Endophytic fungi from the roots of horseradish (Armoracia rusticana) and their interactions with the defensive metabolites of the glucosinolate - myrosinase - isothiocyanate system

Table 3 Summary of the tested parameters of endophytic fungi isolated from horseradish and soil fungi

	Sole C source^a	Glucosinolate decomposition in horseradish extract Residual amount after 16d (%)^b				Decomposition rate in horseradish extract (mM d^-1)				IC₅₀ liquid culture (mM)
ID	SGN	SGN	GIB	GLN	GBR	SGN	GIB	GLN	GBR	AITC	PEITC
E1	+	0.2 ± 0%	3.7 ± 0.9%	0 ± 0%	17 ± 3.1%	1.125	0.006	0.057	0.005	0.2834	0.0903
E2	+	0.3 ± 0%	25.6 ± 1.9%	0.4 ± 0.1%	28.1 ± 1.6%	1.476	0.002	0.033	0.004	0.2590	0.1004
E3	+	3.6 ± 0.8%	7.4 ± 0.9%	0.5 ± 0.2%	6.5 ± 1%	0.606	0.003	0.030	0.008	0.1925	0.0907
E4	+	0.3 ± 0%	36.3 ± 12.2%	0.4 ± 0.3%	33.9 ± 11.7%	0.734	0.003	0.036	0.006	0.1096	0.0288
E5		16 ± 18.9%	85 ± 10.3%	50.5 ± 14.8%	71.6 ± 8.1%	0.624	0.001	0.018	0.003	0.0920	0.0404
E6		0.2 ± 0.1%	42.5 ± 6.1%	3.3 ± 1.4%	26.6 ± 4.6%	0.783	0.001	0.032	0.006	0.0764	0.0328
E7		110.9 ± 4.9%	103.5 ± 4.4%	108.1 ± 2.3%	92.5 ± 10.1%	-	-	-	-	0.2565	0.0257
S1	+	0.1 ± 0%	5.1 ± 0.2%	0 ± 0%	65.3 ± 3.7%	3.037	0.007	0.214	0.008	0.1084	0.1511
S2	+	0.1 ± 0%	0 ± 0%	0 ± 0%	0 ± 0%	2.111	0.015	0.148	0.030	0.0743	0.0266
S3	+	85.2 ± 4.9%	75 ± 1.9%	74.8 ± 0.6%	83.9 ± 1%	-	-	-	-	0.2639	0.0700
S4		58.7 ± 5.7%	72 ± 5%	33.4 ± 5.7%	47.3 ± 4.7%	-	-	-	-	0.0338	0.0246
S5		87.5 ± 18.2%	101.4 ± 4.6%	106.7 ± 3.8%	98.7 ± 2%	-	-	-	-	0.1251	0.0176
S6		67.3 ± 12.1%	61.8 ± 9.4%	67.4 ± 14.4%	63.2 ± 10.4%	-	-	-	-	0.0277	0.0187
S7		105.2 ± 4.9%	90.3 ± 3.4%	95.7 ± 3.6%	89.8 ± 2.9%	-	-	-	-	0.0930	0.0738
S8		100.8 ± 2.5%	88 ± 4.8%	87.9 ± 4%	92.2 ± 3.5%	-	-	-	-	0.0867	0.0149
S9		0.3 ± 0.2%	0.1 ± 0.2%	0.2 ± 0.1%	0.4 ± 0.1%	2.982	0.012	0.206	0.018	0.0221	0.0553
S10		0.1 ± 0.1%	0.1 ± 0.1%	0.1 ± 0%	0.2 ± 0%	2.669	0.021	0.178	0.032	0.1954	0.1393

^aSpecies marked by '+' accepted sinigrin as the sole carbon source
^bData for other glucosinolates is available in Additional file 3: Table 2
Decomposing ability was tested in pure horseradish extract as the growth medium. IC₅₀ values of the isothiocyanates of horseradish against growth of fungi are given in end-concentration in the medium (mM). Fungi: E1, Fusarium oxysporum; E2, Macrophomina phaseolina; E3, Fusarium oxysporum; E4, Setophoma terrestris; E5, Paraphoma radicina; E6, Paraphoma radicina; E7, Oidiodendron cerealis; S1-S10: soil fungi from the same site as one of the horseradish samples
Abbreviations: AITC allyl isothiocyanate, GBR glucobrassicin, GIB glucoiberin, GLN gluconasturtiin, n.d. not determined, PEITC 2-phenylethyl-isothiocyanate, SGN sinigrin

ISSN: 1471-2229