Higher Bacterial Diversity of Gut Microbiota in Different Natural Populations of Leafhopper Vector Does Not Influence WDV Transmission

Abstract

The bacterial communities in the gut of an insect have important ecological and functional effects on the insect. However, the community composition and diversity of the gut microbiota in insects that vector plant viruses are poorly understood. As an important insect vector, Psammotettix alienus transmits various viruses including wheat dwarf virus (WDV). Here, we used the combination of leafhopper and WDV as model to survey the influence of gut microbiota on virus transmission characteristic of insect vector and vice versa. We have characterized 22 phyla and 249 genera of all gut bacterial communities in the leafhopper populations collected from six geographic regions in China. Community composition and diversity varied across different geographic populations. However, WDV transmission efficiencies of these six field populations were all greater than 80% with no significant difference. Interestingly, the transmission efficiency of WDV by laboratory reared insects with decreased gut bacterial diversity was similar to that of field populations. Furthermore, we found that the composition of the leafhopper gut bacteria was dynamic and could reversibly respond to WDV acquisition. Higher bacterial diversity and abundance of gut microbiota in different leafhopper populations did not influence their WDV transmission efficiency, while the acquisition of WDV changes gut microbiota by a dynamic and reversible manner. This report provides insight into the complex relationship between the gut microbiota, insect vector and virus.

Keywords: 16S rDNA high-throughput sequencing; European grass feeding leafhopper (Psammotettix alienus); geographic location; gut bacterial community; wheat dwarf virus (WDV).

FIGURE 1

Analysis of gut microbiota and transmission efficiency of wheat dwarf virus for the field populations of leafhoppers from six locations in China. Taxonomic composition at the phylum level (A) and genus level (B); The number of OTUs (C); WDV transmission efficiency (D). Only the top 10 most abundant taxa are shown for each. Results are shown for three bulked samples (N = 15 adults/sample) for each geographic population. The bacterial community composition varied among the locations. TS: Tianshui; HC: Hancheng; LF: Linfen; TY: Tianjin; BD: Baoding; TJ: Tianjin.

FIGURE 2

Similarity of bacterial communities of leafhoppers among six locations in China. PCoA analysis (A), NMDS analysis (B), heatmap analysis (C), and UPGMA (D). G1TS: Tianshui; G2HC: Hancheng; G3LF: Linfen; G4TY: Tianjin; G5BD: Baoding; G6TJ: Tianjin.

FIGURE 3

Distinct biomarkers of the bacterial community from different leafhopper populations revealed by linear discriminant analysis (LDA). Multiple regression results are shown for LDA of microbiomes from different populations with LDA > 4. Colors indicate the different populations of the phylogenetic component contributing to group uniqueness (A). Cladogram of the LDA results in panel A. Levels of the cladogram represent, from the inner to outer rings, phylum, class, order, family, and genus. Color codes indicate the six populations, and lower-case letters indicate the taxa that contribute to the uniqueness of the corresponding leafhopper populations (B). (C–K) Relative abundance of distinct bacteria in the different populations: Wolbachia (C), Acinetobacter (D), Candidatus_Sulcia (E), Neisseria (F), Streptococcus (G), Pectobacterium (H), Rickettsia (I), Candidatus_Nasuia (J), Rickettsiella (K). G1TS: Tianshui; G2HC: Hancheng; G3LF: Linfen; G4TY: Tianjin; G5BD: Baoding; G6TJ: Tianjin.

FIGURE 4

Comparison of gut bacterial community composition (A) and virus transmission efficiencies (B) between field populations (LFF) from China and laboratory-maintained leafhoppers (LFL). Two nonviruliferous populations (NV) were originally collected from Linfen in 2010. Only the top 10 most abundant are shown.

FIGURE 5

Composition and abundance of the gut bacterial community during the WDV acquisition period. Composition of gut bacterial community at the genus level (A). Only the top 10 most abundant are shown. Comparison of similarities of leafhopper gut bacterial communities at various times during the WDV acquisition period based on Heat map analysis (B). Relative abundance of Rickettsia (C) and Candidatus_Nasuia (D) during WDV acquisition. NV: nonviruliferous leafhopper; V05: viruliferous leafhopper after 5 d AAP; V10: viruliferous leafhopper after 10 d AAP; V20: viruliferous leafhopper after 20 d AAP.