Physcomitrium patens response to elevated CO2 is flexible and determined by an interaction between sugar and nitrogen availability

Authors: MOHANASUNDARAM, BOOMINATHAN - Donald Danforth Plant Science Center; KOLEY, SOMNATH - Donald Danforth Plant Science Center; Allen, Douglas - Doug; PANDEY, SONA - Donald Danforth Plant Science Center

Submitted to: New Phytologist
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/5/2023
Publication Date: 1/10/2024
Citation: Mohanasundaram, B., Koley, S., Allen, D.K., Pandey, S. 2024. Physcomitrium patens response to elevated CO2 is flexible and determined by an interaction between sugar and nitrogen availability. New Phytologist. 241(3):1222-1235. https://doi.org/10.1111/nph.19348.
DOI: https://doi.org/10.1111/nph.19348

Interpretive Summary: Photosynthetic systems including plants, algae, mosses and cyanobacteria all contribute to capture carbon from the atmosphere in the form of carbon dioxide and convert it with the energy from sunlight into biomass. The biomass includes protein, oil and carbohydrates that are sources of food and feed and valuable renewable feed stocks that can supplant petroleum as part of a sustainable world. Mosses predate plants and often cover parts of our world such as bogs and cold areas where other plants do not grow and therefore are an opportunity for future agricultural exploitation to meet societal needs. We examined central carbon metabolism under perturbed carbon dioxide and nitrogen conditions to understand how the moss changes its growth and metabolism to accommodate the altered conditions. We describe differences in moss development from varying the amount of carbon dioxide and the forms and amounts of nitrogen, either nitrate or ammonium. The work is important because it describes how plant systems adapt to changes with different availability to carbon and nitrogen that is tied to future climates and also the more sustainable use of less synthetic fertilizer in agricultural practices that can also improve farm economics. Plants that are capable of higher productivity with fewer inputs are needed and important to achieving sustainability goals.

Technical Abstract: Mosses hold a unique position in plant evolution and are crucial for protecting natural, long-term carbon storage systems such as permafrost and bogs. Due to small stature, mosses grow close to the soil surface and are exposed to high levels of CO2, produced by soil respiration. However, the impact of elevated CO2 (eCO2) levels on mosses remains underexplored. We determined the growth responses of the moss Physcomitrium patens to eCO2 in combination with different nitrogen levels and characterized the underlying physiological and metabolic changes. Three distinct growth characteristics, an early transition to caulonema, the development of longer, highly pigmented rhizoids, and increased biomass, define the phenotypic responses of P. patens to eCO2. Elevated CO2 impacts growth by enhancing the level of a sugar signaling metabolite, T6P. The quantity and form of nitrogen source influences these metabolic and phenotypic changes. Under eCO2, P. patens exhibits a diffused growth pattern in the presence of nitrate, but ammonium supplementation results in dense growth with tall gametophores, demonstrating high phenotypic plasticity under different environments. These results provide a framework for comparing the eCO2 responses of P. patens with other plant groups and provide crucial insights into moss growth that may benefit climate change models.