STOREKEEPER RELATED 1/G-element Binding Protein (STKR1) interacts with protein kinase SnRK1
Sucrose non-fermenting related kinase 1 (SnRK1) is a conserved energy sensor kinase that regulates cellular adaptation to energy deficit in plants. Activation of SnRK1 leads to down-regulation of ATP consuming biosynthetic processes and the stimulation of energy-generating catabolic reactions by transcriptional reprogramming and post-translational modifications. Although considerable progress has been made during the last years in understanding the SnRK1 signaling pathway, many of its components remain unidentified. Here we show that the catalytic α subunits KIN10 and KIN11 of the Arabidopsis thaliana SnRK1 complex interact with the STOREKEEPER RELATED 1/G-element Binding Protein (STKR1) inside the plant cell nucleus. Overexpression of STKR1 in transgenic Arabidopsis plants led to reduced growth, a delay in flowering and strongly attenuated senescence. Metabolite profiling revealed that the transgenic lines exhausted their carbohydrates during the dark period to a greater extent than the wild type and accumulated a range of amino acids. At the global transcriptome level, genes affected by STKR1 overexpression were broadly associated with systemic acquired resistance and transgenic plants showed enhanced resistance towards a virulent strain of the biotrophic oomycete pathogen Hyaloperonospora arabidopsidis Noco2. We discuss a possible connection of STKR1 function, SnRK1 signaling and plant immunity.
Nietzsche, M.; Guerra, T., Alseekh, S.; Wiermer, M.; Sonnewald, S.; Fernie, A.R.; Börnke, F. 2017. STOREKEEPER RELATED 1/G-element Binding Protein (STKR1) interacts with protein kinase SnRK1. Plant Physiology.