Researchers from the University of California, Riverside, found a protein, IRK, which controls plant growth, while looking for clues to the ways plant cells divide or expand. They discovered IRK in the root cells of a plant related to mustard.
“When this protein is present, the root perceives a signal that tells cells not to divide,” said Jaimie Van Norman, who led the study and is an assistant professor of plant sciences at UCR. “If we can get the plant to ignore those signals, we may be able to get it to grow in conditions where it might not otherwise.”
The team’s work on IRK was published in Developmental Cell. The research demonstrates that turning off the gene producing IRK causes an increase in the number of times the plant’s root cells divide. Additional cells can lead to bigger roots, and perhaps to plants that are better at taking up nutrients from the soil.
There may be some instances in which farmers also want to limit plant growth. For example, keeping weeds small, or trying to pause crop growth until a severe storm passes. IRK can be instrumental in achieving both goals.
This research is notable not only for its potential impact on crop and food security, but also because roots have historically been less well studied than the above-ground parts of plants. This is likely due to the relatively inaccessible nature of roots, Van Norman said.
However, the roots are critical for plant survival and for the production of above-ground plant organs. Therefore, understanding their function and development is critical in efforts to improve crop productivity.
“It may be the case that by understanding what happens when the IRK-producing gene is turned off, we can make root growth less sensitive to conditions that pose a threat to food security,” Van Norman said.