Scientific Area
Abstract Detail
Nº613/2312 - A laboratory-to-field approach for determining the genetic and environmental factors underlying mutualism within a Sphagnum peatland system
Format: ORAL
Authors
David J. Weston (1), Alyssa Carrell (1), Jun Hyung Lee (1), Sara Jawdy (1), Dale Pelletier (1), Jon Shaw (2), Gustaf Granath (3), Adam Healey (4), Jeremy Schmutz (4)
Affiliations
(1) Oak Ridge National Laboratory, Oak Ridge, TN; (2)Duke University, Durham NC, Uppsala University, Sweden; (4)Joint Genome Institute, Walnut Creek, CA
Abstract
The importance of plant-microbiome systems on terrestrial carbon and nitrogen processes is perhaps most pronounced in Sphagnum dominated ecosystems, which occupy 3% of the Earth’s land surface yet store approximately 30% of terrestrial carbon as recalcitrant organic matter (i.e., peat). The foundation plant Sphagnum is responsible for much of the primary production in peatland ecosystems and produces recalcitrant dead organic matter. Sphagnum together with associated microorganisms, contributes substantial nitrogen inputs into peatlands and influences host resilience to extreme climatic events. Under changing environmental conditions, a central question about these ecosystems is whether the Sphagnum-microbiome will maintain its beneficial interactions, or will it shift to neutral or even antagonistic interactions that ultimately influence peatland carbon gain and storage. Here, we test the hypothesis that the thermal origin of the microbiome influence Sphagnum host performance and resilience to warming. Briefly, we mechanically separated the microbiome from Sphagnum plants residing in a whole-ecosystem warming study, transferred the component microbes to germ-free plants, and exposed the new hosts to temperature stress. Although warming decreased plant photosynthesis and growth in germ-free plants, the addition of a microbiome from a thermal origin that matched the experimental temperature completely restored plants to their pre-warming growth rates. Metagenome and metatranscriptome analyses revealed that warming altered microbial community structure, including the composition of key cyanobacteria symbionts, in a manner that induced the plant heat shock response, especially the Hsp70 family and jasmonic acid production. The plant heat shock response could be induced even without warming, suggesting that the warming-origin microbiome provided the host plant with thermal preconditioning. Together, our findings show that the microbiome can transmit thermotolerant phenotypes to host plants, providing a valuable strategy for rapidly responding to environmental change.