Fig. 4.

Distribution of encysted Ph. capsici zoospores around the apical segments of tomato hairy roots. (A) Cyst distribution around nontransformed (wt) tomato hairy roots (a) and around hairy roots that expressed pAKK 1467B (b), ZmCKX1 (c), ZmCKX1-His (d), ZmCKX1-Pc87 (e), or ZmCKX1-Pc42 (f). Each root segment was incubated with 20,000 zoospores for 90 min before examination. (B) Density of encysted zoospores in relation to distance from the surface of roots that expressed ZmCKX1 peptides. Cyst density was estimated as the average gray-level value of pixels along 15 random transect in three images per hairy root treatment. Transects positioned perpendicularly to the root surface were 2 mm in length by 10 μm in width. Transect samples were made along the first 3 mm of root length from the root cap. Assessments of gray levels along transects were made by using MetaMorph software, Version 6.2r6 (Universal Imaging).