Concentration of phenolic compounds is increased in lettuce grown under high light intensity and elevated CO.

The present study was focused on lettuce, a widely consumed leafy vegetable for the large number of healthy phenolic compounds. Two differently-pigmented lettuce cultivars, i.e.

Elevated CO and salinity are responsible for phenolics-enrichment in two differently pigmented lettuces.

Both salt stress and high CO level, besides influencing secondary metabolism, can affect oxidative status of plants mainly acting in an opposite way with salinity provoking oxidative stress and elevated CO alleviating it. The aim of the present work was to study the changes in the composition of phenolic acids and flavonoids as well as in the antioxidant activity in two differently pigmented lettuce cvs (green or red leaf) when submitted to salinity (200 mM NaCl) or elevated CO (700 ppm) or to their combination in order to evaluate how a future global change can affect lettuce quality. Following treatments, the red cv.