Comparison of barley seed proteomic profiles associated with fusarium head blight reaction

Fusarium head blight (FHB) incited primarily by Fusarium graminearum Schwabe, is a destructive disease that affects the quality and yield of barley (Hordeum vulgare L.) grain. At present, there is a limited understanding of the molecular mechanisms involved in barley resistance against infection by and the spread of F. graminearum. The objective of the current study was to identify proteins that were differentially expressed in FHB susceptible and resistant barley accessions. Mature seed from six barley accessions and five pairs of barley sister lines differing in FHB reactions were subject to proteome analysis by two-dimensional gel electrophoresis (2DE). Coomassie Brilliant Blue staining visualized about 1000 seed protein spots of pI 4-7 on 2DE gels. Proteins were identified by liquid chromatography and tandem mass spectrometry (LC-MS/MS) sequencing after in-gel digestion by trypsin. In our first study, we compared the 2DE seed protein profiles of two FHB susceptible varieties 'AC Lacombe' and 'Stander' with four partially FHB resistant barley accessions CI4196, 'Chevron', 'Penco/Chevron' and I92130. One hundred and seventy-one protein spots differed in abundance between the six barley accessions. Ten proteins were identified from 19 protein spots with different abundance between resistant and susceptible FHB barley genotypes. In our second study, we compared the 2DE seed protein profiles from five pairs of sister lines differing in FHB resistance. Ninety-seven protein spots differed in abundance between the five pairs of sister lines. Ten proteins were identified from 20 protein spots with different abundance between resistant and susceptible sister lines. In total, 11 proteins were identified as associated with plant disease or stress resistance. Proteins identified at higher abundance in seed from resistant barley lines included alpha amylase inhibitor (BDAI-1), aldehyde dehydrogenase (BIS1), aconitate hydratase, and NADP dependent malic enzyme. The knowledge gained in the current study will be used to aid the development of an in vitro test to screen barley lines for FHB resistance.