Growing up in the countryside of China, Li-Qing Chen understood the challenges of farming from a young age. Her family owned a small farm, so she became aware of the many conditions and stresses that plants face.

When Chen began her college education, she decided that she wanted to learn more about plants at a deeper level.

“As farmers, we don’t care much about what is going on within plants at the molecular and the genetic level,” she said. As a scientist, Chen could finally work toward understanding the fundamental mechanisms of plants.

Xueyi Xue, Ya-Chi Yu, Gabriel Beuchat, and other members of Li-Qing Chen’s lab group harvest samples for transcriptome and metabolome analysis after source-sink manipulation in one of CABBI Co-Investigator Steve Moose’s sorghum fields.

Now an Assistant Professor of Plant Biology at the University of Illinois at Urbana-Champaign and a CABBI Co-Investigator, Chen is researching how plants control the flow of sugar from their source tissues, such as leaves, to their sink tissues, such as roots, flowers and seeds.

Sugar is an important part of plant nutrition. Plants’ source tissues can make enough sugar for themselves and other parts of the plant, but their sink tissues need to import sugar to support their own growth.

Chen wants to understand how this flow of sugar is regulated at the molecular level — a process that is not well understood.

“We only know a little about sugar flux regulation,” Chen said. “That’s why I feel that my research is so urgent.”

This fundamental research can have a real-world application. Sugar-rich tissues are a favorable trait for some crops because sugar can be converted into biodiesel and ethanol, two major alternative renewable fuels. Sugar also contributes greatly to crop yields.

If scientists can better understand how sugar is allocated through plants, they might be able to one day manipulate these processes to increase the amount of sugar in the plant and maximize crop yields.

“Can we allocate more sugar to the desirable tissues to increase crop yields and/or biofuel production?” Chen said. “That’s our goal.”

Chen is a member of CABBI’s Feedstock Production theme, which focuses on using plants as “factories” to create biofuels, bioproducts, and important molecules.

With CABBI, Chen is working on understanding why sweet sorghum can accumulate more sugar in its stem than grain sorghum can.

Sorghum, a versatile crop, is one of the world’s highest producers of biomass, a renewable source of energy. Sweet sorghum has mainly been grown for its sugary syrup, but it has recently become a promising crop for biofuel and chemical production.

“We know sweet sorghum can accumulate a lot of sugar. Can we maximize this potential?” Chen said. “That’s a fundamental question — we have to get a better understanding of the mechanism behind it.”

Chen believes that her research and expertise can contribute to solving several crucial problems our world faces today — including urgent needs for renewable fuels due to fossil fuel depletion, and food insecurity due to growing populations and the loss of arable land.

“I think I may be able to contribute to resolving these issues, a little bit,” Chen said. “That’s my career goal too. That drives me to continue the research in this field.”

— Written by Emily Scott, IGB Science Writer and Outreach Specialist