Functional analysis of theFusarium culmorumgenome: gene silencing, transposon tagging and gene knock-out by homologous recombination

F. culmorumis an important cereal pathogen having a widespread distribution and able to produce mycotoxins dangerous to humans and animals. The genome ofF. culmorumis being sequenced but for many genes the function is yet unknown. A high-throughput strategy for gene identification and for functional genomics analysis is needed. In this project we evaluated the efficiency of 3 complementary approaches to explore theF. culmorumgenome. A silencing approach was adopted to downregulatingTRI6gene which regulates the expression of multiple biosynthetic genes. This demonstrated that the type B trichothecenes play an important role as virulence factors in the crown and foot rot (CFR) disease of durum wheat caused byF. culmorum. Hence, this biosynthetic pathway can be regarded as a suitable molecular target for the development of new CFR control tools. The deletion ofFcstuA, a member of APSES protein inF. culmorum, enabled to understand its role in CFR pathogenicity, in the biosynthesis of pectolytic enzymes such as polygalacturonase and in the main metabolic or morphological processes regulating the biological cycle of thefungus. Random mutagenesis performed by themimp1/impaladouble-component system allowed a complete vision ofF. culmorumgenome suggesting a valuable exploratory role of this tool. Our results demonstrate that the 3 approaches are useful tools to improve the knowledge onF. culmorumgenome and offer new insights for future studies.