Fig. 2
EMS1-TPD1 and BRI1-BRs receptor-ligand pairs can cross-complement. a The phenotypic recovery of bri1-116 null allele by expressing BRI1, TPD1, EMS1 independently and EMS1 together with TPD1 under the control of BRI1 promoter. Scale bar, 1 cm. b Analyses of the expression levels of the transgenes in the rosette leaves of the corresponding plants shown in a Protein expression levels were detected with anti-GFP antibody. Actin served as the loading control. TPD1 expression levels were detected by semi-quantitative RT-PCR. ACT2 served as an internal control. c Quantification of the transgenic lines with the diameter of the rosette leaves in the whole plants grown for 4 weeks, n = 15 plants, *P < 0.05, **P < 0.0001 as one-way ANOVA with a Tukey’s test. d Dephosphorylation of BES1 by both BRI1-BRs and EMS1-TPD1 signaling pathways. Expression of BRI1, or EMS1 together with TPD1 under the control of BRI1 promoter rescued the dephosphorylation of BES1 in BR-dependent and BR-independent manner, respectively. BL brassinolide, BRZ brassinozole. Phosphorylated BES1 (pBES1) and dephosphorylated BES1 were detected with BES1 antibodies in the extracts of 10-day-old seedlings of the indicated genotypes. e, f Co-expression of EMS1 & TPD1 in bri1-116 partially rescued the hypocotyl elongation of bri1-116 mutant but did not restore the sensitivity to BRZ. 5-day-old dark-grown seedlings in 1/2 MS medium treated with or without 5 μM BRZ. Scale bar, 1.5 cm. n = 10 seedlings. **P < 0.0001 (two-way ANOVA with Sidak’s test). g Anthers with or without pollen grains in the transgenic lines expressing EMS1 or BRI1 under the control of EMS1 promoter in ems1 background. Arrows, fertile siliques. h Protein expression levels of the transgenes with GFP tag were detected in the inflorescences of the corresponding plants shown in g with anti-GFP antibody. Actin served as the loading control. i Semi-thin sections of stage-5 anthers showing the normal anther cell differentiation in Ler, proEMS1::EMS1 in ems1 or proEMS1::BRI1 in ems1 as well as the abnormal anther cell differentiation in ems1 (lack of tapetal cells). E epidermis, En endothecium, ML the middle layer, T tapetal cells, and M microsporocytes. Scale bars, 10 μm
