Fig. 8: Involvement in pathogenicity and elicitor function of SGP1 during U. virens infection of rice panicles and challenge of rice leaves.
a The relative expression of SGP1 during different stages of infection. SGP1 expression was normalized to its expression level prior to inoculation (0 hpi) using Tubulin as an internal reference. hpi, hours post inoculation; dpi, days post inoculation. Values are the means ± SEM of three biological replicates. The different letters indicate statistically significant differences (P < 0.05) as measured by Duncan’s multiple range test. b Relative transcript levels of SGP1 in different U. virens transgenic lines. The transcript levels were measured by qRT-PCR and normalized to those in the WT strain using Tubulin as an internal reference. ST, SGP1-silenced transformants of U. virens; OT, SGP1 overexpression transformants of U. virens; OTm, SGP1W44A overexpression transformants of U. virens. Values are the means ± SEM of three biological replicates. (**P < 0.01; two-sided t-test). c Western blot analysis of SGP1 and SGP1W44A in U. virens WT and transgenic lines with anti-GFP antibody. d–f Pathogenicity phenotypes of transgenic U. virens lines and WT. In box plots, whiskers indicate minimum and maximum values, line indicates the median, the box boundaries indicate the upper (25th percentile) and lower (75th percentile) quartiles. d Representative photographs of disease symptoms on rice panicles. e Quantification of the number of false smut balls per panicle. Data were collected from five independent experiments, with a total of at least 31 panicles per line. (*P < 0.05; **P < 0.01 compared with WT, two-sided Dunnett’s test). f Relative U. virens biomass in infected spikelets, measured by qPCR of genomic DNA and normalized to WT. Values from five biological replicates were shown, which include three technical replicates for each biological replicate. (**P < 0.01 compared with WT, two-sided Dunnett’s test). g Relative induction of PR10 transcription in rice leaves and panicles at 12 hpi. The induction of PR10 expression in U. virens-inoculated rice was normalized to that in mock-inoculated rice, with Actin serving as an internal reference. Values are the means ± SEM of three biological replicates. (**P < 0.01; *P < 0.05; two-sided t-test).
