Insights into the structure and role of seed-borne bacteriome during maize germination.

Seed germination events modulate microbial community composition, which ultimately influences seed to seedling growth performance. Here we evaluate the germinated maize (variety SHS 5050) root bacterial community of disinfected seed (DS) and non-disinfected seed (NDS). Using a gnotobiotic system, sodium hypochlorite (1.25%, 30 min) treated seeds showed a reduction of bacterial population size and an apparent increase of bacterial community diversity associated with a significant selective reduction of Burkholderia related sequences. The shift in the bacterial community composition in DS negatively affects germination speed, seedling growth, and reserve mobilization rates compared with NDS. A synthetic bacterial community (syncom) formed by twelve isolates (9 Burkholderia spp.; 2 Bacillus spp. and 1 Staphylococcus sp.) obtained from natural microbiota maize seeds herein were capable of recovering germination and seedling growth when reintroduced in DS. Overall results showed that changes in bacterial community composition and selective reduction of Burkholderia related members dominance interfere with germination events and initial growth of the maize plantlets. By cultivation-dependent and independent approaches, we deciphered seed-maize microbiome structure, bacterial niches location, and bacterial taxa with relevant roles in seedlings growth performance. A causal relationship between seed microbial community succession and germination performance open opportunities in seed technologies to build-up microbial communities to boost plant growth and health.