Work

Nitrogen status exerts dynamic control over phosphorus sensing and acquisition via PSR1 in colimited marine diatoms

Year: 2025

Type: article

Abstract: Nutrient availability controls phytoplankton growth in aquatic ecosystems globally. Phytoplankton frequently experience a limiting supply of multiple nutrients simultaneously (colimitation). Ocean warming is predicted to exacerbate marine nutrient limitation. Yet, how phytoplankton adapt their physiology and regulate responses to colimitation is poorly understood. Here, we show that when the crucial macronutrients nitrogen (N) and phosphorus (P) colimit growth of globally abundant phytoplankton, the diatoms, cellular resources are diverted to prioritize N uptake over P sensing and acquisition. Regulatory mechanisms for responding to fluctuating P supply, including Phosphate Starvation Response 1 (PSR1) and P-resupply sensing via Ca 2+ signaling, are strictly nitrate dependent. Further, P-Ca 2+ signaling is impaired in psr1 mutants, suggesting that PSR1 is necessary for this response and coordinates adaptations to colimitation. Our study demonstrates a hierarchy of resource allocation during colimitation that points to N starvation mechanisms overriding those of P and could lead to N-P colimitation being masked in many marine ecosystems.

Source: Science Advances

DOI: 10.1126/sciadv.adw8260

Authors: Ellen Harrison, Yasmin Meeda, Trupti Gaikwad, Glen Wheeler, Katherine Helliwell

Institutions: Marine Biological Association of the United Kingdom, University of Exeter

Language: English

Topic: Plant nutrient uptake and metabolism

Subfield: Plant Science

Field: Agricultural and Biological Sciences

Domain: Life Sciences

Open Access status: gold

Estimated APC paid: $4,500

Funders: Norges Teknisk-Naturvitenskapelige Universitet, Directorate for Biological Sciences