– How are metals transferred from arbuscular mycorrhizal fungi to the host plant?
Arbuscular mycorrhizal fungi are key endosymbionts of over 80% of plants, being involved in plant mineral nutrition, and tolerance to biotic and abiotic stresses. They can provide over 50% of the host plant metal requirements when grown in metal-deficient soils. We are studying the metal transporters and the interface between the symbionts that mediate this transfer.
– How are metals shared with nitrogen-fixing rhizobia within the nodule?
Symbiotic nitrogen fixation carried out by the endosymbiosis of rhizobia with legumes requires relatively large amounts of already scarce metals to synthesize many of the key enzymes involved in the process. These nutrients have to be provided by the host plant and limit nitrogen fixation rates. We are studying the transporters that mediate metal exchange as a mean to increase N-fixation rates and contribute towards the efforts of reducing the use of polluting nitrogen fertilizers by improving biological nitrogen fixation.
– How do plants use metals to fend off pathogenic microorganisms?
Evidence in animals suggest that metals play a part in the innate immune response either by being sequestered, limiting access to growth-limiting nutrients, or by locally increasing their concentrations to toxic levels. We are currently studying how plants also use this strategy.