TY  - JOUR
A1  - Nukarinen, Ella
A1  - Nägele, Thomas
A1  - Pedrotti, Lorenzo
A1  - Wurzinger, Bernhard
A1  - Mair, Andrea
A1  - Landgraf, Ramona
A1  - Börnke, Frederik
A1  - Hanson, Johannes
A1  - Teige, Markus
A1  - Baena-Gonzalez, Elena
A1  - Dröge-Laser, Wolfgang
A1  - Weckwerth, Wolfram
T1  - Quantitative phosphoproteomics reveals the role of the AMPK plant ortholog SnRK1 as a metabolic master regulator under energy deprivation
JF  - Scientific Reports
N2  - Since years, research on SnRK1, the major cellular energy sensor in plants, has tried to define its role in energy signalling. However, these attempts were notoriously hampered by the lethality of a complete knockout of SnRK1. Therefore, we generated an inducible amiRNA::SnRK1α2 in a snrk1α1 knock out background (snrk1α1/α2) to abolish SnRK1 activity to understand major systemic functions of SnRK1 signalling under energy deprivation triggered by extended night treatment. We analysed the in vivo phosphoproteome, proteome and metabolome and found that activation of SnRK1 is essential for repression of high energy demanding cell processes such as protein synthesis. The most abundant effect was the constitutively high phosphorylation of ribosomal protein S6 (RPS6) in the snrk1α1/α2 mutant. RPS6 is a major target of TOR signalling and its phosphorylation correlates with translation. Further evidence for an antagonistic SnRK1 and TOR crosstalk comparable to the animal system was demonstrated by the in vivo interaction of SnRK1α1 and RAPTOR1B in the cytosol and by phosphorylation of RAPTOR1B by SnRK1α1 in kinase assays. Moreover, changed levels of phosphorylation states of several chloroplastic proteins in the snrk1α1/α2 mutant indicated an unexpected link to regulation of photosynthesis, the main energy source in plants.
KW  - phosphoproteomics
KW  - SnRK1
KW  - energy deprivation
KW  - plants
Y1  - 2016
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-167638
VL  - 6
IS  - 31697
ER  - 
TY  - JOUR
A1  - Weiste, Christoph
A1  - Pedrotti, Lorenzo
A1  - Selvanayagam, Jebasingh
A1  - Muralidhara, Prathibha
A1  - Fröschel, Christian
A1  - Novák, Ondřej
A1  - Ljung, Karin
A1  - Hanson, Johannes
A1  - Dröge-Laser, Wolfgang
T1  - The Arabidopsis bZIP11 transcription factor links low-energy signalling to auxin-mediated control of primary root growth
JF  - PLoS Genetics
N2  - Plants have to tightly control their energy homeostasis to ensure survival and fitness under constantly changing environmental conditions. Thus, it is stringently required that energy-consuming stress-adaptation and growth-related processes are dynamically tuned according to the prevailing energy availability. The evolutionary conserved SUCROSE NON-FERMENTING1 RELATED KINASES1 (SnRK1) and the downstream group C/S\(_{1}\) basic leucine zipper (bZIP) transcription factors (TFs) are well-characterised central players in plants’ low-energy management. Nevertheless, mechanistic insights into plant growth control under energy deprived conditions remains largely elusive. In this work, we disclose the novel function of the low-energy activated group S\(_{1}\) bZIP11-related TFs as regulators of auxin-mediated primary root growth. Whereas transgenic gain-of-function approaches of these bZIPs interfere with the activity of the root apical meristem and result in root growth repression, root growth of loss-of-function plants show a pronounced insensitivity to low-energy conditions. Based on ensuing molecular and biochemical analyses, we propose a mechanistic model, in which bZIP11-related TFs gain control over the root meristem by directly activating IAA3/SHY2 transcription. IAA3/SHY2 is a pivotal negative regulator of root growth, which has been demonstrated to efficiently repress transcription of major auxin transport facilitators of the PIN-FORMED (PIN) gene family, thereby restricting polar auxin transport to the root tip and in consequence auxin-driven primary root growth. Taken together, our results disclose the central low-energy activated SnRK1-C/S\(_{1}\)-bZIP signalling module as gateway to integrate information on the plant’s energy status into root meristem control, thereby balancing plant growth and cellular energy resources.
KW  - root growth
KW  - sucrose
KW  - auxins
KW  - meristems
KW  - regulator genes
KW  - genetically modified plants
KW  - gene expression
KW  - plant growth and development
Y1  - 2017
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-157742
VL  - 13
IS  - 2
ER  -