Molecular characterization of LMW-GS genes in Brachypodium distachyon L. reveals highly conserved Glu-3 loci in Triticum and related species
- Equal contributors
1 Key Laboratory of Genetics and Biotechnology, College of Life Science, Capital Normal University, 100048, Beijing, China
2 Institute of Crop Sciences, Chinese Academy of Agricultural Sciences/National Key Facility for Crop Gene Resources and Genetic Improvement, 100081, Beijing, China
3 Division of Plant Breeding and Applied Genetics, Technical University of Munich, D-85350, Freising-Weihenstephan, Germany
4 State Agriculture Biotechnology Centre, Murdoch University; Western Australian Department of Agriculture and Food, Perth, WA, 6150, Australia
BMC Plant Biology 2012, 12:221 doi:10.1186/1471-2229-12-221Published: 21 November 2012
Brachypodium distachyon L. is a newly emerging model plant system for temperate cereal crop species. However, its grain protein compositions are still not clear. In the current study, we carried out a detailed proteomics and molecular genetics study on grain glutenin proteins in B. distachyon.
SDS-PAGE and RP-HPLC analysis of grain proteins showed that Brachypodium has few gliadins and high molecular weight glutenin subunits. In contrast the electrophoretic patterns for the albumin, globulin and low molecular weight glutenin subunit (LMW-GS) fractions of the grain protein were similar to those in wheat. In particular, the LMW-C type subunits in Brachypodium were more abundant than the equivalent proteins in common wheat. Southern blotting analysis confirmed that Brachypodium has 4–5 copies of LMW-GS genes. A total of 18 LMW-GS genes were cloned from Brachypodium by allele specific PCR. LMW-GS and 4 deduced amino acid sequences were further confirmed by using Western-blotting and MALDI-TOF-MS. Phylogenetic analysis indicated that Brachypodium was closer to Ae. markgrafii and Ae. umbellulata than to T. aestivum.
Brachypodium possessed a highly conserved Glu-3 locus that is closely related to Triticum and related species. The presence of LMW-GS in B. distachyon grains indicates that B. distachyon may be used as a model system for studying wheat quality attributes.