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Understanding Plant Energy Sensing and Homeostasis
Author(s) -
Williams Sarah Phoebe,
Yen Jiun,
Gillaspy Glenda
Publication year - 2017
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.31.1_supplement.628.11
Subject(s) - arabidopsis , ampk , biology , wild type , energy homeostasis , nutrient sensing , protein kinase a , kinase , microbiology and biotechnology , arabidopsis thaliana , yeast , phosphorylation , mutant , serine , signal transduction , biochemistry , gene , receptor
The Sucrose non‐Fermenting Related Kinase 1 (SnRK1) protein family has been shown to play a critical role in metabolic energy regulation and stress signaling. SnRK1, a homolog of yeast Snf‐1 ( Su crose no n‐ f ermenting‐1) and human AMPK (AMP Kinase), is a serine/threonine kinase which is activated by phosphorylation and in turn acts to regulate key metabolic enzymes and transcriptions factors, resulting in the metabolic reprograming of the cell. The SnRK1 gene family contains three members, SnRK1.1, 1.2, and 1.3. The up‐regulation of SnRK1.1 in Arabidopsis has generated plants with enhanced biomass and altered developmental rate. SnRK1.1 over‐expressing (OE) plants grown on soil are smaller than wild‐type plants pre‐flowering, have a delay in flowering, increased biomass post‐flowering, and delayed senescence. The underlying metabolic mechanism of this valuable trait, increased biomass, has not been fully elucidated due to its complexity. In this work, we sought to understand the metabolic changes associated with these phenotypes. In conjunction with Metabolon, Inc., we took a metabolomics approach to measure over 300 metabolites in SnRK1 OE and WT plants. These data were used to address two main questions. The first, Are SnRK1‐induced metabolic changes the same in early development (where growth is suppressed), as compared to later development (where growth is increased)? From these data we found 65% of the metabolites detected in wildtype plants were significantly different as a result of developmental transition suggesting plant metabolism changes with developmental state. While SnRK1 OE alters metabolism across development, it does not do so equally, with the greatest differences observed post‐flowering. SnRK1 OE and wildtype plants were more similar at the pre‐flowering stage, with 54 metabolites elevated and 58 decreased in SnRK1 OE plants as compared to wildtype. In contrast, 116 metabolites were elevated and 140 decreased in post‐flowering SnRK1 OE plants as compared to wildtype. These changes suggest differences in carbohydrate metabolism, lipid composition, nitrogen assimilation and stress response and autophagy pathways. We posed the second question, How does SnRK1 OE alter metabolism, and are changes similar to those seen in carbon starvation or other putative energy‐sensing mutants? The set of metabolic changes were compared to known metabolic and transcriptional profiles of carbon starved plants. There was significant overlap between these data sets and the metabolic changes observed in a SnRK1 OE plant at both pre‐ and post‐flower stages. Overall, these data suggest that SnRK1 overexpression is likely inducing carbon starvation metabolic pathways.