Foo, E and Ferguson, BJ and Reid, JB, The potential roles of strigolactones and brassinosteroids in the autoregulation of nodulation pathway, Annals of Botany, 113, (6) pp. 1037-1045. ISSN 0305-7364 (2014) [Refereed Article]
Copyright 2014 The Author
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.
|Item Type:||Refereed Article|
|Keywords:||autoregulation of nodulation, AON, brassinosteroids, CLAVATA2, NARK, Pisum sativum, RDN1, strigolactones|
|Research Division:||Biological Sciences|
|Research Group:||Plant biology|
|Research Field:||Plant physiology|
|Objective Division:||Plant Production and Plant Primary Products|
|Objective Group:||Environmentally sustainable plant production|
|Objective Field:||Environmentally sustainable plant production not elsewhere classified|
|UTAS Author:||Foo, E (Associate Professor Eloise Foo)|
|UTAS Author:||Ferguson, BJ (Dr Brett Ferguson)|
|UTAS Author:||Reid, JB (Professor Jim Reid)|
|Funding Support:||Australian Research Council (DP140101709)|
|Web of Science® Times Cited:||19|
|Deposited By:||Plant Science|
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