TOR Signaling Promotes Accumulation of BZR1 to Balance Growth with Carbon Availability in Arabidopsis

Copyright © 2016 Elsevier Ltd. All rights reserved..

For maintenance of cellular homeostasis, the actions of growth-promoting hormones must be attenuated when nutrient and energy become limiting. The molecular mechanisms that coordinate hormone-dependent growth responses with nutrient availability remain poorly understood in plants [1, 2]. The target of rapamycin (TOR) kinase is an evolutionarily conserved master regulator that integrates nutrient and energy signaling to regulate growth and homeostasis in both animals and plants [3-7]. Here, we show that sugar signaling through TOR controls the accumulation of the brassinosteroid (BR)-signaling transcription factor BZR1, which is essential for growth promotion by multiple hormonal and environmental signals [8-11]. Starvation, caused by shifting of light-grown Arabidopsis seedlings into darkness, as well as inhibition of TOR by inducible RNAi, led to plant growth arrest and reduced expression of BR-responsive genes. The growth arrest caused by TOR inactivation was partially recovered by BR treatment and the gain-of-function mutation bzr1-1D, which causes accumulation of active forms of BZR1 [12]. Exogenous sugar promoted BZR1 accumulation and seedling growth, but such sugar effects were largely abolished by inactivation of TOR, whereas the effect of TOR inactivation on BZR1 degradation is abolished by inhibition of autophagy and by the bzr1-1D mutation. These results indicate that cellular starvation leads sequentially to TOR inactivation, autophagy, and BZR1 degradation. Such regulation of BZR1 accumulation by glucose-TOR signaling allows carbon availability to control the growth promotion hormonal programs, ensuring supply-demand balance in plant growth.

Medienart:

E-Artikel

Erscheinungsjahr:

2016

Erschienen:

2016

Enthalten in:

Zur Gesamtaufnahme - volume:26

Enthalten in:

Current biology : CB - 26(2016), 14 vom: 25. Juli, Seite 1854-60

Sprache:

Englisch

Beteiligte Personen:

Zhang, Zhenzhen [VerfasserIn]
Zhu, Jia-Ying [VerfasserIn]
Roh, Jeehee [VerfasserIn]
Marchive, Chloé [VerfasserIn]
Kim, Seong-Ki [VerfasserIn]
Meyer, Christian [VerfasserIn]
Sun, Yu [VerfasserIn]
Wang, Wenfei [VerfasserIn]
Wang, Zhi-Yong [VerfasserIn]

Links:

Volltext

Themen:

7440-44-0
Arabidopsis Proteins
BZR1 protein, Arabidopsis
Carbon
DNA-Binding Proteins
EC 2.7.1.137
Journal Article
Nuclear Proteins
TOR protein, Arabidopsis
Transcription Factors

Anmerkungen:

Date Completed 26.12.2017

Date Revised 10.12.2019

published: Print-Electronic

Citation Status MEDLINE

doi:

10.1016/j.cub.2016.05.005

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM261770179