Expression Kinetics of Regulatory Genes Involved in the Vesicle Trafficking Processes Operating in Tomato Flower Abscission Zone Cells during Pedicel Abscission.

Srivignesh Sundaresan,Joseph Riov,Sonia Philosoph-Hadas,Shimon Meir,Shoshana Salim

doi:10.3390/life10110273

Srivignesh Sundaresan, Joseph Riov + Show 3 more

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https://doi.org/10.3390/life10110273

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Abstract

The abscission process occurs in a specific abscission zone (AZ) as a consequence of the middle lamella dissolution, cell wall degradation, and formation of a defense layer. The proteins and metabolites related to these processes are secreted by vesicle trafficking through the plasma membrane to the cell wall and middle lamella of the separating cells in the AZ. We investigated this process, since the regulation of vesicle trafficking in abscission systems is poorly understood. The data obtained describe, for the first time, the kinetics of the upregulated expression of genes encoding the components involved in vesicle trafficking, occurring specifically in the tomato (Solanum lycopersicum) flower AZ (FAZ) during pedicel abscission induced by flower removal. The genes encoding vesicle trafficking components included soluble N-ethylmaleimide-sensitive factor attachment protein receptors (SNAREs), SNARE regulators, and small GTPases. Our results clearly show how the processes of protein secretion by vesicle trafficking are regulated, programmed, and orchestrated at the level of gene expression in the FAZ. The data provide evidence for target proteins, which can be further used for affinity purification of plant vesicles in their natural state. Such analyses and dissection of the complex vesicle trafficking networks are essential for further elucidating the mechanism of organ abscission.

Highlights

Organ abscission is a complex developmental process, which involves anatomical, physiological, biochemical, and molecular aspects [1,2]
The experimental design of the present study was based on our previous article [12], which described the kinetics of the tomato flower pedicel abscission following flower removal
This study demonstrated the expression of genes encoding for the synthesis of enzymes and metabolites that constitute the cargo required to reach the cell wall and the inter-cellular space

Summary

Introduction

Organ abscission is a complex developmental process, which involves anatomical, physiological, biochemical, and molecular aspects [1,2]. Transcriptome analyses of tomato flower and soybean leaf AZs, focusing on genes associated with disassembly of the cell wall, and genes linked to the biosynthesis of a new extracellular matrix, were recently performed [12]. These studies demonstrated the upregulation of AZ-specific genes associated with cell wall disassembly, including CELs, PGs, and EXPs, as well as an early upregulation of genes related to the synthesis of a waxy-like cuticle involved in the formation of an extensible boundary layer on the surface of separating cells

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