Zinc discovery could transform agriculture and combat climate change
According to the latest findings from scientists described in "Nature," zinc may contribute to safeguarding crops against climate change. This is due to its key role in regulating the nitrogen fixation process by leguminous plants.
Scientists from Aarhus University in Denmark made the discoveries in collaboration with the Polytechnic University of Madrid and the European Synchrotron Radiation Facility in France. They determined that zinc, along with the transcription regulator Fixation Under Nitrate (FUN), influences the efficiency of nitrogen fixation by leguminous plants. This discovery could revolutionise legume-based agriculture by optimising crop efficiency and reducing dependence on synthetic fertilisers.
New scientific discovery
As explained, FUN responds to "zinc signals" and regulates nitrogen fixation in root nodules, where symbiotic bacteria live. Knowing how zinc and FUN regulate nitrogen fixation could increase its supply, improve yields, and promote more sustainable farming practices. Plants would become more resilient to adverse climate changes and the extreme weather events associated with them. Yields would be more stable, and the demand for artificial fertilisers would decrease. This would make cultivating leguminous plants possible in areas that are not feasible.
"Bacteria can cooperate with legumes to fix nitrogen from the air in root nodules. However, the nodules are sensitive to environmental influences such as temperature, drought, flooding, soil salinity, and high concentrations of nitrogen in the soil," explained Jieshun Lin, the study's lead author.
From the farmers' perspective, continuous nitrogen fixation can be beneficial, increasing nitrogen availability for the legumes and other crops grown in rotation with or after them, which depends on the nitrogen left in the soil after legume cultivation.
"It's truly remarkable to discover zinc's role as a secondary signal in plants. It is a vital micronutrient, and it has never been considered as a signal before. After screening over 150,000 plants, we finally identified the zinc sensor FUN, shedding light on this fascinating aspect of plant biology," explained Jieshun Lin, who believes that FUN is an important transcription factor controlling nodule breakdown when soil nitrogen levels are high.
"FUN is regulated by a peculiar mechanism that monitor the cellular zinc levels directly and we show that FUN is inactivated by zinc into large filament structures and liberated into the active form when zinc levels are low," added Professor Kasper Røjkjar Andersen.
The study's authors believe that the new findings could lay the groundwork for further research, providing new ways to manage agricultural systems, reduce the use of nitrogen fertilisers, and diminish their environmental impact.
