Table 2.

Types of stem cells on the basis of location

Stem cell niche in shoot tip

Stem cell niche in root tip

Found in dome-shaped organ called shoot apical meristem Has organizing centre which is responsible for the maintenance of the stem cell Stem cells divide into new cells on their own and transit-amplifying cells (group of intermediate cells produced before cell differentiation) by asymmetric division Transit-amplifying cells-play an important role in retaining activity of the cell and accumulate to give to new organs Upper region of shoot apical meristem with stem cell niche-forms central zone of the center This region has slower rate of cell division which reduces the probability of producing mutations Peripheral zone is situated around the central zone, where cell division is more rapid

Different from stem cell niche in shoot tips in their structural arrangement Small amount of organizing cells are surrounded by different types of plant stem cells These centres rarely undergo cell division, so called as Quiescent centres These cells divide in an asymmetrical manner Form stem cells on their own and also form differentiated root cells without forming transit-amplifying cells Stem cells present on the tip side of the root cap are sloughed off in a continuous manner and serves the key role of protecting the stem cell niche