Elevated CO2 and high endogenous ABA level alleviate PEG-induced short-term osmotic stress in tomato plants

Elevated CO2 concentration (e[CO2]) alleviates the impact of drought stress on plants where abscisic acid (ABA) is involved. To explore mechanisms by which tomato respond to short-term osmotic stress, Solanum lycopersicum cv. Ailsa Craig (AC), a transgenic line overproducing ABA (sp5), and an ABA-deficient mutant (flacca) were hydroponically grown under ambient (400 ppm) e[CO2] (800 then exposed 10% or 15% (w/v) polyethylene glycol (PEG) 6000 for 24 h before transferring PEG-free nutrient solution h. Under non-stress condition, decreased root hydraulic conductance (Kroot), was overridden high endogenous in sp5 through increasing specific leaf area branching intensity. Basically, improved resistance enhanced water status. PEG stomatal potential AC but these effects less pronounced sp5, exhibited stronger adjustment (OA) plant fitness. A greater flexibility system reduced sensitivity Kroot might confer great ability recover from stress. On contrary, density, size pore aperture flacca rendered suffering severe Moreover, premise that could mimic soil deficit sufficient achievement OA. Our results indicate level improve via adjustments.