A protein involved in moving lipids into wheat grains graces the cover of the Journal of Experimental Botany this month. Scientists at the Australian Centre for Plant Functional Genomics (ACPFG) discovered this protein, called TdPR61, while trying to find out how to express genes in the grain of wheat plants. The protein is expressed in specific parts of the grains of wheat, barley and rice, and it transports lipids (fats and oils). The new knowledge about where the gene is expressed can be used to improve grain quality or to increase the nutritional quality of grains.
Most genes are expressed in particular places or at particular times. For example your red blood cells express a gene that makes haemoglobin for transporting oxygen, but your hair doesn’t. Where a gene gets expressed depends on its promoter. ACPFG scientists are interested in what promoters cause genes to be expressed in the grains of cereal plants. That will allow the researchers to target nutrients that are important to human health, like iron or zinc, to the grain of the plant which people eat.
Expressing genes in specific parts of plants is an important part of modern plant genetics. Scientists working with genetically modified plants don’t want plants wasting energy expressing the genes throughout the plant. Instead they want to target a gene-product to where it’s needed. If researchers want to fortify a grain with nutrients that are good for human health, then it’s most important for these to be in the part of the plant that we eat. In wheat, barley or rice, that’s the grain.
Researching plant promoters also gives us clues about how plants make grain at a cellular level. TdPR61, the protein on the cover of the Journal of Experimental Botany, transports lipids into different parts of the grain. The clue to finding out that TdPR61 carries lipids came from its structure. TdPR61 is very similar to a protein from Arabidopsis (the lab-rat of plant biology). This similarity allowed scientists to model its structure and find that it has an oily surface suitable for binding lipids. The plant probably uses these lipids to form a waxy layer that keeps out pathogens like bacteria and fungi.
Future research will use the new knowledge of how to express genes in plant grains to improve the quality and nutritional qualities of cereal grains.
The research is the result of a collaboration between the Drought Biotechnology group led by Sergiy Lopato and the Structural Biology group led by Maria Hrmova. This article was written by Arwen Cross.
The authors on the paper were: Nataliya Kovalchuk, Jessica Smith, Natalia Bazanova, Tatiana Pyvovarenko, Rohan Singh, Neil Shirley, Ainur Ismagul, Alexander Johnson, Andrew S. Milligan, Maria Hrmova, Peter Langridge and Sergiy Lopato