Strigolactones activate different hormonal pathways for regulation of root development in response to phosphate growth conditions.
BACKGROUND
Strigolactones (SLs) - a group of plant hormones and their derivatives - have been found to play a role in the regulation of root development, in addition to their role in suppression of lateral shoot branching: they alter root architecture and affect root-hair elongation, and SL signalling is necessary for the root response to low phosphate (Pi) conditions. These effects of SLs have been shown to be associated with differential activation of the auxin and ethylene signalling pathways.


METHODS
The present review highlights recent findings on the activity of SLs as regulators of root development, in particular in response to low Pi stress, and discusses the different hormonal networks putatively acting with SLs in the root's Pi response.


CONCLUSIONS
SLs are suggested to be key regulators of the adaptive responses to low Pi in the root by modulating the balance between auxin and ethylene signalling. Consequently, they impact different developmental programmes responsible for the changes in root system architecture under differential Pi supply.
Institute of Plant Sciences, Agricultural Research Organization (ARO), the Volcani Center, Bet Dagan 50250, Israel. hkoltai@agri.gov.il
Hinanit
H
Koltai
D005030:Ethylenes / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental / Q000187:drug effects; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D007210:Indoleacetic Acids / Q000378:metabolism; D007783:Lactones / Q000494:pharmacology*; D010710:Phosphates / Q000378:metabolism*; D010937:Plant Growth Regulators / Q000378:metabolism*; D018517:Plant Roots / Q000187:drug effects* / Q000254:growth & development* / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects
D005030:Ethylenes; D007210:Indoleacetic Acids; D007783:Lactones; D010710:Phosphates; D010937:Plant Growth Regulators; C036216:ethylene