Potential role of the gymnosperm microbiome in a changing climate

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The plant microbiome, i.e., microorganisms that colonize internal and external plant tissues, has been shown to be very influential on plant growth and development. These microorganisms represent all three domains of life, the Eukarya, particularly the fungi, the Bacteria and the Archaeabacteria, or Archaea for short. While soil and external plant tissue colonizing microbes have been studied intensively, internal plant tissue colonizing microbes belongingj only to the bacteria  and fungi have been characterized with respect to their identity and effects on plant growth and development, including many gymnosperm species. However, very little work has been reported on members of the Archaea. Recently, using gene identification and bioinformatics, there is tantalizing evidence to suggest that some members of the Archaea not only colonize internal plant tissues, but also interact with plants by auxin biosynthesis, increasing nutrient supply, and protection against abiotic (especially oxidative and osmotic) stress. There is also some evidence for a degree of plant specificity regarding plants and Archaea. Functional signatures of Archaea reveal the genetic capacity for the interplay with fungi as well as playing an important role in the carbon and nitrogen cycle: e.g., CO2 and N2 fixation. These facts reveal an important, yet unobserved role for the Archaea in most plants and trees. With climate change already manifesting through warmer and drier summers in the northern hemisphere, the potential ameliorating effects of the gymnosperm microbiome may be very important for gymnosperm growth and survival under changing environmental conditions. Using a combination of molecular and culture-based techniques, I propose to (i) continue evaluating the role of external and internal plant tissue colonizing bacteria in gymnosperm growth and development; (ii) provide the first evidence of the occurrence and potential function of external and/or internal plant tissue colonizing Archaea in gymnosperm growth and development using molecular techniques; (iii) attempt to be the first to isolate and culture external and/or internal plant tissue colonizing Archaea from any plant; and (iv) evaluate the interactive effects of external and internal plant colonizing bacteria, fungi and Archaea (if available) on growth and development of gymnosperms under stressful environmental conditions that are anticipated to occur with a warming climate. These stressful conditions will include elevated temperatures, drought and nutrient deprivation, with studies performed under controlled environments. This work will be the first to evaluate the occurrence and role of the Archaea in gymnosperm growth and development. In addition, this work may result in obtaining the first Archaea strain(s) ever to be isolated from external and/or internal tissues of any plant species and to evaluate the interactive effects of bacteria, fungi and Archaea on gymnosperm growth under stressful conditions.