Expression of nitrate assimilation pathway in <i>Ph</i>. <i>infestans</i>, <i>Ph</i>. <i>mirabilis</i>, and <i>Py</i>. <i>ultimum</i>.

(A) Expression of nitrate reductase, nitrite reductase, and nitrate transporter. The top three rows indicate mRNA levels of the three genes determined by RT-qPCR; data are presented as per-gene normalized values. The tissue samples were taken from early (E) or late (L) timepoints in rye broth media supplemented with 10 mM potassium nitrate (+) or unsupplemented media (-). Error bars represent standard error based on two biological replicates. (B) specific activity of nitrate reductase enzyme, expressed as μmoles min-1 mg-1. (C) Nitrate reductase protein in Ph. infestans. Indicated is a western blot using hyphae from wild-type (WT) or transformants silenced for the nitrate reductase gene (SIL), using tissues from early or late timepoints in rye broth with or without 10 mM potassium nitrate. The two right lanes contain protein from E. coli expressing the Ph. infestans nitrate reductase containing a hexahistidine tag; the right-most lane is a shorter exposure. (D) Nitrate reductase protein in Ph. infestans, Ph. mirabilis, and Py. ultimum. The top panel shows a western blot using hyphae from early and late timepoints with and without 10 mM potassium nitrate; the lower panel is a Ponceau-stained membrane. The arrow indicates the position of the nitrate reductase protein.