Expression of all the genes in the Qphs.pseru-3AS region during spike sprouting determined the wheat MFT homolog (TaMFT) as TaPHS1. (A) TaMFT was amplified in the PHS resistant (R) NIL, but not in the susceptible (S) NIL, during sprouting. RNA was extracted from the embryos of seeds harvested from the spikes at 0 hr, 1 day, 3 days, and 7 days after imbibing. “All germinated” embryos were obtained by incubating the spikes at 4° for 3 days after imbibing and then keeping them at room temperature for 1 day. (B) TaPHS1 is expressed only in the embryo of the resistant (R) NIL after 10 days and before physical maturity during seed development, not in the susceptible (S) NIL. (C) TaPHS1 expression occurs only in the embryo, not in other tissues at 15 days after anthesis. Actin was used as control. TaPHS1-CDS refers to the primer pair P1 + P6 that were used in RT–PCR and designed from the full-length cDNA sequence of Rio Blanco (Table S1).