A research team led by Dr Guilhem Reyt from the School of Biosciences and Future Food Beacon at the University of Nottingham in the UK have discovered how a protein in plant roots controls the uptake of minerals and water. The study shows that members of the blue copper proteins family, the Uclacyanins, are vital in the formation of Casparian strips. These strips are essential structures that control mineral nutrient and water use efficiencies by forming tight seals between cells in plants, blocking nutrients and water leaking between.
This is the first evidence showing the implications of the Uclacyanins in the biosynthesis of lignin, one of the most abundant organic polymers on Earth. The study, which was published in Current Biology in September, reveals that the molecular machinery required for Casparian strip lignin deposition is highly ordered by forming nano-domains which can have a huge impact on plant nutrition, a finding that could help in the development of crops that are efficient in taking in the nutrients they need.
Food security represents a pressing global issue. Crop production must double by 2050 to keep pace with global population growth. This target is even more challenging given the impact of climate change on water availability and the drive to reduce fertiliser inputs to make agriculture become more environmentally sustainable. In both cases, developing crops with improved water and nutrient uptake efficiency would provide a solution to this.
Reyt says: “This research is important in revealing the molecular mechanics underpinning efforts to improve mineral nutrient and water use efficiencies and enhanced stress tolerance, making crops more able to withstand flooding, drought, nutrient deficiencies and trace element toxicities.”
Such improvements in agricultural and horticultural crops could also potentially benefit subsistence farmers with limited access to inorganic fertilisers which include nitrogen, phosphate and potassium and also sulphur and magnesium. This would help to reduce the cost burden such fertilisers impose and lower the environmental and ecological damage that their production and excessive use causes. Improved water use efficiency and stress tolerance will also improve yields for subsistence farmers cultivating marginal lands.
“An improved understanding of how roots acquire important trace element and minerals should provide an important molecular mechanistic underpinning of efforts to improve food quality by helping to increase the content of essential mineral nutrients and reduce toxic trace elements in food crops,” Reyt maintains.
(University of Nottingham/wi)
Guilhem Reyt et al.: Uclacyanin Proteins Are Required for Lignified Nanodomain Formation within Casparian Strips. Current Biology, August 2020; DOI:https://doi.org/10.1016/j.cub.2020.07.095