Combined effects of salt stress and cucurbit downy mildew (Pseudoperospora cubensis Berk. and Curt. Rostov.) infection on growth, physiological traits and antioxidant activity in cucumber (Cucumis sativus L.) seedlings

•Combined and solely effects of abiotic and biotic stress on cucumber were analyzed.•Fungal infection when combined with salt stress affected plants to a higher extend.•Each cultivar had a different way of acquisition of responses against two stressors.•Higher SOD, CAT, POX and proline protected cv Sardes better against combined stresses.

Abiotic and biotic stresses both decrease quality and quantity of cultivated plants. We compared responses of Cucumis sativus L. cvs Sardes and Beith alpha which were treated with 50 or 100 mM NaCl and/or infected by Pseudoperospora cubensis Berk. and Curt. Rostov.. Both cultivars were affected remarkably when fungus infection was combined with salt stress however; cv Sardes was found out to be relatively tolerant with sustainable growth performance, better leaf water status and lower lipid peroxidation levels under this condition. This relative tolerance could be related to the fine tuning of the activities of the antioxidative enzymes and proline levels.