Table 4. Quantitative analysis of SSO FRET-FLIM measurements performed in planta on roots of 5 day old Arabidopsis roots expressing BRI1-GFP or BRI1-GFP -SERK3/BAK1-mCherry.

	Treatment	τ (ps)	FRET (%)	IPS (%)	n
BRI1-GFP	BRZ	2402 ± 33	0	0	25
BRI1-GFP + SERK3/BAK1-mCherry	BRZ	2227 ± 134a	7	15	32
BRI1-GFP + SERK3/BAK1-mCherry	BRZ+BL	2241 ± 103a	7	10	27

^a The mean difference is significant at the (p<0.001) when compared to the donor only sample (BRI1-GFP).

All seedlings were depleted of endogenous brassinosteroids with BRZ and treated with 1 μM BL. τ represents the average fluorescence lifetime of the GFP in picoseconds ± SEM. IPS represents the percentage of interacting pixels, and n the number of fluorescence lifetime images analysed.