apical meristem


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apical meristem

a region of dividing tissue at the growing tips of roots and shoots that is responsible for increase in length of the plant body. MERISTEM cells are small, with thin walls and CYTOPLASM containing few vacuoles. They undergo active MITOSIS when growth is occurring (depending on the season) and the new cells look similar to the parental ones but become more vacuolated and elongated. Eventually, further away from the meristem, the cells undergo the process of CELL DIFFERENTIATION, taking on the appearance of mature plant cells.

Meristematic tissues are delicate and in need of protection. In shoots the apices are covered by tiny leaves forming apical buds at the tips of the branches and axillary buds at the nodes where the leaves join the stem. Root structures are less complex, each root-tip meristem being protected by a shield of loose cells called a ROOT CAP. Compare CAMBIUM.

References in periodicals archive ?
AtTPST is expressed throughout the plant, and the highest expression is in the root apical meristem.
The combinations of BAP and NAA were tested for its effect on apical meristem cultures.
Therefore, it is possible that the longer growth period, to plants deferred for 65 days, enabled more elevation of the apical meristem in relation to the other periods.
Beyond that, of course, is the possibility of the endophyte's presence in the host's apical meristem that will need to be explored.
We selected Macrocystis sporophytes with a minimum number of 15 and a maximum of 25 free blades from the apical meristem.
Apical meristem showed higher shoot regeneration potential compared to cotyledon leaf explants.
Intercalary meristems are found in grasses and are independent from the apical meristems.
A longitudinal section through a typical dicot stem reveals a dome of tissue at the apex, the apical meristem itself, flanked by lateral protrusions that eventually become leaves.
Because we clipped aspens on the main stem, a loss of apical meristem dominance may help explain the compensatory response we observed.
The apical meristem or bud of an axis is thus characterized by the PA of the growth unit that it may produce and a metamer is characterized by its PA i (which is the PA of the growth unit that it belongs to).
Flowers and flower buds are located at the tip of the apical meristem.
The effect of geomagnetic field fluctuations upon the changes in the cellular structure of apical meristem in Allium cepa L.