Open AccessPILS proteins provide a homeostatic feedback on auxin signaling output
Author(s) -
Elena Feraru,
Mugurel I. Feraru,
Jeanette Moulinier-Anzola,
Maximilian Schwihla,
Jonathan Ferreira Da Silva Santos,
Lin Sun,
Sascha Waidmann,
Barbara Korbei,
Jürgen KleineVehn
Publication year - 2022
Publication title -
development
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.754
H-Index - 325
eISSN - 1477-9129
pISSN - 0950-1991
DOI - 10.1242/dev.200929
Subject(s) - auxin , biology , microbiology and biotechnology , arabidopsis , endoplasmic reticulum , mutant , signal transduction , homeostasis , intracellular , biochemistry , gene
Multiple internal and external signals modulate the metabolism, intercellular transport and signaling of the phytohormone auxin. Considering this complexity, it remains largely unknown how plant cells monitor and ensure the homeostasis of auxin responses. PIN-LIKES (PILS) intracellular auxin transport facilitators at the endoplasmic reticulum are suitable candidates to buffer cellular auxin responses because they limit nuclear abundance and signaling of auxin. We used forward genetics to identify gloomy and shiny pils (gasp) mutants that define the PILS6 protein abundance in a post-translational manner. Here, we show that GASP1 encodes an uncharacterized RING/U-box superfamily protein that impacts on auxin signaling output. The low auxin signaling in gasp1 mutants correlates with reduced abundance of PILS5 and PILS6 proteins. Mechanistically, we show that high and low auxin conditions increase and reduce PILS6 protein levels, respectively. Accordingly, non-optimum auxin concentrations are buffered by alterations in PILS6 abundance, consequently leading to homeostatic auxin output regulation. We envision that this feedback mechanism provides robustness to auxin-dependent plant development.