A new method developed by Penn State biologists allows them to turn stripped-down plant cells into other types of cells, similar to the way stem cells differentiate into different cell types. The research team explored the banding patterns that increase the stability of plant cell walls, much like the corrugated patterns in cardboard, and how they are created. The researchers revealed how the assembly of these structures can go astray in different mutant plant cells, which could inform methods to break down plant cells for biofuels. The paper describing the research appeared in the October issue of the journal The Plant Cell.
Cellulose, a structural component of plant cell walls, is an abundant and promising source of biofuels. However, common techniques to extract cellulose from the cell walls require chemical solvents, enzymes, and reactions at high temperatures, adding cost and complexity to the process. Improving the understanding of how cell walls are built could illuminate new, more cost-efficient ways to extract cellulose. The researchers aim to enhance the efficiency of cellulose extraction by manipulating other polymers in the cell wall that can obstruct the process, like xylan and lignin. The unique structures formed by ‘xylem tracheary element’ cells often fail to develop properly in mutant plants, leading to reduced plant growth and extractable cellulose.
Xylem tracheary elements (XTEs) are cells that allow water to move from a plant’s roots to its leaves and have thick cell walls. Polymers like cellulose, xylan, and lignin are deposited in specific locations in the cell walls of XTEs, creating a banding pattern that increases stability. When these patterns are not formed correctly in mutant cells, the cells can collapse due to pressure from moving water against gravity. The banding patterns in xylem tracheary elements act similarly to the corrugated pattern in cardboard, providing stability to the cell wall. The new method developed by the researchers allows them to observe individual cells without neighboring cells getting in the way, providing clear insights into how banding patterns break down in mutant cells.
The new method developed by the research team uses protoplasts, individual cells stripped of their cell walls, to observe how they differentiate into a new type of cell. By providing protoplasts with nutrients and a genetic trigger, they induce differentiation into the unique XTE cell type. The interactions between cellulose and xylan are essential for the banding patterns to form correctly, with a properly assembled cell wall network of polymers acting as a scaffold to dictate the banding pattern. In different mutant cells, the banding pattern failed in various ways. Understanding how cell walls are built is crucial for various industries like forestry, materials science, and biofuel production.
The study found that the structure of the cell wall influences what happens inside the cell and vice versa, providing valuable insights into how cell walls are created. This research is beneficial for forestry, materials science, and biofuel production. The research team plans to use their new method to explore how other types of cell walls are created. By exploring different combinations in individual cells rather than breeding mutant plants together, researchers can study various genetic traits more efficiently. The new method allows for studying different cell types using various genetic triggers, with potential implications across plant biology.
In addition to Sarah Pfaff, postdoctoral scholar at Penn State, the research team includes Edward Wagner, senior research technician, and Daniel Cosgrove, Eberly Family Chair of Biology. The research was supported by the Center for Lignocellulose Structure and Formation at Penn State, an Energy Frontier Research Center funded by the U.S. Department of Energy, and the Human Frontier Science Program. By developing a new method to observe individual plant cells as they differentiate into unique cell types, this research provides valuable insights into how cell walls are created, with potential applications in various fields, including biofuel production, forestry, and materials science.
