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Summary Affecting biodiversity, plants with larger genome sizes (GS) may be restricted in nutrient‐poor conditions. This pattern has been attributed to their greater cellular nitrogen (N) and phosphorus (P) investments and hypothesized nutrient–investment tradeoffs between cell synthesis and physiological attributes associated with growth. However, the influence of GS on cell size and functioning may also contribute to GS‐dependent growth responses to nutrients.To test whether and how GS is associated with cellular nutrient, stomata, and/or physiological attributes, we examined > 500 forbs and grasses from seven grassland sites conducting a long‐term N and P fertilization experiment.Larger GS plants had increased cellular nutrient contents and larger, but fewer stomata than smaller GS plants. Larger GS grasses (but not forbs) also had lower photosynthetic rates and water‐use efficiencies. However, nutrients had no direct effect on GS‐dependent physiological attributes and GS‐dependent physiological changes likely arise from how GS influences cells. At the driest sites, large GS grasses displayed high water‐use efficiency mostly because transpiration was reduced relative to photosynthesis in these conditions.We suggest that climatic conditions and GS‐associated cell traits that modify physiological responses, rather than resource–investment tradeoffs, largely explain GS‐dependent growth responses to nutrients (especially for grasses).
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This content will become publicly available on December 11, 2025
Genome size influences plant growth and biodiversity responses to nutrient fertilization in diverse grassland communities
Experiments comparing diploids with polyploids and in single grassland sites show that nitrogen and/or phosphorus availability influences plant growth and community composition dependent on genome size; specifically, plants with larger genomes grow faster under nutrient enrichments relative to those with smaller genomes. However, it is unknown if these effects are specific to particular site localities with speciifc plant assemblages, climates, and historical contingencies. To determine the generality of genome size-dependent growth responses to nitrogen and phosphorus fertilization, we combined genome size and species abundance data from 27 coordinated grassland nutrient addition experiments in the Nutrient Network that occur in the Northern Hemisphere across a range of climates and grassland communities. We found that after nitrogen treatment, species with larger genomes generally increased more in cover compared to those with smaller genomes, potentially due to a release from nutrient limitation. Responses were strongest for C3grasses and in less seasonal, low precipitation environments, indicating that genome size effects on water-use-efficiency modulates genome size–nutrient interactions. Cumulatively, the data suggest that genome size is informative and improves predictions of species’ success in grassland communities.
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- Award ID(s):
- 1941309
- PAR ID:
- 10566042
- Author(s) / Creator(s):
- ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; more »
- Editor(s):
- Tanentzap, Andrew J
- Publisher / Repository:
- The data used in this study and the R code used for data analysis are publically available on the Environmental Data Initiative (EDI) at: https://doi.org/10.6073/pasta/ 0d6b08fbcf08605881edfb7acf0a1741.
- Date Published:
- Journal Name:
- PLOS Biology
- Volume:
- 22
- Issue:
- 12
- ISSN:
- 1545-7885
- Page Range / eLocation ID:
- e3002927
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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