Fig. 3.

Expression of the IbCAD1 gene in sweetpotato. a Tissue-specific expression of IbCAD1. Total RNA was isolated from leaves (L), petioles (P) and roots (R) of sweetpotato, and RT-PCR was performed. Tubulin was used as an internal control. b IbCAD1 expression in response to various stresses. Sweetpotato plants were subjected to cold, methyl viologen (MV), wounding, and H₂O₂ treatments, respectively. The cold treatment consisted of exposing the plants to 15°C. For the MV treatment, a 50 μM solution containing 0.125% Triton X-100 was sprayed onto whole plants. The wounding treatment consisted of cutting sweetpotato leaves into small pieces and incubating these at 25°C. For the H₂O₂ treatment, two or three leaves from the top of the growing tip were removed from sweetpotato plants and incubated in a 440 mM H₂O₂ solution. RNA was isolated from leaves and subjected to RT-PCR analysis. Tubulin was used as an internal control