Researchers from CBGP of UPM discovered a symbiotic association between an endophytic fungus and the plant Arabidopsis thaliana, which could lead to a more sustainable agriculture.
The research group of Soledad Sacristán, from Centro de Biotecnología y Genómica de Plantas (CBGP(UPM-INIA)) of Universidad Politécnica de Madrid (UPM), has cooperated with Max Planck Institute from Germany in a paper published in CELL journal, which demonstrates, for the first time, the symbiotic association between the plant Arabidopsis thaliana and an endophytic fungus (Colletotrichum tofieldiae). This symbiosis, unknown till now, improves the crop capacity to grow and it could contribute to decrease the use of inorganic fertilizers, helping to reach a more sustainable agriculture.
Plants grow more and better when they establish symbiotic associations with microorganisms that improve its capability to absorb water and nutrients, protect them from stress or increase pest resistance. Mycorrhiza fungi are the most common symbiotic microorganisms related to plants. Mycorrhizas make huge mycelium nets all around plant roots and help them to absorb phosphorus from the ground, which is one of the most important macronutrients for plants.
Plants belonging to Brassicaceae family, such as colza, cauliflower, mustard or Arabidopsis thaliana, are not able to associate with mycorrhizas. Soledad Sacristán and her team, isolate the endophytic fungus Colletotrichum tofieldiae from wild plants of Arabidopsis thaliana in Spain. They discovered that Colletotrichum tofieldae makes a natural mutualism with Arabidopsis thaliana, as plants inoculated with this fungus produce more fruits and seeds than the control plants. In collaboration with researchers from Max Planck Institute, they found that Colletotrichum tofieldae colonizes the whole plant starting with roots. The fungus transmits phosphorus to leaves and stems, fostering growing and improving plant fertility in conditions of lack of phosphorus.
Colletotrichum tofieldiae is not a mycorrhiza, but it is a sort of fungus called endophytic (fungi that grow inside a plant without causing disease symptoms), and it carries out a function similar to the one performed by mycorrhizas.
Although Colletotrichum tofieldiae exists in several parts of the World, it has been in Spain where it has been detected for the first time in association with Arabidopsis thaliana. Soledad Sacristán and her team have found a high presence of this fungus in different wild populations of Arabidopsis thaliana from the centre of Spain, in places whose soil is poor in phosphorus. This discovery generates new expectations regarding the implementation of microorganisms to improve crop growing, reducing the use of inorganic fertilizers and fostering a more sustainable agriculture that respects the environment.
Kei Hiruma, Nina Gerlach, Soledad Sacristán, Ryohei Thomas Nakano, Stéphane Hacquard, Barbara Kracher, Ulla Neumann, Diana Ramírez, Marcel Bucher, Richard J. O’Connell, Paul Schulze-Lefert. Root Endophyte Colletotrichum tofieldiae Confers Plant Fitness Benefits that Are Phosphate Status Dependent. Cell Journal, 17 March 2016. DOI: http://dx.doi.org/10.1016/j.cell.2016.02.028