The origins and mechanisms of diversity in starch composition in wheat and wild relatives

SEUNG_J21DTP

We are looking for a motivated student to join the labs of Dr. David Seung (John Innes Centre) and Dr. Jemima Brinton (Royal Botanic Gardens, Kew) to work on an exciting collaborative project to uncover genetic factors controlling starch composition in wild grasses. The discovery of these factors could lead to novel strategies for improving the quality of cereal crops.

Starch is one of the most important resources that we obtain from plants. It is a major source of calories in our diet, and an important raw material for producing many essential non-food items. Starch is composed of two glucose polymers – amylopectin and amylose. The composition of starch (ratio between amylopectin and amylose) varies greatly between species, and between varieties of the same species. Starch composition has a major impact on crop quality as it affects the cooking and nutritional properties of starch.  However, the genetic control of starch composition is poorly understood.

In this project, we will exploit the vast collection of wild grasses at Kew to understand the genetic basis of variation in starch composition. Populations of wild species with established genome-wide association pipelines will be used to identify candidate genes that underpin the variation in composition. We will also examine polymorphisms in known genes encoding starch biosynthetic enzymes that affect starch composition, and the impact of these polymorphisms on enzyme function will be examined. Allele diversity at these genes will be compared between wild and cultivated species to reveal the effect of domestication on starch composition. The student will gain experience and knowledge in a broad range of techniques in bioinformatics, phylogenetics, genetics and biochemistry.

This interdisciplinary project provides an opportunity to train broadly at two leading plant science institutes, and to make fundamental discoveries that can contribute towards translational outcomes.

References:

Seung D (2020). Amylose in starch: Towards an understanding of biosynthesis, structure and function. New Phytologist doi:10.1111/nph.16858

Seung D, Echevarria-Poza A, Steuernagel B, Smith AM (2020). Natural polymorphisms in Arabidopsis result in wide variation or loss of the amylose component of starch. Plant Physiology 182(2): 870-881.