Muchero, a biologist at ORNL said that as they repeated experiments multiple times, they kept seeing that the same gene involved in making amino acids also regulates the function of genes involved in producing lignin. They found that poplar plants with certain mutations created unexpectedly low levels of lignin across different environments and tree ages.
The scientists noted the amino acid-producing enzyme deviated from its anticipated journey through the plant's cells seeking out chloroplasts, but instead, they discovered that the additional section of the enzyme allowed the enzyme to enter the nucleus, which is the plant cell's brain center, and "moonlight" as a DNA-binding regulator of gene expression. Their discovery opens new opportunities to tweak how lignin is produced in poplar without impacting other biological processes that could kill the plant.
For more details, read the news release from ORNL.