Kei Hiruma / Nara Institute of Science and Technology
In nature, plants often rely on root-associated beneficial fungi for uptake of nutrients from soils. It has been extensively studied some of the beneficial fungi during interactions with the hosts in controlled laboratory conditions to dissect molecular mechanisms underlying the beneficial interactions. It is, however, poorly understood whether and if so how these beneficial fungi influence plant growth in a field condition, where both fungi and hosts are influenced by fluctuating environments and also by other microbiome.
The ascomycete fungus Colletotrichum tofieldiae (Ct) colonizes roots of non-mycorrhizal Brassicaceae plants including Arabidopsis thaliana without causing disease and promotes plant growth under low-phosphate (Pi) conditions via transferring phosphorus to plants (Hiruma et al., Cell 2016).
Here, we report that Ct promotes several Brassicaceae vegetables in an open field condition in different seasons. The plant growth promotion by Ct is specifically observed in conditions without adding a conventional chemical fertilizer. Interestingly, by measuring soil nutrients, we found that plant available Pi abundantly exists even in the absence of the chemical fertilizer, suggesting that Ct-mediated plant growth promotion in field is not mediated by phosphorus transfer via Ct hyphae. In this presentation, I would like to propose a model how Ct-mediated plant growth promotion occurs in field by introducing bacterial microbiota as players.