Oral Presentation 25th Annual Lorne Proteomics Symposium 2020

Proteogenomic characterization of einkorn wheat cultivars with low celiac disease response (#14)

Angela Juhasz 1 , Mitchell Nye-Wood 1 , Zsofia Birinyi 2 , Gyongyver Gell 2 , Michelle Colgrave 1
  1. Edith Cowan University, Joondalup, WESTERN AUSTRALIA, Australia
  2. Applied Genomics, Centre for Agricultural Research, Martonvasar, Hungary

Wild wheat species and wheat genome donors represent an important source in breeding wheat with altered gluten content and composition. Previously, nearly 200 wild and cultivated einkorn accessions have been characterized. Gluten protein content has been measured using gluten specific G12 and R5 monoclonal antibodies in commercial sandwich ELISA methods. Genotypes with significantly lower gluten (below 500 ppm) content compared to bread wheat have also been analysed for gluten-specific IgA and IgG antibody response using human blood sera collected from celiac diseases (CD) patients. Altogether four genotypes have been identified as potentially suitable for low gluten breeding programs of which two cultivars showed relatively stable expression pattern across environments. These lines were grown, harvested and milled in a confirmed gluten-free environment.

In this study we aim to explore the differences at the genetic and protein levels of these genotypes in order to understand the variation in gluten protein composition and to explain the potentially low CD response. Grain proteomes of seven Triticum monococcum cultivars and one bread wheat were compared using information dependent data acquisition and SWATH-MS analysis. Transcriptome data collected from developing seeds of the two low CD responsive genotypes at 20 days post-anthesis was used to relate the cultivar specific allelic information to the expressed protein characteristics. Although a significant variation was observed in the detected number of gluten proteins when T. monococcum accessions were compared to the bread wheat cultivar, there was no significant variation in the number of gluten proteins within the T. monococcum cultivars. Mapping of the RNAseq read data confirmed the presence of the major gluten protein genes, however a significant variation was observed in their expressed amounts. In this presentation, we provide an insight in the unique genetic characteristics of these T. monococcum accessions by exploring the expression differences observed in the gluten proteins and their regulating genetic factors.