Response to Fusarium in near-isogenic lines harboring resistance QTLs Fhb1 and Qfhs.ifa-5A

Resistance mechanisms of wheat to Fusarium graminearum are still poorly understood. Multiple reports have investigated transcriptomic differences between resistant and susceptible genotypes. To investigate the genetic determinants underlying the two major contributor QTL Fhb1 and Qfhs.ifa-5A, we generated a set of near-isogenic lines, that we have used for transcriptomic studies using the Affymetrix wheat GeneChip: 4 near-isogenic lines (BC5F2) derived from a cross of CM82036 and cv Remus (susceptible recurrent parent) and the resistant parent CM82036 have been inoculated with Fusarium spore suspension or water as control at anthesis. Samples have been taken at 3 timepoints 8, 24 and 72 hours after inoculation. Five wheat heads per condition were pooled into one sample, that has been used for RNA preparation. Including 3 replicates a total of 90 microarrays have been hybridized. Our results identify a wide variety of genes (631 transcripts) that are differentially regulated for Fusarium graminearum in all genotypes after 72 h and 339 genes that are upregulated only in lines without Qfhs.ifa.5A. Few genes were found differentially regulated for Fusarium and QTL. Many interesting candidates emerge from the set of QTL-specific genes that are constitutively expressed when comparing water-treated samples. ****[PLEXdb(http://www.plexdb.org) has submitted this series at GEO on behalf of the original contributor, Wolfgang Schweiger. The equivalent experiment is TA41 at PLEXdb.]

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