Hydrogen sulfide inhibits ethylene-induced petiole abscission in tomato (Solanum lycopersicum L.)

Danmei Liu,Jianing Li,Yanxi Pei,Zhuowen Li

doi:10.1038/s41438-019-0237-0

Abstract

Abscission is a dynamic physiological process that is ubiquitous in plants and can also be an essential agronomic trait in crops, thus attracting attention from plant growers and breeders. In general, the process of plant organ abscission can be divided into four steps, among which the step to obtain the competence to respond to abscission signals (step 2) is the most complex; however, the molecular mechanism underlying this process remains unclear. In this study, we found that hydrogen sulfide (H2S) inhibited the abscission of the tomato petiole in a dose-dependent manner, and the abscission of the petiole was accelerated when an H2S scavenger was applied. Further enzymatic activity and gene expression analyses showed that H2S suppressed the activity of enzymes capable of modifying the cell wall by inhibiting the usual upregulation of the transcription of the corresponding genes during the abscission process but not by affecting the activities of these enzymes by direct posttranslational modification. H2S treatment upregulated the expression levels of SlIAA3 and SlIAA4 but downregulated the transcription of ILR-L3 and ILR-L4 in the earlier stages of the abscission process, indicating that H2S probably functioned in the second step of the abscission process by preventing the abscission zone cells from obtaining the competence to respond to abscission signals by modulating the content of the bioactive-free auxin in these cells. Moreover, similar H2S inhibitory effects were also demonstrated in the process of floral organ abscission and anther dehiscence in other plant species, suggesting a ubiquitous role for H2S in cell separation processes.

Highlights

Abscission is a critical process at different stages during the life span of a plant and ensures unwanted organs are shed from the main body of the plant[1]
The results showed that, in the ethylene treatment group, the tomato petioles started to abscise at 28 h after the initiation of the experiment, nearly half of the petioles had abscised by 36 h of treatment, and all the tomato petioles abscised by 48 h of treatment (Fig. 1a)
Hydrogen sulfide functioned as a novel regulator during the process of plant organ abscission

Summary

Introduction

Abscission is a critical process at different stages during the life span of a plant and ensures unwanted organs are shed from the main body of the plant[1]. It is an important agronomic trait with major implications in terms of yield, quality, and postharvest storage in some crops[2,3]. The formation of an AZ is the first step of the abscission process. Thereafter, through the perception of environmental and developmental signals, AZ cells attain the competence to respond to abscission signals (step 2) before the activation and

Methods

Results

Conclusion