Fig 1.
Methodological overview of the factorial manipulation of hormone treatment and inoculation treatment.
Abbreviations are as follows: “Mock (Single)” = plants that received a mock inoculation of R. solani; “Mock (Co)” = plants that received a mock co-inoculation of R. solani and C. cereale; “Single” = plants that received an inoculation of R. solani; “Co” = plants that received a co-inoculation of R. solani and C. cereale. Plants across inoculation treatment groups either received a hormone treatment of sterile water (control), or salicylic acid.
Table 1.
Symptomatic rates of R. solani and C. cereale. Inoculation with C. cereale produced symptoms most often when co-inoculated with R. solani, and inoculation with R. solani led to symptomatic infection most often when co-inoculated with C. cereale. Bold numbers represent the number of plants in each treatment combination that were symptomatic, and numbers in parentheses represent the total number of plants in each treatment group.
Fig 2.
Salicylic acid did not influence the diversity of the fungal or bacterial leaf microbiome across inoculation treatment groups.
Panels show (A) the application of salicylic acid did not influence the Shannon diversity of fungi on plant leaves (p = 0.17) and (B) the application of salicylic acid did not influence the Shannon diversity of bacteria on plant leaves (p = 0.46).
Fig 3.
Salicylic acid did not influence the community composition of fungi or bacteria on plant leaves across inoculation treatment groups.
Panels show (A) the application of salicylic acid did not influence the Bray-Curtis dissimilarity of fungi on plant leaves (p = 0.95) and (B) the application of salicylic acid did not influence the Bray-Curtis dissimilarity of bacteria on plant leaves (p = 0.79).
Fig 4.
Salicylic acid application did not alter the relative abundance of fungal or bacterial taxa across inoculation treatment groups.
Panels show that (a.) none of the 20 most abundant fungal genera were significantly different in their relative abundance by hormone treatment group (univariate GLM (0/20), p > 0.05 (adjusted)) and (b.) none of the 20 most abundant bacterial genera were significantly different in their relative abundance by hormone treatment group (univariate GLM (0/20), p > 0.05 (adjusted)). Genera, like Allorhizobium spp. were denoted as multiple species by our classifier because the classifier could not differentiate between the closely related species – as such, the genus name appears as a combination of the 4 separate, closely related genera. HSB_OF53.F07 spp. is a common soil bacterium in the phylum Chloroflexi [41].
Fig 5.
Inoculation treatment influenced fungal, but not bacterial Shannon diversity across hormone treatment groups.
Panels show (A) inoculation treatment influenced fungal Shannon diversity (p = 0.0496) and (B) inoculation treatment did not influence bacterial richness (p = 0.92).
Fig 6.
Inoculation treatment influenced the community composition of fungi, but not bacteria on plant leaves across hormone treatment groups.
Panels show (A) inoculation treatment influenced the community composition of fungi on plant leaves (p = 0.021) and (B) inoculation treatment did not influence the community composition of bacteria on plant leaves (p = 0.47).
Fig 7.
Inoculation treatment did not alter the relative abundance of fungal or bacterial genera across hormone treatment groups.
Panels show that (A) none of the 20 most abundant fungal genera were significantly different in their relative abundance by inoculation treatment group (univariate GLM (0/20), p > 0.05 (adjusted)) and (B) none of the 20 most abundant bacterial genera were significantly different in their relative abundance by inoculation treatment group (univariate GLM (0/20), p > 0.05 (adjusted)). Genera, like Allorhizobium spp. were denoted as multiple species by our classifier because the classifier could not differentiate between the closely related species – as such, the genus name appears as a combination of the 4 separate, closely related genera. HSB_OF53.F07 spp. is a common soil bacterium in the phylum Chloroflexi [41].