A forward genetic screen for new regulators of auxin mediated degradation of auxin transport proteins in Arabidopsis thaliana Journal Article

Author(s): Zemová, Radka; Zwiewka, Marta; Bielach, Agnieszka; Robert, Hélène S; Friml, Jiřĺ
Article Title: A forward genetic screen for new regulators of auxin mediated degradation of auxin transport proteins in Arabidopsis thaliana
Affiliation IST Austria
Abstract: The plant hormone auxin (indole-3-acetic acid) is a major regulator of plant growth and development including embryo and root patterning, lateral organ formation and growth responses to environmental stimuli. Auxin is directionally transported from cell to cell by the action of specific auxin influx [AUXIN-RESISTANT1 (AUX1)] and efflux [PIN-FORMED (PIN)] transport regulators, whose polar, subcellular localizations are aligned with the direction of the auxin flow. Auxin itself regulates its own transport by modulation of the expression and subcellular localization of the auxin transporters. Increased auxin levels promote the transcription of PIN2 and AUX1 genes as well as stabilize PIN proteins at the plasma membrane, whereas prolonged auxin exposure increases the turnover of PIN proteins and their degradation in the vacuole. In this study, we applied a forward genetic approach, to identify molecular components playing a role in the auxin-mediated degradation. We generated EMS-mutagenized Arabidopsis PIN2::PIN2:GFP, AUX1::AUX1:YFP eir1aux1 populations and designed a screen for mutants with persistently strong fluorescent signals of the tagged PIN2 and AUX1 after prolonged treatment with the synthetic auxin 2,4-dichlorophenoxyacetic acid (2,4-D). This approach yielded novel auxin degradation mutants defective in trafficking and degradation of PIN2 and AUX1 proteins and established a role for auxin-mediated degradation in plant development.
Keywords: Polar auxin transport; Plasma membrane; AUX1; Root development; PIN2; Vacuolar degradation
Journal Title: Journal of Plant Growth Regulation
Volume: 35
Issue 2
ISSN: 1435-8107
Publisher: Springer  
Date Published: 2016-06-01
Start Page: 465
End Page: 476
DOI: 10.1007/s00344-015-9553-2
Notes: We thank Eva Huspekova and David John Hanley for kindly help in preparing this manuscript, and Klara Harmanova and Radka Holbova for technical help. This work was supported by the European Research Council (project ERC-2011-StG-20101109-PSDP); European Social Fund (CZ.1.07/2.3.00/20.0043) and the Czech Science Foundation GAČR (GA13-40637S) to JF. Work was realized in CEITEC – Central European Institute of Technology (CZ.1.05/1.1.00/02.0068). M.Z. was supported by Project Postdoc I (CZ.1.07/2.3.00/30.0009) co-financed by the European Social Fund and the state budget of the Czech Republic. H.S.R was supported by the SoMoProII program (3SGA5602), co-financed by the South-Moravian Region and the EU (FP/2007-2013, Grant Agreement No. 291782).
Open access: yes (repository)