二穗短柄草低分子量谷蛋白亚基基因的分子特征

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 showed that Brachypodium has few gliadins and high molecular weight glutenin subunits, but possessed similar wheat electrophoretic patterns in albumins, globulins and low molecular weight glutenin subunits (LMW-GS) compositions. In particular, the LMW-C type subunits in Brachypodium were more abundant than these 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, MALDI-TOF-MS, respectively. Phylogenetic analysis indicated that Brachypodium was closer to Ae. markgrafii and Ae. umbellulata than to T. aestivum.