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Strigolactone regulation of shoot branching in chrysanthemum (Dendranthema grandiflorum).

Published version
Peer-reviewed

Type

Article

Change log

Authors

Liang, Jianli 
Zhao, Liangjun 
Challis, Richard 

Abstract

Previous studies of highly branched mutants in pea (rms1-rms5), Arabidopsis thaliana (max1-max4), petunia (dad1-dad3), and rice (d3, d10, htd1/d17, d14, d27) identified strigolactones or their derivates (SLs), as shoot branching inhibitors. This recent discovery offers the possibility of using SLs to regulate branching commercially, for example, in chrysanthemum, an important cut flower crop. To investigate this option, SL physiology and molecular biology were studied in chrysanthemum (Dendranthema grandiflorum), focusing on the CCD8/MAX4/DAD1/RMS1/D10 gene. Our results suggest that, as has been proposed for Arabidopsis, the ability of SLs to inhibit bud activity depends on the presence of a competing auxin source. The chrysanthemum SL biosynthesis gene, CCD8 was cloned, and found to be regulated in a similar, but not identical way to known CCD8s. Expression analyses revealed that DgCCD8 is predominantly expressed in roots and stems, and is up-regulated by exogenous auxin. Exogenous SL can down-regulate DgCCD8 expression, but this effect can be overridden by apical auxin application. This study provides evidence that SLs are promising candidates to alter the shoot branching habit of chrysanthemum.

Description

Keywords

Amino Acid Sequence, Carotenoids, Chrysanthemum, Molecular Sequence Data, Oxygenases, Phylogeny, Plant Growth Regulators, Plant Proteins, Plant Shoots, Sequence Alignment

Journal Title

J Exp Bot

Conference Name

Journal ISSN

0022-0957
1460-2431

Volume Title

61

Publisher

Oxford University Press (OUP)