Figure 3.

Expression of PEP genes during early stages of mantle development. A, Expression of PDA-GUS in germinating spores exposed to pisatin; B, expression of PDA-GUS in border cell mantles 24 h post inoculation; C, expression of PDA-GUS in older mantle surrounding infected root tip; and D, expression of PEP5 (left) and PEP2 (right) genes of N. haematococca at time 0 and at 24 h after inoculation. Two-day-old seedlings containing a full set of border cells were inoculated with 10⁶ spores of N. haematococca, and RNA from root tips was recovered at specific time points after inoculation, as described in “Materials and Methods.” A 100-bp ladder was used to establish agreement between expected size and actual size of fragments obtained by amplification of each gene.