ABSTRACT

Distribution and availability of water and nutrients in the soil vary with time and space (Hodge 2006). e adaptation of a plant’s root architecture by the initiation and elongation of lateral roots is an important strategy used by plants, being sessile organisms, to cope with the changing nutritional conditions (Malamy 2005; Hodge et  al. 2009). e de novo formation of lateral roots allows the plant to explore the soil and to proliferate into nutrient-rich patches. Alternatively, plants can save energy by inhibiting elongation of lateral roots in regions where water and nutrients are scarce, while maintaining primary root growth to reach underground resources (Deak and Malamy 2005; Malamy 2005). When competing with other plants for the acquisition of immobile ions as phosphate, extensive branching oers great advantage (Fitter et al. 2002).