Abstract
Abscission is a developmental process with important implications for agricultural practices. Ethylene has long been considered as a key regulator of the abscission process. The existence of an ethylene-independent abscission pathway, controlled by the complex of INFLORESCENCE DEFICIENT IN ABSCISSION (IDA) peptide and the HAESA (HAE) and HAESA-like2 (HSL2) kinases, has been proposed, based mainly on observations that organ abscission in ethylene-insensitive mutants was delayed but not inhibited. A recent review on plant organ abscission signaling highlighted the IDA-HAE-HSL2 components as the regulators of organ abscission, while the role of auxin and ethylene in this process was hardly addressed. After a careful analysis of the relevant abscission literature, we propose that the IDA-HAE-HSL2 pathway is essential for the final stages of organ abscission, while ethylene plays a major role in its initiation and progression. We discuss the view that the IDA-HAE-HSL2 pathway is ethylene independent, and present recent evidence showing that ethylene activates the IDA-HAE-HSL2 complex. We conclude that the ability of an organ to abscise is tightly linked to cell turgidity in the abscission zone, and suggest that lack of cell turgidity might contribute to the failure of floral organ abscission in the ida mutants.
DOI
10.1093/jxb/erz038
Publication Date
2019-02-06
Publication Title
Journal of Experimental Botany
Volume
70
Issue
5
Publisher
Oxford University Press (OUP)
ISSN
1460-2431
Embargo Period
2024-11-25
First Page
1461
Last Page
1467
Recommended Citation
Meir, S., Philosoph-Hadas, S., Riov, J., & et al. (2019) 'Re-evaluation of the ethylene-dependent and -independent pathways in the regulation of floral and organ abscission', Journal of Experimental Botany, 70(5), pp. 1461-1467. Oxford University Press (OUP): Available at: https://doi.org/10.1093/jxb/erz038
