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

Abstract

Seed germination events modulate microbial community composition, which ultimately influences seed to seedling growth performance. Here we assess the seed-borne bacteria community in disinfected and non-disinfected maize seeds and seedlings. Using a gnotobiotic system, sodium hypochlorite (1.25%, 30 min) treated-seeds showed a reduction of bacteria population size and an increase of bacteria community diversity associated with selective suppression of Burkholderia related taxon. The shift in the bacteria community composition in disinfested-seeds negatively affects germination speed, seedling growth, and reserve mobilization rates in comparison with non-disinfected maize seeds. A synthetic bacteria community formed by twelve isolates (9 Burkholderia spp.; 2 Bacillus spp. and 1 Staphylococcus sp.) obtained from natural microbiota of maize seeds herein were capable of recovering germination and seedling growth when reintroduced in disinfected seeds. 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 taxon 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. One sentence summarypartial removal of the seed-borne microbiota negatively affects maize seedling growth performance and altered bacteria community structure. Partial microbial recomposition, mainly with Burkholderia-related isolates, restores the germination phenotype of disinfested seeds.