Effects of abiotic stress on seed microbiome assembly

This study aimed to profile the taxonomic composition of bacterial seed-endophytic microbiota following the application of abiotic stress treatment to mother plants. The study composed of two main parts. In Study A, an experiment wherein salinity stress was applied for three consecutive generations to oat (Avena sativa) and perennial ryegrass (Lolium perenne) plants, with 16S rDNA amplicon sequencing used to profile the bacterial endophytic communities harboured by the seed harvested from each generation. The experiment was repeated with oat for one generation on a Phenotyping platform with the application of stronger salinity stress and with drought stress and an additional treatment. In study B, a common garden experiment was conducted by sowing oat seed from each of the three generations grown in Study A (including both control and salinity treatment groups) and applying control, salinity or drought treatments to each group; phenotypic data was collected from plants and seed representing a 4th generation of treatment (i.e. harvested from plants sown from the 3rd generation seed harvested from Study A) were analysed by 16S rDNA amplicon sequencing, with the aim of testing if there were signatures of 'memory' within the seed microbiota (based on the hypothesis of vertical transmission of endophytes).