Ex vivo bioassay for Foc resistance in transgenic banana plants.
pPhDef1-1301 and pPhDef2-1301 transgenic plants and untransformed control banana plants hardened in a greenhouse for 2 months were challenged with Foc mass culture. External and internal symptoms of Foc infection on pPhDef1-1301 (A and B) and pPhDef2-1301 (C and D) transgenic and untransformed control banana plants (UC). Untransformed control plants showed yellowing of leaves and wilting whereas transgenic plants showed negligible infection. Corm sections of control plants showed intense discoloration whereas the transgenic plants showed significantly less discoloration of the corm tissue.