While growing up in England’s West Midlands during the 1950s and 1960s, David Baulcombe became fascinated with algae, mosses and other “lower plants.” That interest led him to the University of Leeds, whose department of botany was strong in that area. “But while I was there, I found molecular biology to be my main interest, and in particular the ways that genes switch on and off,” he recalls. “So that is what I studied for my PhD [at the University of Edinburgh], and that topic has been the theme in all of my research.
After receiving his PhD in 1977, Baulcombe went to North America for three years of postdoctoral training, first at McGill University in Montreal and then at the University of Georgia in Athens. In 1980, he returned to the United Kingdom, where he took a research position with the Plant Breeding Institute in Cambridge. It was there that he began working with plant viruses, research he continued when he left Cambridge in 1988 for the Sainsbury Laboratory in Norwich. “I started to study viruses to help the potato breeders develop diagnostic tests,” he says, “and then wondered whether one could set up a genetic immunization against viruses—express part of a viral gene in a plant and see whether it could interfere with the viral infection cycle.” The process worked, but the protection mechanisms did not have the properties that Baulcombe had predicted. The immunity did not need the viral protein. Instead, it was operating at the RNA level.
In 1999, Baulcombe and his colleague Andrew Hamilton, now at the University of Glasgow, announced the groundbreaking discovery that plants use small RNA molecules (about 20-25 nucleotides in length) to defend themselves against virus attacks. A few years earlier, across the Atlantic, molecular biologists Victor Ambros and Gary Ruvkun, had described similarly sized RNAs in the nematode Caenorhabditis elegans, but it was thought at the time that such molecules were restricted to that worm. Baulcombe’s discovery now suggested that these small regulatory RNAs might exist in many organisms. And, indeed, subsequent research proved that hypothesis to be true. “Gene or RNA silencing,” as this defense mechanism is now called, is recognized as being central to the modulation of gene expression in both plants and animals.
Since 2007, Baulcombe has been a professor of botany at the University of Cambridge. “We are now working on small RNA silencing and epigenetics—the science of how RNA can mediate changes to the genetic program in a cell that persist from one cell generation to the next,” he says. “We think that this RNA medicated epigenetic silencing is particularly important in hybrid plants. It is a process that may explain how hybrids can be more vigorous than their parents. I think it is a key to understanding evolution, and is important in plant breeding. It might also be important in animals.” Outside the laboratory, Baulcombe has been tirelessly promoting the use of plant biotechnology for crop improvement.
Baulcombe currently lives between Norwich and Cambridge with his wife, Rose. They have four adult children. “If I ever indulge in self-congratulation, it is when I look at what fine and caring people they are,” he says. Baulcombe has received numerous honors and awards throughout his long and distinguished career, including being elected to the U.K.’s Royal Society (which awarded him the Royal Medal in 2006) and to the U.S.’s National Academy of Sciences as a foreign associate. In 2009, Baulcombe was awarded a knighthood, the U.K’s highest civil service honor.