Isolation of Phyllosphere Bacterial Community Members in Forage Grasses

As global warming continues, forage grasses that are critical to agricultural activity are exposed to increasing occurrences of drought, which brings about the question of how microorganisms can help crops resist and recover from drought conditions. There is much to be learned about the bacteria present on the leaf surface, or phyllosphere, of forage grasses. In particular, there is a current lack of understanding on how phyllosphere communities respond to drought. We hypothesize that different species of host plants have distinct phyllosphere communities, have different core members and some possess the ability to fix nitrogen in drought conditions. To investigate this topic, we took phyllosphere samples from Festuca arundinacea, Dactylis glomerata and Lolium perenne exposed to drought and control conditions over a 13-week period. Their DNA was isolated for gene marker analysis of the 16S rRNA and nifH gene, allowing us to determine isolate identity and nitrogen fixation potential. Using graphical analyses, the relative abundance of different phyllosphere community members, including core community members, was determined. Results show that host plant species determines the composition of the phyllosphere. In addition, the core community is less prevalent in drought conditions. Lastly, the nifH gene was not present in the bacteria isolated from the study.