Differential gene expression profiles induced by Fusarium graminearum in the resistant durum wheat line LDN(Dic-3A)10

Fusarium head blight (FHB), caused by Fusarium graminearum, is a wheat disease that leads to economic losses due to reduced grain yield and quality together with rejection or downgrading of grain at marketing due to contamination by mycotoxins. Environmental temperature and humidity during flowering affect the onset of the infection. Resistance to FHB is quantitatively inherited, but is the result of the combined effect of several genes. Thus, development of resistant cultivars has been difficult because of the complex inheritance of resistance and confounding environmental effects. The RICL LDN(Dic-3A)10 (Langdon durum wheat background substituted by a T. dicoccoides chromosome 3A fragment) showed resistance to FBH. We postulate that the responsible genes could be induced by the presence of the pathogen. Thus, changes in gene expression profiles subsequent to artificial inoculations with F. graminearum were analyzed by ADNc-AFLP technique. Artificial infections were performed in housegreen at in spikes at early anthesis. Total RNA was extracted from spikes at 0, 6, 48 and 72 hs post inoculation, followed by DNAc and second strand synthesis. Then, samples were digested with PstI and MseI, the adaptors were ligated, and preselective (PstI+0, MseI+0) and selective (PstI+CG, MseI+CG) amplifications were conducted. The assay was also performed for Langdon genotype. Time dependent pathogen-induced changes in the expression profiles were detected in both genotypes. Nevertheless, differences between susceptible and resistant genotypes profiles were evidenced. Such differences could correspond to genes responsible for resistance. Cloning and sequencing of the amplification bands would reveal the identity of the involved genes.