Identification of Proteomic Components Associated with Resistance to Fusarium Head Blight in Rye

Abstract

Rye was used here to dissect molecular mechanisms of resistance to Fusarium head blight (FHB) and to go deeper with our understanding of that process in cereals. F. culmorum-damaged kernels of two lines different in their potential of resistance to FHB were analyzed using two-dimensional gel electrophoresis and mass spectrometry to identify resistance markers. The proteome profiling was accompanied by measurements of ${\alpha}-$ and ${\beta}-amylase$ activities and mycotoxin content. The proteomic studies indicated a total of 18 spots with clear differences in protein abundance between the more resistant and more susceptible rye lines after infection. Eight proteins were involved in carbohydrate metabolism of which six proteins showed a significantly higher abundance in the resistant line. The other proteins recognized here were involved in stress response and redox homeostasis. Three remaining proteins were associated with protease inhibition/resistance and lignin biosynthesis, revealing higher accumulation levels in the susceptible rye line. After inoculation, the activities of ${\alpha}-$ and ${\beta}-amylases$, higher in the susceptible line, were probably responsible for a higher level of starch decomposition after infection and a higher susceptibility to FHB. The presented results could be a good reference for further research to improve crop resistance to FHB.

Fig. 1. The single representative 2-DE protein maps of rye kernels in the control conditions (C) and after Fusarium culmorum infection (FDK - Fusarium-damaged kernels) 2-dimensional electrophoresis for the line more resistant (R) and more susceptible (S) to Fusarium head blight. The spots with differentially accumulated (P ≤ 0.05) proteins (1-18) between both analyzed lines, are numbered.

Fig. 2. Comparison of α-amylase (A) and β-amylase (B) activity in the kernels of rye S (line more susceptible to Fusarium head blight) and R (line more resistant to Fusarium head blight) after Fusarium culmorum infection (FDK – Fusarium-damaged kernels) and in control conditions (HLK – healthy looking kernels). The enzyme activity was expressed in Ceralpha Units (CU) per gram of flour. The means of three biological replicates and standard deviation bars are shown. Values marked with the same letter did not differ at a significance level of 0.05 (Fisher’s LSD-test).

Table 1. The components of the resistance to Fusarium head blight in the more resistant (R) and more susceptible (S) rye lines and their yields under control conditions

Table 2. Fusarium culmorum biomass in the kernels of more resistant (R) and more susceptible (S) rye lines [mg/g]

Table 3. The results of MS analysis performed on the spots that showed at least a 2.0 ratio (P ≤ 0.05) in protein abundance between the more resistant and more susceptible rye lines