To investigate the effects of the Pi application, wild-type rice plants (WT) were grown under six different Pi levels ranging from 0.06 to 3.0 mM (Figure 1). Compared to the low-Pi and control-Pi treatments (0.06 and 0.6 mM), higher Pi application (above 1.2 mM) caused chlorosis and necrosis at the tip of the leaf blade (Figure 1a). Such a phenomenon has been observed previously in rice plants that accumulate excess Pi (Aung et al., 2006; Wang et al., 2009; Liu et al., 2010). The plant height was not affected by Pi application (Figure 1b). The Chl content of the leaf blade was the highest in the plants treated with 0.06 mM Pi and decreased gradually with increasing Pi application (Figure 1c). The total dry weight including roots was reduced in the 0.06 mM Pi treatments, and Pi applications higher than 1.2 mM further decreased the dry weight (Figure 1d). The leaf sheath weight was the most susceptible to an increase in Pi application, and Pi levels higher than 1.8 mM significantly decreased the leaf sheath weight compared to the control-Pi treatments (Figure 1d).