Potato invertase inhibitor (StInvInh2) positively regulates cold-induced sweetening (CIS) resistance by inhibiting the activity of vacuolar invertase. The distinct expression patterns ofStInvInh2have been thoroughly characterized in different potato genotypes, but the related CIS ability has not been characterized. The understanding of the regulatory mechanisms that controlStInvInh2transcription is unclear. In this study, we identified an ERF‐VII transcription factor,StRAP2.3, that directly regulatesStInvInh2to positively modulate CIS resistance. Acting as a nuclear-localized transcriptional activator, StRAP2.3 directly binds the ACCGAC cis-element in the promoter region ofStInvInh2, enabling promoter activity. Overexpression ofStRAP2.3in CIS-sensitive potato tubers inducedStInvInh2mRNA abundance and increased CIS resistance. In contrast, silencingStRAP2.3in CIS-resistant potato tubers repressed the expression ofStInvInh2and decreased CIS resistance. We conclude that cold-responsiveStInvInh2is due to the binding of StRAP2.3 to the ACCGAC cis-element in the promoter region ofStInvInh2. Overall, these findings indicate that StRAP2.3 directly regulatesStInvInh2to positively modulate CIS resistance, which may provide a strategy to improve the processing quality of potatoes.

中文翻译：

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ERF-VII 转录因子 StRAP2.3 直接激活 StInvInh2 以增强马铃薯的冷诱导甜味抗性

马铃薯转化酶抑制剂（StInvInh2) 通过抑制液泡转化酶的活性来正向调节冷诱导甜味 (CIS) 抗性。不同的表达模式StInvInh2已经在不同的马铃薯基因型中进行了彻底的表征，但尚未表征相关的 CIS 能力。对调控机制的理解StInvInh2转录不清楚。在这项研究中，我们鉴定了一个 ERF-VII 转录因子，StrAP2.3, 直接调节StInvInh2正向调节 CIS 电阻。作为核定位转录激活因子，StRAP2.3 直接结合 ACCGAC 顺式元件的启动子区域StInvInh2，使启动子活动。过度表达StrAP2.3在 CIS 敏感的马铃薯块茎中诱导StInvInh2mRNA 丰度和增加的 CIS 抗性。相比之下，静音StrAP2.3在 CIS 抗性马铃薯块茎中抑制了StInvInh2并降低 CIS 电阻。我们得出结论，冷反应StInvInh2是由于 StRAP2.3 与启动子区域中的 ACCGAC 顺式元件的结合所致StInvInh2. 总的来说，这些发现表明 StRAP2.3 直接调节StInvInh2正向调节 CIS 抗性，这可能为提高马铃薯加工质量提供一种策略。