Table 2 Plant height and chlorophyll content of overexpressing
wild-type (WT) and biuret hydrolase - rice plants under the effect
of biuret toxicity. Biuret treatment (0.3 mmol L-1)
was started two days after sowing, and nine plants were harvested. Two
transgenic lines, B3-9-1 and B2-3-3-3, were grown in separate
experiments. Values are expressed means ± SD.
Line Biuret Plant height Chlorophyll content Number of
(mmol L-1) (cm) (µg / mg FW) plants
WT 0 18.9 ± 1.05 3.43 ± 0.19 16
0.3 18.2 ± 1.40 n.s. 1.81 ± 1.10 * 13
B3-9-1 0 19.3 ± 1.14 3.10 ± 0.31 16
0.3 20.5 ± 1.10 * 3.46 ± 0.28 * 12
WT 0 19.0 ± 1.39 2.80 ± 0.27 12
0.3 16.3 ± 2.18 * 1.01 ± 0.80 * 12
B2-3-3-3 0 19.3 ± 1.29 2.89 ± 0.39 16
0.3 20.3 ± 1.41 * 3.14 ± 0.41 n.s. 16
Asterisks indicate significant differences between biuret treatments
(p < 0.05, Student’s t-test).
n.s.: not significant
Table 3 Biuret-derived 15N in shoots ofbiuret hydrolase overexpressing rice plants. Nineteen-day-old
seedlings were exposed to 0.3 mmol L-115N-biuret for 48 hr. Two plants were maintained in a
40-mL vial. Values are expressed means ± SD (WT: n = 2, B2-3-3-11 and
B3-9-1-5: n = 3).
Dry weight Total-N Biuret-derived N
(mg vial-1) (mmol g-1 DW) (µmol
g-1 DW) (µmol vial-1)
WT 109b ± 11.2 2.30a ± 0.13
16.4a ± 1.76 1.80a ± 0.38
B2-3-3-11 76.2a ± 6.67 2.35a ± 0.21
42.3b ± 5.39 3.20b ± 0.13
B3-9-1-5 77.6a ± 5.79 2.42a ± 0.12
91.4c ± 1.98 7.09c ± 0.59
Different alphabets indicate significant differences between rice lines
(p < 0.05, Tukey’s test).