Table 1.
Photon counting histogram analysis of the fluorescent proteins expressed in plant protoplasts
| Construct | ηCFP chan (kHz/mol) | NCFP chan (−) | ηYFP chan (−) | NYFP chan (kHz/mol) |
|---|---|---|---|---|
| no FP* | 0.4 ± 0.2 | 3.5 ± 1.4 | 0.3 ± 0.0 | 2.0 ± 0.7 |
| no FP† | 0.4 ± 0.1 | 22 ± 16 | 0.3 ± 0.1 | 24 ± 12 |
| ECFP† | 8.9 ± 0.5 | 1.2 ± 0.4 | – | – |
| EYFP† | – | – | 9.3 ± 0.5 | 0.85 ± 0.22 |
| AtSERK1-FP* (1st component) | 10.9 ± 1.3 | 1.3 ± 0.3 | 11.0 ± 0.5 | 1.4 ± 0.4 |
| (2nd component) | 22.3 ± 0.2 | 0.20 ± 0.04 | 19.8 ± 1.1 | 0.19 ± 0.10 |
| AtSERK1-FPΔLZ* | 10.6 ± 1.8 | 1.8 ± 0.5 | 11.0 ± 0.7 | 1.6 ± 0.3 |
| AtSERK1-FPkin† | 9.2 ± 0.6 | 0.95 ± 0.09 | 9.1 ± 0.7 | 1.1 ± 0.3 |
| AtSERK3-FP* | 11.4 ± 0.9 | 2.0 ± 0.6 | 11.3 ± 0.9 | 2.0 ± 0.3 |
| BRI1-FP* (1st component) | 11.0 ± 0.6 | 1.6 ± 0.5 | 11.1 ± 1.1 | 1.7 ± 0.4 |
| (2nd component) | 22.5 ± 1.0 | 0.31 ± 0.07 | 20.8 ± 1.3 | 0.40 ± 0.06 |
| CAAX-ECFP* | 10.6 ± 0.2 | 2.0 ± 0.4 | – | – |
| CAAX-(ECFP)2* | 20.3 ± 0.8 | 1.9 ± 0.6 | – | – |
The molecular brightness, η, and number of molecules, N, were retrieved by PCH analysis from the data acquired in the CFP and YFP detection channels. All PCH curves were fitted according to a single-species 2D (membrane) or 3D (cytoplasm) model, except for the data of AtSERK1 and BRI1, which had to be fitted by a two-species model to obtain a satisfactory fit. The standard deviations represent the variation of the parameter over experiments in different cells (n = 35).
*
Experiments in the plasma membrane.
†
Experiments in cytoplasmic regions lacking chloroplasts.