Strigolactones are an ancient group of plant signalling molecules. They play a critical role in the rhizosphere where they facilitate the formation of symbioses with fungi, crucial for the acquisition of plant nutrients in over 80 % of land plant species. Strigolactones have also been exploited by parasitic weeds as a rhizosphere signal indicating the presence of a host species, resulting in devastating losses in some agricultural systems. Recently, they have also been shown to act endogenously as plant hormones controlling shoot branching and have been implicated in a wide range of other physiological processes, including root growth, root-hair elongation, adventitious rooting, secondary growth, photomorphogenesis, seed germination, nodulation, and protonemal development in mosses. Here, we discuss the evidence for the involvement of strigolactones as endogenous regulators of these processes and highlight some examples where the evidence is inconclusive. One major gap in our understanding is the identity of the endogenous strigolactone( s) that are biologically active. A discussion of the interactions between the different plant hormones and the possible role of strigolactones as integrators of the root-toshoot balance, nutrient acquisition, and thus resource allocation illustrates some important future directions for this area of research.

Item Type:	Refereed Article
Keywords:	Strigolactones, Branching, Root growth, Secondary growth, Photomorphogenesis, Mycorrhizae, Nodulation, Protonema, Auxin
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 Environmental Sciences
Author:	Foo, E (Dr Eloise Foo)
Author:	Reid, JB (Professor Jim Reid)
ID Code:	81010
Year Published:	2013 (online first 2012)
Funding Support:	Australian Research Council (DP110102085)
Deposited By:	Plant Science
Deposited On:	2012-11-21
Last Modified:	2015-07-28
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