FIGURE 8.

BSMV-mediated HIGS of Pst_8713 decreased susceptibility of wheat plants to Puccinia striiformis f. sp. tritici (Pst). (A) Pst_8713 transcript with CDS and 5′ and 3′UTRs. The dotted parts are two specific sequence regions for HIGS. (B) Phenotypes of the fourth leaves of wheat plants after inoculation with FES buffer (mock), BSMV:00 (control), BSMV:TaPDS, BSMV:Pst_8713-1as, and BSMV:Pst_8713-2as. (C) Phenotypes of the wheat leaves pre-inoculated with BSMV:00 (control), BSMV:Pst_8713-1as, and BSMV:Pst_8713-2as and then inoculated with Pst virulent isolate CYR32. (D) Quantification of Pst uredinia formation. The means and standard errors were from three biological replicates, and for each replicate, at least six treated leaves were used for uredinia accumulation. (E) Fungal biomass measurements using qRT-PCR analysis of total genomic DNA extracted from control (BSMV:00-inoculated) and Pst_8713-silenced wheat plants. Ratio of total Pst genomic DNA to total wheat genomic DNA was assessed using the Pst gene PsEF1 and the wheat gene TaEF1. The means and standard errors were from three biological replicates. (F) The relative expression of Pst_8713 after knocking down. The expression values are relative to the Pst endogenous gene EF1, with the empty vector (BSMV:00) set at 1. In (D–F), samples were taken at 14 day post-inoculation with Pst. Asterisks indicate significant differences (P < 0.05) using Student’s t-test.