Chromosomes are covered with chemical modifications that help control gene expression. I study this secondary genetic code - the epigenome - and how it is guided by small mobile RNAs in plants and fission yeast. Our discoveries impact plant breeding and human health, and we use this and other genomic information to improve aquatic plants as a source of bioenergy.
Epigenetic mechanisms of gene regulation—chemical and conformational changes to DNA and the chromatin that bundles it—have had an important impact on genome organization and inheritance and on cell fate. These mechanisms are conserved in eukaryotes and provide an additional layer of information superimposed on the genetic code. Robert Martienssen, a pioneer in the study of epigenetics, investigates mechanisms involved in gene regulation and stem cell fate in yeast and model plants including Arabidopsis and maize. He and his colleagues have shed light on a phenomenon called position-effect variegation, caused by inactivation of a gene positioned near densely packed chromosomal material called heterochromatin. They have discovered that small RNA molecules arising from repeating genetic sequences program that heterochromatin. Martienssen and colleagues have described a remarkable process by which “companion cells” to sperm in plant pollen grains provide them with instructions that protect sperm DNA from transposon damage. They found that some of these instructions, or epigenetic marks, could be inherited in the next generation. These marks, and the small RNA responsible that guide them, can sense the number of chromosomes inherited from pollen and may allow Arabidopsis, a flowering plant, to produce egg cells without meiosis, an important step toward a long-time goal of plant breeding: generating clonal offspring to perpetuate hybrid vigor. The lab has also shown that when RNA polymerase II has transcribed a stretch of DNA, the RNA interference mechanism causes the enzyme to release its hold on the DNA and fall away. This allows the replication fork to progress smoothly and the DNA strands to be copied; histone-modifying proteins, which follow right along, establish heterochromatin. Martienssen’s group also continues to work on problems related to the creation of plant-based biofuels. As part of a collaborative project to generate a high-quality full genome map of the oil palm plant, Martienssen and his colleagues identified a transposon whose modification controls the yield of oil palm trees. This discovery will increase yields and should lessen the environmental burden of oil palm production, which often threatens already endangered rainforest lands.
Martienssen named 2020 Royal Society winner
Rob Martienssen wins Martin Gibbs Medal for plant research
CSHL’s Rob Martienssen honored with prestigious Barbara McClintock Prize
Plant scientist Rob Martienssen receives prestigious appointment as HHMI-GBMF Investigator
“Breakthrough of the Year” for 2002
CSHL Ph.D. program: Graduating class of 2021
August 22, 2021
The CSHL School of Biological Sciences awarded Ph.D. degrees to seven students this year, who describe some of their experiences.
How plants leave behind their parents’ genomic baggage
May 20, 2021
A baby plant resets its genome, erasing the changes that its parents accumulated. CSHL scientists found how the plant adds back a few necessary ones.
How to bury carbon? Let plants do the dirty work.
February 5, 2021
Carbon sequestration could slow or reverse human emissions—and nothing is better at sequestration than a green plant.
Martienssen named 2020 Royal Society winner
August 3, 2020
Professor and HHMI Investigator Rob Martienssen wins a 2020 Royal Society medal for his RNAi research.
The world destroyer in your shampoo and ice cream
July 6, 2020
Palm oil is an environmental scourge. Genetics has a solution.
Nobelist Sir Richard Roberts talks GMOs at CSHL
June 26, 2020
Nobelist and CSHL alum Sir Richard Roberts spoke about GMOs and the future of agriculture with Pamela Ronald and Rob Martienssen.
Nobelist Sir Richard Roberts talks GMOs at CSHL hosted event
June 25, 2020
Nobelist and CSHL alum Sir Richard Roberts spoke about GMOs and the future of agriculture with Pamela Ronald and Rob Martienssen in this video.
Coronavirus research in plants
May 15, 2020
Purified coronavirus proteins are in short supply for COVID-19 researchers, so CSHL plant scientists are jumping in to make them.
Barbara McClintock: Free to discover
March 23, 2020
Nobel laureate Barbara McClintock spent half her life at CSHL, enjoying the freedom to explore new ideas and ignore criticism. This is her journey.
An essay from the President: Biology for the planet
May 16, 2019
CSHL plant scientists are looking for solutions to the biggest questions in agriculture as environments are reshaped by climate change.