The disaccharide Suc cannot be utilized directly; rather, it is irreversibly hydrolyzed by invertase to the hexoses Glc and Fru to shape plant growth. In this context, Glc controls the stability of the transcription factor Ethylene-Insensitive3 (EIN3) via the function of Hexokinase1 (HXK1), a Glc sensor. Thus, invertase, especially the major neutral cytosolic invertase (CINV), constitutes a key point of control for plant growth. However, the cognate regulatory mechanisms that modulate CINV activity remain unclear. Here, we demonstrate that in Arabidopsis (Arabidopsis thaliana), EIN3 binds directly to both the promoters of Production of Anthocyanin Pigment1 (PAP1) and Phosphatidylinositol Monophosphate 5-Kinase 9 (PIP5K9), repressing and enhancing, respectively, their expression. Subsequently, PAP1 binds directly to and promotes transcription of the Cytosolic Invertase1 (CINV1) promoter, while PIP5K9 interacts with and negatively regulates CINV1. The accumulated CINV1 subsequently hydrolyzes Suc, releasing the sequestered signaling cue, Glc, which has been shown to negatively regulate the stability of EIN3 via HXK1. We conclude that a CINV1-Glc-HXK1-EIN3-PAP1/PIP5K9-CINV1 loop contributes to the modulation of CINV1 activity regulating root growth by Glc signaling.

二糖Suc不能直接利用；相反，它会被转化酶不可逆地水解为己糖 Glc 和 Fru，从而促进植物生长。在这种情况下，Glc 通过 Glc 传感器己糖激酶 1 (HXK1) 的功能控制转录因子 Ethyl-Insensitive3 (EIN3) 的稳定性。因此，转化酶，特别是主要的中性胞质转化酶（CINV），构成了植物生长的关键控制点。然而，调节 CINV 活性的同源调节机制仍不清楚。在这里，我们证明在拟南芥（ Arabidopsis thaliana ）中，EIN3 直接与花青素色素产生 1 ( PAP1 ) 和磷脂酰肌醇单磷酸 5-激酶 9 ( PIP5K9 ) 的启动子结合，分别抑制和增强它们的表达。随后，PAP1 直接结合并促进胞质转化酶 1 ( CINV1 ) 启动子的转录，而 PIP5K9 与 CINV1 相互作用并负向调节。积累的 CINV1 随后水解 Suc，释放隔离的信号线索 Glc，Glc 已被证明可以通过 HXK1 负向调节 EIN3 的稳定性。我们得出结论，CINV1-Glc-HXK1-EIN3-PAP1/PIP5K9-CINV1 环有助于通过 Glc 信号传导调节 CINV1 活性，调节根生长。