Wheat Research Team Uses UK's Most Powerful 'Microscope' To Pinpoint Nutrient Hotspots

Diamond Light Source could help address global nutritional deficiencies by revealing where calcium sits in wheat grain cells

Rothamsted wheat researchers took a short trip down the M40 to put grain samples under the microscope at the Diamond Light Source at the the Harwell campus near Didcot .

Diamond is the UK’s national synchrotron. It works like a giant microscope, harnessing the power of electrons to produce bright light that scientists can use to study anything from fossils to jet engines to viruses and vaccines. It is 10,000 times more powerful than a traditional microscope.

The machine accelerates electrons to near light speeds so that they give off light 10 billion times brighter than the sun. These bright beams are then directed off into laboratories known as beamlines. Here, scientists use the light to study a vast range of subject matter, from new medicines and treatments for disease to innovative engineering and cutting-edge technology.

So why the need to investigate wheat grains with this powerful tool?

The Delivering Sustainable Wheat (DSW) programme has identified wheat lines developed from crosses between AE Watkins landraces and the spring wheat cultivar Paragon, which contain calcium levels more than 50% higher compared to standard commercial varieties.

Calcium is essential for bone health and muscle function, but as increasing numbers of people move away from dairy – traditionally the richest source of dietary calcium – there is an urgent need for plant-based alternatives that can deliver the same nutritional benefits. Some selected lines have elevated calcium levels, even in the starchy endosperm - the part of the grain used to make white bread. This is exciting as usually minerals are concentrated in the outer bran layers and bound to an antinutrient called phytate.

“This is really promising,” said Dr Anneke Prins, who leads this area of research. “We’re seeing calcium concentrated in specific ‘hotspots’ inside the part of the grain that people actually eat, even in refined flour products.”

It’s not just about how much calcium is there. We need to understand how it’s bound within the grain. That determines whether our bodies can actually make use of it.

The next phase of the research is to examine how well this calcium can be absorbed by the human body – a factor known as bioavailability. That is where the Diamond Light Source synchrotron comes in. At the DLS' Beamline I18, in collaboration with researchers from the Jožef Stefan Institute, University of Ljubljana and University of Nova Gorica (Slovenia), the team are mapping calcium hotspots and analysing their chemical form using a technique known as X-ray absorption near edge structure.

This analysis is vital. “It’s not just about how much calcium is there,” said Prins. “We need to understand how it’s bound within the grain. That determines whether our bodies can actually make use of it.”

Initial images show clear deposits of calcium in the starchy endosperm tissue of the grain, against a background of sulphur from the gluten proteins. Potassium is concentrated in the single layer of aleurone cells which surround the starchy endosperm cells.

“These stunning images are hugely helpful,” said Prins. “However, we still have a long way to go. We are hopeful that ultimately high-calcium wheat will not only offer a more nutritious staple food but also help ease reliance on calcium supplements and dairy, supporting more sustainable and inclusive diets around the world.”

If successful, the findings could pave the way for new varieties of biofortified wheat, helping tackle one of the world’s most persistent hidden hunger problems – all through a simple slice of white bread.