Fig. 1: Exogenous application of Austropuccinia psidii-specific double-stranded RNA (dsRNA) provides significant protection against myrtle rust when applied 48 h prior to infection.
From: Double-stranded RNA prevents and cures infection by rust fungi
One-to-two-year-old Syzygium jambos trees (n = 6) grown under glasshouse conditions were treated with nuclease-free H2O (negative control), a non-specific dsRNA control (green fluorescent protein (GFP)), or A. psidii-specific dsRNAs beta-tubulin (β-TUB), or transcription elongation factor (EF1-a) at 100 ng/μL and challenged with A. psidii urediniospore inocula 48 h post-dsRNA treatment. Disease was assessed two weeks post-inoculation. a Photo comparison of S. jambos trees, one from each treatment and control group. -dsRNA and GFP control trees showed severe symptoms of myrtle rust, whereas EF1-a and β-TUB-treated plants showed significantly reduced symptoms. Photos were taken two weeks post-inoculation. b Box plot with superimposed scatter of diseased tissue as mean (n = 6) percent (%) coverage of leaf. Each biological replicate includes all young (susceptible) growth in the disease assessment (usually four to eight leaves). Disease was measured automatically using the Leaf Doctor application57 two weeks post-inoculation. EF1-a and β-TUB dsRNAs significantly reduced diseased portions of leaves, as compared to -dsRNA and GFP controls. Significance is represented by asterisks (* = <0.05, ** = <0.01, *** = <0.001 (Welch’s t-test)). Bars represent standard error of the mean. Figure was made in R 4.0.359.
