Manjula Gunawardana1, Embriette R Hyde2, Sean Lahmeyer3, Brian L Dorsey3, Taylor P La Val1, Madeline Mullen1, Jennifer Yoo1, Rob Knight4, Marc M Baum5. 1. Department of Chemistry, Oak Crest Institute of Science, 128-132 W. Chestnut Ave., Monrovia, California 91016 USA. 2. BioFrontiers Institute, the University of Colorado at Boulder, 3415 Colorado Avenue, Boulder, Colorado 80303 USA; present address: Department of Pediatrics, the University of California at San Diego, 9600 Gilman Drive, La Jolla, California 92093 USA. 3. The Huntington Library, Art Collections, and Botanical Gardens, 1151 Oxford Road, San Marino, California 91108 USA. 4. BioFrontiers Institute, the University of Colorado at Boulder, 3415 Colorado Avenue, Boulder, Colorado 80303 USA; present address: Department of Pediatrics, the University of California at San Diego, 9600 Gilman Drive, La Jolla, California 92093 USA Departments of Chemistry and Biochemistry and Computer Science, the University of Colorado at Boulder, 3415 Colorado Avenue, Boulder, Colorado 80303 USA; present address: Departments of Pediatrics and Computer Science and Engineering, the University of California at San Diego, 9600 Gilman Drive, La Jolla, California 92093 USA m.baum@oak-crest.org. 5. Department of Chemistry, Oak Crest Institute of Science, 128-132 W. Chestnut Ave., Monrovia, California 91016 USA m.baum@oak-crest.org.
Abstract
PREMISE OF THE STUDY: The antimicrobial properties and toxicity of Euphorbia plant latex should make it a hostile environment to microbes. However, when specimens from Euphorbia spp. were propagated in tissue culture, microbial growth was observed routinely, raising the question whether the latex of this diverse plant genus can be a niche for polymicrobial communities. METHODS: Latex from a phylogenetically diverse set of Euphorbia species was collected and genomic microbial DNA extracted. Deep sequencing of bar-coded amplicons from taxonomically informative gene fragments was used to measure bacterial and fungal species richness, evenness, and composition. KEY RESULTS: Euphorbia latex was found to contain unexpectedly complex bacterial (mean: 44.0 species per sample; 9 plants analyzed) and fungal (mean: 20.9 species per sample; 22 plants analyzed) communities using culture-independent methods. Many of the identified taxa are known plant endophytes, but have not been previously found in latex. CONCLUSIONS: Our results suggest that Euphorbia plant latex, a putatively hostile antimicrobial environment, unexpectedly supports diverse bacterial and fungal communities. The ecological roles of these microorganisms and potential interactions with their host plants are unknown and warrant further research.
PREMISE OF THE STUDY: The antimicrobial properties and toxicity of Euphorbia plant latex should make it a hostile environment to microbes. However, when specimens from Euphorbia spp. were propagated in tissue culture, microbial growth was observed routinely, raising the question whether the latex of this diverse plant genus can be a niche for polymicrobial communities. METHODS: Latex from a phylogenetically diverse set of Euphorbia species was collected and genomic microbial DNA extracted. Deep sequencing of bar-coded amplicons from taxonomically informative gene fragments was used to measure bacterial and fungal species richness, evenness, and composition. KEY RESULTS: Euphorbia latex was found to contain unexpectedly complex bacterial (mean: 44.0 species per sample; 9 plants analyzed) and fungal (mean: 20.9 species per sample; 22 plants analyzed) communities using culture-independent methods. Many of the identified taxa are known plant endophytes, but have not been previously found in latex. CONCLUSIONS: Our results suggest that Euphorbia plant latex, a putatively hostile antimicrobial environment, unexpectedly supports diverse bacterial and fungal communities. The ecological roles of these microorganisms and potential interactions with their host plants are unknown and warrant further research.
Authors: Embriette R Hyde; Jose A Navas-Molina; Se Jin Song; Jordan G Kueneman; Gail Ackermann; Cesar Cardona; Gregory Humphrey; Don Boyer; Tom Weaver; Joseph R Mendelson; Valerie J McKenzie; Jack A Gilbert; Rob Knight Journal: mSystems Date: 2016-08-02 Impact factor: 6.496