Figure 6: DELLAs can interact with the NF signalling transcription factors NSP2 and NF-YA1, and MtDELLA1 can enhance ERN1 transcriptional activation.

(a–d). Bimolecular fluorescence complementation analysis of the interaction between nYFP-NSP1 and cYFP-MtDELLA1 to 3 (a), cYFP-NSP2 and nYFP-MtDELLA1 to 3 (b), and nYFP-NF-YA1 and cYFP-MtDELLA1 to 3 (c) in N. benthamiana leaves. The negative controls (each construct alone) are shown in the different panels, as well as the nYFP-NSP1-cYFP-NSP2-positive control (d). In all panels, YFP fluorescence alone (left) and bright-field merged images (right) are shown. Scale bars, 100 μm. (e,f) Co- immunoprecipitation of MtDELLA1-GFP, MtDELLA2-GFP or MtDELLA3-GFP proteins expressed in N. benthamiana leaves with either the HA-NSP2 protein (e) or the HA-NF-YA1 protein (f). Blots were revealed with an anti-GFP (upper panel) or an anti-HA (middle and lower panels) antibody. Inputs were used as loading controls. (g,h) Transactivation assays in A. thaliana protoplasts of the pERN1:LUC construct by NSP1/NSP2 (a) or NF-YA1 (b) with or without MtDELLA1. An empty vector is used as negative control. Results represent the means of two biological replicates, error bars represent the s.e., and letters indicate significant differences (α<0.01) using a Kruskal and Wallis test.