Table 1.
Endogenous SA levels in transgenic plants
| Plants | Uninfected
|
TMV-infected
|
|
|---|---|---|---|
| Free SA | Free SA | Bound SA | |
| Wild type | 0.042 ± 0.005 | 2.845 ± 0.5 | 2.254 ± 0.574 |
| SCaM-4 | 0.031 ± 0.010 | 4.121 ± 1.0 | 2.465 ± 0.832 |
| SCaM-5 | 0.035 ± 0.005 | 2.523 ± 0.5 | 1.621 ± 0.564 |
| NahG | 0.029 ± 0.025 | 0.067 ± 0.5 | 0.085 ± 0.014 |
| SCaM-4 + NahG | 0.038 ± 0.072 | 0.083 ± 0.7 | 0.079 ± 0.021 |
| SCaM-5 + NahG | 0.036 ± 0.056 | 0.072 ± 0.4 | 0.065 ± 0.035 |
The levels of SA (μg/g fresh weight) were determined from the top forth or fifth middle leaves of mature plants as described (41). SCaM-4, SCaM-5, and NahG indicate transgenic SCaM-4, SCaM-5, and NahG plants, respectively. SCaM-4 + NahG and SCaM-5 + NahG indicate transgenic plants that coexpress SCaM-4 and nahG gene, and SCaM-5 and nahG gene. TMV was infected in the leaves of 6-week-old transgenic plants that did not form lesions and leaf samples for SA assay were taken from TMV-infected leaves 10 days after inoculation, which appeared as HR lesions on leaves. Data are the means of two determinations from five independent transgenic plant lines. Bound SA levels were below detection limit in uninfected plants.