description
- Current models predict that the world's population will reach 9 billion by 2050 and that crop yields will need to increase by 70-100% to sustain the population growth. Wheat is the UK's most highly grown cereal, with high average yields in comparison with the world average. However, there are concerns that rates of wheat yield increases have now stalled. In contrast, Brazil is currently a net wheat importer, but recent initiatives, including the cultivation of wheat in tropical savannah areas (the Cerrado), aim to increase production and productivity so that Brazil will initially become self-sufficient in wheat production and eventually an exporter of this globally important crop. Developing improved and advanced sustainable wheat production methods, therefore, is a priority research area for both countries, as evidenced by the joint wheat research programme between Embrapa and BBSRC. Current intensive agricultural practices that depend on unsustainable levels of inorganic fertilisers, pesticides and other chemical inputs are environmentally damaging and unsustainable - it is clear that expansion of these agricultural practices to meet future needs is not economically or environmentally feasible and so we urgently need to explore other options to meet the global food security challenge. Plants are colonized by an astounding number of microorganisms that can reach cell densities much greater than the number of plant cells. Recent research has found that soil microbes benefit crop plants in a number of ways, including improved plant nutritional status and disease suppression. However, the exact nature of these communities and the microbial partners required are poorly understood, let alone the mechanisms by which they benefit host plants. As such, it is important that we determine how the soil microbial community influences wheat plant health to achieve sustainable intensification of production. Determining the optimum composition of soil microbiomes associated with plants, especially the root systems (the rhizosphere), to inform sustainable soil management strategies represents a novel and unique strategy to boost plant growth and health that has not previously been attempted. The rhizosphere microbiome can provide a range of functions to sustain plant development such as: nitrogen fixation, nutrient solubilisation or defence against pathogens. However, elucidation of the mechanisms underlying beneficial interactions between microbes and plants are not well understood. Understanding these mechanisms will be key to developing the rhizosphere microbiome for sustainable wheat production, and is central to the work planned in this proposal. In this project, we will elucidate the relative importance of the host plant (both modern and ancestral wheat) in terms of genotype and root chemistry, as well as farming practices such as crop rotation and fertilisation regime, in shaping the wheat rhizosphere microbiome. The microbiome will be assessed using meta-genomic and meta-transcriptomic techniques; whereas the plant host genotype will be determined using diversity arrays technology and plant root chemistry through metabolomics. We will also identify keystone members of the rhizosphere microbiome through 'proof of principle' experiments to assess how manipulation of the microbiome structure influences plant performance. As such, we will obtain a holistic understanding of the factors influencing the microbiome structure, as well as how the microbiome influences both crop health and yield - both of which are required to optimise microbiome function for enhanced plant production in a sustainable manner.