Researchers at Dartmouth College in New Hampshire have discovered a gene that controls the regulation of iron uptake in plants. The newly-discovered gene, known as Upstream Regulator of IRT1 (URI), controls when genes should be expressed in plant roots to begin iron uptake. According to the team, URI controls as many as 1,500 other genes, including those that have nothing to do with iron.
The researchers found that the URI protein is always present in plants, and this constant presence created the additional challenge of understanding how the protein senses the status of iron sufficiency in order to regulate itself and avoid toxic overexposure to the element. However, the researchers found that the abundance of URI protein is not changed by iron conditions. Under iron-poor conditions, the protein combines with a phosphate molecule and activates a sequence of genetic events to turn on the iron uptake system. URI also controls a protein that shuts down the transport of iron through the plant root under iron-sufficient conditions.
Iron plays a key role in photosynthesis and plant growth, but it is highly reactive and toxic that plants tend to overregulate it. The research team is now developing a plant with a regulator that stays in the “on” position for a longer amount of time. Their goal is to have plants take up enough iron for the benefit of human consumption.
Kim et al. 2019 The iron deficiency response in Arabidopsis thaliana requires the phosphorylated transcription factor URI. PNAS https://doi.org/10.1073/pnas.1916892116
Source: Crop Biotech Update