Meet a Whitehead Postdoc: Roland Kersten

Roland Kersten is a postdoctoral researcher who investigates plants to find new natural product chemistry and biosynthetic pathways in the lab of Whitehead Member Jing-Ke Weng. Kersten, who is originally from Berlin, Germany, completed his graduate studies in Marine Chemical Biology at Scripps Institution of Oceanography (UC San Diego). He is an alumnus of the Howard Hughes Medical Institute postdoctoral fellowship of the Life Sciences Research Foundation. We sat down with Kersten to learn a bit more about him and his experiences in the lab.

What do you investigate?

I work on genome-sequenced plants. I use plant genome sequence information to find new small molecule chemistry from plants that we might be able to use for pharmaceutical or agricultural applications.

The number of plants that have been genome sequenced is rapidly growing. This genetic information can potentially be used to predict chemistry that a plant is producing to, for instance, defend itself from pests or signal with symbiotic partners to help it grow. I'm trying to develop workflows to connect plant genes to the molecules they produce. In particular, I focus on plant peptides as a starting point for these workflows. Most plant peptides are ribosomal peptides which means that the sequence information of the peptide is directly encoded in the genome, so you can make a structural prediction right from the genetic sequence, and use that to guide analytical experiments to find the compounds that are connected with a biosynthetic gene.

What part of your research is the most fun to do?

I generally enjoy chemical analysis of natural products. The most fun thing is when you find new chemistry. Since being at Whitehead, growing plants has been also becoming an exciting part of my research.

What’s the hardest part of your job?

Staying focused and dealing with failure.

What’s the biggest surprise you’ve ever had in the lab?

That you can discover new chemistry in the produce section of the grocery store. Most plants that are genome sequenced are crop plants, like potatoes, soybeans, eggplant, and pepper, so all of them are in the produce aisle. After I predict plant chemistry from the genome sequences of these plants, I look for the chemistry in specimens I pick out at Trader Joe's. For example, I did some analysis of potato genomes and transcriptomes, which indicated that the compounds I was looking for were in the sprout. So I picked a couple of varieties of potatoes and let the potatoes sit for a couple of weeks until they started to sprout. Then I analyzed the sprout and found the compounds that I was predicting based on bioinformatic analysis. For me that was a little bit of a teaching moment because the potato has probably been studied quite a lot, but based on a genetic prediction I was still able to find new chemistry from it.

What’s your favorite spot at Whitehead? Why?

The greenhouse—especially in the winter, it is a nice bright place to do some work.

What’s the most expensive thing you’ve broken? How did it happen?

I dented a centrifuge rotor. Not the best lab day of my life.

What are your hobbies and what do you enjoy about them?

I play soccer because it connects me with friends and I surf since I enjoy the energy of the ocean. As an undergraduate, I went to UC San Diego for a year-long internship. The campus is right on top of a cliff next to beaches so I started hanging out on the beaches and surfing there. I really enjoyed it. I went back and got my PhD from Scripps Institution of Oceanography at UC San Diego.

I kept surfing after moving from San Diego to Massachusetts. There's a little bit more planning involved to go surf New England, but it’s worth it. The surf can be really good during fall and winter. The water temperature gets colder than California, so it's a little bit more raw. I mainly go at sunrise here, which has a different atmosphere than sunset surf in San Diego.

What's the best location where you've traveled to collect specimens?

I’ve been to the reefs off the coast of California and islands off the Pacific coast of Panama with Jing-Ke [Weng].

Do you collect anything?

At this point of my time at Whitehead, I might have started a seed collection.

Have you had to work with any dangerous plants?

I was interested in a compound in the Australian stinging nettle, but the plant was too dangerous to grow for work, so we studied the same compound in another plant, celosia, which is an ornamental amaranth plant in the family of spinach and beets. Celosia is not toxic or harmful. Then for fun I got some seeds of the stinging nettle to grow it at home. I didn’t dare to touch it because it is supposed to be a very painful sensation like touching a hot stove. [Ed. Note: The sting is so famously painful and long-lasting that the plant is also known as the suicide plant.] I had a plastic dome around it so nothing could touch it or get out of it. When I had to interact with it, I wore latex gloves like in the lab.

Where did you get the stinging nettle seeds?

I got them from a Facebook group for hobby botanists. I don’t have the plant anymore since it is native to rain forests and doesn't last very long in Massachusetts.

Where do you see yourself in 10 years?

Doing research that I’m interested in, hopefully somewhere coastal with good surf.