Table 3. EC50 and resistance factor values of CYP51 variants and structural changes conferring resistance.

CYP51 variant	Number of strains	Epoxiconazole		Prochloraz		Tebuconazole		Triadimenol		Structural mechanism of resistance
		Mean EC50a(mg l−1)	RFb	Mean EC50(mg l−1)	RF	Mean EC50(mg l−1)	RF	Mean EC50(mg l−1)	RF
Wild-type	4	0.003±0.001	-	0.016±0.005	-	0.072±0.026	-	0.864±0.227	-	No resistance
Y137F	4	0.015±0.004	5.1	0.084±0.019	5.1	0.262±0.042	3.6	14.73±3.224	17	Obstruction of binding site by F137, particularly triadimenol
L50S, Y461H	2	0.048±0.016	17	0.070±0.007	4.3	1.185±0.075	16	NDc		Azole interaction lost at H461
L50S, I381V, Y461H	17	0.249±0.029	87	0.079±0.025	4.8	3.882±0.327	54	“		Constriction of binding cavity, azole interaction lost at H461
L50S, V136A, Y461H	8	0.205±0.030	71	0.455±0.076	28	0.385±0.188	5.4	“		Loss of interaction between Y137 and prochloraz
L50S, S188N, ΔY459/G460, N513K	4	0.088±0.032	31	0.069±0.021	4.2	2.214±0.939	31	“		Massive increase in binding cavity volume. I381 near prochloraz
L50S, S188N, I381V, ΔY459/G460, N513K	4	0.196±0.072	68	0.078±0.025	4.8	2.930±0.556	41	“		Massive increase in binding cavity volume. V381 near prochloraz
L50S, V136A, S188N, ΔY459/G460, N513K	3	0.255±0.024	89	0.359±0.122	22	0.114±0.025	1.6	“		Large increase in binding cavity volume. K148 near tebuconazole.
L50S, S188N, A379G, I381V, ΔY459/G460, N513K	16	0.447±0.079	155	0.012±0.003	0.7	9.439±1.382	131	“		Massive increase in binding cavity volume. V381 near prochloraz

^aMean EC50 of strains with ± standard error.

^bResistance factors (RF) of strains calculated as the fold changes in EC50 compared to the mean EC50 of wild-type strains.

^cnot determined.