Scanning Electron Microscopy Reveals Different Response Pattern of Four Vitis Genotypes to Xylella fastidiosa Infection

摘要: The xylem-limited bacterium Xylella fastidiosa causes Pierce's disease (PD), whose symptoms are primarily the result of xylem vessel blockage in susceptible grapevines. Stem internode and petiole tissues from infected uninfected control plants four grape genotypes (Vitis vinifera, V. rufotomentosa, smalliana, arizonica/candicans) differing PD susceptibility were examined using scanning electron microscopy (SEM). Tyloses, fibrillar networks, gum plugs observed lumens tracheary elements petioles internodes both water-inoculated X. fastidiosa-inoculated all genotypes. Bacteria not plants. In tissues, greatest number occluded vessels vinifera smallest arizonica/candicans. infested with was did differ among other three Systemic infection found frequency which SEM corresponded well bacterial levels estimated by enzyme-linked immunosorbent assay. Among plants, tylose formation lowest arizonica/candicans Infection strongly induced smalliana but Analysis across indicated an induction networks occlusions response to infection, whereas treatment comparisons within significant except for petioles. Limiting spread conduit does appear be mechanism conferring resistance or tolerance arizonica/candicans, rufotomentosa. contrast, strong tyloses may detrimental rather than beneficial survival after infection.