Yeast two hybrid and bimolecular fluorescence complementation assay
For Y2H analysis, all cDNAs of SlUVI4 and SlCCS52s were cloned into pDEST-GADT7 and pDEST-GBKT7 (Rossignol, Collier, Bush, Shaw, & Doonan, 2007) and assays were performed following the user manual of Matchmaker Gold Yeast Two-Hybrid System (Clontech Laboratories, Inc.). For BiFC analysis, SlUVI4 cDNA was cloned into the destination vector pSPYNE-35S GW and cDNAs of SlCCS52 genes were cloned into the destination vector pSPYCE-35S GW (Walter et al., 2004). These vectors were transiently transformed into onion cells via Agrobacterium tumefacien strain GV3101 together with gene silencing inhibitor P19 (Schutze, Harter, & Chaban, 2009; W. Sun, Cao, Li, Zhao, & Zhang, 2007). GFP signals were detected using Nikon fluorescence microscope ECLIPSE Ni-U.