Fig. 3

The load of gut-derived bacteria in the hemolymph increases at 12 h and decreases at 48 h post-M. rileyi infection. A, B The quantification of total bacterial load in the hemolymph (A) and gut (B) of H. armigera larvae at 0, 12, and 48 hpi of M. rileyi blastospores or PBS. The quantitative PCR analysis was performed against the bacterial genomic DNA using universal primers of the bacterial 16S rRNA gene. C Analysis of the hemolymph and gut bacterial operational taxonomic units (OTUs) from the larvae at 48 hpi. HB and HP indicate hemolymph from blastospore-injected and PBS-injected larvae, respectively. GB and GP represent guts from blastospore-injected and PBS-injected larvae, respectively. D Analysis of bacterial (species level) abundance in the hemolymph from larvae at 48 hpi. The most abundant 13 species are shown. Gut-derived A. johnsonii is in red. E-G Quantification of hemolymph A. johnsonii (E), S. rhizophila (F), and E. ludwigii (G) load from the larvae at 0, 12, and 48 hpi of M. rileyi blastospores or PBS. Quantitative PCR analysis was performed using specific primers of bacterial 16S rRNA gene and bacterial genomic DNA in the hemolymph as templates. The statistical differences were analyzed using the Mann–Whitney U test (*p < 0.05) or Student’s t test (*p < 0.05 and **p < 0.01)