First it was stem cells from rare apples touted as a revolution in anti-aging skin care. Then every other plant (seller) decided to get into the game. So is it true, or is it a con? Can stem cells from plants benefit your skin, and if so how? Is stem cell just a buzz word that unscrupulous marketers use to dupe you into thinking they are scientifically on the leading edge?

Plant Stem Cell Basics

A fertilized ovum (egg) is the ultimate stem cell. Every animal and plant that reproduces sexually begins as a fertilized ovum, with half of its genetic material contributed by the male parent and half from the female parent. In the case of flowering plants, structures within the flower play both roles. Pollen from the stamen is the equivalent of animal sperm and the pistol is the female receptive organ. A stem cell with the ability to repeatedly sub-divide and eventually differentiate into all types of cells found within an individual animal or plant is termed totipotential.

In the animal kingdom, a fertilized ovum divides, creating daughter totipotential stem cells, for only about four days. Daughter cells subsequently differentiate into pluripotential stem cells, which can differentiate into different various types of cells, but not all types. Plants, on the other hand, have totipotential stem cells throughout their life. These cells can develop into a complete adult plant.

Totipotential plant stem cells exist in very small numbers and are found in highly specialized tissues, structures called meristems. Meristems exist in root and shoot sprouts and are the cells from which all other plant cells and structures originate. Every root and stem shoot tip contains a very small number of these extraordinarily important cells. Meristems in shoot sprouts are called apical meristems, and those on the tips of roots are called root meristems. Remove the meristem and all growth in that part of the plant ceases.

Meristem stem cells are under external control and respond to local humoral factors from adjacent cells (quiescent cells) as well as more systemic plant hormones called cytokinin and auxin. Apical and root meristems have different specific, but complementary, controlling mechanisms. Generally speaking, hormonal influences that make an apical meristem grow may be inhibitory to root meristems, and vice versa. It is an intricately coordinated process in which stem cell activity is very tightly controlled and the number of totipotential stem cells is maintained at a very sparse population in comparison to the total plant cellular number.

Of paramount interest for this discussion is the fact that both apical and root meristems have control systems that act upon them, which are controlled by the needs of the entire plant. Without these outside influences, the cells in the meristem do not divide to produce daughter cells. While indispensable for plant growth, meristem stem cells are incapable of function without external influences dictating their response. These cells are followers, not leaders.

The photos show the relative size of structures within the meristem regions of a growing plant.

In the first photo (at right), the stem cells within the root meristem and adjacent quiescent cells are colored blue. The root meristem is also extremely tiny, consisting of only a few, albeit very important cells.

Link:
Botanical Stem Cells in Skin Care | BareFacedTruth.com

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