biostudies-literatureSrivastava MEuropean Research CouncilBiotechnology and Biological Sciences Research Council2892-2906https://www.ebi.ac.uk/biostudies/studies/S-EPMC9338799biostudies-literatureUnknown34(8)A key function of photoreceptor signaling is the coordinated regulation of a large number of genes to optimize plant growth and development. The basic helix loop helix (bHLH) transcription factor MYC2 is crucial for regulating gene expression in Arabidopsis thaliana during development in blue light. Here we demonstrate that blue light induces the SUMOylation of MYC2. Non-SUMOylatable MYC2 is less effective in suppressing blue light-mediated photomorphogenesis than wild-type (WT) MYC2. MYC2 interacts physically with the SUMO proteases SUMO PROTEASE RELATED TO FERTILITY1 (SPF1) and SPF2. Blue light exposure promotes the degradation of SPF1 and SPF2 and enhances the SUMOylation of MYC2. Phenotypic analysis revealed that SPF1/SPF2 function redundantly as positive regulators of blue light-mediaThe Plant cellThe conjugation of SUMO to the transcription factor MYC2 functions in blue light-mediated seedling development in Arabidopsis.PMC9338799310235BB/V003534/1BB/T010533/1Srivastava AKMansi MGough CSadanandom ABhagat PKRoy DSrivastava MZhang CfalseThe conjugation of SUMO to the transcription factor MYC2 functions in blue light-mediated seedling development in Arabidopsis.A key function of photoreceptor signaling is the coordinated regulation of a large number of genes to optimize plant growth and development. The basic helix loop helix (bHLH) transcription factor MYC2 is crucial for regulating gene expression in Arabidopsis thaliana during development in blue light. Here we demonstrate that blue light induces the SUMOylation of MYC2. Non-SUMOylatable MYC2 is less effective in suppressing blue light-mediated photomorphogenesis than wild-type (WT) MYC2. MYC2 interacts physically with the SUMO proteases SUMO PROTEASE RELATED TO FERTILITY1 (SPF1) and SPF2. Blue light exposure promotes the degradation of SPF1 and SPF2 and enhances the SUMOylation of MYC2. Phenotypic analysis revealed that SPF1/SPF2 function redundantly as positive regulators of blue light-media2022-01-01T00:00:00Z2022 Jul2025-04-19T11:17:45.844Z2025-04-19T11:17:45.844ZS-EPMC93387993556752710.1093/plcell/koac142