Abstract

Summary en This link goes to a English section zh This link goes to a Chinese section The plant hormone abscisic acid (ABA) is historically recognized as a tuberization stimulator, with exogenous application significantly enhancing potato tuber formation. However, the physiological significance of endogenous ABA signaling in tuberization and its underlying molecular mechanisms remain poorly understood. Here, by using ABA-insensitive hypermorphic StHAB1 G276D -overexpression mutant and StHAB1 knockdown mutant, we demonstrate that ABA signaling is essential for normal tuber formation in potato. Blocking of ABA signaling by StHAB1 G276D -overexpression reduces underground stolon sensitivity to leaf-derived tuber-inducing signals. Notably, StHAB1 directly interacts with the tuber-forming signal StSP6A and reduces its phosphorylation level. Transcriptomic and quantitative phosphoproteomic analyses proved that StHAB1 G276D modulates gene expression and phosphorylation of key players in the tuberization pathway and gibberellic acid signaling. Collectively, our findings uncover a critical role of endogenous ABA signaling in potato tuber formation and identify a mechanism linking the conserved FLOWERING LOCUS T and ABA pathways, offering molecular insights for accelerating potato tuberization by modulating hormone signaling. 摘要 en This link goes to a English section zh This link goes to a Chinese section 植物激素脱落酸(abscisic acid，ABA)在历史上被认为是块茎形成的促进因子，外源施用ABA可显著增强马铃薯块茎的形成。然而，内源ABA信号在块茎形成过程中的生理意义及其潜在分子机制仍缺乏深入认识。 本研究通过构建ABA不敏感超显性突变体StHAB1 G276D 过表达材料以及StHAB1干涉材料，证明了ABA信号对马铃薯块茎形成至关重要。阻断ABA信号(通过StHAB1 G276D 过表达)会降低地下匍匐茎对结薯诱导信号的敏感性。 值得注意的是，StHAB1可直接与块茎形成信号StSP6A相互作用，并降低其磷酸化水平。转录组和定量磷酸化蛋白组学分析进一步表明，StHAB1 G276D 能够调控块茎形成通路及赤霉素(gibberellic acid，GA)信号通路中关键因子的基因表达和磷酸化状态。 综上，本研究揭示了内源ABA信号在马铃薯块茎形成中的关键作用，并阐明了一种连接保守的FT通路与ABA信号通路的分子机制，为通过调控激素信号加速马铃薯块茎形成提供了分子层面的理论依据。