The roles of ethylene and transcription factors in the regulation of onset of leaf senescence.

Tomotsugu Koyama

doi:10.3389/fpls.2014.00650

Abstract

Leaf senescence is the last stage of leaf development and is accompanied by cell death. In contrast to senescence in individual organisms that leads to death, leaf senescence is associated with dynamic processes that include the translocation of nutrients from old leaves to newly developing or storage tissues within the same plant. The onset of leaf senescence is largely regulated by age and internal and external stimuli, which include the plant hormone ethylene. Earlier studies have documented the important role of ethylene in the regulation of leaf senescence. The production of ethylene coincides with the onset of leaf senescence, whereas the application of ethylene to plants induces precocious leaf senescence. Recently, many studies have described the components of ethylene signaling and biosynthetic pathways that are involved in modulating the onset of leaf senescence. Particularly, transcription factors (TFs) integrate ethylene signals with those from environmental and developmental factors to accelerate or delay leaf senescence. This review aims to discuss the regulatory cascade involving ethylene and TFs in the regulation of onset of leaf senescence.

Highlights

Leaf senescence occurs alongside color changes in leaves and is an visible phenomenon in the life cycle of a plant
In addition to ethylene, Jasmonic acid (JA) and the developmental signals discussed in this review, additional factors such as cytokinin, auxin, abscisic acid (ABA), and hydrogen peroxide are involved in the regulation of leaf senescence (Ellis et al, 2005; Lim et al, 2010; Smykowski et al, 2010; Yang et al, 2011; Wu et al, 2012; Jaradat et al, 2013)
Ethylene and these signals are integrated for the regulation of the onset of leaf senescence; there have been no reports of a direct interaction between ethylene and such transcription factors (TFs) acting downstream of these signals

Summary

Tomotsugu Koyama*

In contrast to senescence in individual organisms that leads to death, leaf senescence is associated with dynamic processes that include the translocation of nutrients from old leaves to newly developing or storage tissues within the same plant. The onset of leaf senescence is largely regulated by age and internal and external stimuli, which include the plant hormone ethylene. The production of ethylene coincides with the onset of leaf senescence, whereas the application of ethylene to plants induces precocious leaf senescence. Many studies have described the components of ethylene signaling and biosynthetic pathways that are involved in modulating the onset of leaf senescence. Transcription factors (TFs) integrate ethylene signals with those from environmental and developmental factors to accelerate or delay leaf senescence.This review aims to discuss the regulatory cascade involving ethylene and TFs in the regulation of onset of leaf senescence

INTRODUCTION

Ethylene and transcription factors in leaf senescence

CONCLUSIONS AND PERSPECTIVES