Multiple chemical compounds from Mortierella hyalina, a root-colonizing fungus, promote plant performance

Background: We study the beneficial interaction between root-colonizing fungi and plants. Chemical compounds released by the microbes are recognized by root cells and induce a rapid (within 90 seconds) and transient increase in intracellular Ca2+ level. Genetic analyses of Arabidopsis thaliana mutants demonstrate that Ca2+ elevation is necessary for the proper response of the plant to beneficial fungi. We have recently identified a novel root-colonizing fungus, Mortierella hyalina, which promotes plant performance via at least 3 independent mechanisms: (a) induction of cytoplasmic Ca2+ elevation within 90 seconds in the host plants’ roots by two small molecules which are secreted by the fungus, (b) release of a fungal-born volatile compound(s), and (c) an endophytic N2-fixing bacterium that lives inside the fungal cell. The goal of this project is to investigate the molecular mechanism of the beneficial symbiosis between the plant roots and the fungus and to unravel signaling events leading to better plant performance in M. hyalina-colonized Arabidopsis plants.

Project Description: The project studies the three levels of interaction between M. hyalina and Arabidopsis roots. At least three fungal compounds participate in the beneficial interaction of Arabidopsis thaliana with the root-colonizing fungus M. hyalina. (1) rapid cytoplasmic Ca2+ elevation induced by fungal compound(s), (2) a volatile and (3) the reduced N from an N2-fixing bacterium living in the fungus.

1. The two compounds which induce Ca2+ elevation in Arabidopsis roots and are released by the fungus into the rhizosphere will be chemically characterized. Early reversible phosphorylation events elucidated in and around the root plasma membrane will be identified with molecular and biochemical tools and the phosphorylated proteins characterized by reverse genetics and biochemistry.
2. The perception of the fungal volatile in Arabidopsis should be elucidated by a forward genetic screen with Arabidopsis mutant populations. Downstream signaling events induced by the volatile will be analyzed by –omics approaches.
3. The N2-fixing bacterium living in M. hyalina will be characterized by genome sequencing, 15N-labeling experiments and metabolite profiling in Arabidopsis roots.
About us: We offer a stimulating and dynamic working environment as well as excellent, state-of-the-art research facilities. The project is integrated in a long lasting cooperation between the two groups localized at the University and the MPI-CE. The successful candidate will be part of this consortium, interacts with PhD students and Postdocs at both institutions and will be supervised by the two PIs.

Candidate profile:
• A strong background in plant physiology, molecular biology and genetics
• Demonstrated expertise in molecular and genetic techniques
• Previous work with model plants is a plus
• Scientific and critical attitude
• Curiosity, creativity, and ambition
• Excellent time management and organizational skills
• Ability to interact with other scientists in the group
• Good communication skills
• Proficiency in written and spoken English