Fig. 1: Confocal laser scanning microscopy (CLSM) imaging of dsRNA uptake by Magnaporthe oryzae from liquid cultures and the leaf surface.

A Conidia (10⁴mL⁻¹) were incubated with 10 ng/µL dsRNA labeled with Fluorescein (21 bp dsRNA) or Alexa Fluor^® 488 dye (longer dsRNAs; Suppl. Data 2) in 0.002% (v/v) Tween20 for 24 h at room temperature, before images were taken. Scale bar equals 20 µm. Upper row: AF488 and fluorescein imaging [λexcitation (nm): 501; λemission (nm): 591]; lower row: merge with bright field. B CLSM imaging of Phi6-dsRNA uptake. Mo conidia (10⁴mL⁻¹) were incubated with 10 ng/µL of Phi-dsRNAs (2948, 4063 and 7599 bp) labeled with Fluorescein as described under A. Before images were taken, mycelia were treated with dsRNA degrading MNase. Scale bar equals 50 µm. Left: AF488 and fluorescein imaging [λexcitation (nm): 501; λemission (nm): 591]; right: merge with bright field. C CLSM imaging of dsRNA uptake by Mo germ tubes from locally treated Bd leaves. Intact second youngest leaves of three-week-old Bd plants were first drop-treated with 20 µL drops containing 10 ng/µL Cy3-labeled 490 bp SHP-dsRNA in 0.002% (v/v) Tween20. After 3 h, the treated leaf areas were drop-inoculated with 10 µL drops containing 100 Mo conidia and imaged 48 h after inoculation. Scale bar equals 50 µm. Cy3 [λexcitation (nm): 565; λemission (nm): 626] signal left and merged with bright field, right. All dsRNA sequences are shown in Suppl. Data 2 and Suppl. Data 3.