Figure 2.

Effects of foliar application of plant hormones on systemic plant defense against M. graminicola infection. Shoots of 15-d-old rice plants were sprayed until runoff with 500 μm ethephon, 100 μm MeJA, 250 μm BTH, or the corresponding control solution. At 24 h after hormone treatment, plant roots were inoculated with 300 second-stage juveniles of M. graminicola. A, Number of galls per plant 2 weeks after inoculation. Bars represent means and se of eight plants. Different letters indicate statistically significant differences (Duncan’s multiple range test with α = 0.05). Data represent one of three independent experiments with similar results. B, Representative root system 2 weeks after infection with M. graminicola and with the corresponding foliar hormone application. C, Developing RKN inside root galls, visualized with acid fuchsin. Roots were boiled in acid fuchsin. This leads to intense pink staining of galls, giant cells (GC), nematodes (N), and egg mass (E).