Constitutive expression of transgenes encoding derivatives of the synthetic antimicrobial peptide BP100: impact on rice host plant fitness

Table 1 Antibacterial, phytotoxicity and hemolytic activity of BP100 derivatives

BP100 derived peptide	# Amino acids	Antimicrobial activity					Phytotoxicity (germination)	Phytotoxicity at 150 μM(inoculation)	Hemolytic activity at 150 μM
		Ea	Pss	Xav	Dc	Fv
BP100	11	2.5 - 5.0	2.5 - 5.0	5.0 - 10	5-10	<2.5	64	0.90 ± 0.05^a	22.0 ± 2.8
unmodified BP100	11	5.0 - 10	5.0 -10	10 - 20	10 - 20	<2.5	64	0.80 ± 0.02^a	1
BP100.1	15	2.5 - 5	2.5 - 5	1.25 - 2.5	10 - 20	<2.5	64	1.17 ± 0.09^ab	<1
BP100.2	30	5.0 - 10	5.0 -10	5.0 - 10	>40	<2.5	32	1.15 ± 0.07^ab	3
BP100.2i	30	2.5 - 5	2.5 - 5	1.25 - 2.5	20 - 40	2.5 - 5	16	1.32 ± 0.06^b	4
BP100.3	45	>20	>20	10 - 20	>40	5-10	16	1.38 ± 0.04^b	4
BP100.2mi	48	2.5 - 5	2.5 - 5	<0.6	20 - 40	2.5 - 5	16	1.46 ± 0.12^b	5

Antibacterial activity was determined against Erwinia amylovora (Ea), Pseudomonas syringae pv. syryngae (Pss) and Xanthomonas axonopodis pv.vesicatoria (Xv) as reporter species, and against the rice pathogens Dickeya chrysanthemi (Dc) and Fusarium verticillioides (Fv).
Minimal inhibitory concentrations (MIC) are given in μM and were calculated with 10⁸ bacterial CFU/ml or 10⁴ conidia/ml. Phytotoxicity values in rice germination assays are given as minimal peptide concentrations (μM) causing significant alteration of shoot length. Phytotoxicity values in tobacco leaf inoculation assays are given as the mean of the lesion diameter (cm) and standard error upon inoculation of 150 μM peptide solutions. Letters indicate different groups in one-way ANOVA analysis and Tukey's b posttest with α = 0.05. Hemolytic activity is given as the ratio between each peptide and the reference peptide BP100 (calculated at 150 μM and given in % with confidence interval for α = 0.05 [47]).

ISSN: 1471-2229