Figure 3.
MPK6-Silenced Lines Exhibit Reduced Resistance to P. parasitica.
(A) Seven- to ten-day-old seedlings were inoculated with P. parasitica Emwa1 (105 spores/mL). At 6 to 8 dpi, single cotyledons from 35 to 40 seedlings were analyzed under the microscope and categorized into one of six categories (0, 1 to 5, 6 to 10, 11 to 15, 16 to 20, or >20) depending on the number of sporangiophores observed. Col-0 is mostly resistant to this isolate, whereas Ws-0 is highly susceptible. MPK3ihp L5 is the nonsilenced control. Experiments were repeated three times with similar results.
(B) Inoculation of Col-0, MPK3ihp L5, and MPK6 silenced lines with P. parasitica Hiks1, which is virulent on the Keswick (Ksk) accession. Inoculation and analysis of 40 to 44 seedlings was done as described in (A).
(C) Trypan blue staining of P. parasitica Emwa1-inoculated cotyledons at 96 hpi. Trypan blue stains dead leaf cells (including xylem cells) and oomycete hyphae.