Fig. 1

Exogenous melatonin treatment enhanced plant resistance to Cucumber green mottle mosaic virus (CGMMV) in tobacco. A Quantitative reverse-transcription polymerase chain reaction (qRT-PCR) was performed to examine CGMMV coat protein (CP) expression levels following treatment with 50, 100, 200, and 400 μM melatonin at 9 days post-inoculation (dpi) via root irrigation. B Symptoms caused by CGMMV after 3 days of melatonin treatment (foliar spray or root irrigation) at 9 dpi. CGMMV CP accumulation in systemically infected leaves at 9 dpi, determined by (C) qRT-PCR and (D) Western blotting using CGMMV CP antibody. E Symptoms observed at 9 dpi in plants treated with 50 μM melatonin for 3 days via irrigation after inoculation with CGMMV for 1, 2, or 3 days. CGMMV CP accumulation in systemically infected leaves at 9 dpi, determined by (F) qRT-PCR and (G) Western blotting analysis using CGMMV CP antibody. Bars are standard error of the mean (SEM) from three biological repeats. Significant differences were tested using a two-sample unequal variance t-test (*P < 0.05; **P < 0.01). Full-length blots/gels are presented in Supplementary Fig. 4