Stele-generated signals and their role in the hormonal regulation of abscission

 

 

 

Sarah J Dorling and Michael T McManus^*

Institute of Molecular Biosciences, Massey University, Palmerston North, New Zealand

 

 

 

Abstract

Purpose of review: This review summarises the key historical findings that have led scientists to consider the abscission zone of higher plants as a functionally specialised tissue in which cell-to-cell separation control is confined. It then details the discovery of an unidentified signal or signals that are generated from vascular tissue remote from the abscission zone. Remote signalling clearly plays an important role in the initiation of cell-to-cell separation. The necessity for remote signals to induce and perhaps amplify the abscission response clearly challenges a common view of abscission zones as the major site of cell separation regulation.

Directions for future research: (i) What is the identity of the remote, stele-generated signal(s)?; (ii) how widespread is the use of such signals in the plant kingdom, particularly in species of horticultural or agronomic importance?; and (iii) once identified, can remote signalling molecules form the basis for the design of new growth regulators that can be used commercially to control the timing of organ shedding? 

 

Keywords: Phaseolus vulgaris; abscission; plant hormones; plant growth regulators; vascular signals; target cells

 

Stewart Postharvest Review 2009, 1:3

Published online 01 February 2009

doi: 10.2212/spr.2009.1.3