Saffron-Fusarium oxysporum R1 dual transcriptomics unravels, defense mechanism of saffron and robust pathogenicity of Fusarium oxysporum R1

Abstract Fusarium oxysporum causes corm rot in saffron (Crocus sativus L.), that is one of the most important fungal diseases impacting saffron yield globally. Despite the fact that the corm rot agent and its symptoms are widely known, little is known about the molecular basis of defense mechanism of saffron in response to Fusarium oxysporum infection. Therefore, the current study was initiated in order to identify differentially expressed genes in response to pathogen infection in saffron. The active participation of Mitogen Activated Kinase pathway (MAPK), Transcription factors (TFs), plant-hormone signalling, plant-pathogen interaction pathway and synthesis of PR proteins in defence of saffron against Fox R1 infection was revealed by Gene Ontology, KEGG pathway and MapMan analysis. In this study, the PR proteins had shown a robust antifungal activity. These findings revealed that the saffron has a powerful defense mechanism in the early stages of infection. In addition, fifty seven Fusarium oxysporum R1 genes linked to pathogenicity and virulence that expressed during the infection phase were also identified. Surprisingly, SIXgenes (secreted in the xylem) were not found in the current investigation, although these genes have been thoroughly described in other Fusarium oxysporum strains and are known to be one of the key virulence factors. Because saffron is a male sterile plant that can only be improved genetically by genome editing, this work will serve as a foundation for identifying genes that can be used to create saffron varieties resistant to Fox infection.