In both Greek and Roman mythology, the god associated with agriculture and grain is Demeter (Greek) and Ceres (Roman). They symbolize the fertility of the earth, the cycles of planting and harvesting, and the nourishment of humanity. Their myths explore themes of life and death, particularly through the story of Demeter's daughter, Persephone, whose seasonal return from the Underworld represents the cycle of growth and decay. This connection underscores agriculture's significance in ancient societies, representing sustenance and survival.