Impact Of Host Plant Xylem Fluid On Xylella Fastidiosa Multiplication ...

4. mature cecropin A with no signal peptide sequence
The authenticity of the PCR-amplified sequences was confirmed by nucleotide sequencing in both directions and the
constructs are currently being used to generate transgenic A. thaliana by standard procedures.
Table 1. Effect of cecropins and kanamycin against the growth of X. fastidiosa
Concentration
(µM)
Increase in bacterial concentration in comparison to cultures lacking antibiotic
Week 1 (% ± s.d.) Week 2 (% ± s.d.) Week 3 (% ± s.d.)
cecropin A 0.5 69 ± 3 47 ± 47 64 ± 42
0.25 72 ± 10 80 ± 21 117 ± 5
0.1 103 ± 13 68 ± 2 87 ± 25
0.05 110 ± 46 50 ± 1 91 ± 22
cecropin B 0.5 69 ± nd 114 ± 6 87 ± 45
0.25 63 ± 31 75 ± nd 110 ± 15
0.1 72 ± 101 128 ± 63 90 ± nd
0.05 93 ± 17 101 ± 18 74 ± 10
cecropin P1 0.5 98 ± 18 70 ± 40 70 ± 62
0.25 82 ± 18 98 ± nd 120 ± 17
0.1 111 ± 52 93 ± 24 72 ± 24
0.05 93 ± 10 99 ± 22 73 ± 18
kanamycin 2 11 ± 3 9 ± 8 16 ± 2
1 19 ± 8 32 ±39 33 ± 22
0.5 42 ±16 77 ± 9 103 ± 16
0.25 60 ± 13 72 ± 17 105 ± 12
nd = not determined
Table 2. Effect of recombinant cecropin A on the growth of E. coli
Source of recombinant cecropin A Inoculum dose Inhibition
(bacteria/mL) (%)
Sf21 cell pellet (1 x 10 5 cells) 1.1 x 10 3 3.1 ± 13.2
Sf21 cell supernatant (undiluted) 1.1 x 10 3 99.7 ± 0.1
Sf21 cell supernatant (undiluted) 1.0 x 10 4 57.9 ± 1.6
Sf21 cell supernatant (undiluted) 8.5 x 10 4 51.6 ± 0.2
Sf21 cell supernatant (undiluted) 7.3 x 10 5 13.1 ± 0.1
Sf21 cell supernatant (1:5 diluted) 7.0 x 10 5 11.1 ± 0.2
Sf21 cell supernatant (1:10 diluted) 7.0 x 10 5 2.5 ± 0.1
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