Fig. 4

The functional characterization of LsaGRF5 gene and characterization of LsaGRF5 protein. A The expression profiles of LsaGRF5 and pri-Lsa-MIR396a in different tissues of the lettuce ‘YDL’. Actin was used as a reference gene. B Subcellular localization of LsaGRF5 in lettuce protoplasts. Confocal images showed that the fluorescence of LsaGRF5-GFP fusion protein was completely overlapped with that of Ghd7-mCherry, which was specifically expressed in the nucleus. The vector with 35S::Ghd7-mCherry only was used as a control. Bar = 5 mm. C The schematic diagrams of the constructions used in transactivation assay in yeast. The full-length, N-terminal region (1–154 aa) containing QLQ and WRC domains and C-terminal region (155–317 aa) of the LsasGRF5 were respectively fused into DNA sequences containing a GAL4 DNA-binding domain in pGBKT7 (BD). D Transactivation assay of different LsaGRF5 constructs in yeast. The constructs in (B) were expressed in the yeast strain Y2HGold with PGBDT7-OsMYB103L as a positive control and the negative control plastid (pGBKT7). The transformants with different diluted concentrates were dropped on the SD/−trp and SD/−trp/AbA/X-alpha-gal plates. After 2–4 days at 30 °C, possible transcriptional activation functions of LsaGRF5-full length and LsaGRF5_155–317 were observed