MMP11 and infection: On the other hand, levels of cell death, as detected by Trypan blue staining, and electrolyte leakage, as estimated by ion conductivity, were comparable in leaves of pTRV2-Sl3-MMP- and pTRV2-GUS-infiltrated plants without infection of B. cinerea but significantly increased after infection with B. cinerea (Fig. 7c and d).