Table 4.
Data from the detached leaf assay on infected citrus (grapefruit) and apple (Red Delicious) leaves measuring the effect of a 0.8-1ml peptide solution at 25 μM concentration.
| Treatment | DNA | RNA |
|---|---|---|
| CLas clearance from infected citrus leaves | ||
| Water (control) | 23.99 ± 0.020 (9.4 × 105 ± 0.051) | 26.04 ± 0.020 (7.4 × 105 ± 0.071) |
| UGK-17 | 31.44 ± 0.013 (9.2 × 103 ± 0.210) | 33.30 ± 0.026 (7.0 × 102 ± 0.310) |
| UGK-9 | 23.07 ± 0.009 (10.3 × 105 ± 019) | 24.56 ± 0.019 (8.8 × 105 ± 0.053) |
| UGK-13 | 28.05 ± 0.012 (5.5 × 104 ± 0.065) | 31.12 ± 0.011 (7.7 × 103 ± 0.065) |
| 30P-3 | 29.08 ± 0.018 (2.3 × 104 ± 0.122) | 31.80 ± 0.028 (6.8 × 103 ± 0.190) |
| Erwinia amylovora clearance from infected apple leaves | ||
| Water (control) | 28.73 ± 0.590 (5.6 × 104 ± 0.07) | 28.91 ± 0.990 (5.4 × 104 ± 0.051) |
| UGK-17 | 34.46 ± 0.028 (400 ± 0.31) | 34.10 ± 0.560 (700 ± 0.210) |
| UGK-9 | 35.66 ± 1.43 (~102) | 32.62 ± 0.570 (4.7 × 103 ± 0.019) |
| UGK-13 | 35.78 ± 2.98 (~102) | 34.44 ± 0.620 (300 ± 0.065) |
| 30P-3 | 36.50 ± 0.89 (~102) | 31.54 ± 0.018 (7.8 × 103 ± 0.122) |
The levels of bacteria in the DNA/RNA extracted from the infected leaves were measured using qPCR, which provided the Ct values for the amplicon generated by the CLas- and E. amylovora-specific primers. The colony-forming units (cfu) of the bacterial load were computed using the cfu vs. Ct standard curve (Bao et al., 2020; Salm and Geider, 2004).
CLas, Candidatus Liberibacter asiaticus.