TABLE 3.

Saprophytic growth and pathogenicity of M. grisea xylanase mutants

Growth and pathogenicity	Strain and genotype
	CP987, wild-type	X7231,axyl-1ΔHygrxyl-2ΔBenr	X7601, xyl-6Δsur
Wild-type
Fresh wt (mg)b on:
CM	107 ± 8	94 ± 9	111 ± 12
Vogel/RCW	86 ± 9	48 ± 4	83 ± 7
Vogel/OSX	71 ± 7	29 ± 6	69 ± 6
Pathogenicityc
No. of lesions	166	158	149
Lesion length (mm)	3.1 ± 1.0	2.7 ± 0.8	3.2 ± 1.2

^aX7231 is a double-knockout strain for the XYL-1 and XYL-2 genes (37).

^bMycelia (fresh weight) were taken from 5-day-old cultures as described by Wu et al. (37). Growth media are complete media (CM) and Vogel's basic salt medium with rice cell walls (RCW) or oat spelt xylan (OSX; Sigma) as the sole carbon source. Medium recipes and sampling methodology were the same as described previously (37).

^cAn infection assay was performed on 17-day-old rice seedlings (compatible cultivar Sariceltik) as described previously (37). The number of lesions was the total from 10 fourth-folial leaves, and lesion length was the average of 30 randomly selected lesions from the 10 fourth-folial leaves 5 days postinoculation of fungal conidial suspension (2 × 10⁴/ml).