The potential roles of strigolactones and brassinosteroids in the autoregulation of nodulation pathway

Foo, E., Ferguson, B. J. and Reid, J. B. (2014) The potential roles of strigolactones and brassinosteroids in the autoregulation of nodulation pathway. Annals of Botany, 113 6: 1037-1045. doi:10.1093/aob/mcu030

Author Foo, E.
Ferguson, B. J.
Reid, J. B.
Title The potential roles of strigolactones and brassinosteroids in the autoregulation of nodulation pathway
Journal name Annals of Botany   Check publisher's open access policy
ISSN 0305-7364
Publication date 2014-05-01
Year available 2014
Sub-type Article (original research)
DOI 10.1093/aob/mcu030
Open Access Status Not Open Access
Volume 113
Issue 6
Start page 1037
End page 1045
Total pages 9
Place of publication Oxford, United Kingdom
Publisher Oxford University Press
Language eng
Formatted abstract
Background and Aims: The number of nodules formed on a legume root system is under the strict genetic control of the autoregulation of nodulation (AON) pathway. Plant hormones are thought to play a role in AON; however, the involvement of two hormones recently described as having a largely positive role in nodulation, strigolactones and brassinosteroids, has not been examined in the AON process.

Methods: A genetic approach was used to examine if strigolactones or brassinosteroids interact with the AON system in pea (Pisum sativum). Double mutants between shoot-acting (Psclv2, Psnark) and root-acting (Psrdn1) mutants of the AON pathway and strigolactone-deficient (Psccd8) or brassinosteroid-deficient (lk) mutants were generated and assessed for various aspects of nodulation. Strigolactone production by AON mutant roots was also investigated.

Key Results: Supernodulation of the roots was observed in both brassinosteroid- and strigolactone-deficient AON double-mutant plants. This is despite the fact that the shoots of these plants displayed classic strigolactone-deficient (increased shoot branching) or brassinosteroid-deficient (extreme dwarf) phenotypes. No consistent effect of disruption of the AON pathway on strigolactone production was found, but root-acting Psrdn1 mutants did produce significantly more strigolactones.

Conclusions: No evidence was found that strigolactones or brassinosteroids act downstream of the AON genes examined. While in pea the AON mutants are epistatic to brassinosteroid and strigolactone synthesis genes, we argue that these hormones are likely to act independently of the AON system, having a role in the promotion of nodule formation. 
Keyword Autoregulation of nodulation
Pisum sativum
Q-Index Code C1
Q-Index Status Confirmed Code
Institutional Status UQ

Document type: Journal Article
Sub-type: Article (original research)
Collections: School of Agriculture and Food Sciences
Official 2015 Collection
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Citation counts: TR Web of Science Citation Count  Cited 7 times in Thomson Reuters Web of Science Article | Citations
Scopus Citation Count Cited 8 times in Scopus Article | Citations
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Created: Thu, 15 May 2014, 20:22:12 EST by Dr Brett Ferguson on behalf of Centre for Integrative Legume Research