Figure 1.

Seed transmission of microbial assemblages at different plant development stages. Community profiling of microbial assemblages associated with the developing seed (A), seed (B), germinating seed (C) and seedling (D). The microbial richness [presented here as bacterial and fungal operational taxonomic units (OTUs)] and relative abundance of microbial taxa (presented here as bacterial and fungal phyla) have been assessed for stages (B), (C) and (D) (Barret et al., 2015). However, the composition of microbial assemblages associated with developing seeds (A) is currently unknown. Notably, the relative influence of the systemic (1), floral (2) and external (3) pathways in seed transmission of the plant microbiota remains to be determined.