(Figure 2)
3. Bacterial community composition and relative abundance among plant rhizospheres after insect attack
In order to understand the individual effect of insect attack per plant species, we made individual PCoA plots comparing microbial control communities versus microbial communities after insect attack. We found that four of the five plant species significantly modulated the bacterial communities’ structure after the plants had been attacked byT.ni (Figures 3A, 3B, 3C, and 3E). Only tomato showed no significant effect (p=0.32) (Figure 3D).
In addition, sweet corn, beans, Arabidopsis , and red beet showed a significant difference (p<0.05) in bacteria phyla across plant species when comparing relative abundances of treatment versus control groups (Figures 3F 3G, 3H, and 3J, and Supplementary tables 1, 2, 3, and 5). The observed pattern did not hold true for tomato (p >0.05) (Figure 3I and Supplementary table 4).
Further, Actinobacteria and Proteobacteria were the most abundant phyla across all plant species (Figures 3F, 3G, 3H, 3I, and 3J). Relative abundance of the phyla Actinobacteria ,Verrucomicrobia , Bacteroides , Firmicutes , andAcidobacteria presented significant differences (p<0.05) in the control samples when compared with insect-attack rhizosphere samples in most of the plant species studied (Figures 3F, 3G, 3H, and 3J). The phylum Proteobacteria showed a significant difference (p <0.05) for insect damage samples for red beet only (Figure 3J).