Abscission

Abstract

The abscission of organs takes place at discrete sites and at specific times during the life cycle of a plant. These observations suggest that the abscission zone comprises a layer of positionally differentiated cells that undergo separation from their neighbours in response to precise developmental and environmental cues. By studying mutants of Arabidopsis that exhibit an attenuated capacity to shed their floral organs, it has been possible to identify a number of genes that may play a role in both the differentiation of abscission zone cells and the timing of organ shedding. The possible applications of this knowledge to agricultural and horticultural species are discussed.

Functional Identification and Characterization of the Brassica Napus Transcription Factor Gene BnAP2, the Ortholog of Arabidopsis Thaliana APETALA2

“…As with most developmental events, proper timing and spacing are crucial during organ separation [47]. Floral organ abscission is a developmentally controlled program that occurs after flower pollination.…”

“…In plants, abscission and senescence events allow the shedding of leaves, flowers, fruits and seeds, and can facilitate growth, reproduction, and defense against pathogens [45] , [46] . As with most developmental events, proper timing and spacing are crucial during organ separation [47] . Floral organ abscission is a developmentally controlled program that occurs after flower pollination.…”

A Novel Approach to Dissect the Abscission Process in Arabidopsis

“…S3, Y-AD). A role for ABA in abscission remains somewhat contentious (Rinne et al, 1992;Roberts and González-Carranza, 2007); however, it is possible that this hormone may play an important role in regulating the expression of At3g53040 and other genes that may be involved in the prevention of water loss in the AZ.…”

A KNOTTED1-LIKE HOMEOBOX Protein Regulates Abscission in Tomato by Modulating the Auxin Pathway

“…Shedding of plant organs occurs at predetermined positions called abscission zones (AZs). The AZ tissue is composed of small isodiametric cells with dense cytoplasm, and it is anatomically distinct long before the initiation of abscission (Roberts and González-Carranza, 2007). In tomato (Solanum lycopersicum), genetic analysis has revealed that several genes are involved in AZ differentiation.…”

“…After the AZ is formed, it remains in a quiescent state from days to months until receiving the signals that initiate abscission (Roberts and González-Carranza, 2007;Nakano et al, 2013). Abscission initiation is triggered by developmental and environmental cues (Taylor and Whitelaw, 2001) and mediated by the interaction of two hormones, auxin and ethylene (Roberts et al, 2002;Estornell et al, 2013).…”