Phosphorus (P) is one of the least available macronutrients to plants in soils, and P limitation is therefore a major constraint to crop productivity. Phosphate rock, as a source for P fertilizer, is non-substitutable (Vance, 2001). Therefore, agriculture needs to increase the efficiency with which P is acquired and used. There are two major ways to enhance P acquisition efficiency, viz., (a) plant breeding for root traits that allows improved acquisition of P, such as longer and denser root hairs, more efficient root architecture, higher specific root length and production of organic anions (carboxylates) or phosphatases (Lynch, 2007) and (b) harnessing the mutualistic relation between crops and arbuscular mycorrhizal fungi (AMF), which form symbiotic relationships with about 80% of higher plants (Smith & Read, 2008). AMF play a major role in enhancing uptake of immobile nutrients, such as P, from the soil, transferring these nutrients to plants in exchange for photosynthetic carbon (C).