Figure 3 Relative expression of genes related to purine degradation and ureide metabolisms in roots and shoots of 4 to 7-day old rice seedlings. Rice plants were hydroponically grown under the control condition and 0.3 mmol L-1 biuret toxicity. (a-h) Relative expression levels of OsXO (a), OsUO (b),OsALNS (c), OsALN (d), OsUPS1 (e), OsUPS2(f), and OsUPS3 (g). The expression levels were normalized to the expression of Ubiquitin and Actin1 and expressed in log2 scale. Gray and black symbols indicate control and biuret treated samples, respectively. Crossbars indicate means of the three samples. (h) Allantoin concentration in 8-day-old seedlings. Ten plants were combined for a single sample. Boxes indicate mean of three samples, and symbols indicate each sample. Asterisks indicate statistically significant difference between the treatments at the time point (Welch’s t-test). *p < 0.05; **p < 0.01; ***p < 0.001.