Epsilon Archive for Student Projects

Abstract

Verticillium longisporum is responsible for severe yield losses, especially of oilseed
rape (Brassica napus). Rapeseed is the third most important source of vegetable oil
worldwide. The need to increase rapeseed oil yield is not only because is a source
of healthy vegetable oil but also because it is used as a biodiesel. The control of
Verticillium longisporum has been limited since this pathogen forms special resting
structures that survive in the soil for a long time and under harsh environment,
showing also delayed expression of symptoms. Volatile secondary metabolites
exuded by plant roots have been involved in plant-plant and plant-herbivore
signalling, while they affect fungal behaviour. For example, monoterpenes display
strong inhibitory or stimulatory activities on fungi. Previous analysis showed that a
group of V. longisporum genes are highly induced during application of
monoterpenes. In this study, RT-qPCR analysis of V. longisporum genes exposed
to terpenes produced by rapeseed plants, previously identified by RNAseq analysis
upon infection of rapeseed showed to be induced. Consistent with the previous
results, the Arabidopsis monoterpene mutant AT5G44630 (sesquiterpene synthase)
was more tolerant to Verticillium infection, suggesting an involvement of this gene
in disease development. An in vitro experiment showed that fungal biomass was
lower in mutant Arabidopsis lines compared to the wild type (WT) plants. Finally,
to produce rapeseed resistant plants to V. longisporum a clustered regulatory
interspaced short palindromic repeats (CRISPR/Cas9) construct to was generated
to produce rapeseed plants lacking the homologous AT5G44630 gene.