Spot the nutrients

Tri-colour map of: Fe (red), Cu (green) and Zn (blue) in a grain of barley.
Tri-colour map of: Fe (red), Cu (green) and Zn (blue) in a grain of barley.

South Australian researchers are using the Australian Synchrotron in their work on how to increase levels of iron and other micronutrients in staple grains such as rice and barley. The intense X-rays of the synchrotron can pinpoint where in the grain those micronutrients are found.

One third of the world’s population suffers from iron deficiency. One of the reasons for this is that more than three-quarters of the iron in rice is lost when the outer layers of the grain are removed during milling.

Enzo Lombi and Erica Donner from the Centre for Environmental Risk Assessment and Remediation at the University of South Australia are using the x-ray fluorescence microscopy (XFM) beam to probe grains of rice, barley and other staple grains that have been designed to boost levels of key micronutrients like iron.

The researchers use the intense synchrotron light to produce images showing concentrations of elements, like iron, copper, zinc and selenium.

One of the new plants they are studying is a strain of rice that has multiple copies of the gene for nicotianamine, which is involved in the long-distance transport of iron. The idea is that more iron will be moved into the inner layers of the rice grain.

The technique used by Enzo and Erica is the only one sensitive enough to determine the chemical form of these elements at the low levels found in cereal grains. It will show how much of the iron will be available when it reaches the consumer.

Photo: Tri-colour map of: Fe (red), Cu (green) and Zn (blue) in a grain of barley.
Credit: Enzo Lombi

Centre for Environmental Risk Assessment and Remediation, Enzo Lombi, Tel: +61 8 830 26267, Enzo.Lombi@unisa.edu.au