Complementation of the xyn11A mutation in B. cinerea with the wild-type xyn11A gene and the site-directed mutant alleles coding for non xylan-hydrolyzing proteins. A) Mean infection areas on tomato leaves generated by the wild-type strain B05.10, the xyn11A mutant N23, and N23 retransformed with either the wild-type xyn11A gene (wt) or the indicated site-directed mutated genes. Mean areas were calculated from at least 50 infections. B) Example leaf of the experiment in (A), 2 days after inoculation. Bars marked with different letters are statistically different (P < 0.05 by Student's t test).