Identification of regulatory pathways controlling cell differentiation during barley grain development

Aubert MK1, Shirley NJ1, Houston K2, Burton RA1 and Tucker MR1

  1. School of Agriculture, Food and Wine, University of Adelaide, Waite Campus, Urrbrae, South Australia, Australia.
  2. Cell and Molecular Sciences, The James Hutton Institute, Dundee, UK.

Barley is a diploid cereal crop used in the feed and brewing industries. The benefits of the barley grain are derived mainly from the endosperm, which is produced after fertilisation. During early stages of seed development, the endosperm differentiates along a radial axis to form two prominent cell types; the peripheral aleurone and the inner starchy endosperm. We have been studying early grain development in barley with a view to understanding how aleurone differentiation is regulated. Microscopic assays were used to measure sub-epidermal details of grain development in a panel of ~200 barley cultivars. Association mapping identified multiple genomic regions that contribute to variation. Candidate genes underlying variation in aleurone development were identified using a combination of RNAseq profiling, laser capture microdissection and plant transformation. The results of these assays will be discussed. The fundamental knowledge generated in this project is providing insight into how different tissues and cells contribute to grain development. This knowledge may be applied in future to tailor specific improvements in grain composition.