Repository logo
 

Impairment in karrikin but not strigolactone sensing enhances root skewing in Arabidopsis thaliana.

Published version
Peer-reviewed

Change log

Authors

Swarbreck, Stéphanie M 
Guerringue, Yannick 
Matthus, Elsa 
Jamieson, Fiona JC 
Davies, Julia M 

Abstract

Roots form highly complex systems varying in growth direction and branching pattern to forage for nutrients efficiently. Here mutations in the KAI2 (KARRIKIN INSENSITIVE) α/β-fold hydrolase and the MAX2 (MORE AXILLARY GROWTH 2) F-box leucine-rich protein, which together perceive karrikins (smoke-derived butenolides), caused alteration in root skewing in Arabidopsis thaliana. This phenotype was independent of endogenous strigolactones perception by the D14 α/β-fold hydrolase and MAX2. Thus, KAI2/MAX2 effect on root growth may be through the perception of endogenous KAI2-ligands (KLs), which have yet to be identified. Upon perception of a ligand, a KAI2/MAX2 complex is formed together with additional target proteins before ubiquitination and degradation through the 26S proteasome. Using a genetic approach, we show that SMAX1 (SUPPRESSOR OF MAX2-1)/SMXL2 and SMXL6,7,8 (SUPPRESSOR OF MAX2-1-LIKE) are also likely degradation targets for the KAI2/MAX2 complex in the context of root skewing. In A. thaliana therefore, KAI2 and MAX2 act to limit root skewing, while kai2's gravitropic and mechano-sensing responses remained largely unaffected. Many proteins are involved in root skewing, and we investigated the link between MAX2 and two members of the SKS/SKU family. Though KLs are yet to be identified in plants, our data support the hypothesis that they are present and can affect root skewing.

Description

Keywords

Arabidopsis thaliana, karrikin, root, skewing, strigolactone, waving, 4-Butyrolactone, Arabidopsis, Arabidopsis Proteins, Carrier Proteins, Furans, Gene Expression Regulation, Plant, Hydrolases, Intracellular Signaling Peptides and Proteins, Lactones, Mutation, Phenotype, Plant Growth Regulators, Plant Roots, Pyrans, Signal Transduction, Transcriptome

Journal Title

Plant J

Conference Name

Journal ISSN

0960-7412
1365-313X

Volume Title

98

Publisher

Wiley
Sponsorship
Biotechnology and Biological Sciences Research Council (BB/J014540/1)