Fig. 2.

symrem1 and flot4 mutants are impaired in IT initiation. (A) Mapped Tnt1 transposon insertions. Phenotypical analysis of symrem1 and flot4 mutants. (B and C) Infection structures were scored at 7 d after inoculation with S. meliloti (lacZ) and classified into microcolony (MC)/aborted ITs that were arrested within trichoblasts (B) and elongated ITs that progressed into the root cortex (C). (D–F) Representative elongated ITs as found in WT (D), and infections arrested in the MC stage in symrem1-2 (E) and flot4-3 (F) mutants. In B and C, ***P < 0.001, Tukey–Kramer multiple-comparison test. (Scale bars: 10 μm.)