Seed Transmission of Bacterial Endophytes in Miscanthus

There is increasing interest in developing sustainable agriculture techniques to boost crop yields whilst reducing economic cost and environmental damage. One approach is to utilise plant-associated microbes selected for plant growth promotion, biological nitrogen fixation, or biocontrol properties. Symbiosis is a specialised state, requiring adaptation of both the host and microbe genomes. Bacteria adapted to living within plant tissues are therefore of interest for sustainable crop production.

Miscanthus is a perennial C4 grass grown as a bioenergy crop to substitute fossil fuels for heat, power and biorefining applications. The crop can be grown on low grade land and has minimal requirements in terms of fertilizers or pesticides. However it is not known to what extent these traits are conferred by the plant genome or the wider microbiome.

Using both culturing and culture-independent methodologies, populations of bacterial endophytes were identified within Miscanthus rhizome, root, stem and leaf, and also in seedlings grown from sterilised seed grown in sterile conditions. The seedling population was the most diverse. Vertical transmission through seed may be an important process for sustaining bacterial endophytes in Miscanthus, with potential for sustainable crop production. Genomic analysis to determine whether seed transmitted endophytes may be adapted to life in planta is underway.