Buddha-nature and the seed of Buddhahood

Nichiren Daishonin deviated sharply from the teachings of his immediate predecessor Dengyo the Great. Dengyo taught the primacy of Buddha-nature [Buddha Wisdom] and the doctrine of Original Enlightenment [Hongaku Shiso] while Nichiren taught the primacy of the seed of Buddhahood or Namu Myoho renge kyo. Without the seed of Buddhahood, the field of Buddha-nature lies forever fallow. This is the meaning of the Ceremony in the Air and the rationale for the oneness of Shakyamuni Buddha and we common mortals who both plant the seed of Namu Myoho renge kyo "into the wasteland of the people’s lives in the evil world of the latter age." *

*from Essentials for Attaining Buddhahood