2D-DIGE reveals changes in wheat xylanase inhibitor protein families due to **Fusarium graminearum** <tex>$\Delta Tri5$</tex> infection and grain development
Faculty of Sciences. Biology
Faculty of Sciences. Mathematics and Computer Science
Proteomics. - Weinheim
, p. 2303-2319
University of Antwerp
Wheat contains three different classes of proteinaceous xylanase inhibitors (XIs), i.e. Triticum aestivum xylanase inhibitors (TAXI), xylanase inhibiting proteins (XIP), and thaumatin-like xylanase inhibitors (TLXI), which are believed to act as a defensive barrier against phytopathogenic attack. In the absence of relevant data in wheat kernels, we here examined the response of the different members of the XI protein population to infection with a Tri5 mutantof Fusarium graminearum, the wild type of which is one of the most important wheat ear pathogens, in early developing wheat grain. Wheat ears were inoculated at anthesis, analyzed using 2D-DIGE and multivariate analysis at 5, 15, and 25 days post anthesis (DPA) and compared to control samples. Distinct abundance patterns could be distinguished for different XI forms in response to infection with F. graminearum Tri5. Some (iso)forms were up-regulated, while others were down-regulated. This pathogen specific regulation of proteins was mostly visible at 5 DPA and levelled off in the samples situated further from the inoculation point. Furthermore, it was shown that most identified TAXI- and XIP-type XI (iso)forms significantly increased in abundance from the milky (15 DPA) to the soft dough stages (25 DPA) on a per kernel basis, although the extent of increase differed greatly. Non-glycosylated XIP forms increased more strongly than their glycosylated counterparts.