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Carlactone-independent seedling morphogenesis in Arabidopsis


Scaffidi, A and Waters, MT and Ghisalberti, EL and Dixon, KW and Flematti, GR and Smith, SM, Carlactone-independent seedling morphogenesis in Arabidopsis, The Plant Journal, 76, (1) pp. 1-9. ISSN 0960-7412 (2013) [Refereed Article]

Copyright Statement

Copyright 2013 The Authors, The Plant Journal Copyright 2013 John Wiley & Sons Ltd

DOI: doi:10.1111/tpj.12265


Strigolactone hormones are derived from carotenoids via carlactone, and act through the α/β–hydrolase D14 and the F–box protein D3/MAX2 to repress plant shoot branching. While MAX2 is also necessary for normal seedling development, D14 and the known strigolactone biosynthesis genes are not, raising the question of whether endogenous, canonical strigolactones derived from carlactone have a role in seedling morphogenesis. Here, we report the chemical synthesis of the strigolactone precursor carlactone, and show that it represses Arabidopsis shoot branching and influences leaf morphogenesis via a mechanism that is dependent on the cytochrome P450 MAX1. In contrast, both physiologically active Z–carlactone and the non-physiological E isomer exhibit similar weak activity in seedlings, and predominantly signal through D14 rather than its paralogue KAI2, in a MAX2-dependent but MAX1-independent manner. KAI2 is essential for seedling morphogenesis, and hence this early-stage development employs carlactone-independent morphogens for which karrikins from wildfire smoke are specific surrogates. While the commonly employed synthetic strigolactone GR24 acts non-specifically through both D14 and KAI2, carlactone is a specific effector of strigolactone signalling that acts through MAX1 and D14.

Item Details

Item Type:Refereed Article
Keywords:carlactone, strigolactone, karrikin, Arabidopsis thaliana, seedling development, seed germination.
Research Division:Biological Sciences
Research Group:Plant biology
Research Field:Plant physiology
Objective Division:Expanding Knowledge
Objective Group:Expanding knowledge
Objective Field:Expanding knowledge in the biological sciences
UTAS Author:Smith, SM (Professor Steven Smith)
ID Code:101420
Year Published:2013
Web of Science® Times Cited:77
Deposited By:Plant Science
Deposited On:2015-06-23
Last Modified:2017-11-02

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