Emploi
Identification, synthesis and chemical characterization of mating type hormones of the grapevine downy mildew pathogen (Plasmopara viticola)
The project focuses on the major crop pathogen Plasmopara viticola that causes grapevine downy mildew.
We aim to identify molecular mechanisms that are responsible for the induction of the sexual reproduction of P. viticola. In this species, mating occurs between diploid individuals of different mating-types (heterothallic species). The communication between mating-types through hormones production has been described in an oomycete model species, Phytophthora infestans, the agent of potato late blight. The structure and stereochemistry of the Phytophthora mating hormone, called the a1 hormone, has been well characterized by Qi et al. (2005). This hormone induced the production of sexual spores on the counter-mating type at a nanogram level. It has also been shown to be functional for other Phytophthora species (Tomura et al. 2017). Various synthesis pathways of this hormone involve lengthy syntheses with a number of steps ranging from 12 to 18, leading to very low overall yields.
The aim of this post-doctoral project is to contribute to the total synthesis of the a1 hormone in order to test its role in grapevine mildew reproduction. At the same time, we will seek to extract and isolate the specific hormone for grape downy mildew in crosses between strains of different mating types carried out in grapevine leaves.