Submitted to: International Congress on Molecular Plant-Microbe Interactions
Publication Type: Proceedings
Publication Acceptance Date: February 22, 2007
Publication Date: July 22, 2007
Citation: Skadsen, R.W., Henson, C.A. 2007. Metabolic profiling of early F. graminearum infection in barley seed spike tissues. In: Proceedings of XIII International Congress on Molecular Plant-Microbe Interactions, July 21-27, 2007, Sorrento, Italy. Paper No. PS10-459. CDROM. Technical Abstract: Several studies have utilized microarray analysis to characterize gene expression occurring during infection of barley and wheat by the fungal pathogen Fusarium graminearum (F.g.). We have analyzed this plant-microbe interaction from the other extreme - the changes in the metabolome arising from these expressed genes. Spikes of intact barley plants (Morex cv.) at the early dough stage were immersed in spore suspensions of F.g. Controls were mock inoculated in water. At 24, 48 and 72 h after inoculation, lemma and epicarp outer seed tissues were collected and frozen. Lemmas and, especially, epicarps were previously found to be susceptible routes of infection. Metabolic profiling was done by gas chromatography-mass spectrometry. By 72 h after inoculation, the metabolic profiles of infected tissues were distinctly different from those of control tissues. Differences were also seen by 48 h, but these were less pronounced. Analysis of protein synthesis indicated that these differences were not due to disruption of protein synthesis or protein degradation. Very light growth of F.g. could be detected by GFP fluorescence by 24 h. New protein synthesis, as well as the loss of specific proteins, could be detected at this early stage. Additional changes occurred through 72 h. There was no indication of protein degradation, decrease in methionine incorporation or disrupted protein synthesis due to infection.