The team of Wellington Muchero, Meng Xie, and their colleagues at Oak Ridge
National Laboratory (ORNL) have discovered that key enzymes in plants do not
only produce amino acids. Their experiments on poplar plants consistently
revealed mutations in a structure of the life-sustaining enzyme that was not
previously known to exist.
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.