High nitrogen-induced changes in rhizosphere microbial community structure can modulate disease susceptibility to the rice blast.
Roy M, Shanmugam G, Park S, Bae H, Choi K
Summary
8.2/10Excess nitrogen in soil changes the beneficial microbes around rice roots, making the plant more susceptible to a fungal disease. Surprisingly, these altered microbial communities can persist and spread, suggesting that managing soil health is key to preventing disease in nitrogen-fertilized rice.
Key Findings
High nitrogen significantly alters bacterial and fungal communities in rice rhizosphere and suppresses defense genes OsPAL06 and OsPR10b
Rhizosphere microbiome transplantation from high-nitrogen infected donors to standard-nitrogen recipients reproduced nitrogen-induced susceptibility, indicating a microbiome legacy effect
Network analysis revealed reduced microbial connectivity and loss of keystone taxa under high-nitrogen and infection conditions
Original Abstract
Nitrogen-induced susceptibility (NIS) in rice, where excess nitrogen (N) enhances vulnerability to Magnaporthe oryzae, has been observed but remains mechanistically unclear. Here, we demonstrate that the rhizosphere microbiome plays a central role in mediating NIS. Using an experimental system that separates nitrogen effects from plant growth changes, we found that high N levels significantly reshape bacterial and fungal community composition, and suppressed defense-associated genes, including OsPAL06 and OsPR10b. Predicted functional profiling indicated enrichment of salicylate-degradation and secretion-related signatures under highN. Our findings revealed that both nitrogen treatment and pathogen infection significantly influence rhizosphere community composition, with a strong interaction between the two factors. Network analysis further revealed reduced microbial connectivity and loss of keystone taxa under high-N and infection conditions. Rhizosphere microbiome transplantation from high-N, infected donors to standard-N recipients reproduced the NIS phenotype and suppressed defense gene expression, supporting a microbiome legacy effect. These findings suggest that excess N promotes rhizosphere microbiome configurations with immune-modulatory potential that can persist beyond the immediate nutrient regime. Our results position the rhizosphere microbiome as a determinant of NIS and support microbiome-informed, nutrient-aware disease management strategies.
Species Mentioned
Rice is a cereal grain and in its domesticated form is the staple food of over half of the world's population, particularly in Asia and Africa. Rice is the seed of the grass species Oryza sativa —or, much less commonly, Oryza glaberrima. Asian rice was domesticated in China some 13,500 to 8,200 y...
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