LSU Chemistry Professor Receives NSF CAREER Award to Advance Research on Plant Growth and Resilience

Assistant Professor Amy Xu from the LSU Department of Chemistry received a National Science Foundation’s CAREER Award, the research foundation’s most prestigious award that supports early-career faculty. Xu’s project explores how proteins and complex sugars, known as polysaccharides, interact in the crowded environments of plant cells, a process critical for plant survival and growth.

In biological systems, proteins and polysaccharides exist within highly crowded environments, where molecular crowding influences their interactions and phase behavior. Recent studies reveal that proteins and polysaccharides can undergo liquid-liquid phase separation (LLPS), forming distinct molecular assemblies contributing to essential biological processes. While LLPS has been extensively studied in protein-nucleic acid systems, its role in protein-polysaccharide interactions remains poorly understood.

Xu’s research seeks to fill this gap by examining how protein-polysaccharide interactions contribute to plant functions, such as cell wall expansion and pollen formation. Her project will simulate biologically relevant crowded environments using molecular crowding agents with diverse physical and chemical properties.

Crowding can alter molecular interactions by restricting diffusion, enhancing binding affinities, and modifying phase behavior, leading to emergent properties not observed in dilute conditions. Studying how these factors influence protein-polysaccharide phase separation will provide a deeper molecular-level understanding of how biomolecular assembly governs plant growth and resilience. Findings will contribute to predictive models of phase separation in plant biology, offering new perspectives on how plants adapt to stress.

“By understanding how proteins and polysaccharides interact in crowded environments, our findings could aid in developing more resilient crops,” Xu said. “Uncovering how plants adapt to stressors like drought and extreme temperatures will lay the groundwork for sustainable agricultural practices and help address global food security challenges.”

The Xu group will employ macromolecular crowding agents to recreate the complex intracellular and extracellular environments of plant cells. The team will then characterize the molecular interactions and phase behavior using small-angle X-ray and neutron scattering (SAXS/SANS), combined with complementary techniques such as calorimetry, fluorescence imaging, and electron microscopy. These methods will provide detailed insights into the structural and dynamic properties of protein-polysaccharide complexes, shedding light on how molecular crowding drives phase separation in biological systems. 

“Understanding the structural and dynamic properties of protein-polysaccharide complexes is key to uncovering the principles behind phase behavior,” Xu said. “With this information, we hope to develop predictive models that provide insights into these processes in real-world biological systems.”

Xu's project also includes initiatives to train students in advanced biophysical techniques, providing opportunities for young scientists to acquire cutting-edge skills. “I want students to see themselves in science,” Xu explained. “This award helps us open doors, not just for those working in our lab, but also for students who may not have imagined they could belong in this field.”

Xu received her Bachelor of Science in 2009, a Bachelor of Science, 1st Class Honours in 2012, and her Ph.D. in 2016 from the University of Auckland, New Zealand. She completed post-doctoral research fellowships at the University of Massachusetts Amherst and then the National Institute of Standards and Technology/University of Maryland. In the fall of 2020, Xu joined the LSU chemistry department as an assistant professor. She is a strong advocate for neutron scattering techniques, particularly their applications in biological systems, and has taken on multiple supportive roles in the neutron community. She currently serves as the elected Financial Secretary of the Neutron Scattering Society of America (NSSA).

To learn more about Assistant Professor Amy Xu and the work of her research group, visit their group webpage.