The potato tuber is the main nutrient supply and reproductive organ; however, tuber sprouting can reduce its commercial value. Snakin-2 (StSN2) was first reported as an antimicrobial peptide that positively regulates potato disease resistance. Our recent study suggested StSN2 overexpression inhibited sprout growth, while the sprouting process was accelerated in StSN2 RNAi lines. Cytoplasmic glyceraldehyde-3- phosphate dehydrogenase 1 (StGAPC1) was identified as a candidate protein that interacts with StSN2 by coimmunoprecipitation/mass spectrometry (CoIP/MS) experiments. Here, we report that the expression levels of StSN2 and StGAPC1 decreased during sprouting compared with dormancy. Coexpression of StSN2 and StGAPC1 in bud eyes and apical buds was verified by immunofluorescence analysis of paraffin sections. In addition, interaction of StSN2 and StGAPC1 was confirmed by yeast two-hybrid, coimmunoprecipitation and split luciferase complementation assays. Overexpression of StGAPC1 depressed sprout growth, which is similar to the function of StSN2, and StSN2- and StGAPC1-overexpressing lines showed decreased glucose, fructose and galactose content. The interaction of StSN2 and StGAPC1 enhanced StGAPC1 activity and decreased its oxidative modification to inhibit sprout growth. Our results suggest that StSN2 plays a regulatory role in tuber sprout growth through interaction with StGAPC1.

中文翻译：

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Snakin-2 与胞质甘油醛-3-磷酸脱氢酶 1 相互作用，抑制马铃薯块茎中的芽生长。


马铃薯块茎是主要的营养供给和生殖器官；然而，块茎发芽会降低其商业价值。 Snakin-2 (StSN2) 首次被报道为一种抗菌肽，可积极调节马铃薯抗病性。我们最近的研究表明，StSN2 过表达会抑制芽生长，而 StSN2 RNAi 系中的芽生长过程会加速。通过免疫共沉淀/质谱 (CoIP/MS) 实验，细胞质甘油醛-3-磷酸脱氢酶 1 (StGAPC1) 被鉴定为与 StSN2 相互作用的候选蛋白。在这里，我们报告与休眠期间相比，StSN2 和 StGAPC1 的表达水平在发芽期间下降。通过石蜡切片的免疫荧光分析验证了芽眼和顶芽中 StSN2 和 StGAPC1 的共表达。此外，StSN2 和 StGAPC1 的相互作用通过酵母双杂交、免疫共沉淀和裂解荧光素酶互补测定得到证实。 StGAPC1 的过度表达会抑制芽的生长，这与 StSN2 的功能相似，并且 StSN2 和 StGAPC1 过度表达的品系显示出葡萄糖、果糖和半乳糖含量降低。 StSN2 和 StGAPC1 的相互作用增强了 StGAPC1 的活性并减少其氧化修饰以抑制芽生长。我们的结果表明，StSN2 通过与 StGAPC1 相互作用在块茎芽生长中发挥调节作用。