Enhancing endosymbiotic interaction to increase crops production
Nitrogen (N) and phosphorous (P) are essential for all aspect of plant growth. As a paradox, they are poorly available in soil, leading to extensive use of fertilisers to fulfil the demand of a growing population. However, this agronomical practice is detrimental to the environment. To exploit N and overcome P starvation, numerous plant families interact with mutualistic root-endosymbionts such as nitrogen-fixing bacteria with legumes, or phosphate-delivering arbuscular mycorrhiza (AM) with the 80% of land plants. Despite the benefit of these endosymbioses, P and N fertilizers reduce AM and nitrogen-fixing bacteria endosymbioses. In addition, climate change impact endosymbioses with a decrease in nitrogen-fixing symbiosis at high temperature, in acidic and saline soils. Therefore, it is imperative to develop novel strategies to enhance endosymbioses in crops and optimize N and P nutrition under global warming.

The success of root endosymbioses relies on the molecular dialogue between symbionts and plants. One of the core functions of this dialogue is to stimulate the release of calcium by the plant nucleus to switch on the symbiotic program. This calcium release is mastered by the cyclic nucleotide gated channels (CNGC)15. A recent Mtcngc15c-easy allelic variant discovered in the proposed laboratory presents spontaneous calcium release and increase of nodulation and mycorrhization. My objectives are to reveal the effect of CNGC15c-EASY mutation on the channel activity and symbioses, and use this knowledge to translate this system into crops. In addition to discover a novel strategy to improve plant production, this work will give me training in plant biology technics and structural biology. Simultaneously, the project will benefit from my expertise in microbiology. Finally, the work in the proposed destination centre will also provide me a valuable international network and skills for my future career.