SCOF- 1-expressing transgenic sweetpotato plants show enhanced tolerance to low-temperature stress

Low-temperature stress represents one of the principal limitations affecting the distribution and productivity of many plant species, including crops such as sweetpotato. Transgenic sweetpotato ( Ipomoea batatas L. cv. Yulmi) plants expressing the soybean cold-inducible zinc finger protein (SCOF-1) under control of an oxidative stress-inducible peroxidase ( SWPA2) promoter (referred to as SF plants), were developed and evaluated for enhanced tolerance to low-temperature conditions. Following 4 °C treatment of SF plants, SCOF- 1 expression correlated positively with tolerance to low-temperature stress at the leaf disc level. Increased SCOF- 1 expression also correlated with enhanced tolerance to different low-temperature treatments at the whole plant level. SF plants treated with low-temperature stress (4 or 10 °C for 30 h) exhibited less of a reduction in photosynthetic activity and lipid peroxidation levels than non-transgenic (NT) plants. Furthermore, the photosynthetic activity and lipid peroxidation levels of SF plants recovered to near pre-stress levels after 12 h of recovery at 25 °C. In contrast, these activities remained at a reduced level in NT plants after the same recovery period. Thus, this study has shown that low-temperature stress in sweetpotato can be efficiently modulated by overexpression of SCOF- 1. ► Transgenic sweetpotato plants expressing soybean cold-inducible zinc finger protein (SCOF-1) were generated. ► Transgenic plants showed enhanced tolerance t at 4 °C on the level of leaf disc and whole plant. ► This study has shown that low-temperature in sweetpotato can be efficiently modulated by overexpression of SCOF- 1.