Mendel Medal Lecturer 2017
Professor David Baulcombe
David Baulcombe is the Regius Professor of Botany at the University of Cambridge.
As a botany undergraduate at Leeds University in the 1970s he was inspired by models of genetic regulation that had been recently published by Britten and Davidson. For his PhD at the University of Edinburgh he wanted to test these models using plants and he chose to use an artichoke tissue culture system in which a plant hormone stimulated changes in gene expression. He was not able to make a lot of progress in this system, but during postdocs in Canada and the USA other similar plant hormone systems turned out to be a bit more rewarding.
David then started his career as an independent scientist at the Plant Breeding Institute in Cambridge. Thereafter, he joined the Sainsbury Laboratory in Norwich. In 2007 he became the Professor of Botany at Cambridge University.
David Baulcombe’s attention had turned to viruses and virus resistance in plants and he discovered the power of viruses as experimental tools to probe biology. He realized that there were similarities between viral defense mechanisms and gene silencing in plants and this eventually led him to the discovery of small RNAs. This discovery has had profound implications for the investigation of gene regulation in a very wide variety of animals, fungi and plants and led to the development of tools for manipulating of gene expression experimentally. Using the model organism Arabidopsis, his lab was able to identify some of the key molecular players in this gene silencing mechanism.
David Baulcombe showed that RNA silencing can spread systemically throughout the plant and that it also plays an important role in protecting plant genomes from endogenous transposable elements as well as from viruses. This work led David Baulcombe into the field of Epigenetics – gene silencing triggered by small interfering RNAs (siRNAs) can be inherited, even between generations. Some of his recent work indicates that RNA silencing and epigenetics play a role in hybrid vigor. Taking this work to the next level, David is developing methods to improve the heritable characters of crops without modifying their genome, but rather using RNA to target epigenetic modifications to the chromosomes of crop plants.
David’s current research includes studying RNA silencing in a single cell alga Chlamydomonas, and genetically engineering maize to resist a lethal disease that is a problem in Kenya and nearby regions of Africa. He is also exploring artificial evolution, using random mutagenesis to select mutant forms of the NB-LRR proteins that collectively mediate resistance to a huge range of viruses, bacteria, fungi and insects, but which individually are specific to one or a few plant pests and pathogens. David Baulcombe is generating new NB-LRR proteins that confer broader spectrum disease resistance than the progenitor wild type.
David Baulcombe’s work therefore epitomizes how the highest level of discovery science can not only produce profound new insights into biological mechanisms of gene regulation and genome defense, but that can also be harnessed to bring new approaches to global problems of food security.
David Baulcombe presented his medal lecture at the 2017 meetings of the Genetics Society/BSCB/BSDB (University of Warwick, April 2017).