Fig. 6: SUMOylation is crucial for nuclear localization by interacting with Osimpα, and maintaing the stability of MoHTR1.

A Localization of MoHTR1 and SUMOylation site-directed mutants of MoHTR1 in rice sheath cells. MoHTR1 was transformed in the wild type and SUMO deletion mutant (ΔMosmt3), and SUMOylation site-directed mutants of MoHTR1 were transformed in the wild type. PWL2:eGFP:SV NLS was used as BIC and rice nuclei marker. The localization was observed in each mutant-infected cells at 30–34 hpi. Scale bar; 20 μm. B The nuclear localization percentage of SUMOylation site-directed mutants of MoHTR1 in rice sheath cells. C In vivo interaction between three SUMOylation site-mutated MoHTR1 and Osimpα. Site-muated MoHTR1 variants and Osimpα were cloned into split YFP expressed plasmids, respectively. BiFC assay was performed by co-transfecting of nYFP fused plasmid and cYFP fused plasmid in the rice protoplasts. Scale bar; 10 μm. D Protein stability assay of MoHTR1 and SUMOylation site-mutated MoHTR1. Purified MoHTR1 and double SUMOylation site-mutated MoHTR1 (Double_K-R) was incubated with rice extracts with or without proteasome inhibitor for 0, 1, 2, and 3 h. Western blotting was performed using anti-His antibodies. Mean ± SD, n = 3 independently inoculated rice sheath cells, significance was determined by an unpaired two-tailed Student’s t-test (**p < 0.01 and ***p < 0.001). Representative data are shown from independently experiments and source data are provided as a Source Data file.