Professor Min Chen: catching photons in a rain of light to feed the world

by Natalia Bateman, September 2016

Curiosity has been Professor Min Chen’s companion since she was a little girl. Curiosity about how the world works and about new places and cultures.

“I have been all my life really fond of science, because science is the perfect career for a curious person. As my daughter said to me: every decision about your career has been easy, you have just followed your childhood dream,” Professor Chen says.

Professor Chen’s curiosity is quite contagious as soon as she begins to explain what her research is all about. “To understand what we do here, you have to imagine that light is like rain coming down from the sky, and photons are like rain drops that plants need to grab. What I do, is trying to understand how plant’s pigments or antennas gather this rain, which is the power that drives all the photosynthetic process.”

Pigments, like chlorophyll, are the molecules in charge of harvesting light inside plant’s cells and transfer the energy they catch so it can be transformed. They are the start gate of photosynthesis, the process by which plants use sunlight and convert CO₂ and water into food and oxygen.

Professor Min Chen has been studying plant’s pigments for almost 20 years, and as long as she remembers, she has been involved with a University. “I don’t know how life looks outside the University. I always have been working or studying in one and I feel completely comfortable in this environment”.

It was working at one University, the University of Sydney, that in 2010 Professor Chen and her team discovered a new type of chlorophyll, a finding that changed plant biology for ever. They found chlorophyll f, inside ancient organisms called stromatolites. Today you can find stromatolites in Shark Bay, Western Australia; one of the few locations around the world where these marine colonies still alive.

The significance of this discovery was not just its novelty – no other type of chlorophyll had been discovered since 1943 – but more importantly, the particular ability of chlorophyll f is that it can harvest light from the infrared light spectrum, which other plants can’t use.

“I love the excitement that comes with discovering something completely unknown, to be the first person to see something that nobody has seen before.”

It was discovery of this molecule which made Professor Chen widely known in the scientific world, and she is now considered the world expert on the biology and biochemistry of red-shifted photosynthetic organisms.

One of the most promising applications of this discovery is agriculture. As a Chief Investigator for the ARC Centre of Excellence for Translational Photosynthesis, Professor Min Chen is exploring the possibility of transferring chlorophyll f to other plants such as wheat or rice to make them able to gather a wider area of the light spectrum and increase their crop yield.

“My team and I focus on understanding the biochemistry of this chlorophyll because we still missing fundamental pieces in our understanding of how chlorophylls synthesise and function in the plants capture light processes. One day this knowledge will permit other people to improve the process and get them into crop plants,” she says.

This process is a bit like a surgical procedure to transplant a human heart. “Pigments have functions only when they are arranged in ways that permit them to meet their energy transfer needs. We need to make sure that the recipient plant for the pigment is going to be able to use it, that it will function inside the protein complexes,” she says.

Professor Chen and her team are also interested in the complex and fascinating diversity of the mechanisms used by plants to harvest light.

“Light harvesting complexes are very diverse because they are the ones that have to deal directly with diverse environments outside the plant, in contrast with the reaction centre complexes inside the plant, which are more conservative. We are trying to understand how pigments behave in different environments, for example in the ocean. The organisms that live many metres deep under the ocean need huge antennae to be able to gather light, but at the water surface they have smaller antennae.”

To tackle these complex problems, Chen has put together a team of scientists that is as diverse as the pigments they study. They all come from different parts of the world and this brings refreshing perspectives and expertise. “Each person in my team have their strengths in terms of their expertise on the use of different technologies, and this helps me enormously.

Professor Chen remarks on the importance of having a team that works well together to ensure the success of a scientific project.

“I try to manage this by having my own project and giving each of my staff their own responsibility for one project. That way everyone shares the exciting and the boring parts a bit and everyone feels has ownership of a part of our research.”

“A team also ensures that you can keep up with the current speed of technological change. Technology is a very important part of our work and one that makes it quite challenging. You have to have an open eye on all the endless list of new technologies in your area and keep learning them all the time and this is simply not possible with just one pair of eyes.”

“The other important aspect is ensuring people are enjoying what they do. The thing that I enjoy most about my work is working in the lab, the lab is my extension kitchen, were I can explore and fulfil my curiosity and where I feel the most relaxed and happy. As a scientist, I enjoy solving questions inside this environment and I think my team feels that way too. From an outsider point of view, it looks like we are working extremely hard, but when you enjoy your work so much it doesn’t feel hard or difficult at all.”

There is something quite magical about Professor Min Chen’s laboratory at the University of Sydney. The lab spaces are dark and everyone seems to be focusing in tightly controlled little fires in their lab bench spaces because their mission is to catch and understand light.

This environment also makes you think that scientists resemble the objects they study, and Professor Min Chen, just like chlorophyll, has managed to create a research environment that catches bright ideas and successfully adapt to the ever changing technological evolution.