The transcription factor StC3H14 enhances cold tolerance through the CBF-dependent pathway in potato

The C-repeat binding factor-dependent signaling pathway plays a central role in cold acclimation in potato; however, the transcriptional regulators controlling expression of StCBFs remain poorly understood. Here, we identified StC3H14, a CCCH-type zinc finger transcription factor, which directly activates StCBF1 and StCBF3 by directly binding to their promoters. Overexpression of StC3H14 in potato significantly enhanced cold tolerance, as shown by higher survival rates, reduced electrolyte leakage, and increased soluble sugar accumulation compared with wild-type and RNAi lines. Consistently, the expression of C-repeat binding factor-regulated cold-regulated genes was upregulated in overexpression lines. Moreover, under chilling conditions (15°C day/10°C night), StC3H14 overexpression produced significantly higher tuber yield per plant than wild-type and RNAi plants. Our findings establish StC3H14 as a key regulator of the C-repeat binding factor-dependent signaling pathway and highlight its potential for improving cold tolerance and yield in potato.