Ectopic overexpression of the SnRK1 interacting protein STOREKEEPER RELATED 1/GeBP affects growth and development of Arabidopsis thaliana and leads to a constitutive immune response

We show that the catalytic a 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. 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. For microarray analyses, leaf samples from mature source leaves were taken in triplicate from 4-weeks old wild type plants or 35S-STKR1 lines 1, 2, or 5 either after 6 h of illumination or after an extended dark period for 6 h and total RNA was extracted using the RNAeasy Kit (Qiagen). Transcriptome profiling was performed on ArrayXS Arabidopsis v2 (XS-5010) microarrays in the Agilent 8 × 60K format (Oaklabs GmbH, Hennigsdorf, Germany) that represent 30,541 Arabidopsis genes. The array design is described in GEO accession GPL19779.