Author: Megha Gupta
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Scientists at the University of Maryland have genetically modified poplar trees to produce high-quality structural timber without the use of chemicals or energy-intensive processing. Made from traditional timber, engineered wood is often seen as a renewable substitute for traditional building materials such as steel, concrete, glass and plastic. It also has the potential to store carbon for longer than traditional wood because it is resistant to decay, making it useful in efforts to reduce carbon emissions.
However, the barrier to truly sustainable engineered wood is that it requires treatment with volatile chemicals and significant amounts of energy, and generates significant amounts of waste. The researchers modified a gene in living poplar trees, from which engineered wood was grown without any processing.
The study was published online on August 12, 2024 in the Journal ‘Matter’.
"We are very excited to demonstrate an innovative approach that combines genetic engineering and wood engineering, to sustainably sequester and store carbon in a resilient super wood form, said Yiping Qi, a professor in the Department of Plant Science and Landscape Architecture at UMD and a corresponding author of the study, "Carbon sequestration is critical in our fight against climate change, and such engineered wood may find many uses in the future bioeconomy.” Before wood can be treated to give it more strength or UV resistance, it must be stripped of one of its key components, called lignin. Previously, UMD researchers have successfully developed methods to remove lignin using a variety of chemicals, and others have explored the use of enzymes and microwave technology. With this new research, Qi and his colleagues sought to develop a method that would not rely on chemicals, produce chemical waste or use large amounts of energy. Using a technology called batch editing to delete a key gene called 4CL1, the researchers were able to create poplars with 12.8 percent less lignin than that in wild poplars. This is similar to the chemical treatment used in the processing of engineered wood products. Qi and his colleagues grew the cut plants in a greenhouse for six months, alongside unmodified plants. They found no difference in growth rate or significant difference in structure between the modified and unmodified trees. To test the viability of the genetically modified poplar, a team led by Liangbing Hu, a professor of materials science and engineering, used it to produce small samples of highly durable compressed wood, such as particle board, often used in furniture manufacturing. Compressed wood is made by soaking wood in water under vacuum and then pressing it under heat until it is about one-fifth of its original thickness. This process increases the density of the wood fiber. In natural wood, lignin helps the cells maintain their structure and prevents shrinkage. The lower lignin content in chemically treated or genetically modified wood allows the cells to be compressed to higher densities, thus increasing the strength of the final product. To assess the performance of their genetically modified trees, the team also produced compressed wood from natural poplar, using both untreated wood and wood that had been treated with traditional chemical processes to reduce its lignin content. They found that the genetically modified compressed poplar performed at par with the chemically treated natural wood. Both were denser than untreated compressed natural wood and also more than 1.5 times stronger. The tensile strength of the genetically modified compressed wood was comparable to that of 6061 aluminium alloy and chemically treated compressed wood. This work paves the way for the relatively cheap and environmentally friendly production of a range of building materials on a scale that could play an important role in the fight against climate change.
Reference:
- Yu Liu, Gen Li, Yimin Mao, Yue Gao, Minhua Zhao, Alexandra Brozena, Derrick Wang, Samuel von Keitz, Taotao Meng, Hoon Kim, Xuejun Pan, Yiping Qi, Liangbing Hu. Genome-edited trees for high-performance engineered wood. Matter, 2024; DOI: 10.1016/j.matt.2024.07.003
- University of Maryland. (2024, August 12). New genetically engineered wood can store carbon and reduce emissions. ScienceDaily. Retrieved August 26, 2024 from www.sciencedaily.com/releases/2024/08/240812123203.htm
- Story Source: Materials provided by University of Maryland. Original written by Kimbra Cutlip