Supplemental Materials
Supplemental Figure S1 Pictures of 9-day-old wild-type rice seedlings and two biuret hydrolase overexpressing lines. From left to right: wild type and overexpressing lines B3-9-1 and B2-3-3. Upper: seedlings grown in the control culture solution. Lower: seedlings grown in the culture solution supplemented with 0.3 mmol L-1 biuret. Bars show 10 cm.
Supplemental Figure S2 Allantoin concentration in 9-day-old rice shoots measured by colorimetric and HPLC-UV. Plants were grown hydroponically under the three biuret treatments. Control: plants did not receive biuret; NB: plants were grown without biuret for three days after sowing, and with 0.3 mmol L-1 biuret supplemented in the culture solution from the fourth day; BN: plants were grown with 0.3 mmol L-1 biuret for 6 days after sowing and transferred to new culture solution without biuret on the seventh day. Fresh shoots of 9-day-old seedlings were ground under liquid N2 and extracted with 10-fold volume of distilled water. After centrifugation, the supernatant was used for allantoin determination. Gray boxes indicate mean allantoin concentration determined colorimetrically and black boxes indicate that determined by the HPLC method. Symbols indicate each sample. The statistical significance of the differences between the methods was determined through paired t-test (n = 2). ns: not significant.
Supplemental Figure S3 Relative expression levels of (a)OsALN and (b) OsUO in rice seedlings. Rice plants were hydroponically grown with or without 0.3 mmol L-1biuret supplied in the culture solution. Measurements were made using plants grown in an independent trial, as shown in Figure 5. The relative expression levels were normalized to those of Ubiquitin andActin1 and expressed on a log2 scale. Gray and black squares indicate control and biuret-treated plants, respectively; data represent the mean ± SD (n = 4). Asterisks indicate statistically significant differences between treatments at the time point (Welch’s t-test). *p < 0.05; **p < 0.01; ***p< 0.001.
Supplemental Data S1 Peak intensities in Metabolome analysis.