Exploring the Rhizosphere Microbiome of Hydroponically Grown Leafy Greens

Abstract

Microgreens are immature leafy vegetables that are popular for their short growing times and versatile growing conditions. Classifying the microbial communities for different microgreens can help us understand pathways to prevent diseases and promote plant growth; however, the rhizosphere microbiome of leafy greens is poorly classified. We aimed to: 1) optimize hydroponic manifold assembly to support the growth of microgreen monocultures 2) design and optimize the process for harvesting rhizospheric film for DNA analysis and 3) determine the rhizosphere microbiome composition of four microgreens – Swiss chard, lettuce, kale, and basil. We used 16S rRNA and ITS genetic markers to quantify bacterial and fungal abundance for our four microgreens. We engineered a single-level manifold holding 36 seedlings with its own growth light and water reservoir as an ideal hydroponics set-up. We developed, refined, and optimized a root scraping procedure to maximize the amount of rhizospheric film obtained from plant roots to consistently extract viable DNA.  Future work should classify and explore the mechanistic role of rhizosphere microbiome in promoting plant growth.