Genetic canalization of nutrient resorption in the widespread grass Phragmites australis under salt stress.

Nutrient resorption efficiency (NuRE) in the grass Phragmites australis is largely unaffected by imposed salinity, despite >60% biomass decline and three- to fivefold sodium accumulation.

• Why it matters: It was unclear whether nutrient resorption plastically responds to non-nutrient stress like salinity, which matters for predicting nutrient cycling under global change.
• What they did: In a common garden with 110 Phragmites australis genotypes, salinity triggered strong stress responses and 484 metabolites changed; NuRE was then tested for links to lineage, ecotype, and latitude.
• The result: NuRE was strongly correlated with phylogeographic lineage, ecotype, and latitude of origin, indicating evolutionary canalization; phosphorus resorption stayed concentration-dependent, nitrogen control was disrupted, and potassium showed no stress dependence.