Tomato SlPP2C5 Is Involved in the Regulation of Fruit Development and Ripening

Area of Science:

• Plant Biology
• Molecular Plant Physiology

Background:

• Abscisic acid (ABA) is crucial for plant development, primarily through signaling pathways involving ABA receptors and type 2C protein phosphatases (PP2Cs).
• The specific functions of PP2Cs in fruit development remain largely undefined.

Purpose of the Study:

• To investigate the role of tomato SlPP2C5 as a negative regulator in abscisic acid signaling during fruit development.
• To elucidate the impact of SlPP2C5 on fruit ripening, quality, and ABA sensitivity.

Main Methods:

• Investigated SlPP2C5 interaction with ABA receptors (SlPYLs) and kinases (SlSnRK2s).
• Analyzed SlPP2C5 expression in response to exogenous ABA.
• Utilized transgenic tomato lines with overexpressed (OE) and RNA interference (RNAi) suppressed SlPP2C5.
• Assessed plant phenotypes including seed germination and root growth.
• Evaluated fruit ripening, quality parameters (pericarp thickness, shape, seed traits, soluble solids), and gene expression via RNA-seq.

Main Results:

• SlPP2C5 physically interacts with SlPYLs and SlSnRK2s, functioning as a negative regulator in ABA signaling.
• Overexpression of SlPP2C5 reduced ABA sensitivity, while suppression increased it.
• SlPP2C5-OE delayed fruit ripening, whereas SlPP2C5-RNAi accelerated it.
• Altered SlPP2C5 expression significantly impacted fruit quality traits and the expression of genes involved in ethylene release and lycopene synthesis.

Conclusions:

• SlPP2C5 is a key regulator of ABA signaling in tomato fruit development.
• SlPP2C5 influences fruit ripening, quality attributes, and ABA responsiveness.
• Findings highlight SlPP2C5 as a potential target for improving tomato fruit characteristics.