Root Apex – Korper Kappe Theory, Quiescent Centre Theory
Regarding the organisation of root apex, following theories have been put forward.
1. Korper-Kappe Theory
It was proposed by Schuepp (1917). This theory is comparable with the tunica and corpus theory of shoot apex because it is also based upon plane of division. Korper means body and Kappe means cap.
2. Quiescent Centre Theory
It was proposed by Clowes (1956-58) in maize. According to this theory, root apex consists of an inverted cup like structure called the quiescent centre. The cells of this region show very low mitotic activity (quiescent), They have low amount of RNA, DNA and protein. They are surrounded by layer of actively dividing cells which are responsible for formation of different structures of root. The cells of quiescent centre divide only when the root apex gets injured.