Arbuscular Mycorrhiza Mediates Efficient Recycling From Soil to Plants of Nitrogen Bound in Chitin

0541490 - MBÚ 2022 RIV CH eng J - Journal Article
Bukovská, Petra - Rozmoš, Martin - Kotianová, Michala - Gančaříková, Kateřina - Dudáš, Martin - Hršelová, Hana - Jansa, Jan
Arbuscular Mycorrhiza Mediates Efficient Recycling From Soil to Plants of Nitrogen Bound in Chitin.
Frontiers in Microbiology. Roč. 12, FEB 19 (2021), č. článku 574060. ISSN 1664-302X. E-ISSN 1664-302X
R&D Projects: GA ČR(CZ) GA18-04892S
Institutional support: RVO:61388971
Keywords : chitin * microbial community * mineralization * organic nutrients * root-free zone * stable isotopic labeling * arbuscular mycorrhizal (AM) symbiosis * environmental nitrogen (N) losses
OECD category: Microbiology
Impact factor: 6.064, year: 2021
Method of publishing: Open access
https://www.frontiersin.org/articles/10.3389/fmicb.2021.574060/full

Symbiosis between plants and arbuscular mycorrhizal (AM) fungi, involving great majority of extant plant species including most crops, is heavily implicated in plant mineral nutrition, abiotic and biotic stress tolerance, soil aggregate stabilization, as well as shaping soil microbiomes. The latter is particularly important for efficient recycling from soil to plants of nutrients such as phosphorus and nitrogen (N) bound in organic forms. Chitin is one of the most widespread polysaccharides on Earth, and contains substantial amounts of N (>6% by weight). Chitin is present in insect exoskeletons and cell walls of many fungi, and can be degraded by many prokaryotic as well as eukaryotic microbes normally present in soil. However, the AM fungi seem not to have the ability to directly access N bound in chitin molecules, thus relying on microbes in their hyphosphere to gain access to this nutrient-rich resource in the process referred to as organic N mineralization. Here we show, using data from two pot experiments, both including root-free compartments amended with N-15-labeled chitin, that AM fungi can channel substantial proportions (more than 20%) of N supplied as chitin into their plants hosts within as short as 5 weeks. Further, we show that overall N losses (leaching and/or volatilization), sometimes exceeding 50% of the N supplied to the soil as chitin within several weeks, were significantly lower in mycorrhizal as compared to non-mycorrhizal pots. Surprisingly, the rate of chitin mineralization and its N utilization by the AM fungi was at least as fast as that of green manure (clover biomass), based on direct N-15 labeling and tracing. This efficient N recycling from soil to plant, observed in mycorrhizal pots, was not strongly affected by the composition of AM fungal communities or environmental context (glasshouse or outdoors, additional mineral N supply to the plants or not).
Permanent Link: http://hdl.handle.net/11104/0319056