Understanding how plants make starch

Starch is the main carbohydrate in our diet, it is a major component of many staple crops, such as cereal grains and potato tubers.

It is the primary form of carbohydrate storage in plants, and can be found in the leaves, seeds and storage organs of most plants. Starch is also one of the most abundant and important biopolymers on the planet, used to make many products such as paper, textiles, building materials, biodegradable plastics and pharmaceuticals.

The Molecules from Nature ISP hosts three research groups dedicated to starch research – the labs of Alison Smith and David Seung at the John Innes Centre; and Brittany Hazard, across the John Innes Centre and Quadram Institute.

One of our current research goals is to understand how plants make starch. By studying starch biogenesis and its roles in plant metabolism, we can identify pathways and genes which could be modified to improve processing and nutritional qualities of major staple crops.

Starch is a polysaccharide composed of repeating units of glucose. It is made up of two components: amylopectin and amylose which assemble to form starch granules that are complex in structure.

Our research in the Molecules from Nature ISP aims to understand the formation of these starch granules. Using the available mutant resources in both model and crop species, as well as natural variation, we aim to identify genes that control the number, size, shape and composition of these granules.

We also use our knowledge to produce novel wheat varieties with modified polymer structure and/or granule morphology with a focus to improve the nutritional properties of this staple crop.

For instance, we hope to find a genetic variant which gives wheat a reduced glycaemic index (GI), a trait that may help in combating obesity and type-2 diabetes. We are also looking for genetic variants with altered physical and chemical properties of starch and testing their potential to improve the quality of various food and non-food products