Effect of a regulated deficit irrigation strategy in a hedgerow ‘Arbequina’ olive orchard on the mesocarp fatty acid composition and desaturase gene expression with respect to olive oil quality

•The effect of three RDI strategies on the olive oil quality has been assessed.•The RDI did not alter the mesocarp total oil content.•The 30 RDI increased the oleic/linoleic ratio in olive mature mesocarp.•The 30 RDI strategy increased linolenic acid and FAD7 expression in green mesocarp.•A 30 RDI allowed a sustainable water saving and gave rise to improved quality oils.