Plants and mycorrhizal symbionts acquire substantial soil nitrogen from gaseous ammonia transport.
New Phytol
; 231(5): 1746-1757, 2021 09.
Article
in En
| MEDLINE
| ID: mdl-34077566
ABSTRACT
Nitrogen (N) is an essential nutrient that limits plant growth in many ecosystems. Here we investigate an overlooked component of the terrestrial N cycle - subsurface ammonia (NH3 ) gas transport and its contribution to plant and mycorrhizal N acquisition. We used controlled mesocosms, soil incubations, stable isotopes, and imaging to investigate edaphic drivers of NH3 gas efflux, track lateral subsurface N transport originating from 15 NH3 gas or 15 N-enriched organic matter, and assess plant and mycorrhizal N assimilation from this gaseous transport pathway. NH3 is released from soil organic matter, travels belowground, and contributes to root and fungal N content. Abiotic soil properties (pH and texture) influence the quantity of NH3 available for subsurface transport. Mutualisms with arbuscular mycorrhizal (AM) fungi can substantially increase plant NH3 -N uptake. The grass Brachypodium distachyon acquired 6-9% of total plant N from organic matter-N that traveled as a gas belowground. Colonization by the AM fungus Rhizophagus irregularis was associated with a two-fold increase in total plant N acquisition from subsurface NH3 gas. NH3 gas transport and uptake pathways may be fundamentally different from those of more commonly studied soil N species and warrant further research.
Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Mycorrhizae
Language:
En
Journal:
New Phytol
Journal subject:
BOTANICA
Year:
2021
Type:
Article
Affiliation country:
United States