Differences in susceptibility to B. cinerea and to the isolated Xyn11A protein shown by three N. tabacum cultivars: cv. Havana, cv. Alcalá, and cv. Paraíso. A) Example of the infection caused by B. cinerea in the three cultivars. The fungal strain used was B05.10 (wild-type). Pictures were taken 3 days after inoculation. B) Mean infection areas obtained at different times after inoculation, calculated from at least 15 infections. C) Necrosis inducing activity of purified Xyn11A on the three cultivars. Pictures were taken 4 days after infiltration. Bars marked with different letters are statistically different (P < 0.05 by Student's t test).