Extended Data Fig. 3: Resistances to water diffusion.

Resistances to water diffusion estimated using routine gas exchange calculations (\(R_{{{{\mathrm{H}}}}_{{{\mathrm{2}}}}{{{\mathrm{O}}}}}\)), corrected values (\(cR_{{{{\mathrm{H}}}}_{{{\mathrm{2}}}}{{{\mathrm{O}}}}}\)) and using noble gases (\(R_{{{{\mathrm{argon - H}}}}_{{{\mathrm{2}}}}{{{\mathrm{O}}}}}\),\(R_{{{{\mathrm{neon - H}}}}_{{{\mathrm{2}}}}{{{\mathrm{O}}}}}\) and \(R_{{{{\mathrm{helium - H}}}}_{{{\mathrm{2}}}}{{{\mathrm{O}}}}}\)). Estimations of the unsaturated mesophyll air space resistance as \(R_{{{{\mathrm{unsat}}}}} = R_{{{{\mathrm{H}}}}_{{{\mathrm{2}}}}{{{\mathrm{O}}}}} - cR_{{{{\mathrm{H}}}}_{{{\mathrm{2}}}}{{{\mathrm{O}}}}}\) and the intercellular air space resistance to water as \(R_{{{{\mathrm{ias - H}}}}_{{{\mathrm{2}}}}{{{\mathrm{O}}}}} = R_{{{{\mathrm{x - H}}}}_{{{\mathrm{2}}}}{{{\mathrm{O}}}}} - cR_{{{{\mathrm{H}}}}_{{{\mathrm{2}}}}{{{\mathrm{O}}}}}\). Three leaves are presented as examples for the noble gases experiments, cotton leaf using argon (a and b), sunflower using neon (c and d) and cotton using helium (e and f).