I know this, because it's translated in Bulgaria and it's one of the most watched series. It meens that and によって "The Forbidden Fruit" they mean the 愛 between Behlul And Bihter, because your in 愛 with your uncle's wife.
Turkish actress Beren Saat - もっと見る "Ask-i Memnu" (Forbidden Love) Promos & Behind the Scenes Also including Kivanc Tatlitug, Selcuk Yontem, Hazal Kaya, Nebahat Cehre