Research Questions

Plants do not live isolated, but in close interaction with beneficial and pathogenic microorganisms. This interaction has an effect on how plants control and share scarce, growth-limiting nutrients, such as metallic micro/oligonutrients (Fe, Cu, Zn, Mo,…). We are directing our efforts to address the following biological questions:

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.


Our goals

  • To have a complete view of how plant metal homeostasis modulates and is modulated by plant-microbe interactions, both when beneficial or prejudicial.

  • To translate the results obtained to the private sector.

  • To train researchers & technologists with skills in plant metal homeostasis and in plant-microbe interactions.

Research Projects

  • Diverting metals to Medicago truncatula nodules (2016 ‒ 2018)

    Ministry of Economy and Competitiveness grant AGL-2015-65866-P. Spanish Government. PI: Manuel González-Guerrero

  • Metal homeostasis in the tripartite symbioses arbuscular mycorrhizal fungi-legume-rhizobia (METALSYM) (2014 ‒ 2019)

    European Research Council Starting Grant 335284. European Union. PI: Manuel González-Guerrero

    Plants require transition metals (iron, copper, zinc,…) for most of their biological processes, from photosynthesis to seed production. However, they often grow in soils with low metal bioavailability. This has an impact on plant growth, crop yield, and… 

  • Transporte de metales al nódulo de Medicago truncatula (2013 ‒ 2015)

    Ministry of Economy and Competitiveness grant AGL-2012-32974. Spanish Government. PI: Manuel González-Guerrero

  • MtMTP2, MtZIP6, and MtCOPT1 role in metal transport into Medicago truncatula nodules (2013 ‒ 2015)

    Advanced Photon Source General User Proposal 34231. Argonne National Lab. U.S. Department of Energy. PI: Manuel González-Guerrero

  • Metal homeostasis in nodulated Medicago plants (MENOMED) (2011 ‒ 2015)

    Marie Curie International Reintegration Grant 276771. European Union. PI: Manuel González-Guerrero