a, Co-immunoprecipitation of SGT1b-FLAG, HSP70 and HSP90 using anti-COI1 antibody in roots of SGT1b-FLAG and SGT1b1–250-FLAG transgenic plants in the hsm1 background. Arrow indicates the input HSP90 proteins. b, Co-immunoprecipitation of SGT1b-FLAG, SGT1b1–250-FLAG, SGT1b1–323-FLAG, SGT1a-FLAG, HSC70-1-FLAG, HSP90.2-FLAG, RAR1-FLAG by COI1-HA or TIR1-HA in mesophyll protoplasts. The SGT1b1–250-FLAG construct mimics the premature truncated SGT1b protein in the hsm1 mutant and the SGT1b1–323-FLAG construct mimics the premature truncated SGT1b protein in the eta3 mutant. All experiments were repeated twice with similar results. c, Co-immunoprecipitation of COI1-FLAG, TIR1-FLAG, HSC70-1-FLAG and HSP90.2-FLAG by SGT1b-HA, SGT1b1–250-HA, SGT1b1–323-HA or SGT1a-HA in mesophyll protoplasts. d, Co-immunoprecipitation of COI1-FLAG, HSC70-1-FLAG, HSP90.2-FLAG and RAR1-FLAG by SGT1b-HA variants in protoplast lysates. Numbers on the sides of the blots are protein markers in kDa.