DISCOVERY OF NOVEL SUSCEPTIBILITY GENES FOR FUSARIUM HEAD BLIGHT IN WHEAT

Abstract

Fusarium Head Blight (FHB) caused by Fusarium graminearum is a destructive disease of wheat and barley affecting both quantity and quality of grains. Several resistance genes contributing to partial quantitative resistance against FHB are known. Susceptibility genes facilitating infection and colonization by the pathogen on the other hand, have so far not been studied. With the long-term goal of manipulating such unconventional factors to enhance the resistance of plants, we discovered novel susceptibility genes for FHB in wheat using a multipronged strategy. Systematic Deletion bin mapping revealed a conserved gene on chromosome 7A to enhance susceptibility of plants to FHB. Forward genetic screening followed by greenhouse phenotyping of a chemically mutagenized population of wheat variety Jagger led to the discovery of eight variants with high FHB resistance, indicating loss of susceptibility in those plants. Manipulation of these susceptibility genes will provide a new way of enhancing genetic resistance of plants.