College of Horticulture, China Agricultural University, Beijing, PR China.
The Robert H. Smith Institute of Plant Sciences and Genetics in Agriculture, The Hebrew University of Jerusalem, Rehovot, Israel.
J Exp Bot. 2021 Mar 29;72(7):2403-2418. doi: 10.1093/jxb/eraa593.
Abscisic acid (ABA) plays a vital role in coordinating physiological processes during fresh fruit ripening. Binding of ABA to receptors facilitates the interaction and inhibition of type 2C phosphatase (PP2C) co-receptors. However, the exact mechanism of PP2C during fruit ripening is unclear. In this study, we determined the role of the tomato ABA co-receptor type 2C phosphatase SlPP2C3, a negative regulator of ABA signaling and fruit ripening. SlPP2C3 selectively interacted with monomeric ABA receptors and SlSnRK2.8 kinase in both yeast and tobacco epidermal cells. Expression of SlPP2C3 was ABA-inducible, which was negatively correlated with fruit ripening. Tomato plants with suppressed SlPP2C3 expression exhibited enhanced sensitivity to ABA, while plants overexpressing SlPP2C3 were less sensitive to ABA. Importantly, lack of SlPP2C3 expression accelerated the onset of fruit ripening and affected fruit glossiness by altering the outer epidermis structure. There was a significant difference in the expression of cuticle-related genes in the pericarp between wild-type and SlPP2C3-suppressed lines based on RNA sequencing (RNA-seq) analysis. Taken together, our findings demonstrate that SlPP2C3 plays an important role in the regulation of fruit ripening and fruit glossiness in tomato.
脱落酸 (ABA) 在协调新鲜果实成熟过程中的生理过程中起着至关重要的作用。ABA 与受体结合促进了 2C 型磷酸酶 (PP2C) 共受体的相互作用和抑制。然而，PP2C 在果实成熟过程中的具体机制尚不清楚。在本研究中，我们确定了番茄 ABA 共受体 2C 型磷酸酶 SlPP2C3 的作用，它是 ABA 信号和果实成熟的负调控因子。SlPP2C3 在酵母和烟草表皮细胞中与单体 ABA 受体和 SlSnRK2.8 激酶选择性相互作用。SlPP2C3 的表达受 ABA 诱导，与果实成熟呈负相关。抑制 SlPP2C3 表达的番茄植株对 ABA 的敏感性增强，而过表达 SlPP2C3 的植株对 ABA 的敏感性降低。重要的是，缺乏 SlPP2C3 表达会加速果实成熟的开始，并通过改变外皮层结构影响果实光泽度。基于 RNA 测序 (RNA-seq) 分析，果皮中与角质层相关的基因在野生型和 SlPP2C3 抑制系之间的表达存在显著差异。综上所述，我们的研究结果表明，SlPP2C3 在番茄果实成熟和光泽度的调控中起着重要作用。
