Using siRNA-G55 in first-round analysis. The effects of silencing the marker genes that are involved in the salicylic acid (SA)-related plant defense response pathway in plants that were transfected with a hairpin RNA-G55. The RNA levels of PhaPR1, PhaNPR1, PhaTF15, PhaTF21 and PhaTF60 were analyzed in healthy (H) plants, plants that were infiltrated with Agrobacterium that carried an empty pB7GWIW2 vector (agro-v), or Agrobacterium that carried pB7GWIW2 to deliver different hairpin RNAs that were designed from siRNA G55 (hpRNA-G55) or were specific to PhaTF60 (PhaTF60-hpRNA). The Agrobacterium strain that carried a partial PhaTF15 cDNA was used as a positive control (P), and PhaTF60 was used as a negative control. The plants that were pretreated with SA to induce the SA-related plant defense response are indicated. Phalaenopsis Ubiquitin 10 was used as an internal control.