Fig. 1

Subcellular localization and expression analysis of LbHLH in L. bicolor. A Subcellular localization analysis of 35S::LbHLH-GFP in onion epidermal cells. The GFP-LbHLH fusion protein was expressed in the nucleus. 35S::GFP was used as the empty vector control. Bar = 50 μm. DAPI appears as blue fluorescence specifically in the nucleus, and FM4-64 appears as red fluorescence at the plasma membrane. B LbHLH expression levels in leaves at different developmental stages and under different treatments. A: stage A, undifferentiated, 4–5 days after sowing; B: stage B, salt gland differentiation, 6–7 days after sowing; C: stage C, stomatal differentiation, 8–10 days after sowing; D: stage D, epidermal differentiation, 11–16 days after sowing; E: stage E, mature, more than 17 days after sowing; Mature leaves: fully expanded leaves; NaCl: mature leaves from stage E seedlings after 24 h of 200 mM NaCl treatment; 6-BA: mature leaves from stage E seedlings grown on 0.04 mg/L 6-BA; ABA: mature leaves from stage E seedlings grown on 0.1 mg/L ABA. Roots and stems were collected from stage E seedlings. Data are the means ± SD of three replicates; different letters indicate significant differences at P = 0.05 according to Duncan’s multiple range test. C In situ hybridization of LbHLH using developing leaves in L. bicolor. LbHLH transcripts were detected using a digoxin-labeled anti-sense probe, which produces a blue-violet color