Emergence Shapes the Structure of the Seed Microbiota
Résumé
Seeds carry complex microbial communities, which may exert beneficial or deleterious effects on plant growth and plant health. To date, the composition of microbial communities associated to seeds has been mainly explored through culture-based diversity studies and therefore remains largely unknown. In this work, we analyzed the structure of the seed microbiota of different Brassicaceaeand its dynamics during germination and emergence through sequencing of three molecular markers: the ITS1 region of the fungal internal transcribed spacer, the V4 region of 16S rRNA gene and a species-specific bacterial marker based on a fragment of gyrB. Sequences analyses revealed important variation in microbial community composition between seed samples. Moreover we found that emergence strongly influences the structure of the microbiota with a marked reduction of bacterial and fungal diversity. This shift in microbial community composition is mostly due to an increase in relative abundance of some bacterial and fungal taxa possessing fast growing abilities. Altogether, our results provide an estimation of the role of the seed as a source of inoculum for the seedling, which is crucial for practical application in developing new strategies of inoculation for disease prevention.