Yeast assays
Yeast one-hybrid assays were performed as described by Lin et al. (2007). The yeast two-hybrid and three-hybrid assays were performed using a Clontech kit (PT3024-1 (PR973283)). For yeast two-hybrid assays, the bait vectors (pGBKT7 plus candidate genes) and prey vectors (pGAGT7 plus candidate genes) were transformed into the gold and Y187 yeast strains, respectively, and then each colony was picked for mating, and the mating solution was sprayed on SD/-Trp/-Leu/X-α-Gal/AbA (DDO/X/A) agar plates, and positive results were confirmed by growing them on SD/-Ade/-His/-Trp/-Leu/X-α-Gal/AbA (QDO/X/A) agar plates. For the yeast three-hybrid assay, COP1-pGADT7 and COL3-COL13-pBbidge constructs were co-transformed into the gold yeast strain. Each colony was picked and grown in SD/-Leu/-Met/-Trp and SD/-Leu/-Trp solutions, respectively. Normalized Miller units were calculated as a ratio of α-galactosidase activity in yeast. For all yeast assays, we used empty vectors as controls.