Fig. 5.

Host hypertrophy depends on Phtheirospermum-derived cytokinins. (A) Manually reassembled microscopy images show transgenic Phtheirospermum (Pj) roots expressing pMAS::GFP (Control) and high, medium (med.), and low levels of pMAS::AtCKX3. These transformed hairy roots infected Arabidopsis (At) plants and were stained at 28 dpi with Safranin-O. (B) The amount of hypertrophy in hairy roots was quantified by measuring root diameters above haustoria relative to the root diameter below haustoria (n = 2–3). (C) Relative AtCKX3 transgene expression in Phtheirospermum hairy roots was determined by real-time quantitative PCR (RT-qPCR) using the expression of PjUBC2 as reference. (B and C) Bars represent mean ± SE (*P < 0.05, **P < 0.01 Student’s t test). (Scale bars: 100 µm.)