FIGURE 4.

(A) NIT4 transcript abundance by RT-PCR. RNA was extracted from 100 mg of 5 week-old in vitro cassava roots. RT-PCR was performed using primers for the NIT4 insert while tubulin primers were used for the control. (B) Expression of Nitrilase increases cyanoalanine hydrolase activity in cassava roots. Rates of conversion of cyanoalanine to ammonia were determined for n = 4. (C) IAA analysis in 4 months-old greenhouse-grown wild-type and transgenic cassava tuberous roots and leaves showing decreased IAA in transgenic plants overexpressing NIT4. (D) Storage root fresh weight per plant in WT and transgenic NIT4 (PNIT2, 4, and 6) lines. (E) Total free amino acid analysis in wild-type and NIT4 transgenic lines. The data are averages of three biological trials.