Photosynthesis-dependent/independent control of stomatal responses to CO 2 in mutant barley with surplus electron transport capacity and reduced SLAH3 anion channel transcript

•Rubisco-limited photosynthesis and high ΦNPQ in mutant barley G132.•G132 had greater gs than the wild type, despite lower photosynthesis and higher Ci.•Lower CO2 closure response of stomata in G132 than in the wild type.•Higher stomatal sensitivity to Photosystem II inhibition with DCMU in G132.•Sharp decrease in G132 of the transcript for SLAH3 involved in stomatal closure.•Discussion of photosynthesis and CO2 signalling mediation in stomatal CO2 response.