Table 3.
Lethal time 50 (LT50) for Plutella xylostella larvae upon oral uptake of wild-type and mutant Pseudomonas strains.
| Strain | Phenotype | LT50 (h) | ||
|---|---|---|---|---|
| Experiment 1 | Experiment 2 | Experiment 3 | ||
| CHA0 | Wild type | 24.8 (23.7; 25.8) | 23 (21.8; 24.1) | 20.8 (19.8; 21.8) |
| CHA400 | Pvd− | 26.8 (25.3; 28.2) | 23.6 (22.7; 24.6)* | |
| CHA1196 | Gcd− | 21.9 (21.1; 22.7)† | 23.6 (22.6; 24.6)* | |
| CHA1197 | Gad− | 26.0 (24.9; 27.2) | 23.0 (22.1; 24.0)* | |
| CHA805-g | AprA− | 22.1 (21.1; 23.2) | 22.9 (21.8; 24.1) | |
| CHA1241 | Phl− | 24.3 (23.3; 25.4) | 22.9 (21.9; 23.8)* | |
| CHA5091 | Prn− | 21.1 (20.0; 22.1)† | 20.6 (19.6; 21.7) | |
| CHA5092 | Plt− | 27.1 (25.8; 28.4) | 21.7 (20.8; 22.6) | |
| CHA5098 | Phl−Prn−Plt | 26.4 (25.2; 27.6) | 19.7 (18.7; 20.8) | |
| CHA5101 | Ofa− | 28.9 (27.7; 30.2)* | 31.1 (29.3; 32.9)* | |
| CHA5103 | Hcn− | 27.8 (26.4; 29.3)* | 23.7 (22.8; 24.6)* | |
| CHA5118 | Phl−Prn−Plt−Hcn−Ofa− | 31.6 (30.4; 32.7)* | 34.6 (32.6; 36.5)* | |
| CHA89 | GacA− | >37 | >37 | >37 |
| Control | >37 | >37 | >37 | |
| Experiment 1 | Experiment 2 | |||
| CMR12a | Wild type | 18.0 (15.6; 20.5) | 21.0 (20.0; 22.0) | |
| Clp1 | Ses− | 31.3 (28.0; 34.7)* | 25.8 (23.8; 27.8)* | |
| ΔClp2 | Ofa− | 23.5 (21.2; 25.9)* | 20.9 (19.7; 22.1) | |
| ΔClp2-clp1 | Ofa−Ses− | 37.3 (32.9; 41.7)* | 33.5 (29.2; 37.9)* | |
| ΔPhz | Phz− | 21.9 (20.4; 23.5) | 20.8 (18.9; 22.7) | |
| ΔPhz-Clp1 | Phz−Ses− | 24.0 (22.3; 25.7)* | 35.1 (31.5; 38.6)* | |
| ΔPhz-ΔClp2 | Phz−Ofa− | 20.1 (17.6; 22.6) | 27.9 (26.3; 29.5)* | |
| ΔPhz-ΔClp2-Clp1 | Phz−Ofa−Ses− | 37.2 (33.5; 40.9)* | 30.7 (27.7; 33.7)* | |
| Control | >42 | >42 | ||
| Experiment 1 | Experiment 2 | Experiment 3 | ||
| PCL1391 | Wild type | 17.1 (15.7; 18.5) | 20.9 (19.2; 22.5) | 27.9 (25.4; 30.5) |
| PCL1832 | Clp1391− | 21.2 (19.4; 23.0)* | 23.9 (21.5; 26.2) | |
| PCL1113 | Phz− | 19.5 (18.1; 20.9) | 19.9 (18.1; 21.7) | |
| PCL1123 | GacS− | 37.6 (34.1; 41.2)* | 34.0 (29.3; 38.8)* | |
| PCL5103 | Hcn− | 22.9 (21.7; 24.2) | 30.9 (28.4; 33.4) | |
| Control | >42 | >42 | >42 | |
Lethal time (LT50) values were calculated based on a generalized linear model (MASS package in R) from eight replicates with eight larvae per replicate in case of strain P. protegens CHA0 and from four replicates with eight larvae per replicate for strain P. chlororaphis PCL1391 and Pseudomonas sp. CMR12a. Confidence intervals (95%) for LT50 values are given in brackets. Marked values differed significantly from the LT50 value of the respective wild-type strain (p < 0.05).
significantly faster;
significantly slower; If 50% mortality was not reached by the end of the experiment, LT50 values are given as >X, with X being the last time point at which the larvae were checked for survival. Sterile 0.9% NaCl served as control (Control). Each mutant was tested at least three times and results of two representative experiments are depicted. AprA, extracellular protease; Clp1391, cyclic lipopeptide of strain PCL1391; Gad, gluconate dehydrogenase; Gcd, glucose dehydrogenase; Hcn, hydrogen cyanide; Ofa, orfamide; Phl, 2,4-diacetylphloroglucinol; Phz, phenazine; Plt, pyoluteorin; Prn, pyrrolnitrin; Pvd, pyoverdine; Ses, sessilin.