Understanding the role of secretion in phosphate uptake in plants

Our motivation is to facilitate the development of crops that are more efficient in the uptake of phosphate (P), an essential macronutrient, and reduce dependency on limited P fertilizers. We intend to determine the mechanisms of protein secretion and membrane trafficking in roots that underlie differences in phosphate mobilisation in plant roots. Phosphorus is an essential macronutrient for all organisms because it is a fundamental constituent of phospholipids, nucleic acids, and numerous other compounds within cells. Plants are the basis of our food supply and globally crop growth is frequently limited by P availability, therefore, farmers frequently apply P fertilisers. Plants have evolved mechanisms to cope with low soil P availability, however, these have not necessarily been transferred to high input dependent crops. Understanding these mechanisms and improving their efficiency in domesticated crop species is critical to developing crops suitable for sustainable intensification of our agricultural systems. Plants use physiological changes to increase P mobilisation and acquisition from the soil, such as secretion of protons and acid phosphatases including those with phytase activity, and the exudation of carboxylic acids to supply root rhizosphere microbe populations with carbon.
We will use a combination of plant physiological assays, in conjunction with biochemical assays and proteomics and targeted metabolomics to identify critical differences between varieties of Brassica plants that are efficient, or inefficient, in uptake of P under conditions of low availability.