*3.4. Subcellular Localization of OsbHLH079*

To investigate the subcellular localization of OsbHLH079, the *35S::YFP-OsbHLH079* construct was prepared. The full-length coding sequence of *OsbHLH079* was amplified with gene-specific primers (Table S1), and fused with *YFP* in the pEarleyGate 104 (pEG104) vector through LR reactions using Gateway LR Clonase II Enzyme Mix (Invitrogen, USA). The resultant construct, *35S::YFP-OsbHLH079*, and the *35S::YFP* construct were introduced into onion epidermal cells using a DNA particle delivery system (Biolistic PDS-1000/He; Bio-Rad, Hercules, CA, USA), respectively. The transformed onion epidermal cells were incubated on Murashige and Skoog phytoagar medium (pH 5.7) under dark conditions at 25 ◦C for 18 h, and then onion nuclei were stained with 300 nM 4- ,6-diamidino-2-phenylindole (DAPI; Invitrogen, USA) in phosphate-buffered saline for 5 min. YFP and DAPI fluorescence were observed using a confocal laser scanning microscope (SP8X, Leica, Germany) with excitation wavelengths of 458 and 405 nm and emission wavelengths of 514 and 488 nm for YFP and DAPI, respectively.
