底栖有孔虫卷转虫(Ammonia spp.)对环境磷浓度变化的分子响应机制OA北大核心

Phosphorus is an essential element for all living organisms and a limiting factor in marine primary productivity.As a widely distributed class of single-celled eukaryotic protozoa,benthic foraminifera play a crucial ecological role in the storage,release,migration,and transformation of phosphorus within benthic environments.This study explores the molecular regulatory mechanisms of the representative foraminifera genus,Ammonia,under varying phosphate concentrations using transcriptome analysis.We performed a differential expression analysis of key metabolic pathways,including phosphonate and phosphinate metabolism,as well as signaling cascades like the PI3K-AKT signaling pathway.Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analyses were used to infer the phosphorus metabolism strategies utilized by Ammonia spp.When phosphate concentrations were relatively low,Ammonia spp.preferentially utilized phosphate ester remineralization to sustain their phos-phorus supply and enhance the synthesis of phosphonates as a phosphorus reserve.Additionally,low phosphate concentrations upregulated genes associated with the cell cycle and apoptosis signaling.This upregulation activated downstream targets through signal transduction cascades,promoting fatty acid oxidation and glycolysis for ATP production,inducing autophagy,and triggering apoptosis.Conversely,under high phosphate conditions,Ammonia spp.favorably and specifically degraded 2-aminoethylphosphonate,serving as a dual nitrogen and phosphorus nu-trient source,thus maintaining cellular homeostasis by modulating the cell cycle and limiting cell proliferation.This study provides new insights into the molecular mechanisms by which benthic foraminifera adapt to alterations in environmental phosphorus concentrations.