizontally and look at it in cross section, you can see all the different cell types at once in concentric rings.

“My interest in plants really came from the simplicity of the system,” Benfey said.

He moved to New York University in 1991, rising through the ranks to Full Professor. Then in 2002, with New York City still reeling from the deadly terror attacks of 9/11, he moved his lab and young family from NYU to Duke to become chair of the recently merged biology department.

During his five years in the role, “he oversaw the design of the French Sciences Building, he hired many of our current faculty members, and he attracted and sustained incredible strength in both systems biology and plant molecular biology here at Duke,” said current biology department chair Emily Bernhardt.

Benfey’s leadership style was to “delegate and trust,” said Duke’s Interim Vice Provost for Academic Affairs Mohamed Noor, who 20 years ago served as Benfey’s associate chair.

“He fully empowered me in my role,” Noor said. “He really set me up for successful leadership going forward.”

In 2007 Benfey stepped down as department chair to take the helm of the Duke Center for Systems Biology, which he ran for six years until 2014.

Around the same time, Benfey also found success in the risky start-up world.

He co-founded a biotech company based on a microfluidics device his lab developed, the “RootArray,” which made it possible to visualize gene expression in dozens of roots in real time. Within five years, the company -- Grassroots Biotechnology -- was acquired by Monsanto.

He went on to launch a second agricultural biotech company, Hi Fidelity Genetics, which uses data analytics to improve crop breeding.

He also taught a course on entrepreneurship for graduate students interested in wading into the world of business. It focused on raising money, pitching ideas to investors, and protecting intellectual property.

Nearly six-and-a-half feet tall, Benfey towered over many of his students and colleagues. Duke postdoc Rachel Shahan remembers a time when, to put her at ease when she was interviewing for the job, he said, “Look what I can do,” and reached up to strum the ceiling tiles.

Benfey was a fellow of the American Association for the Advancement of Science, a member of the US National Academy of Sciences, and an investigator of the Howard Hughes Medical Institute.

On multiple occasions, he was included in the annual Highly Cited Researchers list compiled by Clarivate Analytics, which recognizes researchers whose published papers rank in the top 1% of citations for their field and year of publication.

Benfey said he felt fortunate to have stumbled into a field being spurred on by tremendous technological advances, such as next-generation sequencing, genome editing, and high-throughput screens.

“When I started in biology about forty years ago, a fellow graduate student’s thesis consisted of sequencing one gene,” Benfey said. “That an entire human genome can now be sequenced in a few hours is one measure of how much has been accomplished.”

During a lab meeting this summer, though exhausted from chemotherapy, Benfey joked that since he was starting a new therapy that would modify his immune cells to fight the cancer, “he would ‘officially be a GMO,’ ” his lab technician Aiden Brosnan recalled.

“It was such a geeky scientist way of putting it; a hint of excitement that he himself would participate in genetic technology, but this time as a subject,” Brosnan said.

Reflecting on his life in science, Benfey said last year, “I doubt very much that a career as a writer would have been half as interesting as the one that I’ve had.”

Benfey is survived by his wife Elisabeth, and his sons Julian and Sam.